| 引用本文: | 周瑾,周存龙,段晶晶,樊铭洋.基于分子动力学研究孔隙率对FeO/Fe界面裂纹扩展的影响∗[J].中国表面工程,2021,34(3):90~99 |
| Zhou Jin,Zhou Cunlong,Duan Jingjing,Fan Mingyang.Molecular Dynamics-based Study of Effect of Porosity on Crack Propagation at FeO / Fe Interface[J].China Surface Engineering,2021,34(3):90~99 |
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| 摘要: |
| 孔隙率是影响氧化皮与钢基体界面裂纹扩展的重要因素,采用分子动力学模拟软件 LAMMPS 建立模型 I(定孔缺陷数量模型)和模型 II(定孔缺陷尺寸模型)两种模型,从抗拉强度、中心对称分析(CSP)以及界面局部应力分布 3 个方面研究了孔隙率对于界面裂纹扩展的影响。 结果表明,相同孔隙率下,模型 II 比模型 I 的抗拉强度低,表明孔缺陷分布范围比孔缺陷的尺寸对于材料的抗拉强度影响更大。 同时裂纹扩展时动态不稳定性导致裂纹非对称性扩展,孔隙率的增加会阻碍应力增长和裂纹扩展速度,增强裂纹扩展的不对称性。 当孔隙率达到 9%时,在界面裂纹扩展后,模型 I+x 方向裂尖偏转界面上方孔缺陷,模型 II 则为界面裂纹扩展后,上方孔缺陷融合发展。 |
| 关键词: 氧化皮 界面 断裂 孔缺陷 分子动力学 孔隙率 |
| DOI：10.11933/j.issn.1007-9289.20210218001 |
| 分类号:TG335 |
| 基金项目:山西省重点研发计划(201903D421046)和山西省科技重大专项(20181102015,20181101008)资助项目 |
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| Molecular Dynamics-based Study of Effect of Porosity on Crack Propagation at FeO / Fe Interface |
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Zhou Jin, Zhou Cunlong, Duan Jingjing, Fan Mingyang
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Key Laboratory of Metallurgical Equipment Design Theory and Technology of Shanxi Province, Taiyuan University of Science and Technology, Taiyuan 030024 , China
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| Abstract: |
| Porosity is an important factor affecting the crack extension at the interface between oxide and steel matrix. In this paper, two models including Model I (fixed pore defect number model) and Model II (fixed pore defect size model), were established by the molecular dynamics simulation software LAMMPS, and the effect of porosity on the crack extension at the interface was investigated in terms of tensile strength, centrosymmetry parameter (CSP) analysis and local stress distribution at the interface. The results show that the tensile strength of model II is lower than that of model I at the same porosity, indicating that the range of pore defect distribution has more influence on the tensile strength of the material than the size of pore defects. Meanwhile, the dynamic instability during crack expansion leads to asymmetric crack expansion, and the increase of porosity will hinder the stress growth and crack expansion rate and enhance the asymmetry of crack expansion. When the porosity reaches to 9%, after the interface crack extension, the +x direction crack tip in model I deflects the pore defects above the interface, and the upper square pore defects in model II shows the fusion development after the interface crack extension. |
| Key words: oxide scale interface fracture pore defects molecular dynamics porosity |
