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Aluminium Foam Sandwich
Aluminium foam sandwich (AFS) is a sandwich panel product which is made of two metallic dense face sheets and a metal foam core made of an aluminium alloy. AFS is an engineering structural material owing to its stiffness-to-mass ratio and energy absorption capacity ideal for application such as the shell of a high-speed train. Production and materials In terms of the bonding between face sheets and foam core the processing of AFS is categorised into two ways – ex-situ and in-situ bonding.J Banhart, H-W Seeliger, Aluminium foam sandwich panels: manufacture, metallurgy and applications, Advanced Engineering Materials, 2008, 10:793-802. Ex-situ bonded AFS Ex-situ bonding is achieved by gluing face sheets with an aluminium foam by adhesive bonding, brazing or diffusion bonding. Foams used in this method are either closed-cell or open-cell. When a closed-cell foam is used then it is produced from aluminium alloys either by liquid metal route (e.g. Alporas, Cymat) or by powder m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aluminium Foam Sandwich
Aluminium foam sandwich (AFS) is a sandwich panel product which is made of two metallic dense face sheets and a metal foam core made of an aluminium alloy. AFS is an engineering structural material owing to its stiffness-to-mass ratio and energy absorption capacity ideal for application such as the shell of a high-speed train. Production and materials In terms of the bonding between face sheets and foam core the processing of AFS is categorised into two ways – ex-situ and in-situ bonding.J Banhart, H-W Seeliger, Aluminium foam sandwich panels: manufacture, metallurgy and applications, Advanced Engineering Materials, 2008, 10:793-802. Ex-situ bonded AFS Ex-situ bonding is achieved by gluing face sheets with an aluminium foam by adhesive bonding, brazing or diffusion bonding. Foams used in this method are either closed-cell or open-cell. When a closed-cell foam is used then it is produced from aluminium alloys either by liquid metal route (e.g. Alporas, Cymat) or by powder m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metal Foam
Regular foamed aluminium A metal foam is a cellular structure consisting of a solid metal (frequently aluminium) with gas-filled pores comprising a large portion of the volume. The pores can be sealed (closed-cell foam) or interconnected (open-cell foam). The defining characteristic of metal foams is a high porosity: typically only 5–25% of the volume is the base metal. The strength of the material is due to the square–cube law. Metal foams typically retain some physical properties of their base material. Foam made from non-flammable metal remains non-flammable and can generally be recycled as the base material. Its coefficient of thermal expansion is similar while thermal conductivity is likely reduced. Definitions Open-cell Open-celled metal foam, also called metal sponge, can be used in heat exchangers (compact electronics cooling, cryogen tanks, PCM heat exchangers), energy absorption, flow diffusion, scrubbers, flame arrestors, and lightweight optics. The hig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High-speed Rail
High-speed rail (HSR) is a type of rail system that runs significantly faster than traditional rail, using an integrated system of specialised rolling stock and dedicated tracks. While there is no single standard that applies worldwide, lines built to handle speeds above or upgraded lines in excess of are widely considered to be high-speed. The first high-speed rail system, the Tōkaidō Shinkansen, began operations in Japan in 1964 and was widely known as the bullet train. High-speed trains mostly operate on standard gauge tracks of continuously welded rail on grade-separated rights of way with large radii. However, certain regions with wider legacy railways, including Russia and Uzbekistan, have sought to develop a high speed railway network in Russian gauge. There are no narrow gauge high-speed trains; the fastest is the Cape gauge Spirit of Queensland at . Many countries have developed, or are currently building, high-speed rail infrastructure to connect major citie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TWiT
TWiT.tv, which is the operating trade name of TWiT LLC, is a podcast network that broadcasts many technology news podcasts, founded by technology broadcaster and author Leo Laporte in 2005, and run by his wife and company CEO Lisa Laporte. The network began operation in April 2005 with the launch of ''This Week in Tech''. ''Security Now'' was the second podcast on the network, debuting in August of that year. The network hosts 28 podcasts (as of July, 2020) though the number had fallen in half to only 14 regularly scheduled shows by January 2021. Podcasts include ''The Tech Guy'', ''This Week in Tech'', ''This Week in Enterprise Tech'', ''Security Now'', ''FLOSS Weekly'', and ''MacBreak Weekly''. In addition to shows on technology news, TWiT also has podcasts like ''Hands-On Photography". TWiT founder and owner Leo Laporte, in an October 2009 speech, stated that it grossed revenues of $1.5 million per year, while costs were around $350,000. In November 2014, during an interv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cymat Technologies
Cymat Technologies is an innovative materials technology company based out of Mississauga, Ontario, Canada, and one of the world leaders in the production of stabilized aluminum foam. Business Cymat Technologies has the worldwide rights, through patents and licenses, to manufacture Stabilized Aluminum Foam (“SAF”). Cymat is focused on producing SAF for architecture, blast mitigation and automotive industries. The company markets architectural SAF under the Alusion™ trademark and automotive and blast mitigation SAF under the SmartMetal™ trademark. Cymat Technologies operates out of its manufacturing plant in Toronto, Canada. The plant can manufacture approximately $50 million in stabilized aluminum foam annually. Process As described in the patent originally created by Alcan with parallel patents created by Norsk Hydro, "Stabilized Aluminum Foam" is generated in a continuous casting process via direct shop air injection into a Metal Matrix Composite (MMC) melt. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Powder Metallurgy
Powder metallurgy (PM) is a term covering a wide range of ways in which materials or components are made from metal powders. PM processes can reduce or eliminate the need for subtractive processes in manufacturing, lowering material losses and reducing the cost of the final product. Powder metallurgy is also used to make unique materials impossible to get from melting or forming in other ways. A very important product of this type is tungsten carbide (WC). WC is used to cut and form other metals and is made from WC particles bonded with cobalt. It is very widely used in industry for tools of many types and globally ~50,000 tonnes/year (t/y) is made by PM. Other products include sintered filters, porous oil-impregnated bearings, electrical contacts and diamond tools. Since the advent of industrial production–scale metal powder–based additive manufacturing (AM) in the 2010s, selective laser sintering and other metal AM processes are a new category of commercially important p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Age Hardening
Precipitation hardening, also called age hardening or particle hardening, is a heat treatment technique used to increase the yield strength of malleable materials, including most structural alloys of aluminium, magnesium, nickel, titanium, and some steels and stainless steels. In superalloys, it is known to cause yield strength anomaly providing excellent high-temperature strength. Precipitation hardening relies on changes in solid solubility with temperature to produce fine particles of an impurity phase, which impede the movement of dislocations, or defects in a crystal's lattice. Since dislocations are often the dominant carriers of plasticity, this serves to harden the material. The impurities play the same role as the particle substances in particle-reinforced composite materials. Just as the formation of ice in air can produce clouds, snow, or hail, depending upon the thermal history of a given portion of the atmosphere, precipitation in solids can produce many different ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laser Welding
Laser beam welding (LBW) is a welding technique used to join pieces of metal or thermoplastics through the use of a laser. The beam provides a concentrated heat source, allowing for narrow, deep welds and high welding rates. The process is frequently used in high volume and precision requiring applications using automation, as in the automotive and aeronautics industries. It is based on keyhole or penetration mode welding. Operation Like electron-beam welding (EBW), laser beam welding has high power density (on the order of 1 MW/cm2) resulting in small heat-affected zones and high heating and cooling rates. The spot size of the laser can vary between 0.2 mm and 13 mm, though only smaller sizes are used for welding. The depth of penetration is proportional to the amount of power supplied, but is also dependent on the location of the focal point: penetration is maximized when the focal point is slightly below the surface of the workpiece A continuous or pulsed laser ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TIG Welding
Gas tungsten arc welding (GTAW), also known as tungsten inert gas (TIG) welding, is an arc welding process that uses a non-consumable tungsten electrode to produce the weld. The weld area and electrode are protected from oxidation or other atmospheric contamination by an inert shielding gas (argon or helium). A filler metal is normally used, though some welds, known as ''autogenous welds'', or ''fusion welds'' do not require it. When helium is used, this is known as heliarc welding. A constant-current welding power supply produces electrical energy, which is conducted across the arc through a column of highly ionized gas and metal vapors known as a plasma. GTAW is most commonly used to weld thin sections of stainless steel and non-ferrous metals such as aluminum, magnesium, and copper alloys. The process grants the operator greater control over the weld than competing processes such as shielded metal arc welding and gas metal arc welding, allowing for stronger, higher quality ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MIG Welding
Russian Aircraft Corporation "MiG" (russian: Российская самолётостроительная корпорация „МиГ“, Rossiyskaya samolyotostroitel'naya korporatsiya "MiG"), commonly known as Mikoyan and MiG, was a Russian aerospace and defence company headquartered in Begovoy District, Moscow. Mikoyan was successor to the Soviet Mikoyan and Gurevich Design Bureau (Микоя́н и Гуре́вич, МиГ; OKB-155 design office prefix ''MiG'') founded in 1939 by aircraft designers Artem Mikoyan and Mikhail Gurevich. Mikoyan were notable for their fighter and interceptor aircraft which became a staple of the Soviet Air Force and Russian Air Forces, nations within the Soviet sphere of influence, and other nations such as India and many Arab states. Mikoyan aircraft were frequently used in aerial confrontations with American and allied forces during and since the Cold War, and have become commonly featured aircraft in popular culture. Mikoyan aircraft ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Riveting
A rivet is a permanent mechanical fastener. Before being installed, a rivet consists of a smooth cylindrical shaft with a head on one end. The end opposite to the head is called the ''tail''. On installation, the rivet is placed in a punched or drilled hole, and the tail is ''upset'', or ''bucked'' (i.e., deformed), so that it expands to about 1.5 times the original shaft diameter, holding the rivet in place. In other words, the pounding or pulling creates a new "head" on the tail end by smashing the "tail" material flatter, resulting in a rivet that is roughly a dumbbell shape. To distinguish between the two ends of the rivet, the original head is called the ''factory head'' and the deformed end is called the ''shop head'' or buck-tail. Because there is effectively a head on each end of an installed rivet, it can support tension loads. However, it is much more capable of supporting shear loads (loads perpendicular to the axis of the shaft). Fastenings used in traditional wo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Foams
Foams are materials formed by trapping pockets of gas in a liquid or solid. A bath sponge and the head on a glass of beer are examples of foams. In most foams, the volume of gas is large, with thin films of liquid or solid separating the regions of gas. Soap foams are also known as suds. Solid foams can be closed-cell or open-cell. In closed-cell foam, the gas forms discrete pockets, each completely surrounded by the solid material. In open-cell foam, gas pockets connect to each other. A bath sponge is an example of an open-cell foam: water easily flows through the entire structure, displacing the air. A sleeping mat is an example of a closed-cell foam: gas pockets are sealed from each other so the mat cannot soak up water. Foams are examples of dispersed media. In general, gas is present, so it divides into gas bubbles of different sizes (i.e., the material is polydisperse)—separated by liquid regions that may form films, thinner and thinner when the liquid phase drain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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