Study on the wetting interface of Zr-Cu alloys on the SiC ceramic surface

A Zr-Cu alloy, as a new type of filler metal, is proposed for brazing SiC ceramic under special working conditions. The wetting angle of Zr-Cu alloy/SiC ceramic at different temperatures and holding times was investigated by a high-temperature wetting tester. The composition of the wetting interface was tested by XRD, and the interfacial reaction layer was analyzed with SEM and EDS. The results show that the wetting angle decreases sharply with the change in temperature from 1100 °C to 1175 °C and remains unchanged when the temperature is higher than 1175 °C, about 34 ± 1°. The dynamic wetting angle of Zr-Cu/SiC at 1200 °C with the increase in holding time conforms to the law of exponential decay, and the equilibrium wetting angle is 5°. The transition layer with a certain thickness is formed during the spreading process of the Zr-Cu alloy at a high temperature, and the microstructure of the interfacial reaction layer mainly consists of ZrC and Zr₂Si.