Papers by Author: Yves Bréchet

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Authors: G.R. Canova, Yves Bréchet, L.B. Kubin, Benoit Devincre, Vassilis Pontikis, M. Condat
Authors: Ladislas P. Kubin, Benoit Devincre, G.R. Canova, Yves Bréchet
Authors: John Dunlop, Yves Bréchet, Laurent Legras
Abstract: During transport of spent Zircaloy-4 fuel rods, cladding temperatures can be expected to rise well over 400°C for transportation periods longer than 10 days. The kinetics of creep under these conditions will be controlled by both strain hardening and the softening effect of static annealing of cold work and irradiation defects. This paper will focus on the development of a coupled recovery/recrystallisation model for Zircaloy-4 from 400 – 520°C.
Authors: Hatem S. Zurob, G. Zhu, S.V. Subramanian, Gary R. Purdy, Christopher R. Hutchinson, Yves Bréchet
Abstract: A physically based model is used to analyze quantitatively, the relative contributions of solute Nb and strain-induced NbC precipitation to the retardation of static recrystallization during the interpass time. The model explicitly takes into account the time evolution of strain-induced precipitation and its interaction with recovery and recrystallization. It is thus possible to quantitatively model the recrystallization kinetics taking into account: i) the effect of solute drag on the boundary mobility, ii) the effect of particle pinning (Zener drag) on the driving force for boundary motion, and iii) the effect of dislocation pinning by strain-induced precipitates, on the recovery kinetics and the nucleation of recrystallization. The analysis shows that there is an optimum partitioning of Nb between matrix solute and strain induced precipitates. This optimum partitioning maximizes particle pinning while ensuring an adequate solute drag effect to prevent the boundary from breaking away from solute atmosphere. The optimum partitioning of Nb between the matrix and the precipitates is shown to depend upon the temperature window of rolling, pass reduction and interpass time. The effect of delaying the kinetics of strain-induced precipitation of NbC through large Mn addition is shown to be an advantage for ensuring adequate solute drag in the low temperature, large pass deformation schedule used in near-net shape processing of thin slab or thick strip castings.
Authors: Denis Solas, G.R. Canova, Yves Bréchet, P. Sainfort
Authors: Yves Bréchet, Christopher R. Hutchinson, Gary R. Purdy, Hatem S. Zurob
Abstract: The kinetics and morphology of the grain boundary grooving of Zn bicrystals with 16° <1010> tilt GB by Sn(Zn) melt has been studied at 325°C in equilibrium conditions in vacuum. It is shown that grooving process is interface controlled at least on the first stage. Groove walls mobility is evaluated. Changing of GB grove shape from “faceted walls” corner for annealing time < 78 h to concave “Mullins type” groove for annealing time > 78 h at the same experimental temperature was observed for the first time.
Authors: Muriel Véron, Yves Bréchet, Francois Louchet
Authors: Ladislas P. Kubin, G. Canova, M. Condat, Benoit Devincre, V. Pontikis, Yves Bréchet
Authors: Francois Louchet, Yves Bréchet
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