Microstructure and mechanical properties of interface between diamond and oxygen-free copper brazed joints

The vacuum brazing of polycrystalline diamond and OFC using AgCuTi brazing material was conducted. The effects of brazing temperature (830、 870、 910、950 °C) and holding time (1, 10, 30、60 min) on the interface structure and mechanical properties of the joint were studied, and the mechanism of interface formation was elucidated. The results show that the typical interface structure of brazed joints is diamond/TiC/Cu (s, s), Ag (s, s)/OFC; the brazing temperature has a significant impact on the microstructure of the brazed joint. When the temperature is above 910 °C, the mutual dissolution and diffusion phenomenon between AgCuTi brazing material and OFC substrate is obvious. The shear strength first increases and then decreases with the increase in temperature, and the highest shear strength of the brazed joint maintained at 870 °C for 10 minutes is 223.6 MPa. Finally, the fracture location and morphology of the brazed joint were discussed.