Response of 14YWT alloys under neutron irradiation: A complementary study on microstructure and mechanical properties

Date

2019-04-01

Author

Aydoğan Güngör, Eda
Carvajal-Nunez, U.
Schneider, M. M.
Gigax, J. G.
Krumwiede, D. L.
Hosemann, P.
Saleh, T. A.
Mara, N. A.
Hoelzer, D. T.
Hilton, B.
Maloy, S. A.

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

140
views

0
downloads

Nanostructured ferritic alloys (NFAs) having sub-micron grain size with a high density of nano-oxides (NOs) (size of similar to 2-3 nm) are one of the best candidates for structural components in Generation IV nuclear systems. In this study, 14YWT NFA cladding tubes were irradiated in BOR60 reactor up to 7 dpa at 360-370 degrees C. Detailed microstructural analysis has been conducted using bright field transmission electron microscopy, bright field scanning transmission electron microscopy, energy filtered transmission electron microscopy, energy dispersive X-ray spectroscopy, electron energy loss spectroscopy and transmission Kikuchi diffraction techniques. This revealed cavities, and type dislocation loops, and alpha' precipitates forming after irradiation with relationships between cavities and NOs, and alpha' precipitates and NOs. Cavities mostly form on the NOs; whereas, alpha' precipitates form between the NOs where the point defect concentration is high. Moreover, alpha' precipitates are distributed homogenously on and around the dislocation loops which is consistent with the observation that there is no Cr segregation on dislocation loops. Grain boundaries were found to be mostly depleted in Cr; however, the characteristics of each grain boundary determines the Cr behavior and the alpha' denuded zone around the grain boundaries. Mechanical properties of the irradiated tubes have been determined by using both low force and high force nanoindentation techniques, resulting in 1.03 +/- 0.33 GPa and 0.82 +/- 0.20 GPa hardening, respectively. Dispersed barrier hardening calculations and nanoindentation measurements are in good agreement. In this study, 14YWT NFA has been systematically studied after neutron irradiation to better understand its superior performance: low alpha' concentration, low swelling and low radiation-induced hardening. (C) 2019 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Subject Keywords

Electronic, Optical and Magnetic Materials, Polymers and Plastics, Metals and Alloys, Ceramics and Composites

URI

https://hdl.handle.net/11511/69926

Journal

ACTA MATERIALIA

DOI

https://doi.org/10.1016/j.actamat.2019.01.041

Collections

Department of Metallurgical and Materials Engineering, Article

Suggestions

OpenMETU
Core

Nano-scale phase separation in amorphous Fe-B alloys: Atomic and cluster ordering AYKOL, Muratahan; Mehrabov, Amdulla; Akdeniz, Mahmut Vedat (Elsevier BV, 2009-01-01) Nano-scale phase separation encountered in metallic glasses is investigated for amorphous Fe80B20 and Fe83B17 alloys in an interaction field calculated via electronic theory of alloys in pseudopotential approximation combined with MC equilibration and reverse MC simulation. The phenomenon is identified regarding three topological aspects: (1) pure Fe-clusters as large as similar to 0.9 nm and pure Fe-contours similar to 0.72 nm thick are found to exist; (2) Fe-rich highly deformed-bcc regions are observed; ...
Comparison of Natural Halloysite With Synthetic Carbon Nanotubes in Poly(lactic acid) Based Composites Erpek, Canan Esma Yeniova; ÖZKOÇ, GÜRALP; Yılmazer, Ülkü (Wiley, 2017-11-01) The objective of this study is to compare the mechanical properties, structure and degradability of the nanocomposites prepared with tubular nanofillers, halloysite (HNT) and carbon nanotube (CNT) in poly(lactic acid) (PLA), and thermoplastic polyurethane (TPU) toughened PLA (T-PLA) matrices. In the PLA matrix, CNT increased, whereas HNT decreased the tensile strength with increasing filler content. Also, the elongation at break and impact strength decreased with increasing CNT content, but these properties...
Theoretical prediction of bulk glass forming ability (BGFA) of Ti-Cu based multicomponent alloys SUER, Sila; Mehrabov, Amdulla; Akdeniz, Mahmut Vedat (Elsevier BV, 2009-03-01) The bulk glass forming ability (BGFA) of Ti-Cu based multicomponent alloys has been evaluated via theoretical modeling and computer simulation studies based on a combination of electronic theory of alloys in the pseudopotential approximation and the statistical thermodynamical theory of liquid alloys The. magnitude of atomic ordering energies, calculated by means of the electronic theory of alloys in the pseudopotential approximation, was subsequently used for calculation of the key thermodynamic parameters...
Unprecedented irradiation resistance of nanocrystalline tungsten with equiaxed nanocrystalline grains to dislocation loop accumulation El-Atwani, O.; Esquivel, E.; Aydoğan Güngör, Eda; Martinez, E.; Baldwin, J. K.; Li, M.; Uberuaga, B. P.; Maloy, S. A. (Elsevier BV, 2019-02-01) Nanocrystalline metals are often postulated as irradiation tolerant materials due to higher grain boundary densities. The efficiency of these materials in mitigating irradiation damage is still under investigation. Here, we present an in-situ transmission electron microscopy with ion irradiation study on equiaxed 35 nm grained tungsten (NCW-35 nm) and compare its radiation tolerance, in terms of dislocation loop damage, to several other grades of tungsten with different grain sizes at two temperatures (RT a...
Loop and void damage during heavy ion irradiation on nanocrystalline and coarse grained tungsten: Microstructure, effect of dpa rate, temperature, and grain size El-Atwani, O.; Esquivel, E.; Efe, Mert; Aydogan, E.; Wang, Y. Q.; Martinez, E.; Maloy, S. A. (Elsevier BV, 2018-05-01) Displacement damage, through heavy ion irradiation was studied on two tungsten grades (coarse grained tungsten (CGW) and nanocrystalline and ultrafine grained tungsten (NCW)) using different displacement per atom rates and different irradiation temperatures (RT and 1050 K). Percentage of <111> and <100> type loops at the irradiation conditions was determined. Irradiation damage in the microstructure was quantified using average loop areas and densities (method A) and loop areal fraction in the grain matrice...

Citation Formats

E. Aydoğan Güngör et al., “Response of 14YWT alloys under neutron irradiation: A complementary study on microstructure and mechanical properties,” ACTA MATERIALIA, pp. 181–196, 2019, Accessed: 00, 2021. [Online]. Available: https://hdl.handle.net/11511/69926.