Synthesis and characterisation of Cu-W nanocomposite strips.

The present work deals with the preparation of near full density Cu-5 wt-%W, Cu-20 wt-%Wand Cu-40 wt-%W nanocomposite strips from elemental copper and tungsten powders. The proposed route consists of preparing Cu-W nanocomposite powders via high energy ball milling of mixture of elemental powders followed by die compaction of the milled powder, sintering of the powder preforms at 1273 K and hot rolling of the unsheathed sintered preforms at 1273 K under protective atmosphere. The microstructural characteristics of the ball milled Cu-W composite powder as well as finished hot rolled strips of Cu-W composites have been investigated, and the mechanism underlying such microstructural evolution has been discussed. Ball milled composite powder particles as well as hot rolled finished Cu-W composite strips consisted of uniform distribution of submicrometre sized and nanosized tungsten particles embedded in the copper matrix. The microhardness of the finished Cu-W composite strips increased with increasing W content, whereas electrical conductivity decreased with increasing tungsten content in the finished Cu-W nanocomposite strips. [ABSTRACT FROM AUTHOR]