不同温度对含与不含位错α-Fe中He原子行为的影响
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摘要
采用分子动力学模拟了不同温度下0.1%He (原子分数)浓度下含与不含位错α-Fe中He原子偏聚行为和拉伸变形行为。结果表明,当温度为300 K时,预置的位错影响较弱,含与不含位错α-Fe模型中He原子均容易发生自吞噬形成He团簇,He团簇分布弥散且尺寸较小,位错环数目较少;当温度为600 K时,He原子热扩散行为加剧,较多的He原子偏聚到位错,He团簇分布离散且尺寸较大,位错环数目增加。在拉伸变形过程中,位错的存在能够加速He团簇演变成He泡,降低了模型的屈服应力和应变。在低温300 K时,弥散分布的小He团簇容易合并,发生脆性断裂,整个变形过程位错密度较低;在高温600 K时,离散分布的大He泡展现出较好的延展性,发生塑性断裂,整个变形过程中位错大量增殖,塑性较好。
The requirement of meeting rapidly growing demand for energy while maintaining environmentally friendly has been motivating the hot research on thermonuclear fusion. One of the key issues in future fusion reactors is that structural materials, especially fusion device first wall material, will suffer from He cumulative effects and atomic displacements from radiation cascades. Such harsh service conditions lead to the formation of He bubbles, which are responsible for severe degradation of the structural materials(e.g., swelling, embrittlement, loss of ductility etc.). It is thus essential to further understand the formation of He bubbles and hardening characteristics for the development of future nuclear materials. In this work, the behaviors of He segregation and tensile deformation have been investigated by molecular dynamics(MD) simulations in α-Fe with and without dislocations(dislocation densities are 0 and 3.36×1011 cm-2, respectively) and at the annealing temperatures of 300 and 600 K with 0.1%He(atomic fraction) injection. The results show that during the process of 300 K annealing, the effect of dislocation is rather weak, and He atoms are easier to form small He clusters by self-trapping. The size of He clusters and the number of dislocation loops are lower. Furthermore, higher temperature can notably intensify He diffusion, and the size of He clusters and the number of dislocation loops both increase at 600 K. In the process of tensile deformation, dislocations can notably accelerate small He clusters to develop into larger He bubbles, which leads to lower yield stress and strain. In addition, at 300 K, the model mainly occurs to brittle fracture and the dislocations density is lower. At 600 K, larger He bubble can promote dislocation multiply and enhance the deformability. Therefore, there exhibits a better plasticity in the model.
The requirement of meeting rapidly growing demand for energy while maintaining environmentally friendly has been motivating the hot research on thermonuclear fusion. One of the key issues in future fusion reactors is that structural materials, especially fusion device first wall material, will suffer from He cumulative effects and atomic displacements from radiation cascades. Such harsh service conditions lead to the formation of He bubbles, which are responsible for severe degradation of the structural materials(e.g., swelling, embrittlement, loss of ductility etc.). It is thus essential to further understand the formation of He bubbles and hardening characteristics for the development of future nuclear materials. In this work, the behaviors of He segregation and tensile deformation have been investigated by molecular dynamics(MD) simulations in α-Fe with and without dislocations(dislocation densities are 0 and 3.36×1011 cm-2, respectively) and at the annealing temperatures of 300 and 600 K with 0.1%He(atomic fraction) injection. The results show that during the process of 300 K annealing, the effect of dislocation is rather weak, and He atoms are easier to form small He clusters by self-trapping. The size of He clusters and the number of dislocation loops are lower. Furthermore, higher temperature can notably intensify He diffusion, and the size of He clusters and the number of dislocation loops both increase at 600 K. In the process of tensile deformation, dislocations can notably accelerate small He clusters to develop into larger He bubbles, which leads to lower yield stress and strain. In addition, at 300 K, the model mainly occurs to brittle fracture and the dislocations density is lower. At 600 K, larger He bubble can promote dislocation multiply and enhance the deformability. Therefore, there exhibits a better plasticity in the model.
引文
[1]Ullmaier H.The influence of helium on the bulk properties of fusion reactor structural materials[J].Nucl.Fusion,1984,24:1039
[2]Zhou X S,Liu C X,Yu L M,et al.Phase transformation behavior and microstructural control of high-Cr martensitic/ferritic heatresistant steels for power and nuclear plants:a review[J].J.Mater.Sci.Technol.,2015,31:235
[3]Samaras M.Multiscale modelling:The role of helium in iron[J].Mater.Today,2009,12:46
[4]Bloom E E.The challenge of developing structural materials for fusion power systems[J].J.Nucl.Mater.,1998,258-263:7
[5]Feng Y C,Xing W W,Wang S L,et al.First-principles study of hydrogen behaviors at oxide/ferrite interface in ODS steels[J].Acta Metall.Sin.,2018,54:325(冯宇超,邢炜伟,王寿龙等.ODS钢中氧化物/铁素体界面捕氢行为的第一原理研究[J].金属学报,2018,54:325)
[6]Yang L,Gao F,Kurtz R J,et al.Atomistic simulations of helium clustering and grain boundary reconstruction in alpha-iron[J].Acta Mater.,2015,82:275
[7]Zhang L,Fu C C,Hayward E,et al.Properties of He clustering in aFe grain boundaries[J].J.Nucl.Mater.,2015,459:247
[8]Wang Y X,Xu Q,Yoshiie T,et al.Effects of edge dislocations on interstitial helium and helium cluster behavior in α-Fe[J].J.Nucl.Mater.,2008,376:133
[9]Martínez E,Schwen D,Caro A.Helium segregation to screw and edge dislocations in a-iron and their yield strength[J].Acta Mater.,2015,84:208
[10]Ono K,Miyamoto M,Arakawa K,et al.Effects of precipitated helium,deuterium or alloy elements on glissile motion of dislocation loops in Fe-9Cr-2W ferritic alloy[J].J.Nucl.Mater.,2014,455:162
[11]Yamamoto T,Odette G R,Miao P,et al.Helium effects on microstructural evolution in tempered martensitic steels:In situ helium implanter studies in HFIR[J].J.Nucl.Mater.,2009,386-388:338
[12]Xu Q,Yamasaki H,Sugiura Y,et al.Effects of interactions between dislocations and/or vacancies and He atoms on mechanical property changes in Ni[J].Mater.Sci.Eng.,2013,A586:231
[13]Xu Q,Sugiura Y,Pan X Q,et al.Effects of dislocation-trapped helium on mechanical properties of Fe[J].Mater.Sci.Eng.,2014,A612:41
[14]Wei Y P,Liu P P,Zhu Y M,et al.Evaluation of irradiation hardening and microstructure evolution under the synergistic interaction of He and subsequent Fe ions irradiation in CLAM steel[J].J.Alloys Compd.,2016,676:481
[15]Chen J,Jung P,Hoffelner W,et al.Dislocation loops and bubbles in oxide dispersion strengthened ferritic steel after helium implantation under stress[J].Acta Mater.,2008,56:250
[16]Galindo-Nava E I,Basha B I Y,Rivera-Díaz-del-Castillo P E J.Hydrogen transport in metals:Integration of permeation,thermal desorption and degassing[J].J.Mater.Sci.Technol.,2017,33:1433
[17]Li Q,Parish C M,Powers K A,et al.Helium solubility and bubble formation in a nanostructured ferritic alloy[J].J.Nucl.Mater.,2014,445:165
[18]Shi J Y,Peng L,Ye M Y,et al.Molecular dynamics study:Effects of He bubble and Cr precipitate on tensile deformation of grain boundaries in α-Fe[J].IEEE Trans.Plasma Sci.,2017,45:289
[19]Tschopp M A,Gao F,Yang L,et al.Binding energetics of substitutional and interstitial helium and di-helium defects with grain boundary structure in α-Fe[J].J.Appl.Phys.,2014,115:033503
[20]Osetsky Y N,Stoller R E.Atomic-scale mechanisms of helium bubble hardening in iron[J].J.Nucl.Mater.,2015,465:448
[21]Yang L,Gao F,Kurtz R J,et al.Effects of local structure on helium bubble growth in bulk and at grain boundaries of bcc iron:Amolecular dynamics study[J].Acta Mater.,2015,97:86
[22]Morishita K,Sugano R,Wirth B D,et al.Thermal stability of helium-vacancy clusters in iron[J].Nucl.Instrum.Methods Phys.Res.,2003,202B:76
[23]Fu C C,Willaime F.Ab initio study of helium in α-Fe:Dissolution,migration,and clustering with vacancies[J].Phys.Rev.,2005,72B:064117
[24]Stewart D,Osetskiy Y,Stoller R.Atomistic studies of formation and diffusion of helium clusters and bubbles in BCC iron[J].J.Nucl.Mater.,2011,417:1110
[25]Jia X,Dai Y,Victoria M.The impact of irradiation temperature on the microstructure of F82H martensitic/ferritic steel irradiated in a proton and neutron mixed spectrum[J].J.Nucl.Mater.,2002,305:1
[26]Li X C,Shu X L,Tao P,et al.Molecular dynamics simulation of helium cluster diffusion and bubble formation in bulk tungsten[J].J.Nucl.Mater.,2014,455:544
[27]Ono K,Arakawa K,Hojou K.Formation and migration of helium bubbles in Fe and Fe-9Cr ferritic alloy[J].J.Nucl.Mater.,2002,307-311:1507
[28]Yang L,Zu X T,Gao F,et al.Dynamic interactions of heliumvacancy clusters with edge dislocations in α-Fe[J].Physica,2010,405B:1754
[29]Yang L,Zhu Z Q,Peng S M,et al.Effects of temperature on the interactions of helium-vacancy clusters with gliding edge dislocations in α-Fe[J].J.Nucl.Mater.,2013,441:6
[30]Plimpton S.Fast parallel algorithms for short-range molecular dynamics[J].J.Comput.Phys.,1995,117:1
[31]Stukowski A.Visualization and analysis of atomistic simulation data with OVITO-The Open Visualization Tool[J].Modell.Simul.Mater.Sci.Eng.,2009,18:015012
[32]Stukowski A,Albe K.Dislocation detection algorithm for atomistic simulations[J].Modell.Simul.Mater.Sci.Eng.,2010,18:025016
[33]Yang L,Deng H Q,Gao F,et al.Atomistic studies of nucleation of He clusters and bubbles in bcc iron[J].Nucl.Instrum.Methods Phys.Res.,2013,303B:68
[34]Prokhodtseva A,Décamps B,Sch?ublin R.Comparison between bulk and thin foil ion irradiation of ultra high purity Fe[J].J.Nucl.Mater.,2013,442(Suppl.1-3):S786
[35]Heinisch H L,Gao F,Kurtz R J,et al.Interaction of helium atoms with edge dislocations in α-Fe[J].J.Nucl.Mater.,2006,351:141
[36]Wirth B D,Odette G R,Maroudas D,et al.Dislocation loop structure,energy and mobility of self-interstitial atom clusters in bcc iron[J].J.Nucl.Mater.,2000,276:33
[37]Marian J,Wirth B D,Perlado J M.Mechanism of formation and growth of<100>interstitial loops in ferritic materials[J].Phys.Rev.Lett.,2002,88:255507
[38]Wang J,Yu L M,Huang Y,et al.Micromechanics mechanism of aFe with different types of edge dislocations under radiation damage[J].Mater.Lett.,2018,210:325
[39]Ding M S,Du J P,Wan L,et al.Radiation-induced helium nanobubbles enhance ductility in submicron-sized single-crystalline copper[J].Nano Lett.,2016,16:4118
[40]Hale L M,Zimmerman J A,Wong B M.Large-scale atomistic simulations of helium-3 bubble growth in complex palladium alloys[J].J.Chem.Phys.,2016,144:194705
[41]Carrington W,Hale K F,McLean D.Arrangement of dislocations in iron[J].Proc.Roy.Soc.,1960,259A:203
[42]Ohr S M,Beshers D N.Crystallography of dislocation networks in annealed iron[J].Philos.Mag.,1963,8A:1343
[2]Zhou X S,Liu C X,Yu L M,et al.Phase transformation behavior and microstructural control of high-Cr martensitic/ferritic heatresistant steels for power and nuclear plants:a review[J].J.Mater.Sci.Technol.,2015,31:235
[3]Samaras M.Multiscale modelling:The role of helium in iron[J].Mater.Today,2009,12:46
[4]Bloom E E.The challenge of developing structural materials for fusion power systems[J].J.Nucl.Mater.,1998,258-263:7
[5]Feng Y C,Xing W W,Wang S L,et al.First-principles study of hydrogen behaviors at oxide/ferrite interface in ODS steels[J].Acta Metall.Sin.,2018,54:325(冯宇超,邢炜伟,王寿龙等.ODS钢中氧化物/铁素体界面捕氢行为的第一原理研究[J].金属学报,2018,54:325)
[6]Yang L,Gao F,Kurtz R J,et al.Atomistic simulations of helium clustering and grain boundary reconstruction in alpha-iron[J].Acta Mater.,2015,82:275
[7]Zhang L,Fu C C,Hayward E,et al.Properties of He clustering in aFe grain boundaries[J].J.Nucl.Mater.,2015,459:247
[8]Wang Y X,Xu Q,Yoshiie T,et al.Effects of edge dislocations on interstitial helium and helium cluster behavior in α-Fe[J].J.Nucl.Mater.,2008,376:133
[9]Martínez E,Schwen D,Caro A.Helium segregation to screw and edge dislocations in a-iron and their yield strength[J].Acta Mater.,2015,84:208
[10]Ono K,Miyamoto M,Arakawa K,et al.Effects of precipitated helium,deuterium or alloy elements on glissile motion of dislocation loops in Fe-9Cr-2W ferritic alloy[J].J.Nucl.Mater.,2014,455:162
[11]Yamamoto T,Odette G R,Miao P,et al.Helium effects on microstructural evolution in tempered martensitic steels:In situ helium implanter studies in HFIR[J].J.Nucl.Mater.,2009,386-388:338
[12]Xu Q,Yamasaki H,Sugiura Y,et al.Effects of interactions between dislocations and/or vacancies and He atoms on mechanical property changes in Ni[J].Mater.Sci.Eng.,2013,A586:231
[13]Xu Q,Sugiura Y,Pan X Q,et al.Effects of dislocation-trapped helium on mechanical properties of Fe[J].Mater.Sci.Eng.,2014,A612:41
[14]Wei Y P,Liu P P,Zhu Y M,et al.Evaluation of irradiation hardening and microstructure evolution under the synergistic interaction of He and subsequent Fe ions irradiation in CLAM steel[J].J.Alloys Compd.,2016,676:481
[15]Chen J,Jung P,Hoffelner W,et al.Dislocation loops and bubbles in oxide dispersion strengthened ferritic steel after helium implantation under stress[J].Acta Mater.,2008,56:250
[16]Galindo-Nava E I,Basha B I Y,Rivera-Díaz-del-Castillo P E J.Hydrogen transport in metals:Integration of permeation,thermal desorption and degassing[J].J.Mater.Sci.Technol.,2017,33:1433
[17]Li Q,Parish C M,Powers K A,et al.Helium solubility and bubble formation in a nanostructured ferritic alloy[J].J.Nucl.Mater.,2014,445:165
[18]Shi J Y,Peng L,Ye M Y,et al.Molecular dynamics study:Effects of He bubble and Cr precipitate on tensile deformation of grain boundaries in α-Fe[J].IEEE Trans.Plasma Sci.,2017,45:289
[19]Tschopp M A,Gao F,Yang L,et al.Binding energetics of substitutional and interstitial helium and di-helium defects with grain boundary structure in α-Fe[J].J.Appl.Phys.,2014,115:033503
[20]Osetsky Y N,Stoller R E.Atomic-scale mechanisms of helium bubble hardening in iron[J].J.Nucl.Mater.,2015,465:448
[21]Yang L,Gao F,Kurtz R J,et al.Effects of local structure on helium bubble growth in bulk and at grain boundaries of bcc iron:Amolecular dynamics study[J].Acta Mater.,2015,97:86
[22]Morishita K,Sugano R,Wirth B D,et al.Thermal stability of helium-vacancy clusters in iron[J].Nucl.Instrum.Methods Phys.Res.,2003,202B:76
[23]Fu C C,Willaime F.Ab initio study of helium in α-Fe:Dissolution,migration,and clustering with vacancies[J].Phys.Rev.,2005,72B:064117
[24]Stewart D,Osetskiy Y,Stoller R.Atomistic studies of formation and diffusion of helium clusters and bubbles in BCC iron[J].J.Nucl.Mater.,2011,417:1110
[25]Jia X,Dai Y,Victoria M.The impact of irradiation temperature on the microstructure of F82H martensitic/ferritic steel irradiated in a proton and neutron mixed spectrum[J].J.Nucl.Mater.,2002,305:1
[26]Li X C,Shu X L,Tao P,et al.Molecular dynamics simulation of helium cluster diffusion and bubble formation in bulk tungsten[J].J.Nucl.Mater.,2014,455:544
[27]Ono K,Arakawa K,Hojou K.Formation and migration of helium bubbles in Fe and Fe-9Cr ferritic alloy[J].J.Nucl.Mater.,2002,307-311:1507
[28]Yang L,Zu X T,Gao F,et al.Dynamic interactions of heliumvacancy clusters with edge dislocations in α-Fe[J].Physica,2010,405B:1754
[29]Yang L,Zhu Z Q,Peng S M,et al.Effects of temperature on the interactions of helium-vacancy clusters with gliding edge dislocations in α-Fe[J].J.Nucl.Mater.,2013,441:6
[30]Plimpton S.Fast parallel algorithms for short-range molecular dynamics[J].J.Comput.Phys.,1995,117:1
[31]Stukowski A.Visualization and analysis of atomistic simulation data with OVITO-The Open Visualization Tool[J].Modell.Simul.Mater.Sci.Eng.,2009,18:015012
[32]Stukowski A,Albe K.Dislocation detection algorithm for atomistic simulations[J].Modell.Simul.Mater.Sci.Eng.,2010,18:025016
[33]Yang L,Deng H Q,Gao F,et al.Atomistic studies of nucleation of He clusters and bubbles in bcc iron[J].Nucl.Instrum.Methods Phys.Res.,2013,303B:68
[34]Prokhodtseva A,Décamps B,Sch?ublin R.Comparison between bulk and thin foil ion irradiation of ultra high purity Fe[J].J.Nucl.Mater.,2013,442(Suppl.1-3):S786
[35]Heinisch H L,Gao F,Kurtz R J,et al.Interaction of helium atoms with edge dislocations in α-Fe[J].J.Nucl.Mater.,2006,351:141
[36]Wirth B D,Odette G R,Maroudas D,et al.Dislocation loop structure,energy and mobility of self-interstitial atom clusters in bcc iron[J].J.Nucl.Mater.,2000,276:33
[37]Marian J,Wirth B D,Perlado J M.Mechanism of formation and growth of<100>interstitial loops in ferritic materials[J].Phys.Rev.Lett.,2002,88:255507
[38]Wang J,Yu L M,Huang Y,et al.Micromechanics mechanism of aFe with different types of edge dislocations under radiation damage[J].Mater.Lett.,2018,210:325
[39]Ding M S,Du J P,Wan L,et al.Radiation-induced helium nanobubbles enhance ductility in submicron-sized single-crystalline copper[J].Nano Lett.,2016,16:4118
[40]Hale L M,Zimmerman J A,Wong B M.Large-scale atomistic simulations of helium-3 bubble growth in complex palladium alloys[J].J.Chem.Phys.,2016,144:194705
[41]Carrington W,Hale K F,McLean D.Arrangement of dislocations in iron[J].Proc.Roy.Soc.,1960,259A:203
[42]Ohr S M,Beshers D N.Crystallography of dislocation networks in annealed iron[J].Philos.Mag.,1963,8A:1343