Experimental study on tribological behavior of aluminum–copper functionally graded material

Abstract

A five-layered aluminum–copper metal functionally graded material was developed through powder metallurgy process. The sample comprises different weight percentages of copper and aluminum that vary from 0 wt% to 100 wt % along the thickness direction. Erosion wear was performed on air jet erosion testing apparatus at a constant impact angle of 90o and impact velocity of 151 m/s. It was observed that erosion wear decreases when there is an increase in copper content. Layer 1 comprising 100 wt% of copper has shown 76.92% lower wear compared to layer 5 (100 wt% of aluminum). Besides, erosion resistance was enhanced at graded layers due to the formation of Al2Cu phase during sintering. Abrasive wear of metal functionally graded material was evaluated on the pin-on-disc test apparatus. Experiments were conducted at different loading conditions on various abrasive surfaces (P120, P800, and P2000). Irrespective of abrasive surface, the specific wear rate of aluminum–copper metal functionally graded material sample increased with an increase in load from 5N to 15N. At 5N, abrasive wear of metal functionally graded material on P2000 grit surface was 87.7% and 27.19% lower compared to P120 and P800, respectively. Eroded and worn-out surfaces were examined microscopically to understand the wear mechanisms and are discussed in detail.