Preparation and characterization of nanosized W-Cu powders by a novel solution combustion and hydrogen reduction method

In this paper, a novel solution combustion combined with hydrogen reduction was developed to prepare W-30Cu powders using ammonium metatungstate, copper nitrate and ammonium nitrate as raw materials. The results indicate that the combustion products own nanocrystalline and porous structure with high specific surface areas. The combustion products can be completely reduced in hydrogen gas at 700 degrees C and the reduced W-Cu composite powder particles have spherical shape with mean particles size of about 80 nm. The reaction mechanism in the system was also identified. Furthermore, the resultant W-Cu powders show good sinterability and the W-Cu sintered samples have fine grain size and good mechanical properties. Relative density, microhardness and thermal conductivity of the sintered W-Cu specimens reach 98.6%, 245.6 HV and 223.55 W/(m . k), respectively. (C) 2019 Published by Elsevier B.V.