Journal of Materials Research and Technology (Mar 2023)
Feasibility study of thermo-compensated resistance brazing welding of 6061 aluminum alloy to 304 stainless steel
Abstract
The 6061 aluminum alloy/304 stainless steel dissimilar materials with a certain area were successfully achieved by a novelty welding method, named thermo-compensated resistance brazing welding, in which, the high-resistivity graphite was inserted as the auxiliary electrode. The effect of the welding current and welding time on the temperature field of the graphite, mechanical properties, and the fracture surface of the final Al/steel weld was investigated. The results revealed that the temperature field was generated by Joule heat based on graphite, Al alloy, and stainless steel in the welding process. The generated Joule heat was gradually extended from one point to the entire interface in the whole welding process. The temperature field and tensile-shear load of the joint were also improved with the increase of the welding parameters. The degree of diffusion surface was illustrated at the fracture, indicating the “brazing” feature. There were three diffusion regions A, B, and C on the fracture surface with the steel side of the optimal parameters. The mechanical properties of the weld mainly depended on regions B and C. The effective connection was formed at a local area of the entire interface between Al alloy and 304ss at this parameter. Al(s.s) and Fe2Al5 IMC were generated at the interface. The typical inclined interfacial failure was formed after the tensile-shear test due to the heat generation mechanism. The Al(s.s), Fe(s.s), and Fe2Al5 IMC were presented on the fracture surface, which was consistent with the above contents.
