Effect of Mg and Sr additions on the microstructure, mechanical properties and reciprocating wear characteristics of hypereutectic Al- 14Si alloy

摘要

The explorative attempt to harness new materials that could be utilized for manufacturing products with sophisticated geometry for aerospace and automotive applications necessitate the exploitation of Al-Si-Mg alloy family. Al-14Si alloys which posses 1% Mg exhibits a microstructure that contains primary Si particles, eutectic Si and Mg2Si in α-Al matrix. With a view to improve the mechanical properties of this alloy, Sr modification was carried out by adding 0.04% Sr to the molten metal. The Mg_2Si phase has high melting temperature, low density, high hardness, low coefficient of thermal expansion and high elastic modulus. The best results in the microstructure were obtained through a combination of Sr addition and T6 heat treatment which enhances the mechanical properties and wear resistance of the alloy.