Material properties and uses of pure aluminium

Material properties and uses of pure aluminium

The density of pure aluminium is small (ρ=2.7g/cm3), about 1/3 of iron, low melting point (660℃), aluminium is face-centered cubic structure, so it has high plasticity (δ:32~40%, ψ:70~90%), easy processing, can be made into various profiles, plates, good corrosion resistance. But the strength of pure aluminum is very low, annealed state σb value of about 8kgf/mm2, it is not suitable for structural materials.

Through long-term production practice and scientific experiments, people gradually add alloying elements and use heat treatment to strengthen aluminium, which has led to a series of aluminium alloys. The alloys formed by the addition of certain elements are able to maintain the advantages of pure aluminium, such as lightness, and at the same time have a high strength, with σb values of 24-60 kgf/mm2 respectively, which makes its "specific strength" (the ratio of strength to specific gravity σb/ρ) better than many alloy steels, making it an ideal structural material for machinery manufacturing, transport machinery, power machinery and the aviation industry. It is used in mechanical engineering, transport machinery, power machinery and the aviation industry. The fuselage, skin and compressor of aircraft are often made of aluminium alloy to reduce their weight. The use of aluminium alloys instead of welded steel sheets can reduce the weight of the structure by more than 50%.