Experimental investigation on friction drill joining of difficult-to-machine materials: a new methodology for joining of similar and dissimilar materials

Friction drill joining is a one-sided thermo-mechanical joining process to connect similar and dissimilar materials. Due to the excellent potential for multi-material joining and wide application in designing the lightweight and modern vehicle, special attention has been paid to this approach of the friction drilling process. However, the most challenging issue in this process is the joint quality. This paper focuses on the effect of process parameters on joint quality and tool performance. A modification method to improve the joint quality is also provided. The quality of the formed joint is analysed, by applying the tensile shear test. Moreover, the microstructural alteration of the formed joint is characterized. The main contribution of this work is presenting a new approach of friction drilling for the joining of sheet metals. The findings reveal that optimum process parameters, in terms of maximum joint quality and tool performance, are spindle speed 3000 rpm and feed rate 120 mm/min. It is found that the hardness near the formed hole is greater than the base material. The findings also contribute to providing an enhanced microstructural characterization of sheets, which identifies the material behaviour and shows how it affects the joint quality. © 2021 Informa UK Limited, trading as Taylor & Francis Group.