High Strain Rate Superplasticity in Al-16Si-5Fe Based Alloys with and without SiC Particulates

초록

Powder metallurgy (PM) processed hyper-eutectic Al-Si based alloys containing a higher level of Fe and hard SiC particulates were recently succeeded in applying to mass-production engine pistons for two-stroke-cycle snowmobiles. It was revealed that the commercialized PM piston alloys had enhanced high temperature tensile and fatigue strength in addition to the increased abrasion resistance suitable for the piston operating under severe environment. With accompanying high strength level at elevated temperatures for the PM piston alloys, the forming of the PM alloys to net shape is somewhat difficult via conventional processing procedure. So that, careful study on deformation behavior for this type of alloy is required to find out optimum processing parameters. In this work, high temperature tensile properties including high strain rate superplasticity are investigated using PM Al-16Si-5Fe-1Cu-0.5Mg-0.9Zr(wt%) alloys with and without SiC particulates, which are similar composition to the above-mentioned PM piston alloys.