Microstructure and properties of fine grained W–15wt.% Cu composite sintered by microwave from the sol–gel prepared powders

Abstract: The W–15wt.% Cu composite powders were synthesized by a sol–gel method combining with hydrogen reduction. X-ray diffraction patterns show that pure W and Cu phases were obtained at a reduction temperature of 750°C for 2h. The particle size of such powder is in the range from 100 to 400nm and in each particle the W and Cu phases are seemingly mixed homogeneously in the nanometer scale. The powders were microwave sintered for 25min at different temperatures of 1050, 1150 and 1200°C, respectively. The results show that W–15wt.% Cu samples microwave sintered at 1200°C exhibit a relative density higher than 97% and an average particle size of W as small as 600nm. The thermal conductivity and the Vickers microhardness of the sintered W–15wt.% Cu samples are in the range from 140 to 187W/mK and from 235 to 347HV, respectively. [Copyright &y& Elsevier]