Microstructure and reaction phases in Si 3N 4/Si 3N 4 joint brazed with Cu–Pd–Ti filler alloy

Abstract

Si 3N 4 ceramic was self-jointed using a filler alloy of Cu–Pd–Ti, and the microstructure of the joint was analyzed. By using a filler alloy of Cu76.5Pd8.5Ti15 (at.%), a high quality Si 3N 4/Si 3N 4 joint was obtained by brazing at 1100–1200 °C for 30 min under a pressure of 2 × 10 −3 MPa. The microstructure of the Si 3N 4/Si 3N 4 joint which was observed by EPMA, XRD and TEM, and the results indicated that a reaction layer of TiN existed at the interface between Si 3N 4 ceramic and filler alloy. The center of the joint was Cu base solid solution containing Pd, and some reaction phases of TiN, PdTiSi and Pd 2Si found in the Cu [Pd] solid solution.