Brazing mechanism and shear strength of SiAlON/WC‐Co joint using Ag–Cu–Ti active filler

Abstract

This work investigated the formation mechanism and the effects of temperature on the microstructure and shear strength of vacuum‐brazed SiAlON ceramic/WC‐Co cemented carbide joints using an Ag–Cu–Ti active filler as the interlayer. The diffusion of Ti elements toward substrates and their subsequent reaction during the brazing process led to the formation of TiN, TiC, and Ti5Si3 phases, where the featured reaction layers were established. A continuous reaction layer of TiN in the SiAlON substrate side and TiC in the WC substrate side were formed. The ceramic phases (Ti5Si3 TiN, and TiC) were distributed in a brazed intermediate layer. The highest shear strength of the brazed joints obtained at 850°C was 325.28 ± 20.27 MPa, demonstrating the feasibility of the Ag–Cu–Ti active filler in producing robust joints.