Friction stir welding

FSW of Aluminum with PP : Joining different parts that too made of different materials is one of the essential steps while designing/engineering of materials. Presently, the energy-efficient low-weight automotive and aerospace components consist of many classes of materials, such as metals, polymers, ceramics, etc. Efficient and reliable joining of such materials of varied nature is a daunting task. We have demonstrated, for the first time, joining of a metal (aluminum) and a polymer (Polypropylene, pp) using mechanical friction. The detailed characterization (refer to the published articles below) clearly reveals that atomically locked interfaces are formed in such a joining whereas no chemical bonds are formed. Also, a waterproof and strong interface is formed in such a process. Fully atomistic molecular dynamics simulations have been performed in order to further gain deeper insights on the joining process.

FSW of CuCrZr with 316L Stainless Steel: CuCrZr alloy (Cu-0.8wt-%Cr-0.1wt-%Zr) and 316L stainless steel (Fe-0.03wt-%C-16wt-%Cr-10wt-%Ni) plates were successfully friction-stir lap-welded that resulted in significant mechanical mixing of the two matrix elements, Cu and Fe, in the stir zone. The severe mixing not only led to improved load bearing response but also created Cu-rich and Fe-rich regions in the weld nugget. These regions or phases influence the failure mechanism of the joint. Tensile properties of the weld showed promising response when compared with joints made for the similar alloy pair by other welding techniques. This suggests a strong feasibility of applying FSW for joining Cu and steel, especially in nuclear applications.

Amit Arora
Assistant Professor of Materials Science and Engineering

Amit Arora is Assistant Professor of Materials Science and Engineering at Indian Institute of Technology Gandhinagar. He leads the Advanced Materials Processing Research Group at IIT Gandhinagar which works in the area of numerical modeling of welding and joining processes, additive manufacturing processes, and friction stir welding and processing including tool wear during FSW, numerical modeling of dissimilar FSW, and mechanical and electrochemical characterization of friction stir surface composites. Recent works have been published in journals such as Metallurgical and Materials Transactions A, Journal of Materials Processing Technology, International Journal of Advanced Manufacturing Technology, Heat and Mass Transfer.