A hybrid microstructure design strategy achieving W-ZrO2(Y) alloy with high compressive strength and critical failure strain

In this article, we report a hybrid microstructure design strategy for preparing tungsten alloy reinforced by Y2O3-stabilized cubic ZrO2 (W-ZrO2(Y)) with high compressive strength and critical failure strain. The processing route involves a molecular-level liquid-liquid doping technique combined with vertical sintering and hot rotary swaging that causes the uniform distribution of cubic ZrO2(Y) particles in the grain interior. The cubic ZrO2(Y) particles in tungsten matrix are prepared by liquid-liquid incorporation of Zr(NO3)4 and Y(NO3)3 aqueous solutions. The alloy powders with 1.5 wt% ZrO2(Y) present nano/microbimodal distribution. The cubic ZrO2(Y) particles are also uniformly distributed in the grain interior of refined tungsten grains, which consequently improves the relative density, Vickers hardness, compressive strength, and critical failure strain of alloy. The compressive strength and critical failure strain of the swaged W-1.5 wt% ZrO2(Y) alloy are 1680 MPa and 0.24, which are approximately 24.9% and 33.3% higher compared with those of pure tungsten, respectively. The strengthening mechanism of W-1.5 wt% ZrO2(Y) alloy is also discussed.