Uniform nanosized oxide particles dispersion strengthened tungsten alloy fabricated involving hydrothermal method and hot isostatic pressing
Résumé
In this article, we reported a processing route for fabricating extremely uniform and ultrafine Zr(Y)O2 particles diffusely distributed in the tungsten matrix. More than 90% of oxide particles are between 100 and 650 nm in diameter. The refinement mechanism of Zr(Y)O2 particles was discussed. Under TEM observation, lots of Zr(Y)O2 particles with a diameter of less than 50 nm are dispersed in tungsten matrix. HRTEM analysis reveals that the Zr(Y)O2 particles exhibit a good bonding with the tungsten phase, but without coherent relation at interface. The fabricated W alloy reinforced by 0.25wt% Zr(Y)O2 exhibits excellent compressive strength of 1577 MPa and fracture strain of 0.262, higher
than those of the pure W and the published experimental results. The fracture surface mainly consists of transgranular fracture and involves
significant W grain tearing and grain deformations, confirming the strengthening effect caused by nanosized Zr(Y)O2 particles. The hot
deformation behavior of W-Zr(Y)O2 alloy at high temperature was investigated through establishing constitutive equation based on the
Arrhenius model.
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