Effect of variation of WC reinforcement on metallurgical and cavitation erosion behavior of microwave processed NiCrSiC-WC composites clads

Abstract

Components operating in fluid handling systems most frequently experience cavitation erosion. The coatings/claddings fabricated by microwave irradiation method can remarkably improve cavitation erosion. In the present work, WC reinforced NiCrSiC based metal matrix composite clads with varying weight percentage of WC particles were developed on SS 316 steel using microwave heating method. The metallurgical and microstructural study of composite clads were analyzed using SEM/EDS, XRD and porosity, microhardness was also investigated. Cavitation erosion behavior of the claddings were evaluated using vibratory cavitation erosion tester. The failure mechanism due to cavitation erosion was explored using SEM study. The relationship of cavitation erosion behavior with variation in weight percentage (10%, 20%, and 30%) of reinforced particles in the composite clad was also explored. It has been observed that with an increase in the weight percentage of WC particles, the cavitation erosion rates decreased drastically initially (37.9%) and, but later significant change was not observed (4.89%, 2.44%). Eroded surface study revealed that with increase in the weight percentage of WC reinforcement the mode of damage changes from ductile to brittle. Further it was studied that the pits, crater, micro-cracks, and plastic deformation were the primary wear mechanisms.