Simulation of temperature on the wettability behavior of diamond/Cu-based filler alloys during brazing process

Ordered arrangement brazed diamond tools offer enhanced machining efficiency by enabling controlled distribution and exposure height of diamond. However, during the brazing process, variations in process parameters can affect the wettability between the brazing alloy and diamond, resulting in different brazing morphologies. In this study, a computational fluid dynamics (CFD)-based brazing simulation model was built to investigate the effects of temperature and heating rate on exposure height of Cu–20Sn–10Ti alloy and displacement of diamond. The simulation and experimental results both demonstrate that with the increase of temperature, the exposure height of diamond decreases gradually, while the change of particle spacing increases due to excessive wetting. With the increase of heating rate, the exposure height increases first and then decreases, while the change of particle spacing is opposite. The brazing alloy undergoes three stages: solid state, solid-liquid coexistence state and complete liquid state. In the complete liquid state stage, the wettability behavior between alloy and diamond significantly impacts capillary force and interfacial bonding force, which ultimately determine the exposure height and displacement of diamond. To ensure a higher diamond exposure height and reduced particle displacement of the diamond conditioner applied in the semiconductor industry, the optimized brazing temperature is 880 °C and the heating rate is 5 °C/min. This study advances the understanding of wetting-driven morphological evolution of the brazing alloy during vacuum brazing, and provides a scientific basis for optimizing temperature and heating rate to manufacture high-performance ordered arrangement diamond tools.