Point defect evolution in Ni, NiFe and NiCr alloys from atomistic simulations and irradiation experiments
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials and Technology Div.
- Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Nuclear Engineering and Radiological Sciences
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials and Technology Div.; Univ. of Tennessee, Knoxville, TN (United States). Materials Science and Engineering
Using molecular dynamics simulations, we elucidate irradiation-induced point defect evolution in fcc pure Ni, Ni0.5Fe0.5, and Ni0.8Cr0.2 solid solution alloys. We find that irradiation-induced interstitials form dislocation loops that are of 1/3 <111>{111}-type, consistent with our experimental results. While the loops are formed in all the three materials, the kinetics of formation is considerably slower in NiFe and NiCr than in pure Ni, indicating that defect migration barriers and extended defect formation energies could be higher in the alloys than pure Ni. As a result, while larger size clusters are formed in pure Ni, smaller and more clusters are observed in the alloys. The vacancy diffusion occurs at relatively higher temperatures than interstitials, and their clustering leads to formation of stacking fault tetrahedra, also consistent with our experiments. The results also show that the surviving Frenkel pairs are composition-dependent and are largely Ni dominated.
- Research Organization:
- Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); Energy Frontier Research Centers (EFRC) (United States). Energy Dissipation to Defect Evolution (EDDE)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- Grant/Contract Number:
- AC05-00OR22725; AC02-05CH11231
- OSTI ID:
- 1209216
- Alternate ID(s):
- OSTI ID: 1251431
- Journal Information:
- Acta Materialia, Vol. 99; Related Information: EDDE partners with Oak Ridge National Laboratory (lead); Lawrence Livermore National Laboratory; University of Michigan; University of Tennessee; University of Wisconsin; University of Wyoming; Virginia Tech; ISSN 1359-6454
- Publisher:
- ElsevierCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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