Influence of Homogenization and Quench-Aging Heat Treatments on Dry Wear Behavior of Al-40Zn-3Cu Alloy.

The influence of homogenization and quench-aging treatments on the dry sliding friction and wear behavior of Al-40Zn-3Cu bearing alloy was experimentally studied. These treatments removed dendritic structure of the alloy and caused the formation of zinc-rich precipitates distributed homogenously in the matrix of the alloy. It was observed that quench-aging treatment carried out at temperatures of 100 °C and 150 °C significantly improved both hardness and strength of the alloy as compared to homogenization treatment. However, aging at 200 °C lowered these values of the alloy but increased its elongation. Dry sliding wear test results displayed that homogenization and quench-aging treatments increased the wear performance of the alloy. However, it is found that the quench-aging treatment created more powerful effect for improving wear performance of the alloy than homogenization. Quench-aging treatment at 100 °C for 300 min resulted in a decrease in the lowest specific wear rate of the alloy by causing the highest increases in its hardness (from 119 HB to 178 HB), yield strength (from 288 MPa to 383 MPa) and tensile strength (from 319 MPa to 407 MPa) due to the age hardening mechanism. It was observed that the worn surfaces of the alloy samples were composed of adhered and smeared material and delaminated areas. This observation suggested that adhesion and delamination were the operative wear mechanisms of the alloy. The results were explained and discussed in terms of microstructural features, mechanical properties, and wear mechanisms of Al-40Zn-3Cu alloy. [ABSTRACT FROM AUTHOR]