ICME 2023: Linkages: Deformation I
Program Organizers: Charles Ward, AFRL/RXM; Heather Murdoch, U.S. Army Research Laboratory
Tuesday 8:00 AM
May 23, 2023
Room: Caribbean IV
Location: Caribe Royale
Session Chair: Karthik Rajan Venkatesan, Eaton
8:00 AM Invited
Computationally Derived Correlations for
Process-induced Cracking During AM of Nickel-based Superalloys: Hector Basoalto1; Chizhou Fang1; Prashant Jadhav2; Magnus Anderson1; Yu Lu1; Lucia Scotti2; 1University of Sheffield; 2University of Birmingham
A multiscale materials modelling framework is presented for simulating the microstructure and mechanical fields during selective laser melting (SLM) of a precipitate strengthened nickel-based superalloy. The approach accounts for physical phenomena associated with the additive process over a number of spatial and temporal scales including solid-liquid-vapour transitions, solidification microstructures (grains and precipitation of ) and defects. A crystal plasticity model is developed for simulation of the mechanical fields and accounts for dissolution and precipitation of particles for the alloy CM247. Stress jumps acting on grain boundaries are extracted, showing the cyclic thermal loading of these boundaries to be sensitive to local texture as well as spatial gradients of the thermal fields generated by the moving heat source. Location of boundaries (relative to the passing melt pool) with high risk of resulting in cracking of a build are identified and discussed in relation to process parameters.
8:30 AM
3D Full-field Crystal Plasticity Simulations on an Explicit Microstructure: How accurate are We: Nikhil Prabhu1; Martin Diehl1; 1KU Leuven
Digital twins based on full field crystal plasticity models serve as an alternative to expensive and time-consuming micro-mechanical experiments. These experiments are, however, still needed as benchmarks for the predictive quality of the modeling approaches. Here we use experimental data of additively manufactured IN625 alloy provided by the Air Fore Research Laboratory as part of a modeling challenge to study the performance of full field crystal plasticity simulations using DAMASK. In particular, we investigate how the choice of the constitutive model and the incorporation of eigenstrains influence the agreement between simulation and experiment.The challenge of initializing the simulation with a realistic field of eigenstrains when only data from a few grains is available is tackled through the use of an iterative scheme that results in an equilibrated eigenstrain field that is in agreement with the experimental data.
8:50 AM
Validation of Crystal Plasticity Simulations using High-energy X-ray Diffraction Microscopy Measurements: Saikumar Reddy Yeratapally1; George Weber2; Edward Glaessgen2; 1National Institute of Aerospace; 2NASA Langley Research Center
A three-dimensional microstructure of additively manufactured (AM) and post-processed Inconel-625 alloy generated as part of the AFRL’s Additive Manufacturing Challenge Series is considered for the purpose of validating the modeling predictions of a crystal plasticity finite element (CPFE) solver. Far-field high-energy X-Ray diffraction microscopy (ff-HEDM) measurements of grain-average elastic strains, on a specimen loaded in tension at room temperature, are compared with predictions from a CPFE framework. The ff-HEDM measurements, obtained while the specimen was held under load-control, were made on the same microstructure considered in the CPFE framework. This one-to-one comparison enables a detailed study of the sources of discrepancy between simulation and experiment, including a thorough investigation of the sources of modeling errors. It is shown that over-constrained boundary conditions and the inability of the CPFE solver to account for stress-relaxation events (which happens during the constant-load holds) contribute to the modeling errors.
9:10 AM
Integrated Computational Materials Engineering Toolkit to Understand Process-structure-property Relationships of Additively Manufactured Metals: Matti Lindroos1; Napat Vajragupta1; Tatu Pinomaa1; Abhishek Biswas1; Sicong Ren1; Tom Andersson1; Anssi Laukkanen1; 1VTT Research Centre of Finland
This work demonstrates the effective ICME workflow to understand the process-microstructure-property linkage of AM metals. Firstly, melt pool modeling will be performed to predict melt pool temperature distributions, which will be used to simulate microstructure evolution during the AM process with methods like Cellular Automata. We will then create synthetic microstructures of AM using statistical descriptions of microstructural features predicted as input. At the single grain level, we utilize a phase field solidification model coupled with a thermomechanical crystal plasticity, enabling us to assess both intra-grain/polycrystal level dislocation/stress heterogeneities introduced during solidification and residual stresses. In the final step, physics-based crystal plasticity model will be applied to the synthetic microstructures generated from the previous step, and micromechanical simulations will be performed to predict the anisotropic deformation behavior and ultimately damage of AM metals. This aims to significantly reduce time and cost required for AM development with the ICME workflow presented.
9:30 AM
Multi-scale Modeling of Dislocation Plasticity in Nano-architectected Metals: Phu Cuong Nguyen1; Ill Ryu1; 1University of Texas at Dallas
Nano-architectected metals can exploit the combination of resilient architecture with size-dependent enhanced properties at nanoscale to achieve exceptional mechanical performance. To obtain a mechanistic understanding of plastic deformation in these materials requires an integrated computational model which can capture the relation between dislocation microstructure characteristics and macroscopic mechanical behaviors. Recently, we develop a multi-scale model to concurrently couple dislocation dynamics (DD) modeling with finite element method (FEM). The DD simulation keeps track of dynamic motion of dislocations and compute the accompanying plastic strain, while FEM simulation solves for the stress field to satisfy equilibrium condition. By integrating these, our model could provide a unique opportunity to investigate fundamental deformation mechanism based on dislocation plasticity and corresponding macroscopic mechanical response. In this study, multi-scale simulations of meso-scale architected structures under uniaxial compression were performed. The architected structures exhibit increasing strength with decreasing unit cell size, which agrees with experimental observations.
9:50 AM Break