Effect of Sintering Temperature on Microstructure and Property of Powder Metallurgy Al-24Si Alloy

Al-24Si alloy was prepared by powder metallurgy, and then the effects of sintering temperature (550-610℃) on microstructure, density and hardness of the alloy were studied. The results show that the microstructures of the alloy sintered at different temperatures all consisted of aluminum and silicon phases. When the sintering temperature reached 600℃ and above, Mn₄Al₁₆Si₃ phase was precipitated in the microstrucuture. When the sintering temperature was lower than 580℃, the gap amount between aluminum particles in the alloy microstructure decreased with increasing temperature, and therefore the density and hardness of the alloy were improved. When the sintering temperature reached 580℃, the eutectic liquid phase formed by aluminum and silicon penetrated into the interface between the aluminum particles, leaving large holes in the original location of the liquid phase, resulting in an increase in the porosity of the alloy and a decrease in the density and hardness. When the temperature reached 590℃, the eutectic liquid phase content increased and filled the inner pores, and therefore the density and hardness of the alloy increased.