Thermodynamic and kinetic analysis of interfacial reaction between CBN and titanium activated Ag–Cu alloy

Thermodynamic and kinetic analysis was performed in order to study the interfacial reaction mechanism of cubic boron nitride (CBN) abrasive grains and Ti activated Ag–Cu filler alloy during high temperature brazing. Meanwhile, microstructure of the interfacial layer was experimentally detected using scanning electron microscope (SEM), energy dispersion spectrometer (EDS) and X-ray diffraction (XRD) in the present paper. The results indicate that according to the thermodynamic theory, the interfacial reaction has been proved feasible, and during brazing the special active element Ti concentrated to and reacted with the CBN abrasive to form TiB₂ and TiN, which joined hard the abrasive grain and steel substrate. Furthermore, the diffusion activation energy of the growing process in the interfacial reaction layer has discovered that the layer growth largely depends on the new formed TiN under conditions of 1153–1193 K and 5–30 min.