The effects of electropulsing on the recrystallization behavior of rolled pure tungsten

Electropulsing treatment (EPT) has been first applied to the recrystallization of a refractory metal-tungsten (W). We have three major observations: (i) the recrystallization temperature of a rolled pure W under EPT is similar to 900 K higher than its conventional recrystallization temperature (1603 K); (ii) the time required for recrystallization is significantly reduced compared with that of conventional heat treatment (CHT); (iii) the recrystallized grains are also much finer than the ones under CHT. Based on quantitative analysis, we conclude that the huge increase of the recrystallization temperature of the rolled pure W under EPT is due to the high heating rate generated by EPT and high activation energy for vacancy diffusion of W, and the accelerated recrystallization and grain refinement have resulted from the coupling of thermal and electromigration effects of EPT at relatively high temperatures.