Assessment of microstructure and wear behavior of aluminum nitrate reinforced surface composite layers synthesized using friction stir processing on copper substrate

Aluminum nitride (AlN) is a potential ceramic particle to improve the wear resistance of copper surface. The present work is focused on synthesizing Cu/AlN (0,6,12,18 vol%) copper matrix composites (CMCs) on pure copper substrates through friction stir processing (FSP). AlN particles were compacted into grooves machined on the surface of the copper plates. FSP was carried out under a set of fixed experimental conditions. The microstructural features were analyzed using optical, scanning and transmission electron microscopy. The wear behavior was assessed using a pin-on-disc apparatus. AlN particles were distributed homogenously in the surface composite. There were no clusters and segregation of AlN particles. The distribution was almost constant across the depth of the surface composite. There was a good interfacial bonding between AlN particles and the copper matrix. There was no major change in shape and size of AlN particles subsequent to FSP. Fine equiaxed grain structure was observed in the composite induced by dynamic recrystallization and pinning effect of AlN particles. The dry sliding wear behavior of the composite surface was reported in detail.