INTERFACE CHARACTERIZATION OF AL-CU MICRO-LAMINATES FABRICATED BY ELECTRICALLY-ASSISTED ROLL BONDING

摘要

Interface characteristics of Al/Cu micro-laminates fabricated by an Electrically-Assisted Roll Bonding (EARB) process were studied to understand the underlying physical/chemical phenomena that lead to bond strength enhancement when applying electrical current during deformation. Peel tests were conducted for the Al/Cu roll-bonded laminates produced with no current and under 50A and 150A applied current. After peel tests using a micro-tensile machine, the fractured surfaces of both the Al and Cu-sides were examined using scanning electron microscopy (SEM) for fractography and SEM-based energy dispersive (EDS) analysis. Results revealed the strong dependence of the fracture path and its morphology on the strength of the bond, which is influenced by various phenomena occurring at the interface during EARB, such as microextrusion through surface micro-cracks, possible formation of intermetallic components and thermal softening during simultaneous application of strain and high current density.