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Welding

Welding is a fabrication process that joins materials, usually metals or thermoplastics, primarily by using high temperature to melt the parts together and allow them to cool, causing fusion. Common alternative methods include solvent welding (of thermoplastics) using chemicals to melt materials being bonded without heat, and solid-state welding processes which bond without melting, such as pressure, cold welding, and diffusion bonding.

Metal welding is distinct from lower temperature bonding techniques such as brazing and soldering, which do not melt the base metal (parent metal) and instead require flowing a filler metal to solidify their bonds.

In addition to melting the base metal in welding, a filler material is typically added to the joint to form a pool of molten material (the weld pool) that cools to form a joint that, based on weld configuration (butt, full penetration, fillet, etc.), can be stronger than the base material. Welding also requires a form of shield to protect the filler metals or melted metals from being contaminated or oxidized.

Many different energy sources can be used for welding, including a gas flame (chemical), an electric arc (electrical), a laser, an electron beam, friction, and ultrasound. While often an industrial process, welding may be performed in many different environments, including in open air, under water, and in outer space. Welding is a hazardous undertaking and precautions are required to avoid burns, electric shock, vision damage, inhalation of poisonous gases and fumes, and exposure to intense ultraviolet radiation.

Until the end of the 19th century, the only welding process was forge welding, which blacksmiths had used for millennia to join iron and steel by heating and hammering. Arc welding and oxy-fuel welding were among the first processes to develop late in the century, and electric resistance welding followed soon after. Welding technology advanced quickly during the early 20th century, as world wars drove the demand for reliable and inexpensive joining methods. Following the wars, several modern welding techniques were developed, including manual methods like shielded metal arc welding, now one of the most popular welding methods, as well as semi-automatic and automatic processes such as gas metal arc welding, submerged arc welding, flux-cored arc welding and electroslag welding. Developments continued with the invention of laser beam welding, electron beam welding, magnetic pulse welding, and friction stir welding in the latter half of the century. Today, as the science continues to advance, robot welding is commonplace in industrial settings, and researchers continue to develop new welding methods and gain greater understanding of weld quality.

Etymology
The term weld is derived from the Middle English verb well (wæll; plural/present tense: wælle) or welling (wællen), meaning 'to heat' (to the maximum temperature possible); 'to bring to a boil'. The modern word was probably derived from the past-tense participle welled (wællende), with the addition of d for this purpose being common in the Germanic languages of the Angles and Saxons. It was first recorded in English in 1590. A fourteenth century translation of the Christian Bible into English by John Wycliffe translates Isaiah 2:4 as "...thei shul bete togidere their swerdes into shares..." (they shall beat together their swords into plowshares). In the 1590 version this was changed to "...thei shullen welle togidere her swerdes in-to scharris..." (they shall weld together their swords into plowshares), suggesting this particular use of the word probably became popular in English sometime between these periods.

The Old English word for welding iron was samod ('to bring together') or samodwellung ('to bring together hot').

The word is related to the Old Swedish word valla, meaning 'to boil', which could refer to joining metals, as in valla järn (literally "to boil iron"). Sweden was a large exporter of iron during the Middle Ages, so the word may have entered English from the Swedish iron trade, or may have been imported with the thousands of Viking settlements that arrived in England before and during the Viking Age, as more than half of the most common English words in everyday use are Scandinavian in origin.

History

The history of joining metals goes back several millennia. The earliest examples of this come from the Bronze and Iron Ages in Europe and the Middle East. The ancient Greek historian Herodotus states in The Histories of the 5th century BC that Glaucus of Chios "was the man who single-handedly invented iron welding". Forge welding was used in the construction of the Iron pillar of Delhi, erected in Delhi, India about 310 AD and weighing 5.4 metric tons.

The Middle Ages brought advances in forge welding, in which blacksmiths pounded heated metal repeatedly until bonding occurred. In 1540, Vannoccio Biringuccio published De la pirotechnia, which includes descriptions of the forging operation. Renaissance craftsmen were skilled in the process, and the industry continued to grow during the following centuries.

In 1800, Sir Humphry Davy discovered the short-pulse electrical arc and presented his results in 1801. In 1802, Russian scientist Vasily Petrov created the continuous electric arc, and subsequently published "News of Galvanic-Voltaic Experiments" in 1803, in which he described experiments carried out in 1802. Of great importance in this work was the description of a stable arc discharge and the indication of its possible use for many applications, one being melting metals. In 1808, Davy, who was unaware of Petrov's work, rediscovered the continuous electric arc. In 1881–82 inventors Nikolai Benardos (Russian) and Stanisław Olszewski (Polish) created the first electric arc welding method known as carbon arc welding using carbon electrodes. The advances in arc welding continued with the invention of metal electrodes in the late 1800s by a Russian, Nikolai Slavyanov (1888), and an American, C. L. Coffin (1890). Around 1900, A. P. Strohmenger released a coated metal electrode in Britain, which gave a more stable arc. In 1905, Russian scientist Vladimir Mitkevich proposed using a three-phase electric arc for welding. Alternating current welding was invented by C. J. Holslag in 1919, but did not become popular for another decade.

Resistance welding was also developed during the final decades of the 19th century, with the first patents going to Elihu Thomson in 1885, who produced further advances over the next 15 years. Thermite welding was invented in 1893, and around that time another process, oxyfuel welding, became well established. Acetylene was discovered in 1836 by Edmund Davy, but its use was not practical in welding until about 1900, when a suitable torch was developed. At first, oxyfuel welding was one of the more popular welding methods due to its portability and relatively low cost. As the 20th century progressed, however, it fell out of favor for industrial applications. It was largely replaced with arc welding, as advances in metal coverings (known as flux) were made. Flux covering the electrode primarily shields the base material from impurities, but also stabilizes the arc and can add alloying components to the weld metal.

World War I caused a major surge in the use of welding, with the various military powers attempting to determine which of the several new welding processes would be best. The British primarily used arc welding, even constructing a ship, the "Fullagar" with an entirely welded hull. Arc welding was first applied to aircraft during the war as well, as some German airplane fuselages were constructed using the process. Also noteworthy is the first welded road bridge in the world, the Maurzyce Bridge in Poland (1928). During the 1920s, significant advances were made in welding technology, including the introduction of automatic welding in 1920, in which electrode wire was fed continuously. Shielding gas became a subject receiving much attention, as scientists attempted to protect welds from the effects of oxygen and nitrogen in the atmosphere. Porosity and brittleness were the primary problems, and the solutions that developed included the use of hydrogen, argon, and helium as welding atmospheres. During the following decade, further advances allowed for the welding of reactive metals like aluminum and magnesium. This in conjunction with developments in automatic welding, alternating current, and fluxes fed a major expansion of arc welding during the 1930s and then during World War II. In 1930, the first all-welded merchant vessel, M/S Carolinian, was launched. During the middle of the century, many new welding methods were invented. In 1930, Kyle Taylor was responsible for the release of stud welding, which soon became popular in shipbuilding and construction. Submerged arc welding was invented the same year and continues to be popular today. In 1932 a Russian, Konstantin Khrenov eventually implemented the first underwater electric arc welding. Gas tungsten arc welding, after decades of development, was finally perfected in 1941, and gas metal arc welding followed in 1948, allowing for fast welding of non-ferrous materials but requiring expensive shielding gases. Shielded metal arc welding was developed during the 1950s, using a flux-coated consumable electrode, and it quickly became the most popular metal arc welding process. In 1957, the flux-cored arc welding process debuted, in which the self-shielded wire electrode could be used with automatic equipment, resulting in greatly increased welding speeds, and that same year, plasma arc welding was invented by Robert Gage. Electroslag welding was introduced in 1958, and it was followed by its cousin, electrogas welding, in 1961. In 1953, the Soviet scientist N. F. Kazakov proposed the diffusion bonding method.

Other recent developments in welding include the 1958 breakthrough of electron beam welding, making deep and narrow welding possible through the concentrated heat source. Following the invention of the laser in 1960, laser beam welding debuted several decades later, and has proved to be especially useful in high-speed, automated welding. Magnetic pulse welding (MPW) has been industrially used since 1967. Friction stir welding was invented in 1991 by Wayne Thomas at The Welding Institute (TWI, UK) and found high-quality applications all over the world. All of these four new processes continue to be quite expensive due to the high cost of the necessary equipment, and this has limited their applications.

Gas welding
The most common gas welding process is oxyfuel welding, also known as oxyacetylene welding. It is one of the oldest and most versatile welding processes, but in recent years it has become less popular in industrial applications. It is still widely used for welding pipes and tubes, as well as repair work.

The equipment is relatively inexpensive and simple, generally employing the combustion of acetylene in oxygen to produce a welding flame temperature of about 3100 °C (5600 °F). The flame, since it is less concentrated than an electric arc, causes slower weld cooling, which can lead to greater residual stresses and weld distortion, though it eases the welding of high alloy steels. A similar process, generally called oxyfuel cutting, is used to cut metals.

Arc welding
These processes use a welding power supply to create and maintain an electric arc between an electrode and the base material to melt metals at the welding point. They can use either direct current (DC) or alternating current (AC), and consumable or non-consumable electrodes. The welding region is sometimes protected by some type of inert or semi-inert gas, known as a shielding gas, and filler material is sometimes used as well.

Arc welding processes
One of the most common types of arc welding is shielded metal arc welding (SMAW); it is also known as manual metal arc welding (MMAW) or stick welding. Electric current is used to strike an arc between the base material and consumable electrode rod, which is made of filler material (typical steel) and is covered with a flux that protects the weld area from oxidation and contamination by producing carbon dioxide (CO2) gas during the welding process. The electrode core itself acts as filler material, making a separate filler unnecessary.

The process is versatile and can be performed with relatively inexpensive equipment, making it well suited to shop jobs and field work. An operator can become reasonably proficient with a modest amount of training and can achieve mastery with experience. Weld times are rather slow, since the consumable electrodes must be frequently replaced and because slag, the residue from the flux, must be chipped away after welding. Furthermore, the process is generally limited to welding ferrous materials, though special electrodes have made possible the welding of cast iron, stainless steel, aluminum, and other metals.

Gas metal arc welding (GMAW), also known as metal inert gas or MIG welding, is a semi-automatic or automatic process that uses a continuous wire feed as an electrode and an inert or semi-inert gas mixture to protect the weld from contamination. Since the electrode is continuous, welding speeds are greater for GMAW than for SMAW.

A related process, flux-cored arc welding (FCAW), uses similar equipment but uses wire consisting of a steel electrode surrounding a powder fill material. This cored wire is more expensive than the standard solid wire and can generate fumes and/or slag, but it permits even higher welding speed and greater metal penetration.

Gas tungsten arc welding (GTAW), or tungsten inert gas (TIG) welding, is a manual welding process that uses a non-consumable tungsten electrode, an inert or semi-inert gas mixture, and a separate filler material. Especially useful for welding thin materials, this method is characterized by a stable arc and high-quality welds, but it requires significant operator skill and can only be accomplished at relatively low speeds.

GTAW can be used on nearly all weldable metals, though it is most often applied to stainless steel and light metals. It is often used when quality welds are extremely important, such as in bicycle, aircraft and naval applications. A related process, plasma arc welding, also uses a tungsten electrode but uses plasma gas to make the arc. The arc is more concentrated than the GTAW arc, making transverse control more critical and thus generally restricting the technique to a mechanized process. Because of its stable current, the method can be used on a wider range of material thicknesses than can the GTAW process and it is much faster. It can be applied to all of the same materials as GTAW except magnesium, and automated welding of stainless steel is one important application of the process. A variation of the process is plasma cutting, an efficient steel cutting process.

Submerged arc welding (SAW) is a high-productivity welding method in which the arc is struck beneath a covering layer of flux. This increases arc quality since contaminants in the atmosphere are blocked by the flux. The slag that forms on the weld generally comes off by itself, and combined with the use of a continuous wire feed, the weld deposition rate is high. Working conditions are much improved over other arc welding processes, since the flux hides the arc and almost no smoke is produced. The process is commonly used in industry, especially for large products and in the manufacture of welded pressure vessels. Other arc welding processes include atomic hydrogen welding, electroslag welding (ESW), electrogas welding, and stud arc welding. ESW is a highly productive, single-pass welding process for thicker materials between 1 inch (25 mm) and 12 inches (300 mm) in a vertical or close to vertical position.

Arc welding power supplies
To supply the electrical power necessary for arc welding processes, a variety of different power supplies can be used. The most common welding power supplies are constant current power supplies and constant voltage power supplies. In arc welding, the length of the arc is directly related to the voltage, and the amount of heat input is related to the current. Constant current power supplies are most often used for manual welding processes such as gas tungsten arc welding and shielded metal arc welding, because they maintain a relatively constant current even as the voltage varies. This is important because in manual welding, it can be difficult to hold the electrode perfectly steady, and as a result, the arc length and thus voltage tend to fluctuate. Constant voltage power supplies hold the voltage constant and vary the current, and as a result, are most often used for automated welding processes such as gas metal arc welding, flux-cored arc welding, and submerged arc welding. In these processes, arc length is kept constant, since any fluctuation in the distance between the wire and the base material is quickly rectified by a large change in current. For example, if the wire and the base material get too close, the current will rapidly increase, which in turn causes the heat to increase and the tip of the wire to melt, returning it to its original separation distance.

The type of current used plays an important role in arc welding. Consumable electrode processes such as shielded metal arc welding and gas metal arc welding generally use direct current, but the electrode can be charged either positively or negatively. In welding, the positively charged anode will have a greater heat concentration, and as a result, changing the polarity of the electrode affects weld properties. If the electrode is positively charged, the base metal will be hotter, increasing weld penetration and welding speed. Alternatively, a negatively charged electrode results in more shallow welds. Non-consumable electrode processes, such as gas tungsten arc welding, can use either type of direct current, as well as alternating current. However, with direct current, because the electrode only creates the arc and does not provide filler material, a positively charged electrode causes shallow welds, while a negatively charged electrode makes deeper welds. Alternating current rapidly moves between these two, resulting in medium-penetration welds. One disadvantage of AC, the fact that the arc must be re-ignited after every zero crossings, has been addressed with the invention of special power units that produce a square wave pattern instead of the normal sine wave, making rapid zero crossings possible and minimizing the effects of the problem.

Resistance welding
Resistance welding involves the generation of heat by passing current through the resistance caused by the contact between two or more metal surfaces. Small pools of molten metal are formed at the weld area as high current (1,000–100,000 A) is passed through the metal. In general, resistance welding methods are efficient and cause little pollution, but their applications are somewhat limited and the equipment cost can be high.

Spot welding is a popular resistance welding method used to join overlapping metal sheets of up to 3 mm thick. Two electrodes are simultaneously used to clamp the metal sheets together and to pass current through the sheets. The advantages of the method include efficient energy use, limited workpiece deformation, high production rates, easy automation, and no required filler materials. Weld strength is significantly lower than with other welding methods, making the process suitable for only certain applications. It is used extensively in the automotive industry—ordinary cars can have several thousand spot welds made by industrial robots. A specialized process called shot welding, can be used to spot weld stainless steel.

Like spot welding, seam welding relies on two electrodes to apply pressure and current to join metal sheets. However, instead of pointed electrodes, wheel-shaped electrodes roll along and often feed the workpiece, making it possible to make long continuous welds. In the past, this process was used in the manufacture of beverage cans, but now its uses are more limited. Other resistance welding methods include butt welding, flash welding, projection welding, and upset welding.

Energy beam welding
Energy beam welding methods, namely laser beam welding and electron beam welding, are relatively new processes that have become quite popular in high production applications. The two processes are quite similar, differing most notably in their source of power. Laser beam welding employs a highly focused laser beam, while electron beam welding is done in a vacuum and uses an electron beam. Both have a very high energy density, making deep weld penetration possible and minimizing the size of the weld area. Both processes are extremely fast, and are easily automated, making them highly productive. The primary disadvantages are their very high equipment costs (though these are decreasing) and a susceptibility to thermal cracking. Developments in this area include laser-hybrid welding, which uses principles from both laser beam welding and arc welding for even better weld properties, laser cladding, and x-ray welding.

Solid-state welding

Like forge welding (the earliest welding process discovered), some modern welding methods do not involve the melting of the materials being joined. One of the most popular, ultrasonic welding, is used to connect thin sheets or wires made of metal or thermoplastic by vibrating them at high frequency and under high pressure. The equipment and methods involved are similar to that of resistance welding, but instead of electric current, vibration provides energy input. When welding metals, the vibrations are introduced horizontally, and the materials are not melted; with plastics, which should have similar melting temperatures, vertically. Ultrasonic welding is commonly used for making electrical connections out of aluminum or copper, and it is also a very common polymer welding process.

Another common process, explosion welding, involves the joining of materials by pushing them together under extremely high pressure. The energy from the impact plasticizes the materials, forming a weld, even though only a limited amount of heat is generated. The process is commonly used for welding dissimilar materials, including bonding aluminum to carbon steel in ship hulls and stainless steel or titanium to carbon steel in petrochemical pressure vessels.

Other solid-state welding processes include friction welding (including friction stir welding and friction stir spot welding), magnetic pulse welding, co-extrusion welding, cold welding, diffusion bonding, exothermic welding, high frequency welding, hot pressure welding, induction welding, and roll bonding.

Geometry

Welds can be geometrically prepared in many different ways. The five basic types of weld joints are the butt joint, lap joint, corner joint, edge joint, and T-joint (a variant of this last is the cruciform joint). Other variations exist as well—for example, double-V preparation joints are characterized by the two pieces of material each tapering to a single center point at one-half their height. Single-U and double-U preparation joints are also fairly common—instead of having straight edges like the single-V and double-V preparation joints, they are curved, forming the shape of a U. Lap joints are also commonly more than two pieces thick—depending on the process used and the thickness of the material, many pieces can be welded together in a lap joint geometry.

Many welding processes require the use of a particular joint design; for example, resistance spot welding, laser beam welding, and electron beam welding are most frequently performed on lap joints. Other welding methods, like shielded metal arc welding, are extremely versatile and can weld virtually any type of joint. Some processes can also be used to make multipass welds, in which one weld is allowed to cool, and then another weld is performed on top of it. This allows for the welding of thick sections arranged in a single-V preparation joint, for example.

After welding, a number of distinct regions can be identified in the weld area. The weld itself is called the fusion zone—more specifically, it is where the filler metal was laid during the welding process. The properties of the fusion zone depend primarily on the filler metal used, and its compatibility with the base materials. It is surrounded by the heat-affected zone, the area that had its microstructure and properties altered by the weld. These properties depend on the base material's behavior when subjected to heat. The metal in this area is often weaker than both the base material and the fusion zone, and is also where residual stresses are found.

Quality

Many distinct factors influence the strength of welds and the material around them, including the welding method, the amount and concentration of energy input, the weldability of the base material, filler material, and flux material, the design of the joint, and the interactions between all these factors.

For example, the factor of welding position influences weld quality, that welding codes & specifications may require testing—both welding procedures and welders—using specified welding positions: 1G (flat), 2G (horizontal), 3G (vertical), 4G (overhead), 5G (horizontal fixed pipe), or 6G (inclined fixed pipe).

To test the quality of a weld, either destructive or nondestructive testing methods are commonly used to verify that welds are free of defects, have acceptable levels of residual stresses and distortion, and have acceptable heat-affected zone (HAZ) properties. Types of welding defects include cracks, distortion, gas inclusions (porosity), non-metallic inclusions, lack of fusion, incomplete penetration, lamellar tearing, and undercutting.

The metalworking industry has instituted codes and specifications to guide welders, weld inspectors, engineers, managers, and property owners in proper welding technique, design of welds, how to judge the quality of welding procedure specification, how to judge the skill of the person performing the weld, and how to ensure the quality of a welding job. Methods such as visual inspection, radiography, ultrasonic testing, phased-array ultrasonics, dye penetrant inspection, magnetic particle inspection, or industrial computed tomography can help with detection and analysis of certain defects.

Heat-affected zone
The heat-affected zone (HAZ) is a ring surrounding the weld in which the temperature of the welding process, combined with the stresses of uneven heating and cooling, alters the heat-treatment properties of the alloy. The effects of welding on the material surrounding the weld can be detrimental—depending on the materials used and the heat input of the welding process used, the HAZ can be of varying size and strength. The thermal diffusivity of the base material plays a large role—if the diffusivity is high, the material cooling rate is high and the HAZ is relatively small. Conversely, a low diffusivity leads to slower cooling and a larger HAZ. The amount of heat injected by the welding process plays an important role as well, as processes like oxyacetylene welding have an unconcentrated heat input and increase the size of the HAZ. Processes like laser beam welding give a highly concentrated, limited amount of heat, resulting in a small HAZ. Arc welding falls between these two extremes, with the individual processes varying somewhat in heat input. To calculate the heat input for arc welding procedures, the following formula can be used:

 * $$Q = \left(\frac{V \times I \times 60}{S \times 1000} \right) \times

\mathit{Efficiency}$$

where Q = heat input (kJ/mm), V = voltage (V), I = current (A), and S = welding speed (mm/min). The efficiency is dependent on the welding process used, with shielded metal arc welding having a value of 0.75, gas metal arc welding and submerged arc welding, 0.9, and gas tungsten arc welding, 0.8. Methods of alleviating the stresses and brittleness created in the HAZ include stress relieving and tempering.

One major defect concerning the HAZ would be cracking at the toes, due to the rapid expansion (heating) and contraction (cooling) the material may not have the ability to withstand the stress and could cause cracking, one method the control these stress would be to control the heating and cooling rate, such as pre-heating and post- heating

Lifetime extension with after treatment methods
The durability and life of dynamically loaded, welded steel structures is determined in many cases by the welds, in particular the weld transitions. Through selective treatment of the transitions by grinding (abrasive cutting), shot peening, High-frequency impact treatment, Ultrasonic impact treatment, etc. the durability of many designs increases significantly.

Metallurgy
Most solids used are engineering materials consisting of crystalline solids in which the atoms or ions are arranged in a repetitive geometric pattern which is known as a lattice structure. The only exception is material that is made from glass which is a combination of a supercooled liquid and polymers which are aggregates of large organic molecules.

Crystalline solids cohesion is obtained by a metallic or chemical bond that is formed between the constituent atoms. Chemical bonds can be grouped into two types consisting of ionic and covalent. To form an ionic bond, either a valence or bonding electron separates from one atom and becomes attached to another atom to form oppositely charged ions. The bonding in the static position is when the ions occupy an equilibrium position where the resulting force between them is zero. When the ions are exerted in tension force, the inter-ionic spacing increases creating an electrostatic attractive force, while a repulsing force under compressive force between the atomic nuclei is dominant.

Covalent bonding takes place when one of the constituent atoms loses one or more electrons, with the other atom gaining the electrons, resulting in an electron cloud that is shared by the molecule as a whole. In both ionic and covalent bonding the location of the ions and electrons are constrained relative to each other, thereby resulting in the bond being characteristically brittle.

Metallic bonding can be classified as a type of covalent bonding for which the constituent atoms are of the same type and do not combine with one another to form a chemical bond. Atoms will lose an electron(s) forming an array of positive ions. These electrons are shared by the lattice which makes the electron cluster mobile, as the electrons are free to move as well as the ions. For this, it gives metals their relatively high thermal and electrical conductivity as well as being characteristically ductile.

Three of the most commonly used crystal lattice structures in metals are the body-centred cubic, face-centred cubic and close-packed hexagonal. Ferritic steel has a body-centred cubic structure and austenitic steel, non-ferrous metals like aluminium, copper and nickel have the face-centred cubic structure.

Ductility is an important factor in ensuring the integrity of structures by enabling them to sustain local stress concentrations without fracture. In addition, structures are required to be of an acceptable strength, which is related to a material's yield strength. In general, as the yield strength of a material increases, there is a corresponding reduction in fracture toughness.

A reduction in fracture toughness may also be attributed to the embrittlement effect of impurities, or for body-centred cubic metals, from a reduction in temperature. Metals and in particular steels have a transitional temperature range where above this range the metal has acceptable notch-ductility while below this range the material becomes brittle. Within the range, the materials behavior is unpredictable. The reduction in fracture toughness is accompanied by a change in the fracture appearance. When above the transition, the fracture is primarily due to micro-void coalescence, which results in the fracture appearing fibrous. When the temperatures falls the fracture will show signs of cleavage facets. These two appearances are visible by the naked eye. Brittle fracture in steel plates may appear as chevron markings under the microscope. These arrow-like ridges on the crack surface point towards the origin of the fracture.

Fracture toughness is measured using a notched and pre-cracked rectangular specimen, of which the dimensions are specified in standards, for example ASTM E23. There are other means of estimating or measuring fracture toughness by the following: The Charpy impact test per ASTM A370; The crack-tip opening displacement (CTOD) test per BS 7448–1; The J integral test per ASTM E1820; The Pellini drop-weight test per ASTM E208.

Unusual conditions

While many welding applications are done in controlled environments such as factories and repair shops, some welding processes are commonly used in a wide variety of conditions, such as open air, underwater, and vacuums (such as space). In open-air applications, such as construction and outdoors repair, shielded metal arc welding is the most common process. Processes that employ inert gases to protect the weld cannot be readily used in such situations, because unpredictable atmospheric movements can result in a faulty weld. Shielded metal arc welding is also often used in underwater welding in the construction and repair of ships, offshore platforms, and pipelines, but others, such as flux cored arc welding and gas tungsten arc welding, are also common. Welding in space is also possible—it was first attempted in 1969 by Russian cosmonauts during the Soyuz 6 mission, when they performed experiments to test shielded metal arc welding, plasma arc welding, and electron beam welding in a depressurized environment. Further testing of these methods was done in the following decades, and today researchers continue to develop methods for using other welding processes in space, such as laser beam welding, resistance welding, and friction welding. Advances in these areas may be useful for future endeavours similar to the construction of the International Space Station, which could rely on welding for joining in space the parts that were manufactured on Earth.

Safety issues

Welding can be dangerous and unhealthy if the proper precautions are not taken. However, using new technology and proper protection greatly reduces risks of injury and death associated with welding.

Since many common welding procedures involve an open electric arc or flame, the risk of burns and fire is significant; this is why it is classified as a hot work process. To prevent injury, welders wear personal protective equipment in the form of heavy leather gloves and protective long-sleeve jackets to avoid exposure to extreme heat and flames. Synthetic clothing such as polyester should not be worn since it may burn, causing injury. Additionally, the brightness of the weld area leads to a condition called arc eye or flash burns in which ultraviolet light causes inflammation of the cornea and can burn the retinas of the eyes. Goggles and welding helmets with dark UV-filtering face plates are worn to prevent this exposure. Since the 2000s, some helmets have included a face plate which instantly darkens upon exposure to the intense UV light. To protect bystanders, the welding area is often surrounded with translucent welding curtains. These curtains, made of a polyvinyl chloride plastic film, shield people outside the welding area from the UV light of the electric arc, but cannot replace the filter glass used in helmets.

Welders are often exposed to dangerous gases and particulate matter. Processes like flux-cored arc welding and shielded metal arc welding produce smoke containing particles of various types of oxides. The size of the particles in question tends to influence the toxicity of the fumes, with smaller particles presenting a greater danger. This is because smaller particles have the ability to cross the blood–brain barrier. Fumes and gases, such as carbon dioxide, ozone, and fumes containing heavy metals, can be dangerous to welders lacking proper ventilation and training. Exposure to manganese welding fumes, for example, even at low levels (<0.2 mg/m3), may lead to neurological problems or to damage to the lungs, liver, kidneys, or central nervous system. Nano particles can become trapped in the alveolar macrophages of the lungs and induce pulmonary fibrosis. The use of compressed gases and flames in many welding processes poses an explosion and fire risk. Some common precautions include limiting the amount of oxygen in the air, and keeping combustible materials away from the workplace.

Costs and trends
As an industrial process, the cost of welding plays a crucial role in manufacturing decisions. Many different variables affect the total cost, including equipment cost, labor cost, material cost, and energy cost. Depending on the process, equipment cost can vary, from inexpensive for methods like shielded metal arc welding and oxyfuel welding, to extremely expensive for methods like laser beam welding and electron beam welding. Because of their high cost, they are only used in high production operations. Similarly, because automation and robots increase equipment costs, they are only implemented when high production is necessary. Labor cost depends on the deposition rate (the rate of welding), the hourly wage, and the total operation time, including time spent fitting, welding, and handling the part. The cost of materials includes the cost of the base and filler material, and the cost of shielding gases. Finally, energy cost depends on arc time and welding power demand.

For manual welding methods, labor costs generally make up the vast majority of the total cost. As a result, many cost-saving measures are focused on minimizing operation time. To do this, welding procedures with high deposition rates can be selected, and weld parameters can be fine-tuned to increase welding speed. Mechanization and automation are often implemented to reduce labor costs, but this frequently increases the cost of equipment and creates additional setup time. Material costs tend to increase when special properties are necessary, and energy costs normally do not amount to more than several percent of the total welding cost.

In recent years, in order to minimize labor costs in high production manufacturing, industrial welding has become increasingly more automated, most notably with the use of robots in resistance spot welding (especially in the automotive industry) and in arc welding. In robot welding, mechanized devices both hold the material and perform the weld and at first, spot welding was its most common application, but robotic arc welding increases in popularity as technology advances. Other key areas of research and development include the welding of dissimilar materials (such as steel and aluminum, for example) and new welding processes, such as friction stir, magnetic pulse, conductive heat seam, and laser-hybrid welding. Furthermore, progress is desired in making more specialized methods like laser beam welding practical for more applications, such as in the aerospace and automotive industries. Researchers also hope to better understand the often unpredictable properties of welds, especially microstructure, residual stresses, and a weld's tendency to crack or deform.

The trend of accelerating the speed at which welds are performed in the steel erection industry comes at a risk to the integrity of the connection. Without proper fusion to the base materials provided by sufficient arc time on the weld, a project inspector cannot ensure the effective diameter of the puddle weld therefore he or she cannot guarantee the published load capacities unless they witness the actual installation. This method of puddle welding is common in the United States and Canada for attaching steel sheets to bar joist and structural steel members. Regional agencies are responsible for ensuring the proper installation of puddle welding on steel construction sites. Currently there is no standard or weld procedure which can ensure the published holding capacity of any unwitnessed connection, but this is under review by the American Welding Society.

Glass and plastic welding

Glasses and certain types of plastics are commonly welded materials. Unlike metals, which have a specific melting point, glasses and plastics have a melting range, called the glass transition. When heating the solid material past the glass-transition temperature (Tg) into this range, it will generally become softer and more pliable. When it crosses through the range, above the glass-melting temperature (Tm), it will become a very thick, sluggish, viscous liquid, slowly decreasing in viscosity as temperature increases. Typically, this viscous liquid will have very little surface tension compared to metals, becoming a sticky, taffy to honey-like consistency, so welding can usually take place by simply pressing two melted surfaces together. The two liquids will generally mix and join at first contact. Upon cooling through the glass transition, the welded piece will solidify as one solid piece of amorphous material.

Glass welding
Glass welding is a common practice during glassblowing. It is used very often in the construction of lighting, neon signs, flashtubes, scientific equipment, and the manufacture of dishes and other glassware. It is also used during glass casting for joining the halves of glass molds, making items such as bottles and jars. Welding glass is accomplished by heating the glass through the glass transition, turning it into a thick, formable, liquid mass. Heating is usually done with a gas or oxy-gas torch, or a furnace, because the temperatures for melting glass are often quite high. This temperature may vary, depending on the type of glass. For example, lead glass becomes a weldable liquid at around 1600 F, and can be welded with a simple propane torch. On the other hand, quartz glass (fused silica) must be heated to over 3000 F, but quickly loses its viscosity and formability if overheated, so an oxyhydrogen torch must be used. Sometimes a tube may be attached to the glass, allowing it to be blown into various shapes, such as bulbs, bottles, or tubes. When two pieces of liquid glass are pressed together, they will usually weld very readily. Welding a handle onto a pitcher can usually be done with relative ease. However, when welding a tube to another tube, a combination of blowing and suction, and pressing and pulling is used to ensure a good seal, to shape the glass, and to keep the surface tension from closing the tube in on itself. Sometimes a filler rod may be used, but usually not.

Because glass is very brittle in its solid state, it is often prone to cracking upon heating and cooling, especially if the heating and cooling are uneven. This is because the brittleness of glass does not allow for uneven thermal expansion. Glass that has been welded will usually need to be cooled very slowly and evenly through the glass transition, in a process called annealing, to relieve any internal stresses created by a temperature gradient.

There are many types of glass, and it is most common to weld using the same types. Different glasses often have different rates of thermal expansion, which can cause them to crack upon cooling when they contract differently. For instance, quartz has very low thermal expansion, while soda-lime glass has very high thermal expansion. When welding different glasses to each other, it is usually important to closely match their coefficients of thermal expansion, to ensure that cracking does not occur. Also, some glasses will simply not mix with others, so welding between certain types may not be possible.

Glass can also be welded to metals and ceramics, although with metals the process is usually more adhesion to the surface of the metal rather than a commingling of the two materials. However, certain glasses will typically bond only to certain metals. For example, lead glass bonds readily to copper or molybdenum, but not to aluminum. Tungsten electrodes are often used in lighting but will not bond to quartz glass, so the tungsten is often wetted with molten borosilicate glass, which bonds to both tungsten and quartz. However, care must be taken to ensure that all materials have similar coefficients of thermal expansion to prevent cracking both when the object cools and when it is heated again. Special alloys are often used for this purpose, ensuring that the coefficients of expansion match, and sometimes thin, metallic coatings may be applied to a metal to create a good bond with the glass.

Plastic welding
Plastics are generally divided into two categories, which are "thermosets" and "thermoplastics." A thermoset is a plastic in which a chemical reaction sets the molecular bonds after first forming the plastic, and then the bonds cannot be broken again without degrading the plastic. Thermosets cannot be melted, therefore, once a thermoset has set it is impossible to weld it. Examples of thermosets include epoxies, silicone, vulcanized rubber, polyester, and polyurethane.

Thermoplastics, by contrast, form long molecular chains, which are often coiled or intertwined, forming an amorphous structure without any long-range, crystalline order. Some thermoplastics may be fully amorphous, while others have a partially crystalline/partially amorphous structure. Both amorphous and semicrystalline thermoplastics have a glass transition, above which welding can occur, but semicrystallines also have a specific melting point which is above the glass transition. Above this melting point, the viscous liquid will become a free-flowing liquid (see rheological weldability for thermoplastics). Examples of thermoplastics include polyethylene, polypropylene, polystyrene, polyvinylchloride (PVC), and fluoroplastics like Teflon and Spectralon.

Welding thermoplastic with heat is very similar to welding glass. The plastic first must be cleaned and then heated through the glass transition, turning the weld-interface into a thick, viscous liquid. Two heated interfaces can then be pressed together, allowing the molecules to mix through intermolecular diffusion, joining them as one. Then the plastic is cooled through the glass transition, allowing the weld to solidify. A filler rod may often be used for certain types of joints. The main differences between welding glass and plastic are the types of heating methods, the much lower melting temperatures, and the fact that plastics will burn if overheated. Many different methods have been devised for heating plastic to a weldable temperature without burning it. Ovens or electric heating tools can be used to melt the plastic. Ultrasonic, laser, or friction heating are other methods. Resistive metals may be implanted in the plastic, which respond to induction heating. Some plastics will begin to burn at temperatures lower than their glass transition, so welding can be performed by blowing a heated, inert gas onto the plastic, melting it while, at the same time, shielding it from oxygen.

Solvent welding
Many thermoplastics can also be welded using chemical solvents. When placed in contact with the plastic, the solvent will begin to soften it, bringing the surface into a thick, liquid solution. When two melted surfaces are pressed together, the molecules in the solution mix, joining them as one. Because the solvent can permeate the plastic, the solvent evaporates out through the surface of the plastic, causing the weld to drop out of solution and solidify. A common use for solvent welding is for joining PVC (polyvinyl chloride) or ABS (acrylonitrile butadiene styrene) pipes during plumbing, or for welding styrene and polystyrene plastics in the construction of models. Solvent welding is especially effective on plastics like PVC which burn at or below their glass transition, but may be ineffective on plastics like Teflon or polyethylene that are resistant to chemical decomposition.

title: Welding


text:
Vedic (disambiguation)

Vedic may refer to:

 * The Vedas, the oldest preserved Indic texts
 * Vedic Sanskrit, the language of these texts
 * Vedic period, during which these texts were produced
 * Vedic pantheon of gods mentioned in Vedas
 * The historical Vedic religion, of which the Vedas record the liturgy
 * Vedic mythology, the mythological aspects of the historical Vedic religion and Vedas
 * Vedanga, "auxiliary disciplines" explaining the Vedas
 * Upaveda, traditional Hindu disciplines of scholarship
 * Ayurveda (medicine)
 * Gandharvaveda (music)
 * Dhanurveda (martial arts)
 * Sthaptyaveda (architecture)
 * In modern usage, anything loosely related to Hindu tradition
 * Hinduism in general
 * Vedic science (disambiguation)
 * Maharishi Vedic Approach to Health, based on Ayurveda
 * Bharati Krishna Tirtha's Vedic mathematics, system of mental calculation
 * Vedic University (disambiguation)
 * Vedic square, multiplication table
 * Vedic metal, music genre
 * VE-DIC, video-enhanced differential interference contrast microscopy

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Vedic (disambiguation)


text:
Who's Afraid of Virginia Woolf?

Who's Afraid of Virginia Woolf? is a play by Edward Albee first staged in October 1962. It examines the complexities of the marriage of middle-aged couple Martha and George. Late one evening, after a university faculty party, they receive unwitting younger couple Nick and Honey as guests, and draw them into their bitter and frustrated relationship.

The three-act play normally takes just under three hours to perform, with two 10 minute intermissions. The title is a pun on the song "Who's Afraid of the Big Bad Wolf?" from Walt Disney's Three Little Pigs (1933), substituting the name of the celebrated English author Virginia Woolf. Martha and George repeatedly sing this version of the song throughout the play.

Who's Afraid of Virginia Woolf? won both the 1963 Tony Award for Best Play and the 1962–1963 New York Drama Critics' Circle Award for Best Play. It is frequently revived on the modern stage. The film adaptation was released in 1966, written by Ernest Lehman, directed by Mike Nichols, and starring Richard Burton, Elizabeth Taylor, George Segal, and Sandy Dennis.

Act One: "Fun and Games"
George is an associate professor of history, and his wife Martha is the daughter of the president of the college where George teaches. After they return home from a faculty party, Martha reveals she has invited a young married couple she met at the party over for a drink. (Also cut in the definitive edition: Just before the couple—Nick and Honey—arrives, George gives a vague warning about "the bit with the kid" that Martha appears to understand.)

As the four drink, Martha and George engage in scathing verbal abuse of each other in front of Nick and Honey. These interactions embarrass the younger couple, but they stay. At one point, Honey lets on that Martha told her about their son, which appears to unnerve George. After this, Martha's taunts and George's passive aggression only increase. When Martha launches into an embarrassing story about how she humiliated him with a sucker punch at a backyard party, George disappears. The story continues, with Nick and Honey laughing, until George appears with a rifle and fires at Martha. To their surprise, a Chinese parasol pops out of the gun barrel. Everyone finds this extremely funny, but Martha quickly resumes her taunting of George, which culminates in Martha relating how her father had thought that George would eventually rise to lead the college, but George's lack of ambition has made him pathetic to Martha, who calls him a "great big fat flop." George reacts violently by breaking a bottle. Honey, who has grown more and more deliriously drunk, quickly runs to the bathroom to vomit, leaving George alone with glass all over the room.

Act Two: "Walpurgisnacht"

 * (Traditionally, "Walpurgisnacht" is the name of an annual witches' meeting, satiric in the context of the play.)

Nick returns to find George alone. As they talk about their wives, Nick reveals that Honey once had a "hysterical pregnancy". George tells Nick about a time he went to a gin mill with some boarding school classmates, one of whom had accidentally killed his mother by shooting her. This friend was mocked for ordering "bergin" (bourbon). The following summer, the young friend was driving with his father and suddenly swerved to avoid a porcupine, accidentally killing his father. The boy was then sent to an asylum and became mute. As the story concludes, George and Nick discuss children, but the conversation turns insulting before Martha and Honey return.

Honey calls for music, so they put on a record. Because George refuses to dance, Martha dances with Nick, taunting George by making the dance very sensual while she tells another embarrassing story about George: his efforts to publish a novel about a boy who accidentally killed both of his parents (with the insinuation that the deaths were actually murder), but Martha's father would not let it be published. George attacks Martha, but Nick separates them. Clearly not satisfied, George launches into a new "game" called "Get the Guests," in which George begins telling a story about a "mousie" that is a thinly-veiled retelling of everything Nick told George about Honey, including her alcoholism and her "hysterical pregnancy," implying that Honey "trapped" Nick into marrying her by pretending to be pregnant. Honey, devastated, again runs to the bathroom to vomit.

Martha begins to openly seduce Nick in the living room right in front of George, who blithely smiles and pretends to read a book. This greatly annoys Martha, who tells George that if he does nothing to stop her, she'll have sex with Nick. George is unmoved, so Martha goes upstairs with Nick. Immediately, an enraged George throws his book against the house's doorbell chimes, which ring out as he promises to make Martha "regret this."

In some productions until 2006, Honey then returns, wondering who rang the doorbell. George then interrogates Honey about her pregnancy, then openly tells Honey that he is going to inform Martha that their son has died. In a 2006 revision by the author of the script, however, this scene is cut.

Act Three: "The Exorcism"

 * (Exorcism is the expulsion or attempted expulsion of a supposed evil spirit from a person or place.)

Martha enters an empty living room and shouts for the others to come out of hiding. Nick joins her. The doorbell rings, and George enters carrying snapdragons and making literary jokes that Martha seems to actually enjoy. Martha and George then argue about whether the moon is up, an odd game whose metaphors reveal that Nick was too drunk to have sex with Martha upstairs.

George asks Nick to bring Honey back for the final game, "Bringing Up Baby." Nick and Honey sit helplessly as George, at last, talks openly about his and Martha's son. As he accuses Martha of being overbearing to their son, she protests, leading George to ask for her "recitation." Martha agrees, and begins to recall their son's beauty and talents and accuses George of ruining his life. As she speaks, George recites sections of the Libera me (part of the Requiem Mass, the Latin mass for the dead) and Kyrie eleison (ancient Greek: "Lord, have mercy").

This continues until George informs Martha that the doorbell earlier was a messenger from Western Union arriving with a telegram that George says informed him that their son was dead, having been killed in a car crash when he swerved to avoid a porcupine—the exact wording that George earlier used in a story about a completely different person. Martha demands proof, but George insists on the reality of the situation. Martha, distraught, collapses. It slowly dawns on Nick that the son George and Martha have been talking about is not real. The fictional son is a "game" the two have been playing since discovering early in their marriage that they are infertile. George has decided to "kill" him because Martha broke the game's single rule: not to mention the boy to anyone else.

Overcome with pity, Nick and Honey leave. Martha suggests that they could invent a new imaginary child, but George insists they cannot. The play ends with George singing "Who's afraid of Virginia Woolf?", a joke song someone sang that night at the faculty party. Martha weakly replies, "I am, George. I am."

Reality and illusion
Albee has said that the title of the play "means who's afraid of the big bad wolf ... who's afraid of living life without false illusions." Albee's interest in the theme of reality versus illusion is expressed in a number of his plays. In discussing Who's Afraid of Virginia Woolf? he cites Nietzsche's interpretation of the Apollonian/Dionysian dichotomy of ancient Greek drama, as described in The Birth of Tragedy. Albee says,

"There was a time when people believed in deities. And then revolutions came – industrial, French, Freudian, Marxist. God and absolutes vanished. Individuals find this very difficult and uncomfortable. All they have left is fantasy or the examination of the self."

According to Lawrence Kingsley, Albee's characters create illusions to help them evade feelings of their own inadequacy – as "George and Martha have evaded the ugliness of their marriage by taking refuge in illusion." The play demonstrates "how his characters must rid themselves of falsehood and return to the world in which they must live."

The distinction between truth and illusion is at times deliberately unclear. The existence of the child, the "murder" by George of his parents, or Honey's "pregnancy" may be illusions, but they seem real to the characters. Illusions may be exorcised in the play, but no truth or apparent reality is supplied in its place. "All truth", George says, " relative".

Critique of societal expectations
Christopher Bigsby asserts that this play opposes the idea of a perfect American family and societal expectations as it "attacks the false optimism and myopic confidence of modern society". Albee takes a heavy-handed approach to displaying this contrast, making examples of every character and their expectations of the people around them. Societal norms of the 1950s consisted of a nuclear family: two parents and two (or more) children. This conception was picturesque in the idea that the father was the breadwinner, the mother a homemaker, and the children well-behaved.

Who's Afraid of Virginia Woolf? smashes these conventions and shows realistic families that are far from perfect and possibly ruined. The families of Honey and Martha were dominated by their fathers, with no sign of a mother figure in their lives. George and Martha's chance at a perfect family was ruined by infertility and George's failure to become a prominent figure at the university.

Title
The play's title alludes to the English novelist Virginia Woolf. She committed suicide at age 59 in 1941. She left behind a note in which she expressed love for her husband Leonard Woolf and sorrow for the anguish she was causing him. Twenty years later, playwright Edward Albee corresponded with him, asking permission to use his late wife's name in the title of a new play, according to literary critic Leon Edel, an acquaintance of Leonard Woolf. Woolf granted permission, according to Edel.

Edward Albee's title also pokes fun at the song "Who's Afraid of the Big Bad Wolf?" from Walt Disney's animated version of The Three Little Pigs. Because the rights to the Disney song are expensive, most stage versions, and the film, have Martha sing to the tune of "Here We Go Round the Mulberry Bush", a melody that fits the meter fairly well and is in the public domain. In the first few moments of the play, it is revealed that someone sang the song earlier in the evening at a party, although who first sang it (Martha or some other anonymous party guest) remains unclear. Martha repeatedly needles George over whether he found it funny.

Albee described the inspiration for the title:

"I was in there having a beer one night, and I saw 'Who's afraid of Virginia Woolf?' scrawled in soap, I suppose, on this mirror. When I started to write the play it cropped up in my mind again. And of course, who's afraid of Virginia Woolf means who's afraid of the big bad wolf – who's afraid of living life without false illusions. And it did strike me as being a rather typical, university intellectual joke."

The title phrase happened to appear five years before the play's premiere, in a 1957 issue of The New Yorker:

"A coffee fiend we know dropped into an espresso joint in Greenwich Village the other day and found himself whiling away his time reading the graffiti on the wall beside his chair. Most of the stuff was pretty humdrum, but he was arrested by a legend, done in elegant calligraphy, that read, 'Who's afraid of Virginia Woolf?'"

The New Yorker responded in 2013 by suggesting that perhaps the graffiti that Albee saw was the same graffiti that The New Yorker reported in 1957.

Characters
In an interview, Albee said Martha and George were based on two of his friends, married New York socialites Willard Maas and Marie Menken. Maas was a professor of literature at Wagner College and Menken was an experimental filmmaker and painter. Maas and Menken were known for their infamous salons, where drinking would "commence at 4 on Friday and end in the wee hours of night on Monday" (according to Gerard Malanga, an Andy Warhol associate and friend to Maas). The primary conflict between George and Martha in Who's Afraid of Virginia Woolf? derived from Maas's and Menken's tempestuous and volatile relationship.

Original production
The print edition of the play was published in 1962 and was one of the early releases of Atheneum Books. It sold over 70,000 copies in hard and soft cover editions.

Who's Afraid of Virginia Woolf? opened on Broadway at the Billy Rose Theatre on 13 October 1962. The original cast featured Uta Hagen as Martha, Arthur Hill as George, Melinda Dillon as Honey, and George Grizzard as Nick. It was directed by Alan Schneider. Subsequent cast members included Henderson Forsythe, Eileen Fulton, Nancy Kelly, Mercedes McCambridge, and Elaine Stritch.

Because of the play's unusual length (over three hours), the producers also cast a matinee company that performed twice a week, featuring Kate Reid as Martha, Shepperd Strudwick as George, Avra Petrides as Honey, and Bill Berger as Nick. As with the evening company, these matinee performances also sold out.

The play closed on 16 May 1964, after 5 previews and 664 performances. It opened in London in 1965, starring Constance Cummings. Virginia Woolf's widower Leonard attended a performance and enjoyed it, according to an acquaintance of his, literary critic Leon Edel.

Original Broadway cast album
In 1963, Columbia Masterworks released a four-LP boxed recording of the original Broadway cast performing the entire play, directed by Alan Schneider.

The release contained a 16 page booklet with photos from the original production, critical essays by Harold Clurman and Walter Kerr, cast and crew biographies, and a short article by Goddard Lieberson on the task of recording the play. The introduction is by Albee, in which he writes, "I cannot conceive of anyone wanting to buy [this] massive album; but ... every playwright wants as much permanence for his work as he can get."

The recording was issued in both stereo (DOS 687) and monaural (DOL 287) formats. It was out of print for many years, was not released in other formats, and is highly prized among collectors, as a play with such adult themes had never been recorded for the general public before. It was finally re-released in 2014 by Masterworks Broadway.

Notable productions
In 1970, Henry Fonda and Richard Burton attempted to recruit Warren Beatty and Jon Voight for an all-male production, but Albee refused permission.

Colleen Dewhurst and Ben Gazzara starred in a 1976 Broadway revival.

Mike Nichols and Elaine May starred in a 1980 production in New Haven.

Diana Rigg and David Suchet starred in a 1996 production of the play at the Almeida Theatre in London before transferring to the Aldwych Theatre in London's West End in 1997.

Patrick Stewart and Mercedes Ruehl starred in a 2000–2001 production at The Guthrie Theater in Minneapolis.

The play was revived on Broadway at the Longacre Theatre, opening on 12 March 2005, in previews and closing on 4 September 2005, after 8 previews and 177 performances. Directed by Anthony Page, it starred Kathleen Turner as Martha and Bill Irwin as George, with Mireille Enos as Honey and David Harbour as Nick. Irwin won the 2005 Tony Award for Best Performance by a Leading Actor in a Play for his role. The production transferred to London's West End at the Apollo Theatre with the entire original cast, running from 31 January to 13 May 2006. In January 2007, the production played at the Kennedy Center in Washington, DC, for one month. On 6 February 2007, the production began a six-week run at the Ahmanson Theatre in Los Angeles.

Notably, it was this 2005 production that led to the publication of a revised script – one that has been used ever since – although many of its revisions were introduced in earlier productions. Among the revisions was the removal of early references to George and Martha's son, as well as the reference to the fact that George felt that he helped cause his parents' death, which was originally the subject of his failed novel. A roughly 7 page scene with George and Honey at the end of Act II has also been removed completely. These and other changes seem to be there to clarify plot points, but arguably rob the play of some of its ambiguity and tenuous relationship with realism.

The play toured in the US and played in San Francisco at the Golden Gate Theatre from 11 April – 12 May 2007.

On 12 December 2010, the Steppenwolf Theatre in Chicago began performances of the play featuring Amy Morton as Martha, Tracy Letts (the Pulitzer Prize-winning playwright of August: Osage County) as George, Carrie Coon, and Madison Dirks. The production was directed by Pam MacKinnon, who previously directed the premieres of Albee's Peter and Jerry and Occupant. This production began previews on Broadway at the Booth Theatre on 27 September 2012, opening on 13 October, 50 years after the original Broadway opening. MacKinnon again directed, with the Steppenwolf cast reprising their roles. The production and cast received praise in The New York Times from reviewer Charles Isherwood. Letts won the 2013 Tony Award for Best Performance by a Leading Actor in a Play.

Meg Tilly returned to acting in 2011 to play Martha in a production by Blue Bridge Repertory Theatre. The show ran from 5 July – 17 July 2011, in Victoria, British Columbia.

On 21 February 2017, a production directed by James Macdonald began at the Harold Pinter Theatre in London, featuring Imelda Staunton, Conleth Hill, Imogen Poots, and Luke Treadaway. It ran until 27 May 2017.

A Broadway revival was scheduled to premiere on 9 April 2020, in a production directed by Joe Mantello and produced by Scott Rudin. It was canceled due to the COVID-19 pandemic after 9 preview performances, without officially opening. It starred Laurie Metcalf, Rupert Everett, Russell Tovey, and Patsy Ferran. Eddie Izzard had been set to play George, but it was announced on 11 September 2019, that Everett would replace her.

Dance interpretation
In 1995 and 1996, the Canadian One Yellow Rabbit troupe mounted a homage in dance to Albee, Permission, in the form of an hour-long ballet inspired by Who's Afraid of Virginia Woolf. It was performed in Calgary, Toronto, Phoenix, Guadalajara, and Mexico City.

Sequels and parodies
In 2018 the Elevator Repair Service premiered a sequel written by Kate Scelsa, titled Everyone's Fine with Virginia Woolf. This play introduces new plot elements such as vampirism.

Multiple television shows have episodes parodying the original play. Season 3, Episode 1 of American Dad! features a sub-plot in which the characters of Roger and Francine pretend to be a university professor and his wife. After inviting over a young couple, the two behave much like the characters of George and Martha. The episode concludes with Roger "killing" their imaginary child much like George does in the play.

The critically acclaimed "Dinner Party" episode of The Office (Season 4, Episode 13) was originally titled "Virginia Woolf" by writers Gene Stupnitsky and Lee Eisenberg. This episode is a parody in which Michael invites new couple Jim and Pam to a dinner party that slowly devolves into a chaotic exhibition of Michael's tense relationship with his girlfriend and former boss, Jan.

Season 2, Episode 4 of Our Flag Means Death is a parody in which the dysfunctional relationship of Anne Bonny and Mary Read is meant to parallel that of George and Martha, and whose antics instigate a reconciliation of Ed and Stede.

Awards
Who's Afraid of Virginia Woolf? won both the 1963 Tony Award for Best Play and the 1962–1963 New York Drama Critics' Circle Award for Best Play. Its stars won the 1963 Tony Awards for Best Actor and Actress. It was selected for the 1963 Pulitzer Prize for Drama by that award's drama jury, but the award's advisory board – the trustees of Columbia University – objected to its profanity and sexual themes, and overruled the jury, awarding no Pulitzer Prize for drama in 1963.

The 2012 revival won the 2013 Tony Awards for Best Revival of a Play, Best Performance by an Actor in a Leading Role in a Play (Letts), and Best Direction of a Play (MacKinnon).

Film
A film adaptation of the play was released in 1966. It was directed by Mike Nichols and starred Elizabeth Taylor as Martha, Richard Burton as George, George Segal as Nick, and Sandy Dennis as Honey. All four actors were nominated for Academy Awards: Taylor and Burton for Best Actress and Actor and Dennis and Segal for Supporting Oscars. Taylor won the Oscar for Best Actress but Burton was passed over that year in favor of Paul Scofield in A Man For All Seasons. Dennis won Best Actress in a Supporting Role, while Segal lost to Walter Matthau in The Fortune Cookie.

Jack Valenti identified the film as the first controversial film he had to deal with as president of the Motion Picture Association of America (MPAA). It was the first to use the slang "screw" and the phrase "hump the hostess". As he said, "In company with the MPAA's general counsel, Louis Nizer, I met with Jack Warner, the legendary chieftain of Warner, and his top aide, Ben Kalmenson. We talked for three hours, and the result was deletion of 'screw' and retention of 'hump the hostess', but I was uneasy over the meeting."

Original film soundtrack album
The film was given a "Deluxe Edition Two-Record Set" soundtrack album release in 1967 by Warner Bros. Records, and was the first film to have its vocals be released in their entirety on an album, as the film at that time could not be shown on network television. It contains the vocals of the four actors performing in the film. The only music on the album is a song, "Virginia Woolf Rock", that plays while Martha and Nick are dancing (but plays a little differently than it does in the film).

In at least two instances alternative takes were used: Taylor's memorable "Goddamn you!" line is restored to "Screw you!", and some of the dialogue from the dancing sequence was lifted from another take. As Martha tells Nick and Honey her story about punching George in the stomach in front of her father, it is heard very clearly while in the film it becomes muffled as the camera follows George into another room to get a gun. The album also runs half an hour shorter than the film, since most pauses and long silences were removed, but virtually every line remains intact. The album's cover has the four main actors and the back cover has some background information about them, the five-month shooting schedule, and Albee, and a brief synopsis of the film.

title: Who's Afraid of Virginia Woolf?


text:
Pope Sixtus V

Pope Sixtus V (Sisto V; 13 December 1521 – 27 August 1590), born Felice Piergentile, was head of the Catholic Church and ruler of the Papal States from 24 April 1585 to his death, in August 1590. As a youth, he joined the Franciscan order, where he displayed talents as a scholar and preacher, and enjoyed the patronage of Pius V, who made him a cardinal. As a cardinal, he was known as Cardinal Montalto.

As Pope, he energetically rooted out corruption and lawlessness across Rome, and launched a far-sighted rebuilding programme that continues to provoke controversy, as it involved the destruction of antiquities. The cost of these works was met by heavy taxation which caused much suffering. His foreign policy was regarded as over-ambitious, and he excommunicated both Queen Elizabeth I of England and King Henry IV of France. He is recognized as a significant figure of the Counter-Reformation. He is the most recent pope to date to take on the pontifical name "Sixtus".

Early life
Felice Piergentile was born on 13 December 1521 at Grottammare, in the Papal States, to Francesco Piergentile (also known as Peretto di Montalto, from the city of origin Montalto delle Marche), and Mariana da Frontillo. His father had taken refuge in Grottammare to escape the oppression of the Duke of Urbino, finding there a job as a gardener. Felice later adopted Peretti as his family name in 1551, and as a cardinal was known as "Cardinal Montalto" (to reflect his affection for his homeland).

Franciscan
At the age of 9 years, Felice returned to Montalto to join his uncle in the Franciscan Convent of San Francesco delle Fratte. At the age of 12, he was initiated as a novice of the Franciscan Order, assuming the name of Fra Felice (Friar Felix) in 1535, maintaining his birth name. From this year, he started philosophical and theological studies, moving between different convents of the Order. He finally completed his studies in the Franciscan Magna Domus of Bologna on September 1544. Three years earlier he had been ordained as a deacon.

About 1552 he was noticed by Cardinal Rodolfo Pio da Carpi, Protector of the Franciscan order, Cardinal Ghislieri (later Pope Pius V) and Cardinal Caraffa (later Pope Paul IV), and from that time his advancement was assured. He was sent to Venice as inquisitor general of the Venetian Holy Inquisition, but was so severe and conducted matters in such a high-handed manner that he became embroiled in quarrels. In 1560, the Venetian government asked for his recall.

After a brief term as procurator of his order, he was attached in 1565 to the papal legation to Spain headed by Cardinal Ugo Boncampagni (later Pope Gregory XIII) which was sent to investigate a charge of heresy levelled against Bartolomé Carranza, Archbishop of Toledo. The violent dislike which Peretti conceived for Boncampagni had a marked influence on his subsequent actions. He hurried back to Rome upon the accession of Pius V, who made him apostolic vicar of his order and then, in 1570, cardinal.

Cardinal
During the pontificate of his political enemy Gregory XIII (1572–1585), Cardinal Montalto, as he was generally called, lived in enforced retirement, occupied with the care of his property, the Villa Montalto, erected by Domenico Fontana close to the cardinal's beloved church on the Esquiline Hill, overlooking the ancient Baths of Diocletian. The first phase (1576–1580) of the building was enlarged after Peretti became pope and was able to clear buildings to open four new streets in 1585–86. The villa contained two residences, the Palazzo Sistino or "Palazzo di Termini" and the casino, called the Palazzetto Montalto e Felice.

This clearance programme was an undoubted gain in the relief it brought to the congestion of the crowded medieval city. Clearly, however, Romans displaced by it were furious, and resentment was still felt centuries later until the decision was taken to build Roma Termini railway station, inaugurated by Pope Pius IX in 1863, on the site of the Villa, which became doomed to destruction.

Cardinal Montalto's other occupation at this period was with his studies, one of the fruits of which was an edition of the works of Ambrose. As pope he would personally supervise the printing of an improved edition of Jerome's Vulgate.

Election as pope
Though not neglecting to follow the course of affairs, Felice carefully avoided every occasion of offence. This discretion contributed not a little to his election to the papacy on 24 April 1585, with the title of Sixtus V to honour Pope Sixtus IV, also a Franciscan like himself. One of the things that commended his candidacy to certain cardinals may have been his physical vigour, which seemed to promise a long pontificate. His papal coronation was held on 1 May 1585 and he was crowned by the protodeacon Ferdinando de' Medici.

Reforms in the city of Rome
The terrible condition in which Pope Gregory XIII had left the Papal States called for prompt and stern measures. Sixtus proceeded with an almost ferocious severity against the prevailing lawlessness. Thousands of brigands were brought to justice: within a short time, the country was again quiet and safe. It was claimed that there were more heads on spikes across the Ponte Sant'Angelo than melons for sale in the marketplace. And clergy and nuns were executed if they broke their vows of chastity.

Next Sixtus set to work to repair the finances. By the sale of offices, the establishment of a new "Monti" and by levying new taxes, he accumulated a vast surplus, which he stored up against certain specified emergencies, such as a crusade or the defence of the Holy See. Sixtus prided himself upon his hoard, but the method by which it had been amassed was financially unsound: some of the taxes proved ruinous, and the withdrawal of so much money from circulation could not fail to cause distress.

Immense sums were spent upon public works, in carrying through the comprehensive planning that had come to fruition during his retirement, bringing water to the waterless hills via his new aqueduct, the Acqua Felice which fed twenty-seven new fountains; laying out new arteries in Rome, which connected the great basilicas, even setting his engineer-architect Domenico Fontana to replan the Colosseum as a silk-spinning factory housing its workers.

Inspired by the ideal of the Renaissance city, Pope Sixtus V's ambitious urban reform programme transformed the old environment to emulate the "long straight streets, wide regular spaces, uniformity and repetitiveness of structures, lavish use of commemorative and ornamental elements, and maximum visibility from both linear and circular perspective." The Pope set no limit to his plans, and achieved much in his short pontificate, always carried through at top speed: the completion of the dome of St. Peter's; the loggia of Sixtus in the Basilica di San Giovanni in Laterano; the chapel of the Praesepe in Santa Maria Maggiore; additions or repairs to the Quirinal, Lateran and Vatican palaces; the erection of four obelisks, including that in Saint Peter's Square; the opening of six streets; the restoration of the aqueduct of Septimius Severus ("Acqua Felice"); the integration of the Leonine City in Rome as XIV rione (Borgo).

Besides numerous roads and bridges, he improved the city's air by financing the reclamation of the Pontine Marshes. Good progress was made, with more than 9500 acre reclaimed and opened to agriculture and manufacture. The project was abandoned upon his death. Sixtus had no appreciation of antiquities, which were employed as raw material to serve his urbanistic and Christianising programs: Trajan's Column and the Column of Marcus Aurelius (at the time misidentified as the Column of Antoninus Pius) were made to serve as pedestals for the statues of SS Peter and Paul; the Minerva of the Capitol was converted into an emblem of Christian Rome; the Septizodium of Septimius Severus was demolished for building materials.

The spatial organization, monumental inscriptions and restorations throughout the city reinforced the control, surveillance, and authority that alluded to his power.

Church administration
The subsequent administrative system of the Catholic Church owed much to Sixtus. He limited the College of Cardinals to seventy. He doubled the number of the congregations and enlarged their functions, assigning to them the principal role in the transaction of business (1588). He regarded the Jesuits with disfavour and suspicion. He considered radical changes to their constitution, but death prevented the execution of his purpose.

In 1588, he established the 15 congregations by his constitution Immensa Aeterni Dei.

Sixtine Vulgate and Septuagint
In May 1587, the Sixtine Septuagint was published under the auspices of Sixtus V.

In May 1590 the Sixtine Vulgate was issued. The edition was preceded by the Bull Aeternus ille, in which the Pope declared the authenticity of the new Bible. The bull stipulated "that it was to be considered as the authentic edition recommended by the Council of Trent, that it should be taken as the standard of all future reprints, and that all copies should be corrected by it." "This edition was not to be reprinted for 10 years except at the Vatican, and after that any edition must be compared with the Vatican edition, so that "not even the smallest particle should be altered, added or removed" under pain of the "greater excommunication." Jaroslav Pelikan, without giving any more details, says that this edition "proved to be so defective that it was withdrawn".

Consistories
Sixtus V created 33 cardinals in eight consistories during his reign, which included his grandnephew Alessandro Peretti di Montalto and his future successor Ippolito Aldobrandini who would later become Pope Clement VIII.

Beatifications and canonizations
During his pontificate, Sixtus V beatified Ubaldesca Taccini (1587) and canonized one saint, Didacus of Alcalá (10 July 1588).

Roman Curia
In 1588, Sixtus V published the bull Immensa Aeterni Dei which reorganised the Roman Curia into departments.

Foreign relations
In his larger political relations, Sixtus entertained fantastic ambitions, such as the annihilation of the Turks, the conquest of Egypt, the transport of the Holy Sepulchre to Italy, and the accession of his nephew to the throne of France. The situation in which he found himself was difficult: he could not countenance the designs of those he considered as heretical princes, and yet he mistrusted King Philip II of Spain and viewed with apprehension any extension of his power.

Sixtus agreed to renew the excommunication of Queen Elizabeth I of England, and to grant a large subsidy to the Armada of Philip II, but, knowing the slowness of Spain, would give nothing until the expedition actually landed in England. This way, he saved a fortune that would otherwise have been lost in the failed campaign. Sixtus had Cardinal William Allen draw up the An Admonition to the Nobility and People of England and Ireland, a proclamation to be published in England if the invasion had been successful. The extant document comprised all that could be said against Elizabeth I, and the indictment is therefore fuller and more forcible than any other put forward by the religious exiles, who were generally reticent in their complaints. Allen carefully consigned his publication to the fire, and it is only known of through one of Elizabeth's spies, who had stolen a copy.

Sixtus excommunicated King Henry III of Navarre, who was the heir presumptive to the throne of France, and contributed to the Catholic League, but he chafed under his forced alliance with King Philip II of Spain, and looked for an escape. The victories of Henry and the prospect of his conversion to Catholicism raised Sixtus V's hopes, and to a corresponding degree determined Philip II to tighten his grip upon his wavering ally. The Pope's negotiations with Henry's representative evoked a bitter and menacing protest and a categorical demand for the performance of promises. Sixtus took refuge in evasion and temporised until his death on 27 August 1590.

Contraception, abortion, and adultery
Sixtus extended the penalty of excommunication relating to the Roman Catholic Church's teaching on contraception and on abortion. While the Church taught that abortion and contraception were gravely sinful actions, it did not apply to all mortal sins the additional penalty of excommunication.

Some theologians argued that only after proof of the "quickening" (when the mother can feel the fetus's movement in her womb, usually about 20 weeks into gestation) that there was incontrovertible evidence that ensoulment had already occurred. Until Sixtus V, canon lawyers had applied the code from Gratian whereby excommunications were only given to abortions after the quickening. In 1588 the pope issued a papal bull, Effraenatam or Effrenatam ("Without Restraint"), which declared that the canonical penalty of excommunication would be levied for any form of contraception and for abortions at any stage in fetal development. The reasoning on the latter would be that the soul of the unborn child would be denied Heaven.

Sixtus also attempted in 1586 to introduce into the secular law in Rome the Old Testament penalty for adultery, which is death. The measure ultimately failed.

Death and legacy
Sixtus V died on 27 August 1590 from malaria. The pope became ill with a fever on 24 August which intensified the following day.

As Sixtus V lay on his deathbed, he was loathed by his political subjects, but history has recognized him as one of the most important popes. On the negative side, he could be impulsive, obstinate, severe, and autocratic. On the positive side, he was open to large ideas and threw himself into his undertakings with energy and determination; this often led to success. His pontificate saw great enterprises and great achievements.

About 5,000 bandits were executed by Sixtus V in the five years before his death in 1590, but there were reputedly 27,000 more at liberty throughout Central Italy.

Works

 * Latin text of Effraenatum perditissimorum
 * Latin text of Effraenatum perditissimorum

title: Pope Sixtus V