Effect of holding time on interfacial reaction layer characteristics and mechanical performance of brazed diamonds with Cu-Sn-Ti-Ga filler metals

The diamond joints of the diamond/CuSnTiGa solder system were prepared under the holding time of 3 min, 6 min, 9 min, 12 min, and 15 min, respectively. The effect of brazing holding time on the microscopic morphology, interface characteristics, element distribution changes and mechanical properties of brazing diamond was studied. When the holding time is 6 min, a continuous and uniform TiC reaction layer has been formed at the interface. Etching of diamond and XRD results both proved the formation of TiC. The microhardness results show that when the holding time is 6 min, the maximum hardness at the interface is 318 HV0.1, and the uniformly fluctuating friction coefficient and grinding removal amount are obtained at the holding time of 6 min. Finally, combined with the analysis of the worn surface morphology, the interface reaction of the base brazing filler metal is closely connected, and the filler metal has a high holding force on the diamond. The 6 min heat preservation can effectively improve the bonding strength and wear resistance of the filler metal and the diamond, and meet the expected use requirements. [Display omitted] •The relationship between the holding time and the thickness of the reaction layer is studied.•The relationship between the friction coefficient and the mechanical properties of brazed diamond joints was studied.•The reaction mechanism between the holding time and the brazed joint is analyzed.