Abstract
To investigate irradiation-induced embrittlement, molecular dynamics (MD) simulations were applied to explore helium (He) bubble evolution and deformation of single crystal α-Fe. The results show, at 800 K, formation kinetics of He bubbles are considered for two diffusion regimes due to He concentration: One is long-range diffusion of He atoms (< 0.1 at.%), and the other is short-range diffusion (> 0.1 at.%). In long-range diffusion, dislocations play a significant role on the size and spatial distributions of He clusters. He atoms are easier to segregate on dislocations, and therefore, average size of He clusters is increasing with increasing He concentration. In short-range diffusion, the influence of dislocations is rather weaker. He atoms tend to form He clusters by self-trapping, thus leading to decreasing average size. But, total number is monotonically increasing within the entire range (0–1 at.%). In tensile process, with increasing He concentration, yield stress is monotonically decreasing but plasticity is firstly increasing then decreasing. Especially, at 0.05 and 0.1 at.%, larger He bubbles with discrete distribution enhance deformability and promote dislocation multiply. In addition, for different He distributions, two growth mechanisms of He bubbles can be summarized: One is He bubble–He bubble coalescence, and the other is He bubble–void coalescence.
Similar content being viewed by others
References
Ullmaier H (1984) The influence of helium on the bulk properties of fusion reactor structural materials. Nucl Fusion 24(8):1039
Shi J, Peng L, Ye M, Gao F (2017) Molecular dynamics study: effects of He bubble and Cr precipitate on tensile deformation of grain boundaries in α-Fe. IEEE Trans Plasma Sci 45(2):289–293
Kurtz RJ, Alamo A, Lucon E et al (2009) Recent progress toward development of reduced activation ferritic/martensitic steels for fusion structural applications. J Nucl Mater 386:411–417
Lu Q, van der Zwaag S, Xu W (2017) Charting the ‘composition–strength’ space for novel austenitic, martensitic and ferritic creep resistant steels. J Mater Sci Technol 33:1577–1581
Jitsukawa S, Kimura A, Kohyama A et al (2004) Recent results of the reduced activation ferritic/martensitic steel development. J Nucl Mater 329:39–46
Zhou X, Liu C, Yu L, Liu YC, Li HJ (2015) Phase transformation behavior and microstructural control of high-Cr martensitic/ferritic heat-resistant steels for power and nuclear plants: a review. J Mater Sci Technol 31:235–242
Yamamoto T, Odette GR, Miao P, Edwards DJ, Kurtz RJ (2009) Helium effects on microstructural evolution in tempered martensitic steels: in situ helium implanter studies in HFIR. J Nucl Mater 386:338–341
Stewart D, Osetskiy Y, Stoller R (2011) Atomistic studies of formation and diffusion of helium clusters and bubbles in BCC iron. J Nucl Mater 417:1110–1114
Yang L, Gao F, Kurtz RJ, Zu XT, Peng SM, Long XG, Zhou XS (2015) Effects of local structure on helium bubble growth in bulk and at grain boundaries of bcc iron: a molecular dynamics study. Acta Mater 97:86–93
Chen WY, Miao Y, Gan J, Okuniewski MA, Maloy SA, Stubbins JF (2016) Neutron irradiation effects in Fe and Fe–Cr at 300 °C. Acta Mater 111:407–416
Kacher J, Liu GS, Robertson IM (2012) In situ and tomographic observations of defect free channel formation in ion irradiated stainless steels. Micron 43:1099–1107
Robertson C, Gururaj K (2011) Plastic deformation of ferritic grains in presence of ODS particles and irradiation-induced defect clusters: a 3D dislocation dynamics simulation study. J Nucl Mater 415:167–178
Terentyev D, Bonny G, Domain C, Monnet G, Malerba L (2013) Mechanisms of radiation strengthening in Fe–Cr alloys as revealed by atomistic studies. J Nucl Mater 442:470–485
Terentyev D, Osetsky YN, Bacon DJ (2010) Competing processes in reactions between an edge dislocation and dislocation loops in a body-centred cubic metal. Scripta Mater 62:697–700
Nomoto A, Soneda N, Takahashi A, Ishino S (2005) Interaction analysis between edge dislocation and self interstitial type dislocation loop in BCC iron using molecular dynamics. Mater Trans 46:463–468
Xu Q, Yamasaki H, Sato K, Yoshiie T (2011) Can helium actually improve the mechanical properties of a metal? Philos Mag Lett 91:724–730
Xu Q, Yamasaki H, Sugiura Y, Sato K, Yoshiie T (2013) Effects of interactions between dislocations and/or vacancies and He atoms on mechanical property changes in Ni. Mater Sci Eng, A 586:231–235
Xu Q, Sugiura Y, Pan XQ, Sato K, Yoshiie T (2014) Effects of dislocation-trapped helium on mechanical properties of Fe. Mater Sci Eng, A 612:41–45
Wei YP, Liu PP, Zhu YM, Wang ZQ, Wan FR, Zhan Q (2016) Evaluation of irradiation hardening and microstructure evolution under the synergistic interaction of He and subsequent Fe ions irradiation in CLAM steel. J Alloys Compd 676:481–488
Ge H, Peng L, Dai Y, Huang QY, Ye MY (2016) Tensile properties of CLAM steel irradiated up to 20.1 dPa in STIP-V. J Nucl Mater 468:240–245
Galindo-Nava EI, Basha BIY, Rivera-Díaz-del-Castillo PEJ (2017) Hydrogen transport in metals: integration of permeation, thermal desorption and degassing. J Mater Sci Technol 33(12):1433–1447
Ding MS, Du JP, Wan L et al (2016) Radiation-induced helium nanobubbles enhance ductility in submicron-sized single-crystalline copper. Nano Lett 16(7):4118–4124
Plimpton S (1995) Fast parallel algorithms for short-range molecular dynamics. J Comput Phys 117:1–19
Martínez E, Schwen D, Caro A (2015) Helium segregation to screw and edge dislocations in α-iron and their yield strength. Acta Mater 84:208–214
Gai X, Lazauskas T, Smith R, Kenny SD (2015) Helium bubbles in bcc Fe and their interactions with irradiation. J Nucl Mater 462:382–390
Stukowski A, Albe K (2010) Dislocation detection algorithm for atomistic simulations. Model Simul Mater Sci Eng 18:025016
Stukowski A (2009) Visualization and analysis of atomistic simulation data with OVITO—the Open Visualization Tool. Model Simul Mater Sci Eng 18(1):015012
Yang L, Deng HQ, Gao F et al (2013) Atomistic studies of nucleation of He clusters and bubbles in bcc iron. Nucl Instrum Methods B 303:68–71
Chen J, Jung P, Hoffelner W, Ullmaier H (2008) Dislocation loops and bubbles in oxide dispersion strengthened ferritic steel after helium implantation under stress. Acta Mater 56:250–258
Prokhodtseva A, Décamps B, Schäublin R (2013) Comparison between bulk and thin foil ion irradiation of ultra high purity Fe. J Nucl Mater 442:S786–S789
Zhang CH, Chen KQ, Wang YS, Sun JG, Shen DY (1997) Formation of bubbles in helium implanted 316L stainless steel at temperatures between 25 and 550 °C. J Nucl Mater 245(2–3):210–216
Li XC, Shu X, Tao P et al (2014) Molecular dynamics simulation of helium cluster diffusion and bubble formation in bulk tungsten. J Nucl Mater 455:544–548
Li Q, Parish CM, Powers KA, Miller MK (2014) Helium solubility and bubble formation in a nanostructured ferritic alloy. J Nucl Mater 445(1–3):165–174
Wang P, Chou W, Nie AM, Huang Y, Yao HM, Wang HT (2011) Molecular dynamics simulation on deformation mechanisms in body-centered-cubic molybdenum nanowires. J Appl Phys 110(9):093521
Wang J, Huang Y, Li C, Yu LM, Li HJ, Liu YC (2017) Damage micromechanics properties of bicrystalline α-Fe metals with two-voids. Phys B 521:275–280
Wolfer WG (1989) Dislocation loop punching in bubble arrays. Philos Mag A 59(1):87–103
Schaeublin R, Gelles D, Victoria M (2002) Microstructure of irradiated ferritic/martensitic steels in relation to mechanical properties. J Nucl Mater 307:197–202
Marian J, Wirth BD, Schäublin R, Perlado JM, de la Rubia TD (2002) <100>-Loop characterization in α-Fe: comparison between experiments and modeling. J Nucl Mater 307:871–875
Little EA, Eyre BL (1973) The geometry of dislocation loops generated in α-iron by 1 MeV electron irradiation at 550 °C. J Microsc 97(1–2):107–111
Willaime F, Fu CC, Marinica MC, Torre JD (2005) Stability and mobility of self-interstitials and small interstitial clusters in α-iron: ab initio and empirical potential calculations. Nucl Instrum Methods B 228(1–4):92–99
Christian JW, Vitek V (1970) Dislocations and stacking faults. Rep Prog Phys 33(1):307
Marian J, Wirth BD, Perlado JM (2002) Mechanism of formation and growth of <100> interstitial loops in ferritic materials. Phys Rev Lett 88(25):255507
Zhang X, Li M, Park JS, Kenesei P, Almer J, Xu C, Stubbins JF (2017) In situ high-energy X-ray diffraction study of tensile deformation of neutron-irradiated polycrystalline Fe–9%Cr alloy. Acta Mater 126:67–76
Ono K, Miyamoto M, Arakawa K, Matsumoto S, Kudo F (2014) Effects of precipitated helium, deuterium or alloy elements on glissile motion of dislocation loops in Fe–9Cr–2 W ferritic alloy. J Nucl Mater 455(1):162–166
Acknowledgements
The authors are grateful to the National Natural Science Foundation of China (Granted Nos. 51474156 and U1660201), the National Magnetic Confinement Fusion Energy Research Project (Granted No. 2015GB119001) for grant and financial support.
Author information
Authors and Affiliations
Corresponding authors
Ethics declarations
Conflict of interest
The authors declare that they have no conflict of interest.
Rights and permissions
About this article
Cite this article
Wang, J., Ma, Z., Liu, C. et al. Helium bubble evolution and deformation of single crystal α-Fe. J Mater Sci 54, 1785–1796 (2019). https://doi.org/10.1007/s10853-018-2915-y
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10853-018-2915-y