Interfacial microstructure of Si₃N₄/Si₃N₄ joint brazed using Au–Ni–V filler alloy

摘要

By using Au58.74Ni36.50V4.76 at.% filler alloy, a reliable Si₃N₄/Si₃N₄ joint was brazed at 1,423 K for 60 min in vacuum. The microstructure of the joint was investigated and analyzed by scanning electron microscope with energy dispersive spectroscopy, transmission electron microscopy, and X-ray diffraction. The results indicate that the joint consists of three main phases: a continuous VN reaction layer between filler alloy and Si₃N₄ ceramic; an Au[Ni] solid solution as the matrix of the joint; and Ni[Si,V] solid solution particles distributed homogeneously in the Au[Ni] solid solution. The mechanism of formation of the interfacial structure is discussed.