The effects of Mg 2 Si (p) on microstructure and mechanical properties of AA332 composite

This paper describes a study on the effects of Mg2Si(p) addition on the microstructure, porosity, and mechanical properties namely hardness and tensile properties of AA332 composite. Each composite respectively contains 5, 10, 15, and 20 wt% reinforcement particles developed by a stir-casting. The molten composite was stirred at 600 rpm and melted at 900°C ± 5°C. The Mg2Si particles were wrapped in an aluminum foil to keep them from burning when melting. The findings revealed that the microstructure of Mg2Si(p)/AA332 consists of α-Al, binary eutectic (Al+Mg2Si), Mg2Si particles, and intermetallic compound. The intermetallic compound was identified as Fe-rich and Cu-rich, formed as polygonal or blocky, Chinese script, needle-like, and polyhendrons or “skeleton like”. The porosity of Mg2Si(p)/AA332 composite increased from 8-10% and the density decreased from 9-12% from as-cast. Mechanical properties such as hardness increased for over 42% from as-cast and the highest UTS, elongation, and maximum Q.I were achieved in the sample of 10% Mg2Si. The study concludes that combined with AA332, the amount of 10 wt% of Mg2Si is a suitable reinforcement quantity with the combination of AA332.