Coupled effect of Cr and Al on interactions between a prismatic interstitial dislocation loop and an edge dislocation line in Fe-Cr-Al alloy
- Shandong Univ., Qingdao, Shandong (China)
- Shandong Univ., Qingdao, Shandong (China); Jilin Univ., Changchun (China)
- Xi'an High Technology Research Center, Xi'an (China)
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
- Harbin University of Technology (China)
- Shandong Univ., Qingdao, Shandong (China); Chinese Academy of Sciences (CAS), Lanzhou (China)
- Univ. of Michigan, Ann Arbor, MI (United States)
Segregation of alloying elements to a prismatic dislocation loop under irradiation is an important phenomenon in understanding the role of loops in radiation effects in alloys. In this work, various segregation sequences of Cr and Al atoms to a $$\langle$$100$$\rangle$$ and a 1/2 $$\langle$$111$$\rangle$$ prismatic dislocation loop in a Fe-Cr-Al alloy are explored using molecular dynamics method and ab initio energy calculation. Here, the results reveal that Cr can readily segregate to the loops while Al atoms cannot by themselves, but the segregated Cr atoms are able to promote Al segregation at the loops, defined as a coupled segregation of Cr and Al. After interacting with Cr and Al, a previously mobile 1/2 $$\langle$$111$$\rangle$$ loop becomes sessile. Al segregation through the coupled segregation process can further affect the pinning behavior of a dislocation loop to an edge dislocation motion. By varying the Al fraction in the segregated solutes, a nonlinear dependence of the pinning effect on dislocation motion is determined. At lower fractions, the pinning strength increases with the increasing Al fraction until Al fraction reaches a critical value of about 19%, above which the pinning strength decreases with further increase of Al fraction. All these results suggest that, in addition to the effect of Al on the surface resistance to oxidation, Al effect on the dislocation loop behavior is important to optimize the composition of Fe-Cr-Al alloys for their applications in accident tolerant fuel concepts.
- Research Organization:
- Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Fusion Energy Sciences (FES); National Natural Science Foundation of China (NSFC)
- Grant/Contract Number:
- AC05-76RL01830; 12075141; 12105159; 12175125; AC05–76RLO-1830
- OSTI ID:
- 1963909
- Alternate ID(s):
- OSTI ID: 1907303
- Report Number(s):
- PNNL-SA-174761
- Journal Information:
- Acta Materialia, Vol. 245; ISSN 1359-6454
- Publisher:
- ElsevierCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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