Diffusion bonding of copper alloy to stainless steel with Ni and Cu interlayer

CuAlBe alloy is an attractive shape memory alloy with many important usages in industrial field, in order to spread its range of application it is desirable to be able to join CuAlBe soundly with other metallic materials, for example stainless steel; however the weldability between CuAlBe alloy and stainless steel has never been studied, therefore an experimental investigation of different transition metals was carried out in the diffusion bonding joints of Cu alloys (CuAlBe) to stainless steel (1Cr18Ni9Ti). The microstructure and phase composition of the joint were analyzed by SEM, EPMA and X ray diffraction. The following conclusions have been drawn: 1) The joint strength with Ni interlayer is higher than that with Cu interlayer when the welding parameters are the same; 2) When Ni interlayer is thinner, Al will interact with Ni and Fe, and the intermetallic compounds such as Fe 3Al are formed in the interface, which decreases the strength of the joints; 3) When the bonding temperature is higher, because the diffusion of Cu in Ni is faster than Ni in Cu, a Kirkendall effect occurs, which also decreases the strength of the joints.

CuAlBe alloy is an attractive shape memory alloy with many important usages in industrial field, in order to spread its range of application it is desirable to be able to join CuAlBe soundly with other metallic materials, for example stainless steel; however the weldability between CuAlBe alloy and stainless steel has never been studied, therefore an experimental investigation of different transition metals was carried out in the diffusion bonding joints of Cu alloys (CuAlBe) to stainless steel (1Cr18Ni9Ti). The microstructure and phase composition of the joint were analyzed by SEM, EPMA and X-ray diffraction. The following conclusions have been drawn: 1) The joint strength with Ni interlayer is higher than that with Cu interlayer when the welding parameters are the same; 2) When Ni interlayer is thinner, Al will interact with Ni and Fe, and the intermetallic compounds such as Fe3Al are formed in the interface, which decreases the strength of the joints; 3) When the bonding temperature is higher, the joints.