Thermodynamic Analysis of Interfacial Reaction between Diamond and Ni-Cr Alloys
Brazing diamond grits to steel substrate using Ni-based filler alloy was carried out via laser in an argon atmosphere. Thermodynamic analysis was performed in order to research the interfacial reaction mechanism of diamond and Ni-Cr alloy during high temperature brazing. Meanwhile, microstructure of the interfacial layer was experimentally detected by scanning electron microscope (SEM), energy dispersion spectrometer (EDS) and X-ray diffraction (XRD) in this paper. The results indicate that according to the thermodynamic theory the interfacial reaction has been proved feasible, and during brazing high strength bonding between diamond grits and the steel substrate has been successfully realized because the chromium in the Ni-based alloy segregated preferentially to the surface of the diamond to form a chromium-rich reaction product Cr3C2, and the bond between the alloy and the Diamond was established through the reaction product.