Microstructure, mechanical and tribological properties of Al/Cu functionally graded material fabricated through powder metallurgy

Mechanical and tribological behavior of five layered Al/Cu functionally graded material (FGM) produced by powder metallurgy was presented in the study. Compressive strength and hardness was evaluated on Universal testing machine and Vickers hardness tester respectively. Tribological characteristics in terms of frictional coefficient and wear rate was examined on pin-on-disc tribometer under the influence of different normal loading, sliding velocity and sliding distance conditions. FGM showed varied hardness along the thickness direction and maximum hardness of 86 HV was found at graded region due to the formation of intermetallic compound (CuAl₂). Compressive strength of FGM was 40.9% and 22.7% greater than pure Al and pure Cu samples. Al/Cu FGM exhibited superior friction and wear characteristics over base materials. To understand the failure mechanisms on fracture and worn out surfaces, they were observed under Scanning Electron Microscopy (SEM).