Influence of Cu content on mechanical and tribological properties of Al–7Si–Cu alloy

In this study, Al–7Si–Cu alloys with different contents of Cu were prepared by ultrasonic agitation casting method. The microstructures were characterized by scanning electron microscopy (SEM) and energy dispersion spectroscopy (EDS). Dry sliding friction and wear properties with different Cu contents and loads were investigated. The results indicated that the alloy with 3.0 wt% Cu content revealed the optimal microstructure, comprehensive mechanical properties, and tribological properties. The hardness, tensile strength, and yield strength were enhanced by 83%, 57%, and 59%, respectively. The friction coefficient and wear rate reduced by 33% and 24% at 40 N load, respectively. The wear mechanism of Al–7Si–Cu alloy was mainly abrasive wear and delamination wear accompanied by oxidation wear. The improvement of the tribological properties of the alloy was attributed to the combined improvement of the microstructure and mechanical properties.