Electron microscope image contrast from small dislocation loops. IV. Application of theoretical predictions for non-edge loops to defect analysis in irradiated molybdenum

English, C.A.; Eyre, B.L.; Holmes, S. M.

doi:10.1088/0305-4608/10/6/007

Cited by 19 publications

(4 citation statements)

References 6 publications

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“…It should be noted that a 0 100 loops are more frequently observed in Fe relative to other bcc metals. They were observed in Mo [28]. Using, for example, the inside-outside contrast technique in TEM, the a 0 100 loops reveals an interstitial nature [26].…”

Section: Microstructurementioning

confidence: 99%

Helium and point defect accumulation: (i) microstructure and mechanical behaviour

Schäublin

Henry

Dai

2008

Comptes Rendus. Physique

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Ferritic/martensitic (F/M) steels are good candidate structural materials for the future fusion reactors and spallation sources. However, irradiation of steels is known to produce hardening, loss of ductility, shift in ductile to brittle transition temperature (DBTT) and reduction of fracture toughness and creep resistance starting at low doses. Helium (He), produced by transmutation during the irradiation, also impacts mechanical properties. Numerous experimental and theoretical studies on the evolution of the microstructure of steels under irradiation have been conducted until now. We review the effect of irradiation-induced point defects and in particular of He on the mechanical properties of F/M steels.

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Section: Microstructurementioning

confidence: 99%

Helium and point defect accumulation: (i) microstructure and mechanical behaviour

Schäublin

Henry

Dai

2008

Comptes Rendus. Physique

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“…A nucleation model for ah1 0 0i and a/2h1 1 1i dislocation loops in bcc metals has been proposed by Eyre and Bullough [18] based on shearing of initially formed a/2h1 1 0i dislocation loops. TEM observations on irradiated molybdenum and tungsten have provided direct evidence that both interstitial and vacancy loops are nucleated on {1 1 0} planes consistent with the Eyre-Bullough model although in these cases all loops shear to the expected a/2h1 1 1i Burgers vector [19,20]. However, the formation of the ah1 0 0i dislocation loops requires a higher energy shear in the EyreBullough mechanism.…”

Section: Resultsmentioning

confidence: 94%

Characterization of defect clusters in ion-irradiated A533B steel

Fujii¹,

Fukuya²

2005

Journal of Nuclear Materials

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“…Details of loop characterization (type, Burgers vector, etc.) in irradiated bcc bulk metals can be referred to Refs [39][40][41]. The irradiation-induced dislocation loops show clear image contrast in irradiated CG Mo (Fig.…”

Section: O M / L O C a T E / S C R I P T A M A Tmentioning

confidence: 99%

Grain size effect on radiation tolerance of nanocrystalline Mo

Cheng

Wang

et al. 2016

Scripta Materialia

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We report a significant grain size effect on radiation tolerance of nanocrystalline Mo under He ion irradiation. Irradiation-induced dislocation loops mainly contribute to the irradiation-induced hardening of Mo films with grain size of N90 nm, while few such loops in those with grain size of b90 nm. The hardness increment after irradiation decreases with decreasing the grain size, and approaches zero at the grain size of 25 nm. Also, the size and the density of irradiation-induced He bubbles decrease as the grain size decreases. This observation provides direct evidence that nanocrystalline body-centered-cubic metals have greater radiation tolerance than their ultra-fine-grained or coarse-grained counterparts.Published by Elsevier Ltd. Keywords:Radiation damage Body-centered cubic (bcc) Nanocrystalline Grain size effect Magnetron sputtering Radiation damage is one of the critical issues for developing advanced materials used in next generation nuclear plants [1-8] and spacecrafts [9]. Hardening, swelling, embrittlement and creep are some of the critical issues associated with radiation damage. Irradiation can induce interstitials, vacancies or He bubbles in microstructure, which will further agglomerate to form loops, interstitial or vacancy clusters and voids in materials [10,11]. Formation of voids will lead to swelling and embrittlement, which are the main cause of material failure under irradiation environment [12]. Therefore, how to control the generation of irradiation-induced defects and mitigate the negative effects of He bubbles is the key to design advanced radiation tolerant materials with a balance of mechanical and thermal properties [2,13].Body-centered cubic (bcc) metals and alloys have attracted much attention in the past decade due to their reduced-activation under irradiation environment [14][15][16][17][18]. The studies on the oxide-dispersion strengthened (ODS) ferrite steels [19][20][21][22] have showed great radiation tolerance since dispersed nanoparticles in the matrix increase the volume fraction of the interfaces which can act as sinks for irradiation-induced defects, especially for He bubbles.Similarly, nanocrystalline (NC) materials exhibit great potential for such applications because a large fraction of grain and interphase boundaries can act as effective sinks for irradiation-induced vacancies and bubbles [2,6,23,24]. Refining the grains of materials into nanometer size can significantly alter the physical, chemical and mechanical behaviors of the materials [25][26][27][28][29][30][31]. Previous reports [32-35] on fcc/bcc nanolayered composites have showed extreme tolerance to He bubbles, which are prone to segregate at interphase boundaries. Bulk NC metals have also displayed extraordinary radiation healing behavior due to grain boundary (GB) accommodation of defects [36][37][38].Although there are many reports about the radiation damage on NC metals and alloys, it remains elusive about how the change of grain size affects the radiation tolerance. To explore this issue, here we in...

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Electron microscope image contrast from small dislocation loops. IV. Application of theoretical predictions for non-edge loops to defect analysis in irradiated molybdenum

Cited by 19 publications

References 6 publications

Helium and point defect accumulation: (i) microstructure and mechanical behaviour

Helium and point defect accumulation: (i) microstructure and mechanical behaviour

Characterization of defect clusters in ion-irradiated A533B steel

Grain size effect on radiation tolerance of nanocrystalline Mo

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