Molecular Dynamics Simulation of Creep Mechanism in Nanocrystalline α-Zirconium Under Various Conditions

doi:10.11900/0412.1961.2022.00444

IMR OpenIR

	Molecular Dynamics Simulation of Creep Mechanism in Nanocrystalline α-Zirconium Under Various Conditions
	Meng Zikai 1,2; Meng Zhichao 1,2; Gao Changyuan 3; Guo Hui 1,2; Chen Hansen 3; Chen Liutao 3; Xu Dongsheng 1,2; Yang Rui 1,2
通讯作者	Xu Dongsheng(dsxu@imr.ac.cn)
	2024-05-01
发表期刊	ACTA METALLURGICA SINICA
ISSN	0412-1961
卷号	60 期号:5 页码:699-712
摘要	Zirconium alloys have been widely used because of their good mechanical properties, corrosion resistance, and suitable neutron absorption cross section. However, with the development of engineering technology, the requirements on the service performance, safety, and microstructure stability of zirconium structural materials are increasingly high. Creep refers to the phenomenon where the strain of the material increases with time under the action of stress lower than the yield strength, which will lead to the deformation of the structural material and eventually its failure. It is also an important problem faced by zirconium cladding materials in nuclear reactors. Nanocrystalline zirconium is a strengthening and toughening method, which may also improve other properties of nuclear materials. However, there are very few investigations on the microscopic creep mechanism in the atomic scale of nanocrystalline zirconium. Improving the creep resistance of zirconium materials plays an important role in the safety of components. Therefore, studying the creep behavior of nanocrystalline zirconium and its atomic mechanism is conducive to its better application in industries. In this study, the tensile creep behavior of nanocrystalline alpha-Zr under different conditions was investigated via molecular dynamics simulation. The main influencing factors of the creep process were analyzed and the influence of polycrystalline structure evolution and deformation mechanism during the steady-state creep process was studied. The effect of irradiation on the creep process was preliminarily explored. Results showed that temperature, stress, irradiation, and grain size affect the creep behavior of nanocrystalline alpha-Zr. Increasing the temperature and stress level and refining the grains can promote the creep process. The microstructure of the system changed significantly after the creep. Some grains grew up with the creep deformation process, while others gradually shrank, or even disappeared. During deformation, the lattice distortion gradually propagated from the grain boundary to the grains, partly reducing the degree of the hcp order. Simulation results showed that grain boundary migration is the main deformation mechanism of nanocrystalline alpha-Zr during steady-state creep. Increasing the temperature and stress level will thicken the grain boundary and promote the microstructure evolution. After the cascade collision due to neutrons of different energy levels, a large number of point defects were produced in the system and their diffusion contributed to the creep; these defects were finally collected at the grain boundary, improving the grain boundary mobility. Increasing the irradiation energy can increase the number and size of irradiation defects, promoting the creep process of the nanocrystalline system.
关键词	nanocrystalline alpha-Zr molecular dynamics structural evolution creep mechanism
DOI	10.11900/0412.1961.2022.00444
收录类别	SCI
语种	英语
WOS研究方向	Metallurgy & Metallurgical Engineering
WOS类目	Metallurgy & Metallurgical Engineering
WOS记录号	WOS:001208805900012
出版者	SCIENCE PRESS
引用统计
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/185777
专题	中国科学院金属研究所
通讯作者	Xu Dongsheng
作者单位	1.Chinese Acad Sci, Inst Met Res, Shenyang 110016, Peoples R China 2.Univ Sci & Technol China, Sch Mat Sci & Engn, Shenyang 110016, Peoples R China 3.China Nucl Power Technol Res Inst Co Ltd, Shenzhen 518031, Peoples R China
推荐引用方式 GB/T 7714	Meng Zikai,Meng Zhichao,Gao Changyuan,et al. Molecular Dynamics Simulation of Creep Mechanism in Nanocrystalline α-Zirconium Under Various Conditions[J]. ACTA METALLURGICA SINICA,2024,60(5):699-712.
APA	Meng Zikai.,Meng Zhichao.,Gao Changyuan.,Guo Hui.,Chen Hansen.,...&Yang Rui.(2024).Molecular Dynamics Simulation of Creep Mechanism in Nanocrystalline α-Zirconium Under Various Conditions.ACTA METALLURGICA SINICA,60(5),699-712.
MLA	Meng Zikai,et al."Molecular Dynamics Simulation of Creep Mechanism in Nanocrystalline α-Zirconium Under Various Conditions".ACTA METALLURGICA SINICA 60.5(2024):699-712.