Effect of electric current on mechanical properties and microstructure of Ti/Al laminated composite during electrically assisted tension

Abstract

Electrically assisted (EA) forming technology is often applied to difficult to form materials for its convenience and efficiency. As one of the common metal clad plates, explosive welded Ti/Al laminated composite (LC) is hard to form at room temperature (RT). EA forming provides a new idea for Ti/Al LC forming. Explosive welded Ti/Al LC was used as the experimental material to conduct EA tensile experiments with different parameters in this paper. The mechanical properties and microstructure evolution of Ti/Al LC during EA tension were investigated. The flow stress of Ti/Al LC during EA tension was reduced, but the elongation of Ti/Al LC was less than that tension at RT. The reason that induced the fracture in advance was that the local Joule heat temperature was too high. The Ti/Al LC microstructure characterization results showed that dislocation density of matrix diminished, the recrystallization in matrix and atomic diffusion in interface were facilitated. Besides, the high frequency current promoted the transition of Al matrix from ductile fracture to brittle fracture. The primary reason for the decrease of Ti/Al LC flow stress is the decrease of dislocation density in the matrix, and the change of microstructure is also due to dislocation evolution.