Uniform nanosized oxide particles dispersion strengthened tungsten alloy fabricated involving hydrothermal method and hot isostatic pressing

Abstract

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 0.25 wt% 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.