Multi Scale Modeling of Microstructure Deformation in Material Processing: Multi Scale Modeling of Microstructure Deformation in Material Processing
Sponsored by: AIST Metallurgy—Processing, Products and Applications Technology Committee
Program Organizers: Lukasz Madej, AGH University of Science and Technology; Jaimie Tiley, Oak Ridge National Laboratory; Muszka Krzysztof, AGH University of Science and Technology; Danuta Szeliga, AGH University of Science and Technology
Monday 10:00 AM
October 18, 2021
Room: A122
Location: Greater Columbus Convention Center
Session Chair: Xun Liu, The Ohio State University
10:00 AM
Finite Element Simulation of Grain Growth with an Arbitrary Grain Boundary Energy and Explicit Grain Boundary Representation: Erdem Eren1; Jeremy Mason1; 1University of California, Davis
Finite Element Method (FEM) is used to simulate deformation, but high temperature evolution of microstructure using FEM is challenging because of the changes to the embedded surface mesh representing the grain boundaries. Furthermore, some existing formulations cannot be used for predictive simulations because they do not allow for anisotropic grain boundary properties, have unphysical anisotropy from the underlying numerical model, or allow only a restricted set of topological events that bias the grain boundary network evolution. Recent progress will be reported in developing a FEM simulation that (1) uses a volumetric mesh to eventually allow the inclusion of arbitrary material physics, (2) significantly expands the set of topological events to allow for general grain boundary network dynamics, and (3) proposes an energy dissipation criterion to identify the physically most plausible of these events. Moreover, the performance of three proposed equations of motion will be evaluated and compared to analytical results.
10:20 AM
The Formation of Irradiation Induced Defects in NiTi and their Effects on the Martensitic Transformation: Taiwu Yu1; Alejandro Hinojos1; Daniel Hong1; Peter Anderson1; Michael Mills1; Yunzhi Wang1; 1Ohio State University
Nanoscale defects can form during irradiation of NiTi shape memory alloys. These defects, which include amorphous phases, dislocation loops and nano-voids, can produce special characteristics such as a linearlized response during stress-induced MT, with no distinct plateau, as well as other distinct superelastic behavior. In this work, we simulate the nucleation and growth of irradiation induced defects by a phase field model. Then we show how MTs can be tailored at different conditions of irradiation doses using the phase field method. The results indicate that the size, number density and distribution of the nano-size defects have significant impact on the behavior of the MT and tune the overall MT kinetics from a typical first-order transition into a higher-order continuous transition. Such a unique MT characteristic reduces or even eliminates the transformation hysteresis and produces quasi-linear elasticity with ultra-low apparent elastic modulus.
10:40 AM
Microstructural Evolution from Hot Torsion Tests for Material Modeling and Parameterization: Andrew Gilmore1; Xun Liu1; 1The Ohio State University
This study focuses on an integrated experimental and modeling analysis on deformation behavior of AA2219-T87 aluminum alloy at different strain rates and temperature, which are essential to help understand the physic principles in various manufacturing processes and provide accurate constitutive material models. Hot torsion tests were performed with Gleeble machine with starting texture of the specimens either on the rolling or the transverse direction. Microstructure of the tested specimen are examined to reveal recrystallization and deformed grains. These results are used in tandem with a finite element model (FEM) to determine relationships between local strain, strain rates, temperature and microstructure, along with threshold values to induce recrystallization. The Johnson-Cook Plasticity material model is calibrated by matching the predicted torque curve to the experimental data. The ability to use hot torsion tests with calibrated FEM model to perform material characterization allows for wide ranges of microstructural results from singular tests.