Interfacial microstructures and temperatures in aluminium–copper electromagnetic pulse welds

Abstract

Electromagnetic pulse welding can be categorised as a fast, precise, and contactless solid-state joining process. When applied to aluminium and copper, electromagnetic pulse welding opens the possibility of entirely suppressing, or at least minimising, the intermetallic phases of cracking susceptible microstructures. Metallographic examination of aluminium–copper electromagnetic pulse welds revealed that intermetallic-free joints were possible, but rare. When the collision velocity between the workpieces was high (beyond an estimated value of 170 m s−1), a hard copper rich intermetallic phase with the same composition as the equilibrium γ1-(Cu2Al) phase was detected. The presence of both this copper rich intermetallic phase and interfacial voids revealed that melting of the aluminium occurred. A simple analytical model to estimate weld interfacial temperatures was developed and applied to the electromagnetic pulse welding of aluminium with copper. The model not only demonstrated that melting (thus intermetallic phase formation) could have been expected at weld interfaces, but that the model could be extended to estimate appropriate ‘intermetallic-free’ welding conditions.

Electromagnetic impact welding of aluminum to stainless steel sheets

“…Due to the ease in controlling the magnetic field enveloped inside the tube the electromagnetic technique has been widely used for tube welding (Powers, 1967;Hwang, 1992). This has been further investigated in detail for characterizing the EM welding technique for welding of similar and dissimilar metal tubes (Marya and Marya, 2004;Stern and Aizenshtein, 2002;Marya et al, 2005;Shribman et al, 2002;Kimchi et al, 2004;Zhang and Daehn, 2004). In case of flat components controlling the magnetic field is difficult.…”

Electromagnetic impact welding of copper-to-copper sheets

“…Ease in enveloping the magnetic field inside the tube restricted the application of electromagnetic welding technique to tubular workpieces [4,14]. Many researchers have carried out the detailed analysis of EM welding of tubes [5,10,11,16,17,19]. Concentration of magnetic field is difficult in case flat sheets and hence this field has not been widely researched.…”

Effects of 2 mass% Li Addition on the AZ80 Mg Alloy

“…[4][5][6] Some studies of AZ80 alloy have also been reported, including its microstructure and mechanical property, 7) creep behavior, 8,9) forging 10) and welding. 11) However, the AZ80 Mg alloy still has some drawbacks, such as the poor ductility, low thermal conductivity and resistivity, etc. These drawbacks of AZ80 Mg alloy are expected to be improved by addition of Li element.…”