Effect of Cu–Sn–Ti Solder Alloy on Morphology, Bonding Interface, and Mechanical Properties of Brazed Diamond Grits

The present study focused on characterizing Cu₇₀–Sn₂₀–Ti₁₀ solder alloy powder used for brazing diamond grits in a vacuum at 960°C for 20 min. The study covered the macroscopic and microscopic morphology of Cu–Sn–Ti/diamond, the products and thickness of the interfacial reaction layer, the surface morphology of diamond grits, and the phase and morphology of surface attachments after reaction. Additionally, the effects of graphitization and compressive strength of the diamond after the reaction were also studied. The study’s results revealed that the solder alloy could climb up to the diamond grits effectively and exhibited excellent wettability. Microscopically, a TiC reaction layer was observed at the interface between them, and the thickness of the reaction layer was about 1.92 μm, leading to the realization of a chemical metallurgical combination. After brazing, the uncovered surface of diamond grits appeared smooth and did not show graphitization, except for slight graphitization in a few corrosion pits. Moreover, no significant change was observed in the compressive strength of the diamond before and after brazing.