Analysis on interface microstructure of Ni-Cr filler brazed Ti coated CBN

Ni-Cr filler was used to braze Ti coated CBN abrasive and AISI1045 steel in vacuum. SEM, EDS and XRD were used to analyze the morphology of Ti coated CBN abrasive particles after brazing, the microstructure of the interface between CBN and Ni-Cr filler, and the surface products of abrasive after brazing. During the brazing process, Ni-Cr filler climbs the CBN particles along the Ti coating and has good wettability to the abrasive. After brazing, the Ti coating on the exposed part of CBN grains transforms into Ni-Ti metal layer under the diffusion of Ni atoms. However, in the area where the grains are embedded in the filler, the Ti coating of the abrasive diffuses with CBN and Ni-Cr filler during the brazing process, forming an intermediate layer mainly composed of NiTi and Ni_0.3Ti_0.7N, which realizes the metallurgical bonding of Ti coated CBN abrasive and Ni-Cr filler.