The mechanical behavior of commercially pure polycrystalline vanadium (99.8%) has been characterized in compression over a strain rate range of lo4 to 6x10' s-'. In addition, the temperature dependence of the flow stress of vanadium has been examined over a range i f temperatures fiom 25 to 700 "C for a strain rate of 10') s-'. Optical metallography of the deformed specimens revealed no twins, deformation bands or microcracks, suggesting that the deformation proceeded largely by

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... slip. The strain rate and temperature dependence of the strain hardening rate and flow stress is indicative of a BCC material, although a pronounced local peak in the flow stress was observed at about 400 "C. Resume. Le comportement mecanique de polycristaux de Vanadium (purete commerciale : 99,8%) a Ctt caracterist en compression pour des taux de deformation allant de lo4 B 6.10' s-'. L'evolution de la limite d'elasticite en fonction de la temptrature a par ailleurs t t t analyske sur une plage de 25 A 700 'C. L'observation en microscopic optique des tchantillons d6formts a montrt I'absence de mlcle, de bande de deformation ou de micro-fissure, ce qui sugghre un mode de deformation par glissement cristallographique. A I'exception d'une anomalie de limite Blastique vers 400 'C, le taux de deformation et I'evolution de la limite d'elasticite en fonction de la temperature est caracteristique des metaux cubiques centres.