Gas-bubble superlattice formation in bcc metals

Johnson, P.B.; Mazey, D.J.

doi:10.1016/0022-3115(94)00674-1

Cited by 81 publications

(52 citation statements)

References 26 publications

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“…Figure 2 shows post irradiation two-beam bright field (BF) imaging of the dislocation loops after 3 DPA with the circled loops generating contrast when g = 1 ̅ 10 and 020 were excited but no contrast when g = 121 ̅ is excited, indicating they have a Burgers vector of b = ±1/2 [1 ̅ 11]. He bubbles with a diameter of around 1.5 nm were observed to form a bubble lattice (Figure 3) which has been observed previously in W under He + irradiation at similar temperatures [19]. Increasing the irradiation temperature to 750°C revealed a largely different microstructure.…”

Section: Damage Microstructure With a He Apppm/dpa Ratio ~2000supporting

confidence: 73%

Effect of He-appm/DPA ratio on the damage microstructure of tungsten

Harrison¹,

Amari²,

Greaves³

et al. 2016

MRS Advances

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In-situ ion irradiation and transmission electron microscopy has been used to examine the effects of the He appm to DPA ratio, temperature and dose on the damage structure of tungsten (W). Irradiations were performed with 15 or 60 keV He + ions, achieving He-appm/displacements per atom (DPA) ratios of ~40,000 and ~2000, respectively, at temperatures between 500 and 1000°C to a dose of ~3 DPA. A high number of small dislocation loops with sizes around 5-20 nm and a He bubble lattice were observed for both He-appm/DPA ratios at 500°C with a bubble size ~1.5 nm. Using the g.b=0 criterion the loops were characterised as b = ±1/2<111> type. At 750°C bubbles do not form an ordered array and are larger in size compared to the irradiations at 500°C, with a diameter of ~3 nm. Fewer dislocation loops were observed at this temperature and were also characterised to be b = ±1/2<111> type. At 1000°C, no dislocation loops were observed and bubbles grew as a function of fluence attributed to vacancy mobility being higher and vacancy clusters becoming mobile.

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Section: Damage Microstructure With a He Apppm/dpa Ratio ~2000supporting

confidence: 73%

Effect of He-appm/DPA ratio on the damage microstructure of tungsten

Harrison¹,

Amari²,

Greaves³

et al. 2016

MRS Advances

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show abstract

“…In particular, it is well known that He implanted in tungsten does not release until high temperatures due to strong interaction with lattice defects [1]. He drastically enhances the formation of bubbles due to the strong bonding to vacancies and their clusters [2][3][4][5][6][7]. As a result, local swelling and degradation of mechanical properties of bulk materials takes place as well [8].…”

Section: Introductionmentioning

confidence: 99%

Synergistic effects of high heat loading and helium irradiation of tungsten

Tokunaga

Tamura

Yoshida

et al. 2004

Journal of Nuclear Materials

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“…The precipitation of γ-hydride in zirconium generates three possible equivalent orientation variants with an angle of 120°between each other. The non-zero components of the stressfree transformation strain tensor for the hydride formation are along [0 0 0 1], [11][12][13][14][15][16][17][18][19][20], and directions, respectively. In the simulations, the interfacial energy was assumed to be isotropic.…”

Section: Simulations Of Different Phenomena In Radiation-induced Micrmentioning

confidence: 99%

A review: applications of the phase field method in predicting microstructure and property evolution of irradiated nuclear materials

Sun

et al. 2017

npj Comput Mater

127

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Complex microstructure changes occur in nuclear fuel and structural materials due to the extreme environments of intense irradiation and high temperature. This paper evaluates the role of the phase field method in predicting the microstructure evolution of irradiated nuclear materials and the impact on their mechanical, thermal, and magnetic properties. The paper starts with an overview of the important physical mechanisms of defect evolution and the significant gaps in simulating microstructure evolution in irradiated nuclear materials. Then, the phase field method is introduced as a powerful and predictive tool and its applications to microstructure and property evolution in irradiated nuclear materials are reviewed. The review shows that (1) Phase field models can correctly describe important phenomena such as spatial-dependent generation, migration, and recombination of defects, radiation-induced dissolution, the Soret effect, strong interfacial energy anisotropy, and elastic interaction; (2) The phase field method can qualitatively and quantitatively simulate two-dimensional and three-dimensional microstructure evolution, including radiation-induced segregation, second phase nucleation, void migration, void and gas bubble superlattice formation, interstitial loop evolution, hydrate formation, and grain growth, and (3) The Phase field method correctly predicts the relationships between microstructures and properties. The final section is dedicated to a discussion of the strengths and limitations of the phase field method, as applied to irradiation effects in nuclear materials. npj Computational Materials (2017) 3:16 ; doi:10.1038/s41524-017-0018-y INTRODUCTIONHigh energy particle (such as neutron, ion, and electron) radiation can create major changes in the shape and thermo-mechanical properties of nuclear fuels and structural components of nuclear reactors. These changes are caused by radiation-induced evolution of compositions and microstructures. The main effects of radiation on reactor materials are: (1) dimensional change associated with gas bubble swelling, void swelling, grain growth, and creep; 1-5 (2) loss of ductility and increase in ductile-brittle transition temperature (DBTT) due to the formation of secondphase precipitates, self-interstitial atomic (SIA) loops, and dislocation networks; 6, 7 (3) oxidation and corrosion accelerated by high temperature, fission products, and radiation damage; 8-10 and (4) local and bulk changes in chemical composition, including irradiation-enhanced segregation of alloy components and phase separation.11-17 Figure 1 shows typical microstructures observed in irradiated materials.9, 18-21 The radiation-induced heterogeneity of the microstructures depends on the initial phase and defect structure of the fresh (non-irradiated) materials and on the type and severity of the radiation environment. Fundamental understanding of heterogeneous three-dimensional microstructure evolution is crucial to the development of advanced radiation tolerant materials that can significa...

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Gas-bubble superlattice formation in bcc metals

Cited by 81 publications

References 26 publications

Effect of He-appm/DPA ratio on the damage microstructure of tungsten

Effect of He-appm/DPA ratio on the damage microstructure of tungsten

Synergistic effects of high heat loading and helium irradiation of tungsten

A review: applications of the phase field method in predicting microstructure and property evolution of irradiated nuclear materials

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