The Main Characteristics Of Aluminum

Aluminum is a light metal with the chemical symbol Al and atomic number 13. The content of aluminum in the earth's crust is second only to oxygen and silicon, ranking third. It is the most abundant metal element in the earth's crust, and its reserves rank second among metals. Among the metal varieties, it is the second largest metal category after steel.

The Main Characteristics Of Aluminum:

①Aluminum is a silver-white light metal with a density of about 2.72 g/cm3, which is about 1/3 of pure copper.

②The heat capacity and latent heat of cultivation of aluminum are high. The melting point of pure aluminum is about 661 ℃. The boiling point is about 2450 ℃, and its oxide Al2O3 has a melting point of about 2050 ℃.

③ Aluminum is a face-centered cubic structure.

④Industrial pure aluminum plastic sheet is high (Z=80%) and can easily withstand various forming processes, but its strength is too low, so pure aluminum can only be used as a structural material after its strength is improved by cold deformation strengthening or alloying .

⑤ The coefficient of linear expansion of aluminum is 23.5x10*/9 (below 100 C), and its elastic modulus is 70 GPa.

⑥The electrical conductivity of aluminum is about 60% of that of copper, the resistivity is 50% of that of copper, and the thermal conductivity is 70% of that of copper. 

The electrical conductivity of common metals in descending order is: Ag, Cu, Au, Al. In short, aluminum has low density, good plasticity, easy processing, good corrosion resistance, and abundant resources, accounting for about 7.73% (mass fraction) in the crust.

Classification of aluminum alloys

Aluminum alloys can be divided into cast aluminum alloys, deformed aluminum alloys, non-heat-treatable-strengthened aluminum alloys, and heat-treatable-strengthened aluminum alloys. 

Commonly added elements in aluminum alloys are Si, Cu, Mg, Zn, etc. The characteristics of cast aluminum alloy: low strength, low cost, large fluctuation of material chemical composition, poor mechanical properties, but good fluidity. 

Deformed aluminum alloy features: high strength, strict requirements on components, and good mechanical properties. There are AI-Si series and AI-Mn series of aluminum alloys that cannot be heat-treated and strengthened, and AI-Cu series, AI-Mg series and Al-Zn series of heat-treatable strengthened aluminum alloys.