Abstract: In this work, accelerated sintering of Y₂O₃ dispersion strengthened tungsten alloy with a well-regulated structure was achieved by a novel dissolution-precipitation strategy. As indicated, yttrium oxide was firstly dissolved into the lattices of W powder precursor during the thermal plasma synthesis process in a one-step and ultra-fast way, and then homogeneously precipitated out within W grains during sintering. The theoretical calculation reveals that the formation process of Y₂O₃ dispersoids enhanced the driving force of densification by increasing the sintering stress and declining the macroscopic viscosity, resulting in improved diffusion ability for the W skeleton. The microstructural investigation further confirmed the occurrence of mass inter-diffusion at the W-Y₂O₃ interface, which provides a fast diffusion pathway for W atoms, and is responsible for the accelerated densification kinetics. Being sintered at 1600 °C for 1 h, the as-obtained alloy possesses a high relative density of 98.26%, together with a refined grain size of 970 nm for W and 50 nm for intragranular Y₂O₃, respectively.

Key words: Plasma synthesis, Composite nanopowders, W-Y₂O₃ alloy, Dissolution-precipitation, Accelerated densification