Orientation-dependent fatigue damage in planar slip metals

[摘要] Shear banding as a ubiquitous phenomenon is mostly observed in planar slip metals under complex plastic deformation conditions, especially in cyclic deformation. The deformation substructures and local damages during fatigue vary from grain to grain, which depends greatly on the crystallographic orientation. Despite previous extensive studies, the orientation-dependent deformation substructure is still elusive due to the complexity of damage evolution and the limitation of spatial resolution in both reciprocal and real sample spaces by conventional characterization methods. In this study, we conducted synchrotron-based X-ray micro-diffraction (μXRD) experiments to explore the dependence of localized elastic strains on grain orientation. It is demonstrated that the typical intersection of slip shear bands (SSBs) with Lomer-Cottrell locks (LCLs) are the potential damage locations, which are most likely to form in the near [001]//LD grains. The advanced μXRD with ability of spatially quantify the localized strains/fine orientations opens new opportunities for understanding the microscopic mechanisms of damage and failure in bulk materials.

[发布机构] State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing; 100083, China^1;Advanced Photon Source, Argonne National Laboratory, Argonne; IL; 60439, United States^2

[效力级别] 物理学 [学科分类] 材料科学（综合）

[关键词] Characterization methods;Crystallographic orientations;Deformation conditions;Deformation substructures;Lomer-Cottrell locks;Microscopic mechanisms;Orientation dependent;X ray micro diffraction