Si₃N₄ ceramics and 304 stainless steel were brazed by Ti40Zr25B0.2Cu amorphous solder, and the interfacial microstructure of brazed joint Si₃N₄ ceramics/Ti40Zr25B0.2Cu/Cu/Ti40Zr25B0.2Cu/304 stainless steel was analyzed. The mechanical properties of the brazed joint were overtly affected by the brazing temperature and Cu foil thickness. The results revealed that the interface structure of the brazed joint might be 304 stainless steel/FeTi/Cu-Zr+Cu-Ti+Fe-Ti/Cu(s,s)/Cu-Zr+Cu-Ti+Fe-Ti/Ti-Si+Zr-Si/TiN/Si₃N₄ ceramics. The four-point bending strength of the brazed joint decreased sharply as the brazing temperature increased and reached a maximum of 76 MPa at 1223 K. Furthermore, as the Cu foil thickness was increased from 500 μm to 1000 μm, the joint strength rose to 90 MPa at 1223 K.
Keywords: Cu interfacial structure; Si3N4 ceramics; connection strength; intermediate layer.