Improving mechanical properties of W-Ni3Al alloy through Zr element addition: Solid-solution and oxide particle strengthening

In this study, fine Ni3Al flakes facilitated the W-Ni3Al alloy liquid phase sintering, while the added 0.9 wt% Zr element enhanced its mechanical properties, finally obtaining the 1200 °C sintered W-Ni3Al-Zr alloy (WNZ-1200 alloy) with excellent comprehensive properties. Specifically, the relative density, tungsten grain size, bending strength, and macro hardness of WNZ-1200 alloy were 98.26 ± 0.31 %, 3.06 ± 0.65 µm, 1472.56 ± 61.90 MPa, and 76.10 ± 0.82 HRA, respectively. By analyzing the alloy’s phase and microstructure, its excellent mechanical properties were originated from the formed Ni3(Al, W, Zr) solid solution, unique nano-Al2O3 ‘rivet’, the semi-coherent interface of W/t-ZrO2, oxide dispersion strengthening, and the t-ZrO2 phase transformation strengthening. •1200 °C sintered W-9.1Ni3Al-0.9Zr alloy exhibited excellent comprehensive properties.•Fine Ni3Al flakes promoted the low temperature sintering of W-Ni3Al-Zr alloy.•The Ni3(Al, W, Zr) solid-solution was formed in sintering process.•Intragranula-extracrystalline oxides particles accumulated and obstructed dislocations.•The t-ZrO2 phase transformation strengthened W-Ni3Al alloy’s mechanical properties.