Influence of Copper-Sided Tin Coating on the Weldability and Formation of Friction Stir Welded Aluminum-Copper-Joints

Abstract

Although the joining of aluminum and copper is a difficult task, several studies have shown that friction stir welding (FSW) is capable of producing aluminum-copper-joints with excellent performance. Therefore, it is desirable to use this joining technique for the production of cost- and weight-reduced conductors for the automotive sector. The exposed copper contact spots in automobiles are usually coated with tin for design reasons and in order to improve their corrosion resistance. In this context, it is possible to perform the weld at first and to coat afterwards, or to weld already coated copper workpieces. Taking this into account, this paper presents results on the influence of copper-sided tinning on the joint formation as well as the achievable mechanical and electrical properties of friction stir butt welded aluminum-copper joints. Two variants were considered. The first variant included copper blanks with a tinned surface. For the second variant the surface and the abutting edge of the copper were coated. The best welds achieved excellent electrical properties and their tensile strength was only slightly reduced compared to the aluminum base material. Thus, it was shown that if these tensile strength losses are acceptable, FSW of aluminum to tin coated copper is applicable.

Impact Joining of Pure Copper C1100 and Aluminum Alloy A6061-T6 Plates at Edges

“…The joining of aluminum to copper has been attractive in electric or battery parts, and it has been investigated [3][4][5]. Further, the addition of Ni at the interface and the coating of the titanium layer on the copper side increased the strength [6,7]. Friction stir "spot" welding technique is also applied to the joining of aluminum, copper and other metals, where the rotating tool stays [8,9].…”

Archives of Metallurgy and Materials

“…ultrasonic welding process is one of faster welding process, compared to laser and friction stir welding [1,2] material loss is very minimum and also it needs minimum energy compare to resistance spot welding [3,4]. owing to the many advantages of ultrasonic welding, it becomes more appropriate for dissimilar metal joints especially aluminium and copper, which are applicable to aerospace industries.…”

Microstructure and Mechanical Properties of Resistance Heat-Assisted High-Power Ultrasonic Dissimilar Welded Cu/Al Joint

“…Ultrasonic welding can produce welds faster and with less material loss than other common welding methods of dissimilar lap joints, such as laser welding (LW) [1,2] and friction stir welding (FSW) [3,4]. It also requires lower energy input than resistance spot welding (RSW) [5].…”