Effect of innovative faying surfaces on dissimilar metal welds made with friction rotary joining

The conditions made to the faying surfaces of mating specimens can significantly impact the mechanical properties and microstructure of welding joints. In this study, faying surfaces of materials like AA6063 (a nonferrous alloy) and AISI304L (a ferrous alloy) underwent geometric modifications or electroplating with elements like nickel, chromium and silver. The dissimilar weld specimens with these modified faying surfaces were effectively joined through frictional methods using a rotary friction welding machine, employing specific constant and variable parameters to achieve desirable properties. Subsequently, the prepared weld samples were subject to comprehensive testing and analysis to further explore their properties. This investigation demonstrated viable approaches for joining dissimilar metals through various faying surface designs, revealing distinct variations in terms of axial shortening, microhardness, tensile properties, percentage of elongation, strain hardening behaviour analysis and joint efficiency for each joining trial. Notably, a narrow weld interface (WI) was consistently observed, although its thickness exhibited variability in accordance with the applied modifications.