Synthesis of near-spherical W-Cr2O3 composite powders with varying Cr doping levels and their application in cemented carbides

Tungsten powder is an essential raw material for producing tungsten carbide powders and tungsten-based alloys. However, the fabrication of high-performance spherical tungsten powders remains costly, and achieving a uniform distribution of doped elements poses significant challenges. In this study, a molecularly homogeneous W-Cr precursor solution was prepared using soluble salts, namely ammonium metatungstate ((NH₄)₆[H₂W₁₂O₄₀]·xH₂O)) and ammonium chromate ((NH₄)₂CrO₄). Near-spherical W-Cr₂O₃ composite powders with various Cr doping contents were synthesized through spray drying, calcination, and low-temperature hydrogen reduction. Subsequently, WC-10Co-xCr cemented carbides were fabricated via spark plasma sintering (SPS) following carburization. The effects of reduction temperature and Cr content on the morphology and phase composition of the W-Cr₂O₃ composite powders were systematically examined. In addition, the influence of Cr doping on the mechanical properties of the cemented carbides was preliminarily evaluated. The results reveal that, at a reduction temperature of 900 °C and a Cr doping level of 0.5 wt%, the W-Cr₂O₃ composite powders exhibit a uniform near-spherical morphology with fine and consistent particle sizes. The corresponding cemented carbide demonstrates superior overall performance. Furthermore, the Cr element is uniformly dispersed throughout the WO₃ precursor, W-Cr₂O₃ composite powders, and the final alloy matrix.