6th International Congress on 3D Materials Science (3DMS 2022): 4D Data Analysis I: Plasticity II
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
Monday 1:20 PM
June 27, 2022
Room: Capitol B
Location: Hyatt Regency Washington on Capitol Hill
Session Chair: Ricardo Lebensohn, Los Alamos National Laboratory
1:20 PM Invited
Multiscale Scattering Modeling from Deforming Titanium Alloy Polycrystals: Darren Pagan1; Kenneth Peterson1; Rachel Lim1; Jacob Ruff2; 1Pennsylvania State University; 2Cornell University
It is well accepted that distributions of elastic strain (and stress) found in deforming polycrystals have contributions from various features in the microstructure that span length scales and are spatially heterogeneous in 3D. However, to date, efforts to model the effects of these elastic strain distributions on the broadening of X-ray diffraction peaks have primarily focused on a single length scale, likely leading to inaccurate interpretation of experimental results. Here we present a new multiscale scattering framework to capture the effects of both grain interactions and dislocation distributions present. Peak broadening of Ti-6Al-4V during uniaxial deformation, as predicted by the multiscale scattering modeling and crystal plasticity finite element modeling, is compared to experimental peak broadening measured in-situ using new high-dynamic range detection capabilities at the Cornell High Energy Synchrotron Source.
1:50 PM
Influence of Microtextured Regions on Early Plasticity in Ti64: Joseph Wendorf1; James Lamb2; McLean Echlin1; Samuel Hémery3; Paul Dawson4; Tresa Pollock1; 1University of California, Santa Barbara; 2University of California Santa Barbara; 3Institut Pprime - ENSMA; 4Cornell University
Titanium alloys have been extensively used throughout the cold section of jet engines for several decades due to their high strength to weight ratio and excellent fatigue performance. However, many titanium alloys develop microtextured regions (MTRs) during forging which have been shown to significantly reduce dwell fatigue life. Although MTRs typically contain thousands of individual grains, Tribeam serial sectioning enables the collection of 3D EBSD datasets large enough in volume to characterize the 3D structure of MTRs with high enough resolution to also characterize individual grain boundaries. The effect of extreme hard and soft grain neighborhoods found within MTRs on slip initiation within Ti64 has been investigated by combining a 3D EBSD dataset with high resolution surface DIC strain measurements as well as 3D crystal plasticity calculations. The importance of soft grains embedded in hard MTRs will be discussed.
2:10 PM
Imaging Microplasticity Events by Combining High Energy Diffraction Microscopy and Bragg Coherent Diffraction Microscopy: Matthew Wilkin1; 1Carnegie Mellon University
Understanding plasticity events at the grain scale is key to the development of mesoscale models. High Energy x-ray Diffraction Microscopy (HEDM) has proven effective for determining grain-averaged elastic strain and grain orientation in a sample, but it provides no local strain information. Bragg Coherent Diffraction Imaging (BCDI) has been shown to provide 3-D strain fields in individual grains but has largely been applied only to nano-particles, rather than polycrystals. We propose combining these two methods to image the interaction between several grains in a polycrystalline sample. HEDM gives us a 3D map of a microstructure in a sample, providing orientations for each grain. These orientations can be used to locate Bragg peaks for neighboring grains, allowing us to employ BCDI to investigate, in 3D, the interaction between two neighboring grains during heating or loading and the migration of defects within a particular grain.
2:30 PM
Interpretation of Intragranular Strain Fields in High-energy Synchrotron X-ray Experiments via Finite Element Simulations and Analysis of Incompatible Deformation: Diwakar Naragani1; Paul Shade2; William Musinski2; Mark Obstalecki2; Donald Boyce3; Armand Beaudoin3; Joel Bernier4; Darren Pagan5; 1University of Dayton Research Institute; 2AFRL; 3Cornell University; 4Lawrence Livermore National Laboratory; 5Pennsylvania State University
We present an integrated experimental-modeling framework developed to resolve intragranular fields of incompatible deformation. These fields are generated via an anisotropic linear elastic constitutive model augmented by the theory of continuous distribution of dislocations. We model the R=0 cyclic loading of a nickel-based superalloy performed at APS using a finite element simulation, which satisfies boundary conditions, mechanical equilibrium, and strain compatibility. Complementary in-situ X-ray diffraction microscopy measurements yield intergranular lattice orientations and strain tensors at designated states during the loading. The synthesis of simulated and measured deformation fields provides a mesoscopic view of the fundamental heterogeneity in polycrystalline response that creates localized stress “hot spots”. Preferred reorientation of the crystallographic lattices and intergranular stresses foreruns the onset of plasticity and promotes the activation of multiple slip systems. We ultimately show a positive correlation between residual stress and accrued incompatible deformation through specific examples and via a statistical approach.
2:50 PM Cancelled
Correlative Investigation of Strain Localization by Combining SEM-DIC and 3D EBSD: Marie Charpagne1; J.C. Stinville1; A.T. Polonsky2; M.P. Echlin3; T.M. Pollock3; 1University of Illinois; 2Sandia National Laboratories; 3University of California Santa Barbara
A multi-modal data-merging framework that enables the reconstruction of slip bands in three dimensions over millimeter-scale fields of view will be presented. The technique combines 3D electron back-scattered diffraction (EBSD) measurements with high-resolution digital image correlation (HR-DIC) information collected in the scanning electron microscope (SEM). A typical merging workflow involves the segmentation and digitization of strain field features (slip bands, deformation twins), microstructure elements (grains), the careful alignment and merging of SEM and 3D EBSD datasets, and the projection of slip bands into the 3D microstructure using crystallographic considerations. This method enables the automated and statistical study of hundreds of plastic deformation events in relation to the microstructure. Application examples will be presented on two materials: Inconel 718 (FCC) and Ti7Al (HCP)
3:10 PM Break
3:40 PM
Implementing Nonlocal Ductile Damage into a Large Strain FFT-based Model for Predicting Failure in 3D Polycrystalline Materials: Carter Cocke1; Hadi Mirmohammad1; Owen Kingstedt1; Miroslav Zecevic2; Ricardo Lebensohn2; Ashley Spear1; 1University of Utah; 2Los Alamos National Laboratory
Previously developed crystal plasticity finite element method (CP-FEM) models have incorporated porous plasticity or continuum damage mechanics (CDM) to predict ductile failure in polycrystals. However, such CP-FEM models require significant computational resources. Crystal plasticity fast Fourier transform (CP-FFT) models are a growing alternative as they can accurately predict micromechanical fields with significantly reduced computational cost compared to traditional CP-FEM models. However, a need remains to incorporate degradation mechanisms into CP-FFT models to predict ductile failure in polycrystalline materials. This work incorporates a nonlocal triaxiality-based CDM formulation into a large-strain elasto-viscoplastic fast Fourier transform (LS-EVPFFT) model to predict ductile failure in 3D polycrystalline materials. Macroscopic and micromechanical responses are compared between LS-EVPFFT simulations and mesoscale copper tensile specimens experimentally characterized with electron backscatter diffraction and in situ digital image correlation. The computational efficiency of the LS-EVPFFT model with CDM enables tractable predictions of the entire elastic-plastic-failure loading process of polycrystalline materials.
4:00 PM
On the 3D Nature of Dislocation Lines and Core Structures in High Entropy Complex Alloys: Diana Farkas1; Roberto Pasianot2; 1Virginia Polytechnic Institute; 2CNEA Argentina
Dislocations in high entropy complex alloys are wavy and present irregular core structures in three dimensions. We present the results of atomistic level simulations of this phenomena in FCC multicomponent materials. Molecular Dynamics modeling and a model interatomic potential for a quinary alloy are used to investigate the structure and motion of ½ [110] dislocations. The three dimensional shape of the dislocation lines is analyzed as influenced by the random distribution of the component species. We also report the details of the separation of the dislocations into partials and the irregular nature of the resulting dislocation cores. The implications of these structures for the motion of the dislocations under stress are discussed.