Microstructures and Mechanical Properties of Zn–Al Alloy with Addition of Different Si Morphologies

Abstract

The morphology of the Si-containing phase exhibits significant influence on the ultimate strength and wear resistance of a Zn–Al–Si alloy. Metallographic studies showed that Si mainly exists as long and thin eutectic Si phase and blocky primary phase Si. The refinement of Si phases can effectively improve the ultimate strength of Si-modified alloy. Under oil-lubricated wear conditions, the hard Si particles improved the wear resistance of the Zn–Al alloys. However, the blocky primary phase Si has a weak binding force with the matrix, leading to separation from the matrix and a reduction in mechanical properties.