{"title":"标记载荷法表征定向能沉积 Ti-6Al-4V 中疲劳裂纹的生长","authors":"","doi":"10.1016/j.engfracmech.2024.110500","DOIUrl":null,"url":null,"abstract":"<div><div>Fatigue crack growth properties of materials are crucial for evaluating damage tolerance in additive manufacturing (AM) metallic structures. However, the unique microstructures and defects of AM materials result in highly complex fatigue crack growth behaviors. Currently, there is a lack of systematic fatigue crack growth rate measurement methods specifically targeting this characteristic. Therefore, taking directed energy deposited Ti-6Al-4V titanium alloy as the object of the study, fatigue crack growth tests were conducted in three orthogonal build orientations of the material using marker load method. Additionally, the visual measurement and compliance methods were also employed to measure fatigue crack growth rates, and the anisotropy of fatigue crack growth property was analyzed. Subsequently, anisotropic fatigue crack growth behaviors were characterized by optical microscope, scanning electron microscope, confocal microscope, and electron backscatter diffraction, suggesting that the microstructure is the primary factor affecting overall fatigue crack growth. Furthermore, nanoindentation tests were conducted to obtain the micromechanical properties within and among columnar grains in different build orientations, clarifying the homogeneity and anisotropy of mechanical properties. Finally, a fatigue crack growth rate measurement method based on marker load method was established, and the advantages of this method in AM materials and structures were summarized by comparing the results with those obtained using these two mature methods.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":null,"pages":null},"PeriodicalIF":4.7000,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Characterization of fatigue crack growth in directed energy deposited Ti-6Al-4V by marker load method\",\"authors\":\"\",\"doi\":\"10.1016/j.engfracmech.2024.110500\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>Fatigue crack growth properties of materials are crucial for evaluating damage tolerance in additive manufacturing (AM) metallic structures. However, the unique microstructures and defects of AM materials result in highly complex fatigue crack growth behaviors. Currently, there is a lack of systematic fatigue crack growth rate measurement methods specifically targeting this characteristic. Therefore, taking directed energy deposited Ti-6Al-4V titanium alloy as the object of the study, fatigue crack growth tests were conducted in three orthogonal build orientations of the material using marker load method. Additionally, the visual measurement and compliance methods were also employed to measure fatigue crack growth rates, and the anisotropy of fatigue crack growth property was analyzed. Subsequently, anisotropic fatigue crack growth behaviors were characterized by optical microscope, scanning electron microscope, confocal microscope, and electron backscatter diffraction, suggesting that the microstructure is the primary factor affecting overall fatigue crack growth. Furthermore, nanoindentation tests were conducted to obtain the micromechanical properties within and among columnar grains in different build orientations, clarifying the homogeneity and anisotropy of mechanical properties. Finally, a fatigue crack growth rate measurement method based on marker load method was established, and the advantages of this method in AM materials and structures were summarized by comparing the results with those obtained using these two mature methods.</div></div>\",\"PeriodicalId\":11576,\"journal\":{\"name\":\"Engineering Fracture Mechanics\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":4.7000,\"publicationDate\":\"2024-09-21\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Engineering Fracture Mechanics\",\"FirstCategoryId\":\"5\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0013794424006635\",\"RegionNum\":2,\"RegionCategory\":\"工程技术\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"MECHANICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Engineering Fracture Mechanics","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0013794424006635","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MECHANICS","Score":null,"Total":0}
引用次数: 0
摘要
材料的疲劳裂纹生长特性对于评估增材制造(AM)金属结构的损伤容限至关重要。然而,AM 材料独特的微观结构和缺陷导致了高度复杂的疲劳裂纹生长行为。目前,还缺乏专门针对这一特性的系统疲劳裂纹生长率测量方法。因此,以定向能沉积 Ti-6Al-4V 钛合金为研究对象,采用标记载荷法在材料的三个正交构建方向上进行了疲劳裂纹生长测试。此外,还采用目测法和顺应性法测量了疲劳裂纹生长率,并分析了疲劳裂纹生长特性的各向异性。随后,通过光学显微镜、扫描电子显微镜、共聚焦显微镜和电子反向散射衍射对各向异性的疲劳裂纹生长行为进行了表征,表明微观结构是影响整体疲劳裂纹生长的主要因素。此外,还进行了纳米压痕测试,以获得不同构建方向的柱状晶粒内部和之间的微观力学性能,从而明确力学性能的均匀性和各向异性。最后,建立了基于标记载荷法的疲劳裂纹生长率测量方法,并通过与这两种成熟方法的结果对比,总结了该方法在 AM 材料和结构中的优势。
Characterization of fatigue crack growth in directed energy deposited Ti-6Al-4V by marker load method
Fatigue crack growth properties of materials are crucial for evaluating damage tolerance in additive manufacturing (AM) metallic structures. However, the unique microstructures and defects of AM materials result in highly complex fatigue crack growth behaviors. Currently, there is a lack of systematic fatigue crack growth rate measurement methods specifically targeting this characteristic. Therefore, taking directed energy deposited Ti-6Al-4V titanium alloy as the object of the study, fatigue crack growth tests were conducted in three orthogonal build orientations of the material using marker load method. Additionally, the visual measurement and compliance methods were also employed to measure fatigue crack growth rates, and the anisotropy of fatigue crack growth property was analyzed. Subsequently, anisotropic fatigue crack growth behaviors were characterized by optical microscope, scanning electron microscope, confocal microscope, and electron backscatter diffraction, suggesting that the microstructure is the primary factor affecting overall fatigue crack growth. Furthermore, nanoindentation tests were conducted to obtain the micromechanical properties within and among columnar grains in different build orientations, clarifying the homogeneity and anisotropy of mechanical properties. Finally, a fatigue crack growth rate measurement method based on marker load method was established, and the advantages of this method in AM materials and structures were summarized by comparing the results with those obtained using these two mature methods.
期刊介绍:
EFM covers a broad range of topics in fracture mechanics to be of interest and use to both researchers and practitioners. Contributions are welcome which address the fracture behavior of conventional engineering material systems as well as newly emerging material systems. Contributions on developments in the areas of mechanics and materials science strongly related to fracture mechanics are also welcome. Papers on fatigue are welcome if they treat the fatigue process using the methods of fracture mechanics.