Joints performance of diffusion bonding between pure Cu and stainless steel and dynamic analysis of atomic diffusion

The effects of welding parametas on the performance of the joints of pure copper and ferrite 410L and joints of pure copper and austenite 304 stainless steel were researched by microstruture observation, hardness, tensile test and EPMA.And atomic diffusion mechanism of two kinds of joints combined theoretical calculation was also discussed.The result indicated:as bonding pressure and bonding time fixed, the joints tensile strength increased with the bonding temperature.Optimal bonding temperature of Cu/410L is about 50 K lower than that of Cu/304, because the diffusion speed of Cu, bcc ferrite is faster than in fcc austenitic.The measured diffusion speed of Cu atom in stainless steel is smaller than the theoretical value because the theoretical value was obtained based on assuming 100% full adhesion for the surface in initial, but the actual bonding surface is rough in initial stages.