Microstructural investigation after vacuum electrical breakdown of the W-30wt.%Cu contact material

In the present work, characteristics regarding the sub-micron scale microstructure of the W-30 wt%Cu contact material after vacuum electrical breakdown have been investigated by SEM and EDS. EBSD was also utilized to reveal the change of grain size, misorientation and micro-texture for both Cu and W phases after arc erosion. The results revealed that the arc erosion led to distinct grain refinement and intensified local misorientation strain. Besides, with the help of orientation distribution function analysis, strong peak type {112}<4-61> component was identified to be an important arc erosion texture for the first breakdown phase of Cu, which would complicate the following breakdown process during service due to the work function anisotropies.