6th International Congress on 3D Materials Science (3DMS 2022): 4D Data Analysis III: Grain Boundary Structure
Program Organizers: Dorte Juul Jensen, Technical University of Denmark; Marie Charpagne, University of Illinois; Keith Knipling, Naval Research Laboratory; Klaus-Dieter Liss, University of Wollongong; Matthew Miller, Cornell University; David Rowenhorst, Naval Research Laboratory
Tuesday 1:20 PM
June 28, 2022
Room: Capitol B
Location: Hyatt Regency Washington on Capitol Hill
Session Chair: George Spanos, TMS
1:20 PM Invited
Grain Boundary and Dislocation Structures in Metals Resolved by Transmission Electron Microscopy: Kui Du1; Chunyang Wang1; Huichao Duan1; Linglei Zhang1; 1Institute of Metal Research
Grain boundary is one of the most important crystalline defects in crystalline metals and alloys. The structure and behavior of grain boundary often determine the mechanical as well as many physical properties of materials. Grain boundary structures can be dependent on temperature, stress and other factors, thus the grain boundary structures in real materials are usually more complicate than ideal grain boundaries proposed by theory. During the plastic deformation of metals and alloys, grain boundaries become obstacles for dislocation slips and thus introduce a strengthening mechanism to the materials. In this work, we have employed transmission electron microscopy to resolve grain boundary structures in metallic materials and the interaction between dislocation slips and grain boundaries during plastic deformation.
1:50 PM
Implicit Geometrical Measurement of Grain Structures with a Phase Field Representation: Jin Zhang1; Peter Voorhees1; 1Northwestern University
Analysis of grain structures requires the knowledge of quantities like grain size, grain boundary area and triple-line length, which are typically measured from a surface mesh. Generally, a surface mesh is not readily available from experiments, like 3DXRD and DCT, or simulations that utilize an implicit representation of the grain structure, like the phase field method or the level-set method. To avoid the laborious meshing process, in this work, we propose an approach to measure geometrical quantities directly from the implicit representations. Here we focus on the phase field representation. The level-set representation can be easily converted into the phase field one via an analytical relation and the voxelized grain map from experiments can be transformed accordingly by a phase field smoothing process. The proposed method is demonstrated by several examples of measuring these important geometrical parameters on grain structures.
2:10 PM
Thermal Microstructure Evolution of Deformed Mg Investigated in-situ by High-Energy Synchrotron Radiation: Xiaojing Liu1; Klaus-Dieter Liss1; 1Guangdong Technion – Israel Institute of Technology
In the present paper, we describe in-situ heating experiments on rolled AZ31, AZ91 and pure Mg alloys using high-energy synchrotron X-ray diffraction in both Spring-8 (Japan) and DESY (Germany). We found that X-ray diffraction provides rich information on heat-mediated transformation processes, which lead to the formation of different intermetallic phases. The azimuthal distributions of diffraction intensity for each peak can be extracted from the two-dimensional diffractograms within one frame. In-situ synchrotron experiment provides us with thousands of frames during heating, from which important information on the recovery, recrystallization, grain growth and grain rotation processes to be investigated in detail from the multi-dimensional azimuthal-time plot. In addition, texture evolution upon heating can be detected using this data analysis. The obtained results demonstrate that the in-situ synchrotron diffraction combined with multi-dimensional data analysis is a powerful tool to investigate the microstructure evolution in metals and alloys.
2:30 PM Break
3:40 PM
Fingerprints of Abnormal Grain Growth in a Three-Dimensional Microstructure: Marcel Chlupsa1; Eli Rotman1; Jiwoong Kang1; Ashwin Shahani1; 1University of Michigan
Understanding abnormal grain growth (AGG) will enable control of polycrystalline microstructures and their properties. Unfortunately, this task is made difficult due to the rareness of AGG and the limitations on imaging sufficiently large regions via conventional characterization techniques. Here, we overcome this challenge by using 3D x-ray diffraction contrast tomography to visualize over 10,000 grains in a single specimen, a breakthrough in laboratory-based characterization. An Al sample was heated to 300 °C for 1 min. to promote recrystallization and grain growth. From the reconstructed data, we identified 45 abnormally large grains that comprised 10% of the total volume. We selected a set of descriptors to quantify their topological, crystallographic, and geometric attributes and performed a principal component analysis. The data reveal the combination of features that distinguish the abnormally large grains from the other grains in the microstructure, bringing us closer to predicting the occurrence of AGG in real materials.
4:00 PM
Calculating the Grain Boundary Inclination of Voxelated Grain Structures Using a Smoothing Algorithm: Lin Yang1; Floyd Hilty2; Vivekanand Muralikrishnan1; Kenneth Silva-Reyes1; Amanda Krause1; Joel Harley1; Michael Tonks1; 1University of Florida; 2Pacific Northwest National Laboratory
We have developed a flexible method for calculating the grain boundary (GB) inclinations of voxelated grain structure data using smoothing algorithms. We compared the performance of four algorithms: the linear interpolation, Allen-Cahn, level-set, and vertex algorithms. We assessed their accuracy using 2D and 3D cases with known inclinations. The vertex algorithm provided the best balance between accuracy and efficiency for 2D structures while the linear interpolation algorithm provided the best balance for 3D structures. We compared the GB inclinations calculated using our smoothing method on a 3D high energy x-ray diffraction microscopy (HEDM) dataset to those determined by meshing the GBs. The two approaches determined similar GB plane distributions, though they varied significantly at triple junctions. Finally, the smoothing method was demonstrated for two sources of 3D voxelated grain structures: HEDM data and results from Monte Carlo Potts grain growth simulations.
4:20 PM
Methods for Characterizing 3D Grain Boundary Network Structures: Tools from Spectral Graph Theory: Christopher Adair1; Oliver Johnson1; 1Brigham Young University
Grain boundaries form complex, interconnected networks in crystalline materials. Many characterization methods depend on statistical analysis, simplified dimensionality, 2D structures, and binary constitutive models to represent grain boundary networks and their connection to material properties. This style of analysis often neglects the highly interconnected, high-dimensional nature of 3D grain boundaries, which, in turn, obscures valuable characterization opportunities. In this presentation, we utilize spectral graph theory as a method for capturing the 3D network behavior of grain boundaries. We present a method for decoding this spectral representation into network specific characteristics. We then describe the effects these network characteristics have on macroscopic material properties.
4:40 PM
3D Non-destructive Crystallographic Imaging of Peridotite with Lab-based X-ray Diffraction Contrast Tomography: Jun Sun1; Florian Bachmann1; Jette Oddershede1; Erik Lauridsen1; 1Xnovo Technology
The information of lattice-preferred orientation (LPO) of minerals is important to understand the structural anisotropy in earth science, e.g. the relationship between the LPO of olivine and the deformation geometry of Earth’s upper mantle from seismic anisotropy. Non-destructive imaging of minerals using X-ray combining absorption and diffraction contrast tomography provides rich information in resolving the phases as well as mapping out the orientation and morphology of grains non-destructively in 3D. In the present work, we present a multimodal imaging study of a peridotite sample, using both absorption contrast tomography and diffraction contrast tomography on a laboratory X-ray microscope, for a correlative characterisation of between the LPOs of olivine/pyroxene grains and the natural cracks present in the sample. The advantages of non-destructive 3D crystallographic imaging of minerals will be presented and its future applications for geoscience will be discussed.