Laser pressure welding of dissimilar aluminium and copper: microstructure and mechanical property

Abstract

In this work, laser pressure welding of dissimilar aluminium and copper was conducted at a high welding speed of 15 m min −1 . One-micron intermetallic compounds (IMCs) layer with heterogeneous dual-phases (copper and γ -Al 4 Cu 9 phases) laminates in the joint interface were observed by transmission electron microscopy. The results showed that the combination of two joining mechanisms led to improved mechanical property, namely the mechanical interlocking due to the curved interface and the metallurgical bonding by the presence of the thin IMCs layer with heterogeneous laminates. The tensile shear force and the shear strength of the joint reached 2055 N and 111.94 MPa, respectively. The present study provides a more efficient method to join dissimilar aluminium and copper.

A Review: Laser Welding of Dissimilar Materials (Al/Fe, Al/Ti, Al/Cu)—Methods and Techniques, Microstructure and Properties

“…When analyzing publications, it was found that after laser welding, most researchers conduct mechanical tests (mainly tensile or shear strength tests) [ 71 , 72 , 73 , 74 , 75 , 76 , 77 ] while vital Al/Cu joints properties are thermal conductivity and electrical conductivity [ 78 ]. That is, the main area of application is the branch of electrical contact or heat transfer products and devices.…”

“…A significant advantage of laser welding, which allows reducing the thickness of the IMC, is the use of high-speed laser welding up to 95–155 mm/s [ 75 ], 250 mm/s [ 71 ], 80–800 mm/s [ 76 ], which makes it possible to obtain a minimum IMC with a thickness of 1–4 μm with heterogeneous dual-phases (copper and γ-Al 4 Cu 9 phases), which is also formed at solid-state welding [ 82 ]. The recently published work [ 71 ] on laser pressure welding is of particular interest, a process that combines laser welding with rolling welding, with a laser beam directed between two converging sheets of aluminum and copper. The authors of this work were the first to use this technique for welding the pure aluminum, then for pure copper, which are known to reflect laser irradiation strongly, and then for their combination.…”

“…After tensile tests, failure areas of the Al/Cu welded joint were mainly observed in the copper and γ-Al 4 Cu 9 [ 67 , 71 , 83 ] phase and the θ-CuAl 2 phase [ 75 , 84 ]. In comparison with articles on laser welding of Al/Fe, Al/Ti, in articles on Al/Cu welding, little attention is paid to the hypothesis of the welded joint formation, in particular, the formation of various IMC phases and modeling of welding processes and their comparison with experimental data, which is an effective method of scientific research.…”