Mechanical Response of Materials Investigated through Novel In-situ Experiments and Modeling: Session I
Sponsored by: TMS Structural Materials Division, TMS: Thin Films and Interfaces Committee, TMS: Advanced Characterization, Testing, and Simulation Committee
Program Organizers: Saurabh Puri, VulcanForms Inc; Amit Pandey, Lockheed Martin Space; Dhriti Bhattacharyya, Australian Nuclear Science and Technology Organization; Dongchan Jang, Korea Advanced Institute of Science and Technology; Jagannathan Rajagopalan, Arizona State University; Josh Kacher, Georgia Institute of Technology; Minh-Son Pham, Imperial College London; Robert Wheeler, Microtesting Solutions LLC; Shailendra Joshi, University of Houston
Monday 8:30 AM
March 15, 2021
Room: RM 17
Location: TMS2021 Virtual
Session Chair: Minh-Son Pham, Imperial College
8:30 AM
In-situ X-Ray Diffraction Investigation of High-strain Rate, High-temperature Deformation in Microalloyed Steel: Tim Wigger1; Rosa Pineda1; Simon Hunt2; Danielle Fenech3; Ben Thomas4; Thomas Kwok5; David Dye5; Gorka Plata6; Jokin Lozares6; Inaki Hurtado6; Stefan Michalik7; Michael Preuss2; Mohammed Azeem8; Peter Lee1; 1University College of London; 2University of Manchester; 3University of Cambridge; 4University of Sheffield; 5Imperial College London; 6Mondragon Unibertsitatea; 7Diamond Light Source; 8University of Leicester
A novel high-strain rate, high-temperature steel forging process has been developed, substantially reducing material use and processing steps compared with conventional forging or semi-solid forming. This study aims to uncover the micro-mechanical and microstructural evolution during the process at T=1300°C and ἐ=10s-1, which to date is poorly understood. The rapid transient, non-equilibrium transformations were captured in-situ by angle-dispersive high-energy X-ray powder diffraction with high time resolution. The microstructural evolution in different steel grades was examined, revealing that the deformation process involves grain rotation, nucleation and refinement due to the formation of small- and large-angle grain boundaries. A steady-state phase in stress and strain indicates a temporary balance between work hardening and recovery processes, enabling high ductility by dynamic recovery and dynamic recrystallisation. These results improve our understanding of high-temperature, high-strain rate deformation processes in materials with FCC crystal structure, supporting the development of constitutive models for more efficient manufacturing routes.
8:50 AM
In-situ Characterization of Material under Extreme Thermal Cycling Using High-speed Synchrotron X-ray Diffraction: Chihpin Chuang1; Peter Kenesei1; Yan Gao2; Jonathon Almer1; Jun-Sang Park1; 1Argonne National Laboratory; 2GE Global Research
In this presentation, we will discuss recent development in in-situ characterization capabilities at sector-1 of Advanced Photon Source (APS). The setup utilizes high-speed area detector to probe material response under extreme thermal cycling conditions. Key features include a novel hybrid photon counting detector that is capable of recording multiple diffraction cones with a frame rate of 250Hz, and up to 1k Hz in ROI mode. Combination of zero background and six orders of dynamic range, the detector is ideal to monitor both major and minor phases simultaneously. The developed setup aims to explore the uncommon space in temperature/time and to better understand the effect of rapid heating and cooling to the microstructure features of engineering alloys. Selected studies on Ti-6Al-4V and Ni-based alloy will be presented to highlight the advantages of the setup as well as limitations.
9:10 AM
Mechanical Behavior and Microstructural Evolution of a Cu-0.7Cr-0.1Zr Alloy at Cryogenic Temperature: An In-situ Synchrotron X-ray Evaluation: Pedro Oliveira1; Danielle Magalhães1; Marcel Izumi2; Osvaldo Cintho2; Andrea Kliauga1; Vitor Sordi1; 1Federal University Of São Carlos; 2State University Of Ponta Grossa
The present work concerns the evaluation of the mechanical behavior and microstructural changes of a Cu-0.7Cr-0.1Zr alloy (UNS C18150), during deformation at 123 K and 298 K. The alloy was tensile tested at both temperatures using a Gleeble™ 3350 machine. Simultaneously, the microstructural changes were followed by an in-situ synchrotron X-ray diffraction. The results showed an increase of both yield and ultimate tensile strength, and a slightly increase in uniform elongation. It was also noted a general tendency to increase the dislocation density and decrease the crystallite size, as the strain was increased. These microstructural changes were even more pronounced at 123 K. Moreover, the Kokcs-Mecking model showed that the dynamic recovery rate was reduced at 123 K. Hence, it was concluded that the reduced dynamic recovery rate at 123 K led to an increase in the work hardening capacity, which caused the simultaneous increase in strength and ductility.
9:30 AM
A Quantitative Assessment of Stress/Strain Partitioning in a Dual-phase Titanium Alloy: Gaoming Zhu1; Shaolou Wei; Cemal Tasan1; 1Massachusetts Institute of Technology
Dual-phase titanium alloys generally represent a good combination of strength and ductility. The deformation coordination between the α and β phases is the major mechanisms accounting for their load-bearing responses, the corresponding stress/strain distribution and thereby partitioning features, however, still remain elusive and deem detailed considerations. In this presentation, by investigating a Ti-Al-V-Fe (α+β) alloy, we aim to quantitatively elucidate the stress/strain partitioning characteristics with the assist of in-situ synchrotron X-ray diffraction experimentation. We will introduce here a theoretical framework in deriving the stress and strain tensor distribution of α and β phases, based on the two-dimensional diffraction patterns. By coupling these analyses with in-situ micro digital image correlation (DIC) technique, we will also discuss in detail about the role of stress/strain partitioning in the macroscopic deformation behavior.
9:50 AM
Dislocation Density Inference from XRD Simulations of In-situ Microstructure Evolution Using Discrete Dislocation Dynamics: Dylan Madisetti1; Jaafar El Awady1; 1Johns Hopkins University
A computational framework for simulating x-ray diffraction was developed and implemented to track microstructure evolution from three-dimensional discrete dislocation dynamics (DDD) simulations. The model implements ray-tracing techniques and Bragg-scattering theory to track x-ray deflection and to characterize how the evolving dislocation microstructure produces a given diffraction pattern. While other studies have used similar techniques for static or relaxed microstructure configurations, the computational speed-ups provided by this method allow for in-situ tracking of diffraction patterns over the course of a virtual experiment. With this new framework, the evolution of dislocation microstructure can be tracked through time as a function of peak broadening. These results are then utilized to explanation observed in in-situ XRD patterns of micro-pillar loading experiments.
10:10 AM Keynote
Microstructural Anisotropy and Its Influence on the Internal Stress Field within Grains: Experimental Confrontation with Full Field Crystal Plasticity Models: Kaustubh Venkatraman1; Meriem Ben Haj Slama1; Vincent Taupin1; Nabila Maloufi1; Stephane Berbenni1; Anthony Rollett2; Martin Diehl3; Antoine Guitton1; 1Université de Lorraine – CNRS; 2Carnegie Mellon University; 3Max-Planck-Institut für Eisenforschung GmbH
Comprehensive micro-scale studies bring valuable information for extrapolating to the macroscopic mechanical response of materials and they can feed advanced multiscale crystal plasticity models. In this framework, macroscopic mechanical testing of bulk specimens has been successfully combined with a dislocation-scale characterization technique: Accurate Electron Channeling Contrast Imaging (A-ECCI). This study focusses on BCC Titanium where 48 slip systems are potentially active and pencil glide occurs and hence serves as a challenging benchmark for the proposed methodology. The full potentiality of A-ECCI for following the evolution of deformation microstructures will be highlighted. Micro-structural information available from ECCI has been used for examining the effect of anisotropic elastic and plastic properties on the local stress field and dislocation activity distribution within grains at different stages of deformation and gather statistical information for identifying relevant micromechanical and microstructural variables that influence the material behavior.
10:50 AM
Impact of Precipitate Size, Orientation, and Temperature on Strain Hardening Behavior in Al-Cu Alloys: Brian Milligan1; Dong Ma2; Lawrence Allard2; Amit Shyam2; Amy Clarke1; 1Colorado School of Mines; 2Oak Ridge National Laboratory
Recent advances in Al-Cu alloy development have once again put a spotlight on their strain hardening behavior. This study observes strain hardening behavior in both the precipitate and matrix phases as a function of their orientation (with multiple aging conditions and testing temperatures applied) via in-situ neutron diffraction. This technique allows for the study of load transfer from the matrix phase to the precipitate phase, which was used to identify precipitate bypass mechanisms and, by extension, strain hardening mechanisms. Load transfer was found to be highly anisotropic for plate-shaped θ′ precipitates, which mitigated load transfer by rotating instead of deforming elastically. A new phenomenological model was developed which allows for the prediction of stresses in both the matrix and θ′ precipitate phases from bulk stress-strain curves.