Mechanism study of brittle-to-ductile transition temperature in W-0.2 wt% Al2O3 alloy

W-0.2 wt% Al 2 O 3 alloy plates were fabricated using composite powders prepared by the wet chemical method, followed by cold isostatic pressing, vacuum sintering, and hot-rolling. The addition of Al 2 O 3 particles significantly refines the grain of tungsten matrix compared to pure tungsten, reducing the average grain size from 1 μm to 0.73 μm. The bending strength of the W-0.2 wt% Al 2 O 3 alloy reaches 1379 MPa at room temperature, with a maximum bending strength of 5090 MPa at 300 °C, representing increases of 64 % and 45.8 % over pure tungsten, respectively. The mechanical properties of tungsten alloys were significantly enhanced by the introduction of Al 2 O 3 particles. The W-0.2 wt% Al 2 O 3 alloy exhibited a ductile at 200 °C, with its ductile-to-brittle transition temperature reduced by 100 °C compared to pure tungsten. The improvement in performance is attributed to the refinement of the grain of tungsten and the high proportion of low-angle grain boundaries improves the dislocation transfer path, thereby enhancing the toughness of the material. The synergistic effect of grain refinement and low-angle grain boundaries contributes to the increase in bending strength and the decrease in ductile-to-brittle transition temperature.