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Superplastic Forming
Superplastic forming is an industrial process used for creating precise and complex components out of superplastic materials. Process The material is first heated up to promote superplasticity. For titanium alloys e.g. Ti 6Al 4V and some stainless steels this is around and for aluminium alloys e.g. AA5083 it is between 450 and 520 °C. In this state the material becomes soft so processes that are usually used on plastics can be applied, such as: thermoforming, blow forming, and vacuum forming.E. Degarmo, J. Black, and R. Kohser, Materials and Processes in Manufacturing (9th ed.), 2003, Wiley, . Inert gas pressure is applied on the superplastic sheet forcing it into a female die. Advantages and disadvantages The major advantage of this process is that it can form large and complex workpieces in one operation. The finished product has excellent precision and a fine surface finish. It also does not suffer from springback or residual stresses. Products can also be made larger t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Superplasticity
In materials science, superplasticity is a state in which solid Crystallinity, crystalline material is deformed well beyond its usual breaking point, usually over about 600% during tensile deformation. Such a state is usually achieved at high homologous temperature. Examples of superplastic materials are some fine-grained metals and ceramics. Other non-crystalline materials (amorphous) such as silica glass ("molten glass") and polymers also deform similarly, but are not called superplastic, because they are not crystalline; rather, their deformation is often described as Newtonian fluid. Superplastically deformed material gets thinner in a very uniform manner, rather than forming a "neck" (a local narrowing) that leads to fracture. Also, the formation of microvoids, which is another cause of early fracture, is inhibited. In metals and ceramics, requirements for it being superplastic include a fine grain size (less than approximately 20 micrometres) and a fine dispersion of therma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Superplasticity
In materials science, superplasticity is a state in which solid Crystallinity, crystalline material is deformed well beyond its usual breaking point, usually over about 600% during tensile deformation. Such a state is usually achieved at high homologous temperature. Examples of superplastic materials are some fine-grained metals and ceramics. Other non-crystalline materials (amorphous) such as silica glass ("molten glass") and polymers also deform similarly, but are not called superplastic, because they are not crystalline; rather, their deformation is often described as Newtonian fluid. Superplastically deformed material gets thinner in a very uniform manner, rather than forming a "neck" (a local narrowing) that leads to fracture. Also, the formation of microvoids, which is another cause of early fracture, is inhibited. In metals and ceramics, requirements for it being superplastic include a fine grain size (less than approximately 20 micrometres) and a fine dispersion of therma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermoforming
Thermoforming is a manufacturing process where a plastic sheet is heated to a pliable forming temperature, formed to a specific shape in a mold, and trimmed to create a usable product. The sheet, or "film" when referring to thinner gauges and certain material types, is heated in an oven to a high-enough temperature that permits it to be stretched into or onto a mold and cooled to a finished shape. Its simplified version is vacuum forming. In its simplest form, a small tabletop or lab size machine can be used to heat small cut sections of plastic sheet and stretch it over a mold using vacuum. This method is often used for sample and prototype parts. In complex and high-volume applications, very large production machines are utilized to heat and form the plastic sheet and trim the formed parts from the sheet in a continuous high-speed process and can produce many thousands of finished parts per hour depending on the machine and mold size and the size of the parts being formed. Therm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blow Forming
Blow molding (or moulding) is a manufacturing process for forming hollow plastic parts. It is also used for forming glass bottles or other hollow shapes. In general, there are three main types of blow molding: extrusion blow molding, injection blow molding, and injection stretch blow molding. The blow molding process begins with softening plastic by heating a preform or parison. The parison is a tube-like piece of plastic with a hole in one end through which compressed air can enter. The plastic workpiece is then clamped into a mold and air is blown into it. The air pressure inflates the plastic which conforms to the mold. Once the plastic has cooled and hardened the mold opens and the part is ejected. Water channels within the mold assist cooling. History The process principle comes from the idea of glassblowing. Enoch Ferngren and William Kopitke produced a blow molding machine and sold it to Hartford Empire Company in 1938. This was the beginning of the commercial blow mol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vacuum Forming
Vacuum forming is a simplified version of thermoforming, where a sheet of plastic (in various forms HIPS (High impact polystyrene) for low impact products, or for Bathroom shower trays ABS, and exterior vehicle parts HDPE, plus various other types of vacuum formable materials) is heated to a forming temperature, stretched onto a single-surface mould, and forced against the mould by a vacuum. This process can be used to form plastic into permanent objects such as turnpike signs and protective covers. Normally draft angles are present in the design of the mould (a recommended minimum of 3°) to ease removal of the formed plastic part from the mould. Relatively deep parts can be formed if the formable sheet is mechanically or pneumatically stretched prior to bringing it into contact with the mold surface and applying the vacuum. Suitable materials for use in vacuum forming are conventionally thermoplastics. The most common and easiest to use thermoplastic is ''high impact polys ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surface Finish
Surface finish, also known as surface texture or surface topography, is the nature of a surface as defined by the three characteristics of lay, surface roughness, and waviness.. It comprises the small, local deviations of a surface from the perfectly flat ideal (a true plane). Surface texture is one of the important factors that control friction and transfer layer formation during sliding. Considerable efforts have been made to study the influence of surface texture on friction and wear during sliding conditions. Surface textures can be isotropic or anisotropic. Sometimes, stick-slip friction phenomena can be observed during sliding, depending on surface texture. Each manufacturing process (such as the many kinds of machining) produces a surface texture. The process is usually optimized to ensure that the resulting texture is usable. If necessary, an additional process will be added to modify the initial texture. The latter process may be grinding (abrasive cutting), polishing, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Residual Stress
In materials science and solid mechanics, residual stresses are Stress (physics), stresses that remain in a solid material after the original cause of the stresses has been removed. Residual stress may be desirable or undesirable. For example, laser peening imparts deep beneficial compressive residual stresses into metal components such as turbine engine fan blades, and it is used in toughened glass to allow for large, thin, crack- and scratch-resistant glass displays on smartphones. However, unintended residual stress in a designed structure may cause it to Catastrophic failure, fail prematurely. Residual stresses can result from a variety of mechanisms including inelastic (Plasticity (physics), plastic) Deformation (engineering), deformations, temperature gradients (during thermal cycle) or structural changes (phase transformation). Heat from welding may cause localized expansion, which is taken up during welding by either the molten metal or the placement of parts being welde ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aerospace
Aerospace is a term used to collectively refer to the atmosphere and outer space. Aerospace activity is very diverse, with a multitude of commercial, industrial and military applications. Aerospace engineering consists of aeronautics and astronautics. Aerospace organizations research, design, manufacture, operate, or maintain both aircraft and spacecraft. The beginning of space and the ending of the air is considered as 100 km (62 mi) above the ground according to the physical explanation that the air pressure is too low for a lifting body to generate meaningful lift force without exceeding orbital velocity. Overview In most industrial countries, the aerospace industry is a cooperation of the public and private sectors. For example, several states have a civilian space program funded by the government, such as NASA, National Aeronautics and Space Administration in the United States, European Space Agency in Europe, the Canadian Space Agency in Canada, Indian Space Re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
McDonnell Douglas
McDonnell Douglas was a major American aerospace manufacturing corporation and defense contractor, formed by the merger of McDonnell Aircraft and the Douglas Aircraft Company in 1967. Between then and its own merger with Boeing in 1997, it produced well-known commercial and military aircraft, such as the DC-10 airliner, the F-15 Eagle air superiority fighter, the MD-80 airliner, and the F/A-18 Hornet multirole fighter. The corporation's headquarters were at St. Louis Lambert International Airport, near St. Louis, Missouri; its subsidiary, McDonnell Douglas Technical Services Company (MDTSC), was based elsewhere in St. Louis County, Missouri. At its peak in mid-1990, McDonnell Douglas employed 132,500 people. By the end of 1992, employment had dropped to approximately 87,400. History Background The company was formed from the firms of James Smith McDonnell and Donald Wills Douglas in 1967. Both men were of Scottish ancestry, were graduates of the Massachusetts Institute of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
F-15
The McDonnell Douglas F-15 Eagle is an American twin-engine, all-weather tactical fighter aircraft designed by McDonnell Douglas (now part of Boeing). Following reviews of proposals, the United States Air Force selected McDonnell Douglas's design in 1969 to meet the service's need for a dedicated air superiority fighter. The Eagle first flew in July 1972, and entered service in 1976. It is among the most successful modern fighters, with over 100 victories and no losses in aerial combat, with the majority of the kills by the Israeli Air Force.Spick 2000, p. 127. The Eagle has been exported to Israel, Japan, and Saudi Arabia. The F-15 was originally envisioned as a pure air-superiority aircraft. Its design included a secondary ground-attack capability that was largely unused. The aircraft design proved flexible enough that an improved all-weather strike derivative, the F-15E Strike Eagle, was later developed, entered service in 1989 and has been exported to several nations. S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eurofighter Typhoon
The Eurofighter Typhoon is a European multinational twin-engine, canard delta wing, multirole fighter. The Typhoon was designed originally as an air-superiority fighter and is manufactured by a consortium of Airbus, BAE Systems and Leonardo that conducts the majority of the project through a joint holding company, Eurofighter Jagdflugzeug GmbH. The NATO Eurofighter and Tornado Management Agency, representing the UK, Germany, Italy and Spain, manages the project and is the prime customer. The aircraft's development effectively began in 1983 with the Future European Fighter Aircraft programme, a multinational collaboration among the UK, Germany, France, Italy and Spain. Previously, Germany, Italy and the UK had jointly developed and deployed the Panavia Tornado combat aircraft and desired to collaborate on a new project, with additional participating EU nations. However disagreements over design authority and operational requirements led France to leave the consortium to deve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hot Metal Gas Forming
Hot metal gas forming (HMGF) is a method of die forming in which a metal tube is heated to a pliable state, near to but below its melting point, then pressurized internally by a gas in order to form the tube outward into the shape defined by an enclosing die cavity. The high temperatures allow the metal to elongate, or stretch, to much greater degrees without rupture than are possible in previously utilized cold and warm forming methods. In addition, the metal can be formed into finer details and requires less overall forming force than traditional methods. History and comparison with previous techniques HMGF is an evolution in the cost effectiveness and applicability of several existing commercial processes: superplastic forming, hot blow forming,Bill Dykstra (2001). “Hot Metal Gas Forming for Manufacturing Vehicle Structural Components”, MetalForming and hydroforming. Complex tubes can be made from multiple sheet components formed and welded together, but this adds unnece ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
