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Results for “Microstructural evolution”
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Creep lifetime and microstructure evolution in boron-added 9Cr–1Mo heat-resistant steel
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Microstructure evolution of alloy 709 during static-aging and creep-fatigue testing
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Combined effects of grain size and strain-rate on the microstructural evolution and twinning in metastable β phase Ti-15Mo (wt.%) under dynamic compression
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In situ study on heavy ion irradiation induced microstructure evolution in single crystal Cu with nanovoids at elevated temperature
Understanding the response of nanovoids to irradiation damage advances our capability to design radiation tolerant materials. Recent in situ studies reveal the shrinkage of hexagon-shaped nanovoids in (110) textured Cu. However, the evolution of voids with irregular geometries under irradiation is less well understood. Here, in situ Kr ion irradiation was performed at 100 °C on single-crystal Cu (112) that possesses nanovoids with high aspect ratio. In situ studies show these elongated voids fragment into smaller voids and shrink gradually with increasing dose. Phase field simulations confirm that fragmentation of the void is governed by the competing kinetics between atoms diffusing toward and away from the elongated nanovoid. In conclusion, cost irradiation analysis reveals the formation of high-density defect clusters.
In-situ TEM study of microstructural evolution in NFA and Cr 3 C 2 @SiC-NFA composite during ion irradiation
In this article, the ion irradiation responses of a Fe-based nanostructured ferritic alloy or ‘NFA’ (Fe–9Cr–2W–0.2V–0.4Ti–0.3Y 2 O 3 ) and a Cr 3 C 2 @SiC-NFA composite were assessed. In-situ ion irradiation with TEM observation was carried out by using 1 MeV Kr ++ ions at doses of 0, 1, 3, 5, 10 dpa and temperatures of 300 °C and 450 °C. Both the NFA and Cr 3 C 2 @SiC-NFA samples showed significant dislocation density after 10 dpa at 300 °C. However, the Cr 3 C 2 @SiC-NFA composite showed a significantly lower dislocation loop density and a smaller average loop size during the irradiation at 450 °C as opposed to the NFA. At 300 °C, 1/2<111> type dislocation loops were observed in both the NFA and Cr 3 C 2 @SiC-NFA samples. Interestingly, at 450 °C, <100> type loops were dominant in the NFA sample while 1/2<111> type loops were still dominant in the Cr 3 C 2 @SiC-NFA sample. The results were discussed based on the large surface sink effects and enhanced interstitial-vacancy recombination at higher temperatures. Lastly, the additional Si element in the Cr 3 C 2 @SiC-NFA sample might have played a significant role in determining the dominant loop types.
Comparison of microstructure evolution in Fe2+ or neutron-irradiated T91 at 500°C
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Sensitivity of UO 2 fuel performance to microstructural evolutions driven by dilute additives
Use of dilute additives to nuclear fuel is being considered to increase the security of commercial fuel management through traceability of fabricated fuel elements. Taggants, as additives are denoted when included for traceability purposes, may also improve fuel performance, as demonstrated in Cr-containing uranium dioxide as described in the literature, and they may also improve fuel safety. In fact, studies have shown that some additives affect fuel material properties such as grain size and density after sintering. Given the possible range of elements that could be used as additives, the impact of such fuel property variations on the fuel’s thermomechanical behavior becomes relevant. These effects can be evaluated through a sensitivity study of standard fuel models to analyze changes in these properties using a fuel performance code. In this work, the BISON code is being used to investigate these effects through a 2D axisymmetric model of smeared UO 2 fuel pellets and ZIRLO® cladding under realistic pressurized water reactor core irradiation conditions. Here, randomly sampled densities and grain sizes within specified ranges are used as input parameters in the simulations, and several fuel model-related outputs are evaluated. The thermomechanical response of the cladding is also addressed in this study. The simultaneous variation of both input parameters offers a more comprehensive path to identify key sensitivities. Outputs explored include temperature, fission gas release, creep, and radial stress. Results show that although most of these outputs are sensitive to grain size to a certain extent, density mainly affects fuel temperature and elastic strain. Furthermore, sensitivities can vary depending on the radial position within the fuel pellet.
Microstructure evolution during laser direct energy deposition of a novel Fe-Cr-Ni-W-B hardfacing coating
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Microstructure Evolution of Low Carbon Steel via Flash Processing
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Electrochemical Characterization and Microstructure Evolution of Ni-Rich Layered Cathode Materials by Niobium Coating/Substitution
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