The braze joint between Al₂O₃ to 1Cr18Ni9Ti using a nickel foam

In this paper, a metallic foam interlayer is used to relieve the stresses between the ceramic to metal brazed joint. The brazing of Al₂O₃ and 1Cr18Ni9Ti stainless steel was accomplished using different thicknesses of Ni foam interlayer. The shear test of the brazing joint was carried out, and the maximum shear strength of 119.86 MPa was achieved when using 0.2 mm thickness Ni foam as an interlayer. The microstructures and chemical compositions of the joint interfaces were investigated by scanning electron microscopy. It was found that the change of the distribution of element Ti in the interface would restrain the formation of brittle intermetallic compounds when using a Ni foam as the interlayer, which drastically improves the performance of the brazed joint.