Application of microLaue diffraction using a 3D energy-dispersive detector to study the evolution of fatigue damage in polycrystalline structural materialsy

使用 3D 能量色散探测器应用 microLaue 衍射研究多晶结构材料疲劳损伤的演变

• 批准号: 332602495
• 负责人: Professor Dr.-Ing. Hans Jürgen Christ
• 金额: --
• 依托单位: Lehrstuhl für Materialkunde und Werkstoffprüfung
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/332602495?language=en
• 关键词: Application; microLaue; diffraction; using; 3D

Engineering structural alloys are usually polycrystalline and multiphase alloys, i.e. they con-sist of many grains, which differ in crystallographic orientation and lattice structure. Many material properties, such as the quasistatic strength and the fatigue lifetime, depend directly on the interaction between the grains. Grain and phase boundaries represent obstacles for the dislocation motion, determine the propagation behaviour of microstructural short fatigue cracks, and may lead to stress concentrations and eventually to crack initiation as a conse-quence of anisotropic elastic and crystal-plastic deformation. Microscopic techniques, such as scanning electron microscopy, allow visualization of damage at the surface resulting for example from fatigue loading. Experiments applying high-energy synchrotron beam sources enable to determine the stress condition in the grain volume both at the surface and the interior by the evaluation of few reflexes. A new innovative and promising technique, which is intended to be developed further in the framework of this project for the characterisation of the fatigue damage evolution, is the white beam Laue diffraction in combination with the use of an energy-dispersive semiconductor area detector. Since all Bragg angles and reflex energies can be determined simultaneously, all reflexes can be indexed immediately. If the lattice structure is know, it is additionally possible to allocate the reflexes to the reflecting grain. However, thus far it is not possible to determine the spatial relationship of the indexed grains. In damaged grains, the Laue reflexes are expanded. By means of the energy-dispersive detector, the energy dependence of the streaks can be evaluated and assigned to specific defect patterns (dislocation clusters, internal stresses, microcracks, etc.). As soon as some methodical problems (grain-grain neighbourhood relationships, allocation of energy dependence of Laue streaks, correlation between microscopic and roentgenographic defect identification, etc.) have been solved, the white beam Laue diffraction method will be applied to engineering materials. In particular, the grain-grain interaction of singe-phase and multiphase polycrystalline materials during cyclic loading will be studied. From the results obtained, new insights on the efficiency of microstructural barriers will be gained enabling an unerring application of this knowledge to the increase of the fatigue resistance of modern structural materials.

工程结构合金通常是多晶和多相合金，即由许多晶粒组成，这些晶粒具有不同的晶体取向和晶格结构。许多材料性能，如准静态强度和疲劳寿命，直接取决于晶粒之间的相互作用。晶界和相界是位错运动的障碍，决定了显微组织疲劳短裂纹的扩展行为，并可能导致应力集中，最终导致裂纹萌生，这是各向异性弹性和晶塑性变形的结果。显微镜技术，如扫描电子显微镜，允许在表面上的损伤，例如由疲劳载荷造成的可视化。实验应用高能量同步辐射光源，使确定应力条件下的颗粒体积在表面和内部的几个反射的评价。一个新的创新和有前途的技术，这是为了进一步开发的框架内的疲劳损伤演变的特性，是结合使用的能量色散半导体区域检测器的白色光束劳厄衍射。由于所有的布拉格角和反射能量可以同时确定，所有的反射可以立即索引。如果已知晶格结构，则还可以将反射分配给反射颗粒。然而，到目前为止，不可能确定索引颗粒的空间关系。在受损的谷物中，劳厄反射扩大。通过能量色散探测器，可以评估条纹的能量依赖性，并将其分配给特定的缺陷模式（位错簇、内应力、微裂纹等）。一旦一些方法上的问题（晶粒-晶粒邻域关系、劳厄条纹的能量依赖分配、显微缺陷识别与X射线缺陷识别之间的相关性等）得到解决，解决了这一问题，白色光束劳厄衍射法将在工程材料中得到应用。特别地，将研究在循环加载期间单相和多相多晶材料的颗粒-颗粒相互作用。从所获得的结果，新的见解的效率的微观结构的障碍，将获得使这方面的知识，以增加现代结构材料的抗疲劳性的无误的应用。

项目成果

VHCF damage in duplex stainless steel revealed by microbeam energy-dispersive X-ray Laue diffraction

微束能量色散 X 射线劳厄衍射揭示双相不锈钢中的 VHCF 损伤

• DOI: 10.1016/j.ijfatigue.2021.106358
• 发表时间: 2021
• 期刊: International Journal of Fatigue
• 影响因子: 6
• 作者: A. Abboud;A. AlHassan;B. Dönges;J. S. Micha;R. Hartmann;L. Strüder;H.-J. Christ;U. Pietsch
• 通讯作者: U. Pietsch

In situ observations of single grain behavior during plastic deformation in polycrystalline Ni using energy dispersive Laue diffraction

使用能量色散劳厄衍射原位观察多晶镍塑性变形过程中的单晶粒行为

• DOI: 10.1016/j.msea.2019.138778
• 发表时间: 2020
• 期刊: Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
• 影响因子: 6.4
• 作者: M. Shokr;A. Abboud;C. Kirchlechner;N. Malyar;U. Ariunbold;R. Hartmann;L. Strüder;C. Genzel;M. Klaus;U. Pietsch
• 通讯作者: U. Pietsch

Influence of different loading stresses on the peak shape of X-ray rocking curves of an austenitic-ferritic duplex stainless steel during VHCF

不同加载应力对奥氏体-铁素体双相不锈钢VHCF过程中X射线摇摆曲线峰形的影响

• DOI: 10.1007/978-3-658-24531-3_7
• 发表时间: 2018
• 作者: A. K. Hüsecken;B. Dönges;M. Söker;K. Istomin;U. Krupp;H.-J. Christ;U. Pietsch
• 通讯作者: U. Pietsch