Preparation and sintering behavior of ultrafine Cu–20W composite powders by sol–gel with hydrogen reduction technology

Cu–20%W (mass fraction) ultrafine composite powders were prepared by the combination of sol–gel with hydrogen reduction method, using ammonium metatungstate and copper nitrate as the raw materials, and the Cu–20W samples were obtained by pressing and sintering. The morphology and particle size of the powders were characterized, and the effects of sintering temperatures on the microstructure and properties of the Cu–20W sintered samples were investigated. The results show that the Cu–20W composite powders are obtained by the combination of sol–gel with hydrogen reduction method with the average particle size of less than 100 nm. With the increase of sintering temperature, the physical and mechanical properties of the sintered Cu–20W samples are improved. The relative density of the samples sintered at 1080 ℃ is 97.20%, the electrical conductivity (IACS), thermal conductivity, Vickers hardness, and tensile strength are reached as 91.73%, 351.52 W·m^–1·K^–1, HV 96.1, and 431.03 MPa, respectively. In the temperature range of 100～400 ℃, the coefficient of thermal expansion for the sintered Cu–20W samples is 14.871×10^–6~17.422×10^–6·K^–1.