Abstract: Diamond grits are brazed with Cu-10Sn-5Ti alloy powder in air, vacuum and argon gas respectively, and the effect of brazing atmospheres on brazing performance is investigated through the analysis of morphological structure of brazed diamonds by scanning electron microscope, the phase composition between diamond and brazing alloy are detected by X-ray diffraction, the degree of graphite on diamond surface are analyzed by laser Raman spectroscopy, the wear characteristics of diamond are analyzed by wear test. The experimental test indicated that the brazing alloy powder appear oxidation and affect the interfacial reaction due to the oxidation film, the diamond grits appear thermal damage and graphitizing, and there are some grits pull-out during the grinding processing. The wett-ability of the Cu-10Sn-5Ti alloy to the diamond grits is improved in vacuum and argon gas, it realizes strong adhesion between diamonds and brazing alloy, and the graphitization of diamonds is not obvious. The brazed diamonds mainly occur integrity, micro-fracture, fracture and rubdown in grinding process.

Key words: Brazing atmosphere, Brazing performance, Copper based alloy powders, Diamonds