Aluminum alloy is one of the most widely used non-ferrous metal structural materials in the industry and has been widely used in aviation, aerospace, automotive, machinery manufacturing, marine and chemical industries. With the rapid development of science and technology and industrial economy in recent years, the demand for aluminum alloy welded structural parts is increasing, and the research on the weldability of aluminum alloys is also deepened. The wide application of aluminum alloy promotes the development of aluminum alloy welding technology, and the development of welding technology has expanded the application field of aluminum alloy. Therefore, the welding technology of aluminum alloy is becoming one of the research hotspots.
The density of pure aluminum is small (Ï=2.7g/cm3), about 1/3 of iron, low melting point (660Â°C), aluminum is face-centered cubic structure, so it has high plasticity (Î´: 32~40%, Ïˆ: 70~90%), easy to process, can be made into various profiles and plates. The corrosion resistance is good; however, the strength of pure aluminum is very low, and the annealing state Ïƒb value is about 8kgf/mm2, so it is not suitable as a structural material. Through long-term production practices and scientific experiments, people gradually strengthened aluminum by adding alloying elements and applying heat treatment, which resulted in a series of aluminum alloys. The alloy formed by adding certain elements can have higher strength while maintaining the advantages of pure aluminum, and the Ïƒb value can reach 24 to 60 kgf/mm2, respectively. This makes its "specific strength" (the ratio of strength to specific gravity Ïƒb / Ï) outperforms many alloy steels and becomes an ideal structural material, widely used in machinery manufacturing, transportation machinery, power machinery and aviation industry, aircraft fuselage , skins, compressors, etc. are often made of aluminum alloy to reduce their own weight. The use of aluminum alloy instead of steel plate welding can reduce the structural weight by more than 50%.
The aluminum alloy has low density, but high strength, close to or exceeds high-quality steel, good plasticity, can be processed into various profiles, has excellent electrical conductivity, thermal conductivity and corrosion resistance. It is widely used in industry and is used second only to steel. .
Aluminum alloy is divided into two categories: cast aluminum alloy, used in the as-cast state; deformed aluminum alloy, can withstand pressure processing. It can be processed into aluminum alloy materials of various shapes and specifications. Mainly used in the manufacture of aviation equipment, building doors and windows.
The aluminum alloy can be divided into a deformed aluminum alloy and a cast aluminum alloy according to the processing method. The deformed aluminum alloy is further divided into a non-heat treatable reinforced aluminum alloy and a heat treatable reinforced aluminum alloy. The non-heat-treated reinforced type cannot be improved by heat treatment to improve mechanical properties, and can only be strengthened by cold working deformation. It mainly includes high-purity aluminum, industrial high-purity aluminum, industrial pure aluminum, and rust-proof aluminum. The heat-treatable reinforced aluminum alloy can be improved in mechanical properties by heat treatment such as quenching and aging, and can be classified into hard aluminum, wrought aluminum, super-hard aluminum, and special aluminum alloy.
Some aluminum alloys can be heat treated to achieve good mechanical properties, physical properties and corrosion resistance.
Cast aluminum alloy can be divided into aluminum silicon alloy, aluminum copper alloy, aluminum magnesium alloy, aluminum zinc alloy and aluminum rare earth alloy according to chemical composition, among which aluminum silicon alloy has simple aluminum silicon alloy (can not be heat treated and strengthened, low mechanical properties, casting Good performance), special aluminum-silicon alloy (heat treatable, high mechanical properties, good casting performance),
The "Xiangyun" torch of the 2008 Beijing Olympic Games is aluminum.
A name for Silicon Carbide.
It is produced from quartz sand and high quality anthracite under high
temperature in an electric resistance furnace.If looks black and has a
microhardness of 2800-3300kg\mm2,being used for produce the abrasive tools.It
is also fit for process the grind metals and non-metals material of low tensile strength,such as grey cast iron,brass,aluminium ,stone,leather
and hard rubber ect.Also can be used as refractory materials and in electronic
Carbon(+4) Cation,Carbonate Charge,Carbonate Cation,Carbocation Stability
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