Microstructural and mechanical aspects of micrometric and nanometric Ni + 10% Cr₇C₃ composite microwave clads

Abstract

In this paper, we present the development of micrometric and nanometric Ni + 10% Cr7C3 composite clad on ASTM A743 grade CA6NM hydroturbine steel through microwave irradiation. The microstructure of micrometric clad exhibited blade and rod-like structure of carbides embedded in [Formula: see text](Ni, Fe) solid solution, while nanometric clad leads to the evolution of petal-like structure of carbides. The developed nanometric clad shows uniform microstructural features with a low level of carbide decomposition. As a result, the average nanohardness and fracture toughness of nanometric clad improved by 38.11% and 8%, respectively, compared to the micrometric clad. Clads have porosity of the order of 1.1% and 0.81% for micrometric and nanometric clad, respectively.