Applications of Aluminum-Silicon Alloy

Aluminum-silicon alloy is a forging and casting alloy primarily composed of aluminum and silicon. It generally contains around 11% silicon. Small amounts of copper, iron, and nickel are added to enhance its strength. It has a density of 2.6-2.7 g/cm³, thermal conductivity of 101-126 W/(m·℃), Young's modulus of 71.0 GPa, impact strength of 7-8.5 J, and fatigue limit of ±45 MPa.

The aluminum-silicon alloy has the following applications:

In aluminum-silicon alloys with silicon content exceeding the Al-Si eutectic point (11.7% silicon), the silicon particles significantly enhance the wear resistance of the alloy, making it widely used as a wear-resistant alloy.

It is used for manufacturing complex-shaped castings with low to medium strength, such as covers, motor housings, brackets, and also used as brazing filler material.

Aluminum-silicon alloy is a strong composite deoxidizer used in steelmaking. It replaces pure aluminum to improve the utilization of deoxidizers and purify the molten steel, thereby enhancing the quality of the steel. Steel ingots deoxidized with aluminum are commonly referred to as "killed steel." Aluminum, when used as a deoxidizer, is oxidized into aluminum oxide, which refines the austenite grain, resulting in better overall mechanical properties of the steel.

Silicon-aluminum alloy has low density, low coefficient of thermal expansion, good casting performance, and excellent wear resistance. Alloy castings made from it exhibit high impact resistance and excellent high-pressure density, greatly improving their service life. It is commonly used in the production of aerospace vehicles and automotive components.