Densification of W-Cu Powder with Submicron Size Microstructure

The densification of a powder W-20wt%Cu, consisting of submicron size aggregates of W grains, about 250 nm in size, surrounded by Cu is studied by dilatometry and microstructure observation. The shrinkage behaviour is consistent with a rearrangement process limited by the W skeleton deformation. The W network deformation proceeds from the development of selected grain boundaries and could involve some transient mobility at the W-W contacts during the development of the grain boundaries.