Copper-tungsten composite powders by the hydrogen reduction of copper tungstate

Abstract

The reduction of two different samples of copper tungstate at 500, 600 and 700° C has been studied using thermogravimetry, X-ray diffraction analysis and electron optical techniques. The morphologies of the resultant Cu-W powders have been related to the morphologies of the original tungstate samples and to the time and temperatures of reduction. The reduction mechanism of the tungstate has been shown to be equivalent to the reduction of pure tungsten oxides once the initial metallic copper phase has been produced. The end products of reduction are mixtures of β-W and Cu at 500° C and α-W and Cu at 600 and 700° C.