Analysis on vacuum brazing of CBN grits with Ti-base filler

Ti-Zr-Ni-Cu filler was utilized to braze CBN grits in vacuum furnace at different temperatures and times,and good bonding between CBN and steel substrate was gotten.The microstructure and the element distribution of the bonding inter-face,as well as the topography and the phase structure of the compounds on the surface of brazed CBN grits were analyzed by SEM,EDS and XRD.The results show that a layer of needle-like,or block-like Ti compounds such as TiB₂ and TiN are formed on the surface of the CBN,thus CBN grits and Ti-Zr-Ni-Cu filler realize chemical metallurgic joining in the interface.And the analysis on fracture appearance shows that the fracture between CBN and Ti-Zr-Ni-Cu filler occurs in CBN,so it can be considered that the joining strength between CBN and Ti-Zr-Ni-Cu filler is higher than that of the CBN.