Preparation of ultrafine Cu-20W composite powder by sol-gel with hydrogen reduction technology and its sintering behavior

In this paper, Cu-20wt.% (Cu-20W) ultrafine composite powders were prepared by a combination of sol-gel with hydrogen reduction method using ammonium metatungstate and copper nitrate as raw materials, and Cu-20W samples were obtained by pressing and sintering. The morphology and particle size of the powders were characterized and the effect of temperatures on the structure and properties of the Cu-20W samples were investigated. The results show that the Cu-20W composite powders with an average particle size of less than 100 nm by a combination of sol-gel with hydrogen reduction method; with the increase of sintering temperature, the physical and mechanical properties of Cu-20W samples are improved. The relative density of the samples sintered at 1080 °C is 97.20 %, the electrical conductivity (IACS), thermal conductivity, Vickers hardness and tensile strength are respectively reached 91.73 %, 351.52 W·m-1·K-1, 96.1 HV and 431.03 MPa; the CTE values of the Cu-20W samples ranged from 14.871×10-6·K-1 and 17.422×10-6·K-1 in the temperature range of 100 ℃ to 400 ℃.