Niobium was hot deformed in vacuum in uniaxial compression to a true strain of 0·6 in the temperature range of 700–1500°C and the strain rate range of 10−3–10 s−1. Strain rate sensitivity was calculated from the compression tests data and mapped out in contour plots with the aim to optimise the hot workability of niobium. The domain of hot workability was identified in the temperature range of 1200–1500°C and strain rate range of 10−2–1 s−1. In this domain the strain rate sensitivity was ∼0·15, the stress exponent 7·5 and the activation energy 246 kJ mol−1. Microstructure of the deformed samples showed features of dynamic recrystallisation within the high strain rate sensitivity domain and features of flow instability in the regime of low strain rate sensitivity. Compared to a previous study on Nb–1Zr–0·1C alloy, Nb showed a lower flow stress and an optimum hot working domain at lower temperatures.
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