Numerical Analysis of Wavy Interface Formation and Successive Temperature Change in Magnetic Pulse Welded Al/Cu Joint

Abstract

Magnetic pulse welding (MPW) which is one of the impact welding methods is suitable for a wide variety of combinations of similar and dissimilar metals. The flyer plate is accelerated by electromagnetic force and collided to the parent plate. A characteristic wavy interface is formed. The impact velocity and impact angle of the flyer plate during impact are important parameters which affect the interface morphology. In the case of dissimilar metals (e.g. Al/Cu, Al/Fe), the intermediate layer (such as intermetallic compound (IMC)) is formed by wavy interface formation and local temperature increase. The intermediate layer often decreases the bonding strength. Wavy interface formation mechanism and temperature increase at the joint interface should be investigated in order to obtain the dissimilar metal joint with high bonding strength. In this study, the impact velocity and impact angle of the flyer plate were obtained by using ANSYS Emag-Mechanical. Based on the obtained impact velocity and impact angle of the flyer plate in the MPW, the wavy interface formation and temperature change were reproduced by using ANSYS Autodyn for solving non-liner dynamics problems. Al sheets and Cu sheets were joined by the MPW. The joint interface was observed by OM and SEM and compared to the simulation result.

Microstructure and Joint Strength of Magnetic Pulse Welded Aluminum/Aluminum-Coated Steel Joint

“…Therefore, the temperature rise has been investigated by numerical analysis. Nishiwaki et al performed a numerical analysis of the temperature rise at the Al/Cu wavy interface during magnetic pulse welding, and reported that the temperature of the vortex part of the wavy interface reached approximately 3000 K. 28) This temperature is much higher than the melting point of Al (933 K). The melting point of metal under high pressure is known to differ from that under atmospheric pressure, and it is reported that the melting point of Al increases almost linearly from 933 K to 1050 K when the pressure is increased from atmospheric pressure to 2 GPa.…”

Interfacial Microstructure and Hardness of Magnetic Pulse Welded Copper/Nickel Lap Joint

“…Numerical simulation is a good tool to understand the temperature during the welding process. Nishiwaki investigated temperature at the wavy aluminum/copper welding interface during magnetic pulse welding using smoothed particle hy- drodynamics 28) . They reported that the temperature of vortex zone produced at the wavy interface exceeds the melting points of copper (2899 K).…”