Microstructure and mechanical property of aluminium based die-cast alloy (ALDC6) for spider arm component

Abstract

In this paper aims on the development of aluminum alloy (ALDC6) using high pressure die casting (HPDC) for spider arm component in washer. Presently, ALDC3 alloy is commonly used for the fabrication of spider arm but it has poor corrosion resistance. ALDC6 alloy which has good corrosion resistance can be used as an alternative material for spider arm. However due to high Si (Silicon) content of 10wt% in ALDC3 alloy it has good castability compared to ALDC6 alloy with 1wt% of Si. Hence there is a need to modify the ALDC6 alloys by increasing the percentage of silicon and magnesium elements so as to improve the castability, strength and corrosion resistance. The optical microstructure of the developed ALDC6 alloy was investigated and its phases were detected by XRD analysis. It was found out that presence of Mg2Si in ALDC6 alloys is higher than that of the ALDC3 alloy. The microstructure and mechanical properties of ALDC6 alloys were evaluated and compared with existed ALDC3 alloys. The tensile strength and yield strength of the developed ALDC6 alloys has improved but elongation decreased. This implies that the spheroidal primary alpha grains and decrease in grain size due to the presence of Si and Mg within the alloy enhance the strength and yield stress.