Influence of grain size on the high-temperature creep behaviour of M5Framatome1 zirconium alloy under vacuum

The effect of grain size on the viscoplastic behaviour M5Framatome zirconium alloy thin sheets was investigated at high temperature under uniaxial tension, using a variety equiaxed microstructures with controlled sizes. In ? phase domain, Coble diffusional creep regime and dislocation were observed, in agreement literature. A negative sensitivity strain rate to highlighted upper part ?+? two-phase range, consistently For first time, linear evidenced ? domain. this regime, third power is suggesting diffusion along boundaries. Modelling multi-mechanism Norton power-law equations, including dependence homogenous strain-rate assumption (Taylor model), enabled satisfactorily reproduce experimental results over 700–1100 °C especially between 880 930 °C. Very good obtained second order self-consistent full field homogenization schemes.