Electrically-induced dynamic globularization behavior and related kinetics model of TA15 alloy with initial lamellar structure

Abstract:

The dynamic globularization rules, underlying mechanisms and globularization kinetics model of TA15 alloy with initial lamellar structure were studied by pulsed electric current assisted compression tests and quantitative analysis of metallographic structure. The results indicate that the increased current density further promotes the flow softening phenomenon. The globularization rate increases with the increase of current density and pre-deformation. Based on the Avrami equation, a kinetics model of electrically-induced dynamic globularization for TA15 alloy is established. The model predicts that the ranges of the critical strain εc for dynamic globularization and the strain εf for completing dynamic globularization are between 0.090 - 0.187 and 5.02 - 6.31, respectively. And these two critical strains both decrease with the increase of current density. The globularization kinetics rate first increases and then decreases with the increase of pre-strain and current density. In addition, the higher the current density, the greater the peak globularization kinetics rate and the smaller the critical strain for this peak value.