Microstructures and mechanical properties of ZA27-Al2O3 composites obtained by powder metallurgy process

This paper describes a study of the microstructures and mechanical properties of Zn matrix composites reinforced by 10 wt.% Al2O3 particles of 0.7 ?m average size. Commercial Zn-Al-Cu (ZA27) alloy was gas atomized and the resulting powder was mixed with an Al2O3 powder, and then hot pressed into cylindrical pellets. Metal powder and powder mixtures were pressed at 230?C, for 45 min under the pressure of 150 MPa. The compressive strength testing was performed in the temperature range from 20?C to 160?C, with a deformation rate of 2.4?10-3s-1. The microstructures and the fracture surface of the samples were investigated by optical and scanning electron microscopy.