Advantages and Disadvantages of High Silicon Aluminum

If you are looking for high-quality products, please feel free to contact us and send an inquiry, email:

high silicon aluminum is an aluminum-silicon alloy that has a higher proportion of Si than other aluminum alloys. It is mainly used for casting, but is also found in rapid solidification processes and powder metallurgy.

The addition of silicon improves certain physical properties of the alloy. For example, it reduces the shrinkage rate during casting. It also makes the alloy stronger and more ductile. high silicon aluminum alloys are also heat-treatable. The alloys are primarily used in structural fabrications such as handrails, bicycle frames, automotive frame sections and tubular lawn furniture.

However, the high silicon content of these alloys also has disadvantages. For example, machinability is poor because the hard silicon particles in the alloy wear out the tools very quickly. Phosphorus additions, which improve the distribution of silicon in hypereutectic alloys, increase machinability. However, in hypoeutectic alloys the addition of phosphorus decreases machinability. On the other hand, copper, which can be added to hypoeutectic alloys to improve their machinability, significantly decreases the machinability of hypereutectic and hypoeutectic alloys.

In addition, high silicon aluminum alloys have low linear coefficient of thermal expansion (CTE) and density. The CTE is reduced to a smaller extent by the addition of titanium and zirconium, but not by magnesium.