Effect of variation of ceramic reinforcement content on metallurgical and cavitation erosion behaviour of microwave processed composite clads

The effect of varying (0%-30% by weight) reinforcement (Cr3C2) on the different characteristics of microwave processed composite clads (Ni-based (EWAC) matrix) was determined. The microstructure of composite clads showed growth of randomly orientated lamellar bands (Cr-Fe-C) rich phase in the Ni-Fe-Cr rich matrix, which confirmed the metallurgical bonding of clads with substrate. Higher microhardness values, with a lower standard deviation, were observed in the 30% Cr3C2 reinforced clad. Excellent cavitation erosion resistance of EWAC + 30% Cr3C2 composite clads, among all other clads and substrate samples, was observed. Synergy of higher microhardness and toughness resulted in significant improvement in the cavitation erosion resistance. Formation of pits, craters and plastic deformations were mainly responsible for the cavitation erosion failure of clads and substrate samples. The transition of damage from ductile mode to dual (brittle and ductile), and further brittle mode was observed with increase in weight percentage of reinforcement.