Synthesis and characterisation of Cu–W nanocomposite strips

Abstract

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.