Advanced Characterization Techniques for Quantifying and Modeling Deformation: Poster Session
Sponsored by: TMS Extraction and Processing Division, TMS Structural Materials Division, TMS: Advanced Characterization, Testing, and Simulation Committee, TMS: Materials Characterization Committee
Program Organizers: Arul Kumar Mariyappan, Los Alamos National Laboratory; Irene Beyerlein, University of California, Santa Barbara; Wolfgang Pantleon, Technical University of Denmark; C. Tasan, Massachusetts Institute of Technology; Olivia Jackson, Sandia National Laboratories

Tuesday 5:30 PM
March 21, 2023
Room: Exhibit Hall G
Location: SDCC


L-1: Elastic Mismatch and Mixed-mode Buckling-induced Delamination: Influence on Mode I Adhesion Measurements: Stanislav Zak1; Megan Cordill1; 1Erich Schmid Institute of Materials Science, Austrian Academy of Sciences
    Recent progress in modern industry leads to miniaturization and use of thin films and coatings e.g. in microelectronics devices for conductive layers or in harsh environment protective coatings. Such applications combine largely dissimilar materials, which can lead to critical failure at the interface by delamination fracture. Therefore, the investigation of modern thin films adhesion on different substrates is crucial. A straightforward method to measure the adhesion is the buckling induced delamination method by Hutchinson and Suo, assessing the mixed-mode adhesion energy. With a proper assessment of the mixed-mode conditions at the delamination crack tip, the true mode I adhesion GIc of the thin film can be evaluated. The presented work is aimed at quantification of the influence of elastic mismatch on the calculation of GIc for real material combinations and comparison of buckling delamination with/without elastic mismatch influence in regards to pure mode I experimental measurements of thin film adhesion.

L-2: Grain-scale Multiaxial Deformation in Multicomponent Alloys: Yaozhong Zhang1; 1University of Michigan
    Multicomponent alloys (MCAs) demonstrate extraordinary mechanical properties including high strength and ductility synergy and excellent mechanical performance in extreme environments. However, much of our understanding on the mechanical properties of the MCAs is limited to uniaxial loading conditions at macro-scale. Therefore, exploring the mesoscale responses of the MCAs under complex multiaxial loading and connecting them to the macroscale response is of great importance. We present results from mesoscale analysis of MCAs under multiaxial loading using in-situ high energy diffraction microscopy (HEDM) to capture the evolution of grain-resolved stress states and reorientation with plastic straining. Single-phase, equiatomic CoCrNi solid-bar polycrystalline samples were fabricated and evaluated as representative MCAs under: (i) pure torsion, and (ii) axial-torsional loading up to approximately 0.4% effective strain. Additionally, preliminary experimental results were used to instantiate a novel crystal plasticity finite element (CPFE) model for verification of experimental grain-level response.

L-3: Overview of a Versatile Loading System for Anisotropic Material Property Characterization: Malachi Nelson1; David Kamerman1; Peter Hosemann2; 1Idaho National Laboratory ; 2University of California, Berkeley
    Additive manufacturing, cold rolling, and other thermomechanical treatments on metals, especially HCP, can cause texture and oriented grain structures resulting in anisotropic mechanical properties. This can lead to macroscopic response that significantly deviates from isotropic assumptions which motivates studying mechanical properties in multiple directions. In addition, multiaxial loading and complex stress states overlapping the above mentioned material anisotropy can lead to unexpected outcomes. Idaho National Laboratory developed an advanced mechanical testing system to study a range of uniaxial to multiaxial stress states while measuring the anisotropic response bringing insight into the overlap between material properties and stress states. High-temperature capability and stress- or strain-controlled loading is available to enable a variety of experiment types and conditions to measure elastic, plastic, and viscoplastic properties. This poster presents the design and capabilities of this system with preliminary results highlighting the benefits of multiaxial loading and anisotropic analysis in an integrated system.

L-4: Pythonic ODFs and SODFs for EBSD and Far Field HEDM: Austin Gerlt1; Eric Payton2; Donald Boyce3; Joel Bernier4; Paul Shade2; Mark Obstalecki2; Stephen Niezgoda1; 1Ohio State University; 2Air Force Research Lab; 3Cornell University; 4Lawrence Livermore National Laboratory
     Orientation distribution functions (ODFs) describe the statistical likelihood of finding a given local orientation within a volume of interest. Likewise, Stress orientation Distribution Functions (SODFs) give information about the elastic mechanical state of a material as a function of orientation. Several parameterizations exist for efficiently solving both, with H.J. Bunge’s spherical harmonics approach in 1984 and Ashish Kumar’s finite element approach in 1996 being the two most popular. Both methods have had excellent open source adaptations since the early 2000’s (Most notably MTEX by Ralph Hielscher and ODFPF by Donald Boyce, respectively), but to the author’s knowledge, neither have been implemented in a free to use software language. This talk will discuss two parallel efforts for implementing these methods into pythonic toolsets (ORIX for spherical harmonics and HEDM for finite element, respectively), thus lowering the barrier of entry for the global community into the world of texture analysis.

L-5: Shear Behavior of AL2024-T351: Experiments and Modeling: Sara Ricci1; Saryu Fensin2; Benjamin Derby2; J. Valdez2; George Gray2; Gianluca Iannitti1; Andrew Ruggiero1; Nicola Bonora1; G. Testa1; 1University of Cassino and Southern Lazio; 2Los Alamos National Laboratory
    Stress triaxiality is not sufficient to explain the effect of the stress state on the ductility of materials such as Al2024-T351. For such materials, a dependence of the fracture strain on the third invariant of the stress tensor deviator has been proposed. The investigation of ductile fracture under pure shear conditions offers the possibility to qualify shear-driven damage mechanisms and validate material modeling. Here, the influence of microstructural anisotropy on the shear behavior of Al2024-T351 has been systematically investigated with the compact forced-simple-shear (CFSS) sample geometry. A microstructural investigation was carried out on three tested samples whose shear planes are aligned to the rolling, transverse and normal directions. The load-displacement curves and the DIC strain maps were used to validate the plasticity damage self-consistent (PDSC) model, developed in the context of continuum damage mechanics, where the damage dissipation potential accounts for different damage mechanisms (intervoid necking, shearing, and sheeting).

L-6: Tensile Properties and Damage Tolerance of FiberForm: Robert Quammen1; Connor Varney1; Paul Rottmann1; 1University of Kentucky
    Porous materials exhibit a variety of attractive functional properties for aerospace applications such as low density and low thermal conductivity. It is necessary, though, that these porous materials be mechanically robust, as they experience high stresses and vibrational fatigue. Testing these materials under service conditions is prohibitively costly, incentivizing computational approaches. However, the inherent microstructural stochasticity requires extensive experimental validation and benchmarking to accurately model their behavior. This study aims to quantify the tensile properties and impact of previous damage (e.g. cracks, through holes) on the damage and fracture of FiberForm. Damage accumulation will be observed and quantified through the duration of the tests using digital image correlation (DIC) and correlated with optical and electron microscopy of tested samples to observe the underlying mechanisms. These results will provide broad experimental data to inform and benchmark modeling approaches to accurately predict and tailor the reliability of porous parts under service conditions.

L-7: Validating Texture and Lattice Strain Models via In-situ Neutron Diffraction and Shear Tests: Efthymios Polatidis1; Manas Upadhyay2; Jan Capek1; 1Paul Scherrer Institute; 2Ecole Polytechnique
    Modeling the micromechanical behavior of materials is usually challenging under complex deformation stress states, or the availability of experimental setups allowing complex stress states, to verify simulations, is limited. Here we employ an in situ shear and neutron diffraction investigation to follow the crystallographic texture, through diffraction intensity and the lattice strain evolution. A flat shear specimen geometry is utilized and the implemented digital image correlation system in the experimental setup records the macroscopic strain evolution. The experimental macroscopic strain and force values are matched with a finite element simulation, from which it is seen that relatively high normal stress components develop. The evolution of diffraction intensity and lattice strain are simulated using the Taylor model and a Fast Fourier Transformation (FFT) crystal plasticity model respectively. Both simulations show very good match with the experimental results, modeling both the texture and lattice strain evolution under shear.

L-8: (S)TEM Characterization of Stability of Retained Austenite in Medium Mn Steel under Severe Deformation: Italo Oyarzabal1; 1Institut Jean Lamour
    Third-generation Advanced High Strength Steels (AHSS) have potential applications for the automotive industry, due to their balance between strength and ductility. Medium Mn steel microstructure consists of refined ferrite, retained austenite, and sometimes fresh martensite, obtained through intercritical annealing. Controlling the stability of the austenite phase during this thermal process is vital for the steel to show an efficient TRIP effect. Cold-rolled ferritic samples with composition 0.2C-4Mn-0.8Al-1.5Si were processed through different thermal treatments to provide the different medium Mn microstructures. Further, we use (Scanning) Transmission Electron Microscopy ((S)TEM) to investigate the austenite grain structure distribution, and Energy Dispersive Spectroscopy (EDS) was used to provide a chemical characterization of the partitioning element Mn between γ/α. With the results provided, it is possible to comprehend better the interplays between the different deformation mechanisms and the effect of local chemical gradients on austenite stability.