Details

Autor(en) / Beteiligte

• Trego, G.
• Brachet, J.C.
• Vandenberghe, V.
• Portier, L.
• Gélébart, L.
• Chosson, R.
• Soulacroix, J.
• Forest, S.
• Gourgues-Lorenzon, A.F.

Titel

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

Ist Teil von

• Journal of nuclear materials, 2022-03, Vol.560, p.153503, Article 153503

Ort / Verlag

Amsterdam: Elsevier B.V

Erscheinungsjahr

2022

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

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