Experimental Study and Numerical Simulation of Interfacial Morphology by Electromagnetic Pulse Welding with Aluminum to Steel

Abstract

Electromagnetic pulse welding is a new promising method for solid-state joining of dissimilar materials. However, little understanding of the dynamic phenomena that leads interface morphology and intermetallic compounds to change. Initially, using Ansys Maxwell proved that the eddy current heat had a softening effect on aluminum alloy, and could press into the stainless steel in the semi-melted state. IMCs layer transferred from the unwelded zone (FeAl) to the flat welded zone (Fe₂Al₅+FeAl₂+FeAl) to the wave interface (α-Al+FeAl₃), the state of jet determined interface performance. Then, these insights were verified by SPH simulation, dispersed jet made soft aluminum alloy to produce the wave interface, a beam jet that aluminum particles were wrapped by steel particles produced the flat interface. Combination shear tests, the welded interface with high strength was characterized by large waveform, molten metal and a small amount of steel particles, formed Al-rich FeAl₃. The welded seam with low strength shown brittle fracture characteristic of spherical intermetallic compounds iron-rich FeAl formed by retention jets. Therefore, the dominant mechanism of interface formation is that the compression and impact effect of jet accompanied by a softening effect of eddy current heat on aluminum alloy.

Fig. 6 Morphology characteristics of interface: (a) unwelded zone of starting impact; (b) flat welded zone; (c) small wave zone; (d) big wave zone.