Xiaoqing Li¹, John Turner², Karen Bustillo², Rohan Dhall², Andrew M. Minor¹; ¹University of California, Berkeley, ²Lawrence Berkeley National Laboratory

Electroplasticity is a phenomenon in which applied pulsed electric fields during deformation result in reduced flow stress and increased formability in metals. In this work, in situ TEM electromechanical tests of Nickel dog-bone shaped samples on electrical push-to-pull device were performed in order to correlate direct observations of nanostructure change with both mechanical data and applied electrical pulses in an effort to provide clarity on the true origin of this phenomenon. By analyzing the frame-by-frame videos with collected mechanical and electrical data, we found that deformation mechanisms and dislocation behaviors were changed during the pulsing period. Relatively large slip traces with dislocations nucleated from the edges could be triggered by the pulses, and dislocations tend to move with a faster speed and a longer distance compared to the purely mechanically-triggered movement. Results such as local joule heating which was measured indirectly through lattice expansion by diffraction will also be discussed.