Spatial stability analysis of emergent wavy interfacial patterns in magnetic pulsed welding

During magnetic pulsed welding, a flier workpiece impacts a stationary workpiece to create a solid state weld. If the velocity of the flier workpiece is sufficient (e.g., >200 m/s), a wavy pattern is observed at the interface between the two workpieces. The pattern has similarities to shear instabilities observed in fluid dynamics. To investigate this behaviour and assess if a connection between the two phenomena exists, shear-flow stability analyses, informed by finite-element simulations, were performed. The results confirm that the wavy pattern can be caused by a shear instability, as hypothesized. (C) 2014 CIRP.