High mechanical performance in W-Gd₂O₃ composites achieved through sintering optimization and microstructural refinement

W-Gd₂O₃ composites with different Gd₂O₃ content have been fabricated via hot-press sintering at sintering temperatures of 1600 °C-1900 °C. This work presents the first systematic investigation of Gd₂O₃ grain boundary segregation in a W matrix and its remarkable grain-refining effect, achieving an average grain size of 0.73 μm. Adding Gd₂O₃ improves the sintering behavior of the W-Gd₂O₃ composite. When the sintering temperature is 1800 °C, the relative density of W-Gd₂O₃ composites can achieve over 99%. Gd₂O₃ as a dispersion-strengthening phase significantly enhances the mechanical properties of W-based composites. Gd₂O₃ particles, preferentially located at W grain boundaries, effectively suppress grain growth, leading to significant grain refinement and enhancing mechanical properties. The W-Gd₂O₃ composite sintered at 1800 °C exhibits optimized mechanical properties when the Gd₂O₃ content is 9 wt%. The corresponding flexural strength and fracture toughness can reach 1149 MPa and 12.17 MPa‧m^1/2, respectively.