Analysis of the effect of magnesium addition on Al-Si alloy using stirr casting method on physical and mechanical properties

Abstract

The stir casting process is the union of particles into molten metal with mechanical stirring, then poured into a mold. This study aims to determine the effect of adding magnesium to Al-Si alloys using the stir casting method on tensile strength, hardness, and microstructure. The process of making specimens using the stir casting method with a speed of 400 rpm for 5 minutes at a temperature of 650°C with variations in the addition of 1%, 1.5%, 2%, 2.5% Mg of the weight fraction and pouring temperature of 725°C. The tests include tensile, hardness and microstructure testing. Tensile strength testing using the ASTM E8 standard, hardness testing using the ASTM E10 standard and microstructure using the ASTM 407 standard. The results of the microstructure test indicate that with increasing Mg there is a Mg2Si precipitate on Al-Si alloys. The presence of Mg2Si precipitate resulted in increased mechanical properties of aluminum alloys. This is evidenced by the results of tensile strength and hardness testing increases with increasing variation in Mg used. The highest value of tensile strength was found in the addition of 2.5% Mg which was 149.35 N / mm2 and the highest hardness value was obtained in the addition of 2.5% Mg which was 85.05 BHN.