Microstructure and properties characterization of W-25Cu composite materials liquid-liquid doped with La2O3

Hydrothermal synthesis-coreduction techniques were used to convert a mixture of sodium tungstate, copper nitrate and lanthanum nitrate into La2O3 doped nano-W-25Cu-La2O3 composite powders. These high density fine-grain W-25Cu-La2O3 composites were then fabricated using a series of preforming, sintering and canned hot extrusion techniques to afford alloys whose microstructures and properties were characterized using SEM, HRTEM, and XRD analysis. These results revealed that the composite powders were comprised of W, Cu and La2O3 phases that had been formed through a two-stage hydrogen reduction process. Importantly, doped La2O3 with a diameter of 15-30 nm were found to be present on the surfaces of both the W and Cu particles, as well as being distributed throughout the Cu phase. The presence of La2O3 dopant was found to have an important influence on the physical and mechanical properties of their W-Cu alloys. When the content of La2O3 was 2.0 wt %, the resultant alloy demonstrated the best overall performance, affording conductivity, hardness and tensile strength values of 52.5% IACS, 288 HB and 375.9 Mpa, respectively.