Atomic-scale investigation of creep behavior and deformation mechanism in nanocrystalline FeCrAl alloys

Yao, Huan; Ye, Tianzhou; Yu, Wenshan; Wang, Pengfei; Wu, Junmei; Wu, Yingwei; Ping, Chen

doi:10.1016/j.matdes.2021.109766

Cited by 14 publications

(4 citation statements)

References 59 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The improvement of Zr on the creep properties of ODS FeCrAl alloys has also been verified in Kamikawa's research [73]. In Yao's simulation of the creep behavior of FeCrAl alloy based on molecular dynamics [74], it was also observed that the steady-state creep rate increased with the increase of Cr and Al content, as shown in Figure 7. The creep mechanism also transitions from diffusion creep under low stress to dislocation creep and grain boundary sliding under high stress.…”

Section: Thermal Creep Propertiesmentioning

confidence: 54%

Recent Progress on Creep Properties of ODS FeCrAl Alloys for Advanced Reactors

Jia

Wang

et al. 2023

Materials

View full text Add to dashboard Cite

In order to meet the growing energy demand, more environmentally friendly and efficient GEN-IV reactors have emerged. Additionally, nuclear structural materials need larger more safety margins for accident scenarios as a result of the Fukushima accident. In order to extend the failure time and lessen the effect of accidents, this design method for accident-tolerant fuel materials calls for cladding materials to maintain good corrosion resistance and mechanical properties during a beyond design basis accident (BDBA). Accidents involving nuclear reactors would undoubtedly result in higher temperatures, which would make it much harder for materials to withstand corrosion. Oxide dispersion strengthened (ODS) FeCrAl alloys have shown promise as candidate materials because of their extraordinarily slow reaction rates under high-temperature steam. However, the addition of the Al element renders the alloy’s high-temperature mechanical properties insufficient. In particular, studies on the alloy’s creep properties are extremely rare, despite the fact that the creep properties are crucial in the real service environment. Therefore, this paper focuses on the creep properties of ODS FeCrAl alloy, summarizes and analyzes the research results of this material, and provides a reference for future research and applications.

show abstract

Section: Thermal Creep Propertiesmentioning

confidence: 54%

Recent Progress on Creep Properties of ODS FeCrAl Alloys for Advanced Reactors

Jia

Wang

et al. 2023

Materials

View full text Add to dashboard Cite

show abstract

“…Although MD simulation suffers from the limitation of the relatively short time scale and insufficient model size, EAM potential can still be successfully applied to the simulation of vacancy and dislocation activity in metals [16,17], and the characteristics of the obtained creep curve are the same as the three stages of actual creep: initial creep, stable creep, and accelerated creep [18][19][20][21][22]. In addition, the deformation mechanism has also been noted to be consistent with the actual high-temperature creep mechanism [23][24][25]. Pure crystalline Ni, which possesses a face-centered cubic (FCC) crystal structure and has strong solid solution ability [26][27][28], is a typical material to explore the creep deformation mechanism of nanocrystalline metals.…”

Section: Introductionmentioning

confidence: 84%

Initial Vacancy-Dependent High-Temperature Creep Behavior of Nanocrystalline Ni by Molecular Dynamics Simulation

Cui,

Shao,

Shi

et al. 2024

Coatings

View full text Add to dashboard Cite

Nanocrystalline metals possessing excellent mechanical strength have great potential to replace traditional metal materials as structural materials, but their poor resistance to creep deformation seriously restricts their engineering applications at high temperatures. The high-temperature creep behavior of nanocrystalline Ni with different volume fractions of initial vacancies ranging from 0% to 10% was studied systematically by molecular dynamics simulation in this study. The results showed that the steady-state creep displacement first increased and then decreased with increasing initial vacancy concentration, reaching the maximum when the initial vacancy concentration was 6%. The microstructural characteristics, such as quantity increment and distribution of the vacancies, the number and types of dislocations, and shear strain distribution during creeping, were analyzed in detail. The deformation-induced vacancies formed at the grain boundary (GB) in the initial creep stage, and their variation trend with the initial vacancy concentration was consistent with that of the creep displacement, indicating that the initial vacancy-dependent high-temperature creep behavior of nanocrystalline Ni was mainly determined by the rapidly increasing number of vacancies at the GB in the initial creep stage. Afterwards, the deformation-induced, vacancy-assisted 1/6{112} Shockley partial dislocation activities dominated the creep deformation of nanocrystalline Ni in the steady-state creep stage. The results can provide theoretical support for expanding the application of nanocrystalline metals from the perspective of crystal defect engineering.

show abstract

“…The GBs are essential sources and sinks of dislocations and serve as priority channels for atomic diffusion. [33,34] The relationships between yield stress and Young's modulus with grain size in nano-crystalline niobium at 300 K as depicted in Fig. 2, reveals that when the average grain size falls below 11.5 nm, a larger grain size corresponds to superior mechanical properties in nano-polycrystalline niobium.…”

Section: Creep Properties Of Nanopolycrystalline Nbmentioning

confidence: 99%

Influence of temperature, stress, and grain size on behavior of nano-polycrystalline niobium

Yan 晏,

Zhang 张,

zhang 张

et al. 2024

Chinese Phys. B

View full text Add to dashboard Cite

Atomic simulations were executed to investigate the creep responses of nano-polycrystalline (NC) niobium established by employing the Voronoi algorithm. The effects of varying temperature, applied stress, and grain size (GS) on creep properties and mechanisms were investigated. Notably, the occurrence of tertiary creep was exclusively observed under conditions where the applied stress exceeded 4.5 GPa and the temperature surpassed 1100 K. This phenomenon can be attributed to the significant acceleration of grain boundary and lattice diffusion, driven by the elevated temperature and stress levels. It was found that the strain rate increases with an increase in both temperature and stress. However, an interesting trend was observed where the strain rate decreases as the grain size increases. The stress and temperature are crucial parameters governing the creep behavior. As these factors intensify, the creep mechanism undergoes sequential transitions: initially from lattice diffusion under low stress and temperature conditions, subsequently evolving to a mixed mode incorporating both grain boundaries (GBs) and lattice diffusion at moderate stress and temperature levels, and ultimately culminating in a disruption of the power-law controlled creep behavior, inclusive of grain boundary recrystallization for high stress and temperature conditions. This comprehensive analysis provides a deeper understanding of the intricate creep behavior of nano-polycrystalline niobium and its dependence on various physical parameters.

show abstract

Atomic-scale investigation of creep behavior and deformation mechanism in nanocrystalline FeCrAl alloys

Cited by 14 publications

References 59 publications

Recent Progress on Creep Properties of ODS FeCrAl Alloys for Advanced Reactors

Recent Progress on Creep Properties of ODS FeCrAl Alloys for Advanced Reactors

Initial Vacancy-Dependent High-Temperature Creep Behavior of Nanocrystalline Ni by Molecular Dynamics Simulation

Influence of temperature, stress, and grain size on behavior of nano-polycrystalline niobium

Contact Info

Product

Resources

About