Effects of Al-Si/SiCp powder on the sinterability and wear properties of Al-Zn-Mg powder

Al-Zn-Mg alloys are widely used in the aerospace and automotive industries because of their high strength compared to other Al-based alloys. Unfortunately, the application of Al-Zn-Mg alloys in such industries has been limited to parts that are manufactured via powder metallurgy because of their poor sinterability. In this study, an Al-Si alloy powder, which has a relatively low melting point alloy compared to Al-Zn-Mg alloys, was added into an Al-Zn-Mg powder (Alumix 431) as a binder material to enhance the sinterability of the alloy. In addition, SiC particles (SiCp) were added into the Al-Si alloy powder via gas atomization to improve the mechanical properties and wear resistance of the sintered Alumix 431 alloy. The mixed powder was sintered via hot pressing, and the wear properties of the sintered samples were analyzed with respect to two variables: vertical load and linear speed. The observed wear mechanisms included abrasion, adhesion, oxide-layer formation, and delamination. When the Alumix 431 powder was mixed with 5 wt% of the Al-Si/SiCp alloy powder, the various aforementioned wear behaviors were delayed because of the increased densification of the sintered alloy and reinforcing effect of the SiCp.