{"title":"将原子学与实验相结合,深入了解银的疲劳裂纹扩展过程","authors":"Yinan Xie, Xiaoli Hao, Zumin Wang, Yuan Huang","doi":"10.1007/s10704-024-00796-1","DOIUrl":null,"url":null,"abstract":"<div><p>This research utilizes both single crystal and polycrystalline models to probe the fatigue crack propagation mechanism in pure silver via molecular dynamics (MD) simulations. A comprehensive validation approach at both micro and macro scales, incorporating transmission electron microscopy (TEM), electron backscatter diffraction (EBSD), and compact tension (CT) specimen fatigue testing, is developed to verify the reliability of simulation models and results. Simulation findings indicate that the initial crack orientation significantly influences crack propagation. As the crack advances within the crystal, two primary crack propagation mechanisms are discerned: (1) nano-voids appear at the crack tip, and the crack propagates by continuously aggregating with the nano-voids ahead; (2) the formation of Stair-rod dislocations and V-shape stacking faults due to dislocation reactions and slip band movements impedes crack propagation, accompanied by the dislocation reaction of Shockley partial dislocations (<span>\\(\\tfrac{1}{6}\\)</span> <112>) generating Hirth dislocations (<span>\\(\\tfrac{1}{6}\\)</span> <110>). The dislocation reaction is verified through the dislocation analysis of the crack tip area of the CT specimen after fatigue experiment by using TEM. In addition, the results of this study show that the angle between the direction of crack propagation and the grain boundary affects the fatigue crack propagation, e.g. when the angle is less than 60°, the crack rapidly propagates along the grain boundary. The orientation distribution function (ODF) results of EBSD can verify that the polycrystalline model containing 30 grains is a reliable model for the MD simulation of behavior of the crack tip of CT specimen. Lastly, the Paris law constants for pure silver are determined as <i>m</i> = 3.72 and lg <i>C</i> = − 10.77, providing a reference for the fatigue analysis and life prediction of silver components or silver soldering pots in engineering applications.</p></div>","PeriodicalId":590,"journal":{"name":"International Journal of Fracture","volume":"247 3","pages":"383 - 411"},"PeriodicalIF":2.2000,"publicationDate":"2024-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Integrating atomistics and experiments in gaining deeper insights into fatigue crack propagation in silver\",\"authors\":\"Yinan Xie, Xiaoli Hao, Zumin Wang, Yuan Huang\",\"doi\":\"10.1007/s10704-024-00796-1\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>This research utilizes both single crystal and polycrystalline models to probe the fatigue crack propagation mechanism in pure silver via molecular dynamics (MD) simulations. A comprehensive validation approach at both micro and macro scales, incorporating transmission electron microscopy (TEM), electron backscatter diffraction (EBSD), and compact tension (CT) specimen fatigue testing, is developed to verify the reliability of simulation models and results. Simulation findings indicate that the initial crack orientation significantly influences crack propagation. As the crack advances within the crystal, two primary crack propagation mechanisms are discerned: (1) nano-voids appear at the crack tip, and the crack propagates by continuously aggregating with the nano-voids ahead; (2) the formation of Stair-rod dislocations and V-shape stacking faults due to dislocation reactions and slip band movements impedes crack propagation, accompanied by the dislocation reaction of Shockley partial dislocations (<span>\\\\(\\\\tfrac{1}{6}\\\\)</span> <112>) generating Hirth dislocations (<span>\\\\(\\\\tfrac{1}{6}\\\\)</span> <110>). The dislocation reaction is verified through the dislocation analysis of the crack tip area of the CT specimen after fatigue experiment by using TEM. In addition, the results of this study show that the angle between the direction of crack propagation and the grain boundary affects the fatigue crack propagation, e.g. when the angle is less than 60°, the crack rapidly propagates along the grain boundary. The orientation distribution function (ODF) results of EBSD can verify that the polycrystalline model containing 30 grains is a reliable model for the MD simulation of behavior of the crack tip of CT specimen. Lastly, the Paris law constants for pure silver are determined as <i>m</i> = 3.72 and lg <i>C</i> = − 10.77, providing a reference for the fatigue analysis and life prediction of silver components or silver soldering pots in engineering applications.</p></div>\",\"PeriodicalId\":590,\"journal\":{\"name\":\"International Journal of Fracture\",\"volume\":\"247 3\",\"pages\":\"383 - 411\"},\"PeriodicalIF\":2.2000,\"publicationDate\":\"2024-06-12\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"International Journal of Fracture\",\"FirstCategoryId\":\"5\",\"ListUrlMain\":\"https://link.springer.com/article/10.1007/s10704-024-00796-1\",\"RegionNum\":3,\"RegionCategory\":\"工程技术\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"MATERIALS SCIENCE, MULTIDISCIPLINARY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"International Journal of Fracture","FirstCategoryId":"5","ListUrlMain":"https://link.springer.com/article/10.1007/s10704-024-00796-1","RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"MATERIALS SCIENCE, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
摘要
本研究利用单晶和多晶模型,通过分子动力学(MD)模拟探究纯银的疲劳裂纹扩展机制。研究开发了一种微观和宏观尺度的综合验证方法,结合了透射电子显微镜(TEM)、电子反向散射衍射(EBSD)和紧密拉伸(CT)试样疲劳测试,以验证模拟模型和结果的可靠性。模拟结果表明,初始裂纹取向对裂纹扩展有很大影响。随着裂纹在晶体内的扩展,可发现两种主要的裂纹扩展机制:(1) 在裂纹尖端出现纳米空洞,裂纹通过不断与前方的纳米空洞聚集而扩展;(2)由于位错反应和滑移带运动形成的Stair-rod位错和V形堆叠断层阻碍了裂纹的扩展,同时伴随着Shockley部分位错的位错反应(\(\tfrac{1}{6}\ <112>)产生了Hirth位错(\(\tfrac{1}{6}\ <110>)。通过使用 TEM 对疲劳实验后 CT 试样的裂纹尖端区域进行位错分析,验证了位错反应。此外,研究结果表明,裂纹扩展方向与晶界之间的夹角会影响疲劳裂纹的扩展,例如当夹角小于 60°时,裂纹会沿着晶界迅速扩展。EBSD 的取向分布函数(ODF)结果可以验证包含 30 个晶粒的多晶模型是对 CT 试样裂纹尖端行为进行 MD 模拟的可靠模型。最后,确定了纯银的帕里斯定律常数为 m = 3.72 和 lg C = - 10.77,为工程应用中银元件或银焊锅的疲劳分析和寿命预测提供了参考。
Integrating atomistics and experiments in gaining deeper insights into fatigue crack propagation in silver
This research utilizes both single crystal and polycrystalline models to probe the fatigue crack propagation mechanism in pure silver via molecular dynamics (MD) simulations. A comprehensive validation approach at both micro and macro scales, incorporating transmission electron microscopy (TEM), electron backscatter diffraction (EBSD), and compact tension (CT) specimen fatigue testing, is developed to verify the reliability of simulation models and results. Simulation findings indicate that the initial crack orientation significantly influences crack propagation. As the crack advances within the crystal, two primary crack propagation mechanisms are discerned: (1) nano-voids appear at the crack tip, and the crack propagates by continuously aggregating with the nano-voids ahead; (2) the formation of Stair-rod dislocations and V-shape stacking faults due to dislocation reactions and slip band movements impedes crack propagation, accompanied by the dislocation reaction of Shockley partial dislocations (\(\tfrac{1}{6}\) <112>) generating Hirth dislocations (\(\tfrac{1}{6}\) <110>). The dislocation reaction is verified through the dislocation analysis of the crack tip area of the CT specimen after fatigue experiment by using TEM. In addition, the results of this study show that the angle between the direction of crack propagation and the grain boundary affects the fatigue crack propagation, e.g. when the angle is less than 60°, the crack rapidly propagates along the grain boundary. The orientation distribution function (ODF) results of EBSD can verify that the polycrystalline model containing 30 grains is a reliable model for the MD simulation of behavior of the crack tip of CT specimen. Lastly, the Paris law constants for pure silver are determined as m = 3.72 and lg C = − 10.77, providing a reference for the fatigue analysis and life prediction of silver components or silver soldering pots in engineering applications.
期刊介绍:
The International Journal of Fracture is an outlet for original analytical, numerical and experimental contributions which provide improved understanding of the mechanisms of micro and macro fracture in all materials, and their engineering implications.
The Journal is pleased to receive papers from engineers and scientists working in various aspects of fracture. Contributions emphasizing empirical correlations, unanalyzed experimental results or routine numerical computations, while representing important necessary aspects of certain fatigue, strength, and fracture analyses, will normally be discouraged; occasional review papers in these as well as other areas are welcomed. Innovative and in-depth engineering applications of fracture theory are also encouraged.
In addition, the Journal welcomes, for rapid publication, Brief Notes in Fracture and Micromechanics which serve the Journal''s Objective. Brief Notes include: Brief presentation of a new idea, concept or method; new experimental observations or methods of significance; short notes of quality that do not amount to full length papers; discussion of previously published work in the Journal, and Brief Notes Errata.