Weld appearance and microstructural characteristics of friction stir butt barrier welded joints of aluminium alloy to copper

Abstract

Friction stir butt barrier welding, an improved method based on the friction stir butt welding process, in which a barrier was configured on the butt plate, was applied to the Cu-Al combination. The resultant Cu-Al joints presented good appearance when Al was adopted as the barrier. The pin shifting towards the Al side could improve the interior quality of the weld. However, the effect was limited when the pin offset increased to a certain value. As the tool rotation rate increased, the amount and size of the voids decreased first and then increased. There were two types of joint depending on the interfacial morphology: the smooth interface and the chaotic interface. When the pin offset was zero, the interface was occupied by large Cu fragments. As the pin offset increased, the joint interface transited first to the smooth type and then to the chaotic type. As the rotation rate increased, the laminate density around the interface decreased, and the sublayers in the laminates thinned.

An experimental study of friction stir welding parameters effect on joint properties of aluminium alloy and copper plate

“…They are also chemically unstable at higher temperatures. As a result of these variations, complications like cracking, residual stresses, and the huge number of intermetallic compounds (IMC) formation can occur in the weld [5][6][7]. Mechanical bolted joints of Al-Cu plates are also not sustainable joints [8].…”

Multiphysical characterization of FSW of aluminum electrical busbars with copper ends

“…15 Microhardness field of the FSW joint cross section, with the optical macrograph transparent in the background. The indentation load applied was 0.5 N IMC phases and the formation is deeply influenced by process parameters such as rotational speed and lateral tool offset as reported by Galvão et al [19] and Liu et al [26]. Possible composite-like structures composed of Cu, Cu-rich, or IMC particles dispersed in an Al or Al-rich matrix are emphasized in Fig.…”

The Effect of RFSSW Parameters on Load Capacity of EN AW-6082-T6 Aluminium Alloy and AlCu Bimetallic Joints

“…According to the authors, the classic FSW ow model is that aluminium on the retreating side ows towards the advancing Cu, which ows downstream rst and then up again. The morphology of the FSW joint usually consists of two or more intermetallic compound (IMC) phases and the formation is in uenced by process parameters as found by Liu et al [10] and Galvão et al [11]. The most commonly formed IMCs are CuAl 2 (ϴ) and Cu 9 Al 4 (γ 1 ) [12,13].…”