Strain rate sensitivity of Al-Fe magnetic pulse welds

Abstract

To investigate the mechanical properties and fracture behavior of Al-Fe magnetic pulse welds, quasi-static and dynamic tensile tests were performed under five tensile speeds (2 mm/min, 1, 5, 10 and 15 m/s). High-speed cameras were employed to record the tensile process, and the strain maps of the joints were obtained using digital image correlation method. The morphology and microstructures of the fracture surfaces under these tensile speeds were investigated. The Al-Fe joints showed positive strain rate sensitivity in terms of the maximum shear load as it increased by 22% when the tensile speed rose from 2 mm/min to 15 m/s. The strain rate sensitivity also led to the change of failure mode from base metal fracture to interfacial fracture. Strain rate in the weld zone showed sharply nonuniform distribution when the joints suffered high-speed loading. The strain rate sensitivity of intermetallic layer revealed the coexistence reason of cleavage and ductile fracture in the interfacial failure.