Interfacial characteristics and thermal damage of brazed W-coated diamond with Ni- based filler alloy

In this study, the brazing of W-coated diamond to 1045 steel with Ni-based filler alloy was investigated. In addition, the brazing thermal damage of W-coated diamond joints was compared to that of uncoated ones. After brazing, the coating was not fount to affect the good wettability of the Ni-based filler alloy to the diamond. Moreover, the cracks at the interface of W-coated diamond were less and smaller. An ordered and compact Cr3C2 layer was formed on the surface of the uncoated diamond, while a disordered Cr3C2 layer and rod-like Cr7C3 growing into the filler alloy were formed on the surface of the W-coated diamond. The chromium carbide layer on the W-coated diamond surface was thinner, the graphitization degree was lower, and the maximum residual compressive stress was reduced by 11.4% compared to those on the uncoated diamond. The mechanical properties of the W-coated diamond grits were better preserved after brazing, and the coating alleviated the thermal damage of the brazed diamond joint.