The hot forging behaviour and its effects on the oxidation behaviour of W–Cr alloy

•Hot forging on W–20Cr–20Mo–1.5Pd alloy was carried out.•Residual pores were eliminated at suitable condition.•Grain boundaries were rich in both Cr and Pd after hot forging.•Enhanced oxidation resistance after hot forging due to Pd-and Cr-rich grain boundary and fewer residual pores.

For the first time, hot compression of a sintered W–20Cr–20Mo–1.5Pd alloy was performed to improve oxidation resistance. Residual pores in as-sintered alloy were hypothesized to be eliminated through sliding of the viscous Pd–Cr-containing grain boundary during compression at 10−4 s−1 and 1350 °C, which increased the alloy’s oxidation resistance. Because of sufficient Cr from the Pd–Cr phase near the grain boundary after hot compression, Cr could transfer more efficiently into the Cr-depleted zone, and therefore, the oxide film/matrix interface was much stronger and showed fewer interfacial cracks than the as-sintered alloy did.

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