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

Highlights: ► The W–15 wt.% Cu powders were synthesized by a sol–gel method and reduction process. ► The particle size of such powder is in the range from 100 to 400 nm. ► In each particle the W and Cu phases were mixed in the nanometer scale. ► Relative density and average particle size of microwave sintered samples reach 97% and 600 nm. ► The thermal conductivity and the hardness can reach 187 W/m K and 347 HV. - Abstract: The W–15 wt.% 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 2 h. The particle size of such powder is in the range from 100 to 400 nm and in each particle the W and Cu phases are seemingly mixed homogeneously in the nanometer scale. The powders were microwave sintered for 25 min at different temperatures of 1050, 1150 and 1200 °C, respectively. The results show that W–15 wt.% Cu samples microwave sintered at 1200 °C exhibit a relative density higher than 97% and an average particle size of W as small as 600 nm. The thermal conductivity and the Vickers microhardness of the sintered W–15 wt.% Cu samples are in the range from 140 to 187 W/m K and from 235 to 347 HV, respectively.