Interfacial structure and strength of Si₃N₄ ceramics joint brazed with amorphous filler metal and Cu layer

Si₃N₄ ceramics were brazed with TiZrCuB amorphous filler metal and Cu interlayer, the effect of brazing metal compositions and thickness of copper foil on interfacial structure and bonding strength were studied in this paper.The result shows that the joint strength is up to 241 MPa when the brazing temperature is 1 323 K, holding time is 30 min, the thickness of Cu interlayer is 70 μm and the exerted pressure is 0.027 MPa.The reaction layer is TiN and the interface microstructure is compound of Si₃N₄/TiN/Ti-Si+Ti-Zr+Cu-Zr+α-Cu.Changing the thickness of interlayer can adjust the thickness and compositions of the reaction layer.As the thickness of Cu interlayer increased, Ti-Si compound layer was gradually separated from the TiN layer, and was pushed into the weld center and refined to a granular shape.