An electron optical study of hydride precipitation and growth at crack tips in zirconium

Cann, C.D.; Sexton, E.E.

doi:10.1016/0001-6160(80)90076-0

“…For some metals, including zirconium and titanium, such formation has been specifically observed in the vicinity of stress concentrators, following the increased hydrogen transport toward regions of high hydrostatic stresses (Birnbaum 1976;Takano and Suzuki 1974;Grossbeck and Birnbaum 1977;Shih et al 1988;Cann and Sexton 1980). It is also known that the transformation is not only driven by changes of concentration of species, such impurities and alloying elements, but mechanical stresses can per se promote the precipitation of a second phase (Birnbaum 1984;Allen 1978;Varias and Massih 2002).…”

Section: Introductionmentioning

confidence: 99%

Phase structural ordering kinetics of second-phase formation in the vicinity of a crack

Nigro

¹

,

Bjerkén

²

,

Olsson

³

2017

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The formation of a second phase in presence of a crack in a crystalline material is modelled and studied for different prevailing conditions in order to predict and a posteriori prevent failure, e.g. by delayed hydride cracking. To this end, the phase field formulation of Ginzburg-Landau is selected to describe the phase transformation, and simulations using the finite volume method are performed for a wide range of material properties. A sixth order Landau potential for a single structural order parameter is adopted because it allows the modeling of both first and second order transitions and its corresponding phase diagram can be outlined analytically. The elastic stress field induced by the crack is found to cause a space-dependent shift in the transition temperature, which promotes a second-phase precipitation in vicinity of the crack tip. The spatiotemporal evolution during nucleation and growth is successfully monitored for different combinations of material properties and applied loads. Results for the second-phase shape and size evolution are presented and discussed for a number of selected characteristic cases. The numerical results at steady state are compared to mean-field equilibrium solutions and a good agreement is achieved. For materials applicable to the model, the results can be used to predict the evolution of an eventual second-phase formation through a dimen-

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“…For some metals, including zirconium and titanium, such formation has been specifically observed in the vicinity of stress concentrators, following the increased hydrogen transport toward regions of high hydrostatic stresses (Birnbaum 1976;Takano and Suzuki 1974;Grossbeck and Birnbaum 1977;Shih et al 1988;Cann and Sexton 1980). It is also known that the transformation is not only driven by changes of concentration of species, such impurities and alloying elements, but mechanical stresses can per se promote the precipitation of a second phase (Birnbaum 1984;Allen 1978;Varias and Massih 2002).…”

Section: Introductionmentioning

confidence: 99%

Molecular dynamics simulations of liquid crystalline phases of dodecyltrimethylammonium chloride

Kocherbitov

¹

2015

Journal of Molecular Liquids

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The formation of a second phase in presence of a crack in a crystalline material is modelled and studied for different prevailing conditions in order to predict and a posteriori prevent failure, e.g. by delayed hydride cracking. To this end, the phase field formulation of Ginzburg-Landau is selected to describe the phase transformation, and simulations using the finite volume method are performed for a wide range of material properties. A sixth order Landau potential for a single structural order parameter is adopted because it allows the modeling of both first and second order transitions and its corresponding phase diagram can be outlined analytically. The elastic stress field induced by the crack is found to cause a space-dependent shift in the transition temperature, which promotes a second-phase precipitation in vicinity of the crack tip. The spatiotemporal evolution during nucleation and growth is successfully monitored for different combinations of material properties and applied loads. Results for the second-phase shape and size evolution are presented and discussed for a number of selected characteristic cases. The numerical results at steady state are compared to mean-field equilibrium solutions and a good agreement is achieved. For materials applicable to the model, the results can be used to predict the evolution of an eventual second-phase formation through a dimen-

show abstract

“…Zirconium hydride precipitation is complex and governed by factors including, but not limited to, hydrogen concentration, cooling rate, microstructure and secondary phases that result in d-and/ or c-hydride, with other phases known to form at high H concentration [3][4][5][6]. One aspect of zirconium hydride formation that is unclear is the accommodation of the volumetric strain associated with the hydride precipitation.…”

Section: Introductionmentioning

confidence: 99%

Evaluating zirconium–zirconium hydride interfacial strains by nano-beam electron diffraction

Barrow

¹

,

Korinek

²

,

Daymond

³

2013

Journal of Nuclear Materials

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An electron optical study of hydride precipitation and growth at crack tips in zirconium

Cited by 68 publications

References 18 publications

Phase structural ordering kinetics of second-phase formation in the vicinity of a crack

Phase structural ordering kinetics of second-phase formation in the vicinity of a crack

Molecular dynamics simulations of liquid crystalline phases of dodecyltrimethylammonium chloride

Evaluating zirconium–zirconium hydride interfacial strains by nano-beam electron diffraction

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