Please wait a minute...
金属学报  2018, Vol. 54 Issue (1): 47-54    DOI: 10.11900/0412.1961.2017.00228
  本期目录 | 过刊浏览 |
晶体取向和He浓度对bcc-Fe裂纹扩展行为的影响
王瑾, 余黎明, 黄远, 李会军, 刘永长()
天津大学材料科学与工程学院水利安全与仿真国家重点实验室 天津 300354
Effect of Crystal Orientation and He Density on Crack Propagation Behavior of bcc-Fe
Jin WANG, Liming YU, Yuan HUANG, Huijun LI, Yongchang LIU()
State Key Lab of Hydraulic Engineering Simulation and Safety, School of Materials Science & Engineering, Tianjin University, Tianjin 300354, China
全文: PDF(1210 KB)   HTML
摘要: 

采用分子动力学模拟研究了300 K时不同He浓度下(001)[010]和(121)[111] 2种取向bcc-Fe裂纹模型的扩展行为。结果表明,当模型中不存在He时,裂纹取向不同,裂纹扩展机制不同:(001)[010]取向裂纹的扩展机制分为弹性变形、相变、裂纹尖端沿相变区解理断裂;(121)[111]取向裂纹的扩展机制分为弹性变形、堆垛孪晶、孪晶尖端应力集中诱发多空洞合并断裂。(121)[111]取向裂纹的屈服应力和应变大于(001)[010]取向裂纹,说明(121)[111]取向裂纹具有较强的抵制裂纹扩展的能力。He浓度对裂纹扩展行为的影响主要体现在2个方面:当He浓度较低(0.9%,原子分数)时,He的存在减缓了相变或者孪晶转变速率,降低了裂纹扩展速率;当He浓度较高(6.0%,原子分数)时,大量He团簇的存在促进了空洞形成,导致2种裂纹模型的断裂机制均变为He团簇诱发多空洞合并断裂,未出现相变或者孪晶。

关键词 bcc-Fe裂纹扩展He浓度分子动力学    
Abstract

Radiation-induced damage, especially the effect of He, has always been one of the crucial issues in future fusion reactors. It is thus essential to further understand the formation of He bubbles and hardening characteristics for future development of fusion application materials, for instance bcc-Fe as a simple model. Behaviors of crack propagation have been investigated in two different orientated cracks (001)[010] and (121)[111] of bcc-Fe models under different densities of He at 300 K by molecular dynamics simulation. The results show that these behaviors are tailored by crack orientations on the condition of non-He atoms: (001)[010] orientated crack can be divided into elastic deformation, phase transformation and cleavage fracture of crack tip along phase transformation zone; however, (121)[111] orientated crack is elastic deformation, stacking twin and after that formation and coalescence of voids to rupture. Furthermore, the yield stress and strain of (121)[111] orientated crack are higher than (001)[010] orientated crack, therefore (121)[111] orientated crack has stronger ability to resist crack propagation. In addition, it is revealed that the influence of He density on the crack propagation exhibits two major aspects: when the density of He is lower (0.9%, atomic fraction), He can reduce the efficiency of phase or twin transformation and decrease the rate of crack propagation; when the density of He is higher (6.0%, atomic fraction), a large number of He clusters contribute to promote micro-voids nucleation, fracture mechanism for both crack models is the transformation of He clusters to voids, then voids coalescence, accelerating the occurrence of fracture. There is no twin or phase transformation in higher density of He.

Key wordsbcc-Fe    crack propagation    He density    molecular dynamics
收稿日期: 2017-06-14     
ZTFLH:  TG111.91  
基金资助:国家自然科学基金项目Nos.51325401、51474156和U1660201以及国家磁约束核聚变能源研究专项课题项目No.2015GB119001
作者简介: 作者简介 王 瑾,女,1989年生,博士

引用本文:

王瑾, 余黎明, 黄远, 李会军, 刘永长. 晶体取向和He浓度对bcc-Fe裂纹扩展行为的影响[J]. 金属学报, 2018, 54(1): 47-54.
Jin WANG, Liming YU, Yuan HUANG, Huijun LI, Yongchang LIU. Effect of Crystal Orientation and He Density on Crack Propagation Behavior of bcc-Fe. Acta Metall Sin, 2018, 54(1): 47-54.

链接本文:

https://www.ams.org.cn/CN/10.11900/0412.1961.2017.00228      或      https://www.ams.org.cn/CN/Y2018/V54/I1/47

图1  含(001)[010]和(121)[111]取向裂纹的bcc-Fe模型局部断面视图
图2  2种不同取向裂纹的bcc-Fe模型应力-应变曲线
图3  (001)[010]取向裂纹模型随应变增加的构型演变图
Crack orientation Model x / nm y / nm z / nm Atomic fraction of He / % Number of atom
(001)[010] A1 2 42.8 42.8 0 314622
A2 2 42.8 42.8 0.9 317457
A3 2 42.8 42.8 6.0 333522
(121)[111] B1 2 44.5 41 0 315867
B2 2 44.5 41 0.9 318710
B3 2 44.5 41 6.0 334819
表1  含裂纹的bcc-Fe模型几何尺寸
图4  (121)[111]取向裂纹模型随应变增加的构型演变图
图5  不同He浓度下2种取向裂纹模型应力-应变曲线
图6  He浓度分别为0.9%和6.0%时(001)[010]取向裂纹模型随应变增加的构型演变图
图7  He浓度分别为0.9%和6.0%时(121)[111]取向裂纹模型随应变增加的构型演变图
[1] Samaras M.Multiscale modelling: The role of helium in iron[J]. Mater. Today, 2009, 12: 46
[2] Ishiyama Y, Kodama M, Yokota N, et al.Post-irradiation annealing effects on microstructure and helium bubbles in neutron irradiated type 304 stainless steel[J]. J. Nucl. Mater., 1996, 239: 90
[3] Stoller R E, Odette G R.The effects of helium implantation on microstructural evolution in an austenitic alloy[J]. J. Nucl. Mater., 1988, 154: 286
[4] Lewis M B, Farrell K.Migration behavior of helium under displacive irradiation in stainless steel, nickel, iron and zirconium[J]. Nucl. Instrum. Methods Phys. Res., 1986, 16B: 163
[5] Vassen R, Trinkaus H, Jung P.Helium desorption from Fe and V by atomic diffusion and bubble migration[J]. Phys. Rev., 1991, 44B: 4206
[6] Bloom E E. The challenge of developing structural materials for fusion power systems[J]. J. Nucl. Mater., 1998, 258-263: 7
[7] Zinkle S J, Ghoniem N M. Operating temperature windows for fusion reactor structural materials [J]. Fusion Eng. Des., 2000, 51-52: 55
[8] Liu X Y, Xie W B, Chen W X, et al.Effects of grain boundary and boundary inclination on hydrogen diffusion in α-iron[J]. J. Mater. Res., 2011, 26: 2735
[9] Troiano A R.The role of hydrogen and other interstitials in the mechanical behavior of metals[J]. Metallogr. Microst. Anal., 2016, 5: 557
[10] Hirth J P.Effects of hydrogen on the properties of iron and steel[J]. Metall. Trans., 1980, 11A: 861
[11] Li M J, Hu H Y, Xing X S.The relationship between fatigue life and grain size of polycrystalline metals[J]. Acta Phys. Sin., 2003, 52: 2092(李眉娟, 胡海云, 邢修三. 多晶体金属疲劳寿命随晶粒尺寸变化的理论研究[J]. 物理学报, 2003, 52: 2092)
[12] Zhu L, Zhang A H.Mechanism of crack formation at hard brittle particles in steels[J]. Acta Phys. Sin., 2004, 53: 571(朱亮, 张爱华. 钢中脆硬粒子裂纹形成机理[J]. 物理学报, 2004, 53: 571)
[13] Li X F, Fan T Y.Elastic analysis of a mode II crack in a decagonal quasi-crystal[J]. Chin. Phys., 2002, 11: 266
[14] Rice J R.Dislocation nucleation from a crack tip: An analysis based on the Peierls concept[J]. J. Mech. Phys. Solids, 1992, 40: 239
[15] Cao L X, Wang C Y.Phonon spectrum and related thermodynamic properties of microcrack in bcc-Fe[J]. Chin. Phys., 2006, 15: 2092
[16] Ma L, Xiao S F, Deng H Q, et al.Molecular dynamics simulation of fatigue crack propagation in bcc iron under cyclic loading[J]. Int. J. Fatigue, 2014, 68: 253
[17] Uhnáková A, Machová A, Hora P.3D atomistic simulation of fatigue behavior of a ductile crack in bcc iron[J]. Int. J. Fatigue, 2011, 33: 1182
[18] Uhnáková A, Pokluda J, Machová A, et al.3D atomistic simulation of fatigue behavior of a ductile crack in bcc iron loaded in mode II[J]. Comput. Mater. Sci., 2012, 61: 12
[19] Uhnáková A, Pokluda J, Machová A, et al.3D atomistic simulation of fatigue behaviour of cracked single crystal of bcc iron loaded in mode III[J]. Int. J. Fatigue, 2011, 33: 1564
[20] Ren G W, Tang T G.Coupling of two-dimensional atomistic and continuum models for dynamic crack[J]. Chin. Phys., 2014, 23B: 118704
[21] Zhou S J, Beazley D M, Lomdahl P S, et al.Large-scale molecular dynamics simulations of three-dimensional ductile failure[J]. Phys. Rev. Lett., 1997, 78: 479
[22] Cao L X, Wang C Y.Molecular dynamics simulation of fracture in α-iron[J]. Acta Phys. Sin., 2007, 56: 413(曹莉霞, 王崇愚. α-Fe裂纹的分子动力学研究[J]. 物理学报, 2007, 56: 413)
[23] Wu W P, Yao Z Z.Molecular dynamics simulation of stress distribution and microstructure evolution ahead of a growing crack in single crystal nickel[J]. Theoret. Appl. Fract. Mech., 2012, 62: 67
[24] Telitchev I Y, Vinogradov O.Numerical tensile tests of BCC iron crystal with various amounts of hydrogen near the crack tip[J]. Comput. Mater. Sci., 2006, 36: 272
[25] Kanezaki T, Narazaki C, Mine Y, et al.Effects of hydrogen on fatigue crack growth behavior of austenitic stainless steels[J]. Int. J. Hydrogen Energy, 2008, 33: 2604
[26] Song J, Curtin W A.Atomic mechanism and prediction of hydrogen embrittlement in iron[J]. Nat. Mater., 2013, 12: 145
[27] Song H Y, Zhang L, Xiao M X.Molecular dynamics simulation of effect of hydrogen atoms on crack propagation behavior of α-Fe[J]. Phys. Lett., 2016, 380A: 4049
[28] Martínez E, Schwen D, Caro A.Helium segregation to screw and edge dislocations in α-iron and their yield strength[J]. Acta Mater., 2015, 84: 208
[29] Stukowski A.Visualization and analysis of atomistic simulation data with OVITO—the Open Visualization Tool[J]. Modell. Simul. Mater. Sci. Eng., 2009, 18: 015012
[30] Guo L Y, Chen Z, Long J, et al.Study on the effect of stress state and crystal orientation on micro-crack tip propagation behavior in phase ?eld crystal method[J]. Acta Phys. Sin., 2015, 64: 178102(郭刘洋, 陈铮, 龙建等. 晶体相场法研究应力状态及晶体取向对微裂纹尖端扩展行为的影响[J]. 物理学报, 2015, 64: 178102)
[31] Fujiwara H, Inomoto H, Sanada R, et al.Nano-ferrite formation and strain-induced-ferrite transformation in an SUS316L austenitic stainless steel[J]. Scr. Mater., 2001, 44: 2039
[32] Ohr S M.An electron microscope study of crack tip deformation and its impact on the dislocation theory of fracture[J]. Mater. Sci. Eng., 1985, 72: 1
[33] Yu X G, Gou F J, Tian X.Molecular dynamics study of the effect of hydrogen on the mechanical properties of tungsten[J]. J. Nucl. Mater., 2013, 441: 324
[34] Hull D.Twinning and fracture of single crystals of 3% silicon iron[J]. Acta Metall., 1960, 8: 11
[35] Bo?ansky J, ?mida T.Deformation twins-probable inherent nuclei of cleavage fracture in ferritic steels[J]. Mater. Sci. Eng., 2002, A323: 198
[36] Fu R, Rui Z Y, Yan C F, et al.Molecular dynamics simulation of micro-crack propagation behavior in single crystal γ-TiAl[J]. J. Funct. Mater., 2015, 46: 13100(付蓉, 芮执元, 剡昌锋等. 单晶γ-TiAl合金微裂纹扩展行为的分子动力学模拟[J]. 功能材料, 2015, 46: 13100)
[37] Wu Q, Zikry M A.Prediction of diffusion assisted hydrogen embrittlement failure in high strength martensitic steels[J]. J. Mech. Phys. Solids, 2015, 85: 143
[1] 李源才, 江五贵, 周宇. 纳米孔洞对单晶/多晶Ni复合体拉伸性能的影响[J]. 金属学报, 2020, 56(5): 776-784.
[2] 李美霖, 李赛毅. 金属Mg二阶锥面<c+a>刃位错运动特性的分子动力学模拟[J]. 金属学报, 2020, 56(5): 795-800.
[3] 李源才, 江五贵, 周宇. 温度对碳纳米管增强纳米蜂窝镍力学性能的影响[J]. 金属学报, 2020, 56(5): 785-794.
[4] 周霞,刘霄霞. 石墨烯纳米片增强镁基复合材料力学性能及增强机制[J]. 金属学报, 2020, 56(2): 240-248.
[5] 马小强,杨坤杰,徐喻琼,杜晓超,周建军,肖仁政. 金属Nb级联碰撞的分子动力学模拟[J]. 金属学报, 2020, 56(2): 249-256.
[6] 史俊勤,孙琨,方亮,许少锋. 含水条件下单晶Cu的应力松弛及弹性恢复[J]. 金属学报, 2019, 55(8): 1034-1040.
[7] 张清东,李硕,张勃洋,谢璐,李瑞. 金属轧制复合过程微观变形行为的分子动力学建模及研究[J]. 金属学报, 2019, 55(7): 919-927.
[8] 涂爱东, 滕春禹, 王皞, 徐东生, 傅耘, 任占勇, 杨锐. Ti-Al合金γ/α2界面结构及拉伸变形行为的分子动力学模拟[J]. 金属学报, 2019, 55(2): 291-298.
[9] 王瑾, 余黎明, 李冲, 黄远, 李会军, 刘永长. 不同温度对含与不含位错α-Fe中He原子行为的影响[J]. 金属学报, 2019, 55(2): 274-280.
[10] 张啸尘, 孟维迎, 邹德芳, 周鹏, 石怀涛. 预循环应力对高速列车关键结构用铝合金材料疲劳裂纹扩展行为的影响[J]. 金属学报, 2019, 55(10): 1243-1250.
[11] 张海峰, 闫海乐, 贾楠, 金剑锋, 赵骧. Cu/Ti纳米层状复合体塑性变形机制的分子动力学模拟研究[J]. 金属学报, 2018, 54(9): 1333-1342.
[12] 赵鹏越, 郭永博, 白清顺, 张飞虎. 基于微观结构的多晶Cu纳米压痕表面缺陷研究[J]. 金属学报, 2018, 54(7): 1051-1058.
[13] 樊丹丹, 许军锋, 钟亚男, 坚增运. 过热温度和冷却速率对过冷Ti熔体凝固过程的影响[J]. 金属学报, 2018, 54(6): 844-850.
[14] 冯宇超, 邢炜伟, 王寿龙, 陈星秋, 李殿中, 李依依. 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(2): 325-338.
[15] 郭舒,韩恩厚,王海涛,张志明,王俭秋. 核电站316L不锈钢弯头应力腐蚀行为的寿命预测[J]. 金属学报, 2017, 53(4): 455-464.