Results
Title

Plasticity and microstructure evolution of W-CeO rods with different short-duration pulse currents.

Authors

Zhu, Wen-Guang; Yang, Jian-Can; Cao, Jie; Huang, Lin; Xi, Yu-Chen; Nie, Zuo-Ren

Abstract

To improve the formability of W-rare earth electrode, the influence of high-energy pulse on the plasticity property of W-CeO rods was investigated. The effects of current density ( J ), pulse width ( t ), frequency ( f), and strain rate on the plasticity of W-CeO rods were discussed in detail. Results of tensile tests show that the W-CeO rods applied with the electrical pulses obtain a maximum percentage total elongation at fracture (9.65 %), increased by 118.7 % compared to that without pulses. This is owing to both the heat effect and the interaction of current between dislocations and rare earth additions. Electron back scattered diffraction (EBSD)-generated grain boundary (GB) maps suggest that the length of low-angle grain boundaries composed of high-density dislocations decreases after deformation while applying the pulse current. This demonstrates that the short-duration pulsed current enhances the mobility of dislocations. Scanning electron microscopy (SEM) images of the rods after deformation with the pulse current show that the long fiber-shaped additions become discontinuous, which could reduce the stress concentration and hinder the crack propagation.

Publication

Rare Metals, 2017, Vol 36, Issue 12, p981

ISSN

1001-0521

Publication type

Academic Journal

DOI

10.1007/s12598-015-0629-8