Microstructure evolution and mechanical properties of SiC/Mo joint brazed with FeCoCrNi high-entropy alloy filler

The reliable connection between ceramics and metals achieved through brazing is a crucial method to promote their application. In this study, the FeCoCrNi high entropy alloys was adopted as the filler to connect SiC and Mo through vacuum brazing. The microstructure evolution and mechanical properties of the SiC/FeCoCrNi/Mo brazed joint at different brazing temperature and holding time were systematically investigated. With the increase of the brazing temperature or the extension of the holding time, the reaction layer gradually thickened with the increasing precipitation of the soft FCC phase. Notably, the FCC solid solution phase with good plastic deformation ability and the brittle Cr0.46Mo0.4Si0.14 phase have good interface bonding (lattice mismatch degree ∼ 3.12 %). The dispersive and staggered distribution of FCC phase and Cr0.46Mo0.4Si0.14 phase can effectively alleviate the joint stress and hinder crack propagation. This work is expected to provide theoretical guidance for the connection of ceramics and metals through high-entropy alloys.