Improving mechanical properties of AlSi10Mg aluminum alloy using ultrasonic melt treatment combined with T6 heat treatment

Abstract

The purpose of this study is examining the effects of ultrasonic melt treatment on microstructure and mechanical properties of the AlSi10Mg alloy. In this study, ultrasonic melt treatment with different frequencies and duration was applied to AlSi10Mg molten alloy. Also, T6 heat treatment was applied to samples which were obtained by ultrasonic melt treatment (UST) with different application parameters to investigate the combination of T6 heat treatment and UST effect on the microstructure and mechanical properties. The microstructure of cast samples was characterized by optical and scanning electron microscopy. Also, hardness and tensile tests were carried out. The results indicate that primary α-Al phases are transformed from coarse dendrites to smaller dendrites by the ultrasonic melt treatment. Besides, secondary dendrite arm spacing of the alloy decreased and mechanical properties such as hardness and tensile strength increased. UST reduces the secondary dendrite arm spacing (SDAS) of the aluminum alloy to 50 %. Additionally, increasing treatment time contributes to hardness up to 12 % and tensile strength up to 50 %.