Effect of electropulsing treatment on microstructure and mechanical properties of intermetallic Al3Ti alloy

Effects of electropulsing treatment (EPT) on the microstructure evolution, mechanical properties and crack healing of intermetallic Al3Ti alloys were studied in this work. In order to investigate the athermal effect caused by EPT, conventional heat treatment (CHT) was conducted for comparison. The compressive stress-strain curves demonstrated that the failure strains of Al3Ti alloy increase under both the EPT and CHT conditions, while the increment of failure strain of Al3Ti alloy treated by EPT is higher than that treated by CHT. Fracture surface analysis confirmed that the intrinsic brittle fracture of Al3Ti alloy evolves into the quasi-cleavage fracture with increasing frequency of EPT. Based on the systematic investigation into the microstructure evolution, mechanical properties and fracture surface observation, the influence mechanism of EPT on Al3Ti alloy was found to be related to the improvements of atomic diffusion and dislocation movement, which results from the coupling of thermal effect and athermal effect by EPT. Furthermore, the thermal compressive stress and athermal effect could heal the local micro-crack and decrease the crack width of Al3Ti alloy by EPT. Therefore, EPT can work as a novel method for improving the plastic deformation capacity of Al3Ti alloy. (C) 2017 Elsevier B.V. All rights reserved.