Characterization of microstructure and wear resistance of a monotectic Al-Bi-Zn alloy

Abstract

The development of multicomponent Al-Bi alloys is an alternative approach to control either separation or morphology of the phases forming their microstructures. Furthermore, addition of alloying elements in Al-Bi alloys has been settled to pursue an optimized combination of wear resistance and mechanical strength. In the present investigation, solidification conditions are deduced from temperature measurements and the microstructure is thoroughly characterized. The results highlight the impact of the solidification conditions on the Bi distribution and macrosegregation. A relation is established between Bi-droplet spacing and wear resistance and a comparison with previous experiments on Al-Bi-Cu alloys is outlined. It is found that both Bi segregation and spacing between globules of Bi control the wear resistance of the Zn-containing alloy. Despite the similarities of Bi spacings if Cu- and Zn-containing alloys are compared, the wear resistance of the Cu-containing alloy is higher.