Microstructure and mechanical properties of ZrB2–SiC joints fabricated by a contact-reactive brazing technique with Ti and Ni interlayers

A contact-reaction brazing technique with Ti and Ni interlayers was used to join ZrB2–SiC ceramics. The influence of Ti–Ni stack methods and Ti content to the microstructure of the joint was investigated. It was found that Ni could infiltrate into ZrB2–SiC during the heating process and led to excessive interfacial reactions. The TiB whiskers could be in situ synthesized in all range of Ti concentration (55–79 at% Ti) with Ti/Ni/Ti stack foils. Due to the diffusion behavior of Ti, B atoms and low interfacial energy of TiB in TiNi phase, a cross woven structure of TiB whisker was produced in the brazing seam. The microhardness tests demonstrated tight bonding between TiB and the matrix. The highest shear strength of 134 MPa was obtained from 65 at% Ti.