Mechanical Response of Materials Investigated Through Novel In-Situ Experiments and Modeling: Session I
Sponsored by: TMS Structural Materials Division, TMS Functional Materials Division, TMS: Advanced Characterization, Testing, and Simulation Committee, TMS: Thin Films and Interfaces Committee
Program Organizers: Saurabh Puri, Microstructure Engineering; Amit Pandey, Lockheed Martin Space; Dhriti Bhattacharyya, Australian Nuclear Science and Technology Organization; Dongchan Jang, Korea Advanced Institute of Science and Technology; Shailendra Joshi, University of Houston; Josh Kacher, Georgia Institute of Technology; Minh-Son Pham, Imperial College London; Jagannathan Rajagopalan, Arizona State University; Robert Wheeler, Microtesting Solutions LLC

Monday 8:30 AM
February 28, 2022
Room: 206B
Location: Anaheim Convention Center

Session Chair: Daniel Miracle, Air Force Research Laboratory; Alejandro Barrios, Sandia National Laboratories

8:30 AM  Keynote
Emerging Capabilities for the High-throughput Characterization of Structural Materials: Daniel Miracle1; Mu Li2; Zhaohan Zhang2; Rohan Mishra2; Katharine Flores2; 1Air Force Research Laboratory; 2Washington University in St. Louis
    The rate at which societies advance is linked to the rate of materials advances. Characterizing materials properties remains a major barrier in the rapid development of new, society-changing materials. Combinatorial and high-throughput (CHT) methods to characterize new materials have played a central role in accelerating materials advances in the past decades. These methods are widely used in the chemistry, biology and pharmaceutical fields, and more recently for functional materials. CHT methods have barely been used to develop new structural materials due to major challenges offered by the dominant influence of microstructure and length scale on mechanical properties. High-throughput computations can augment or replace experiments and accelerate data analysis, but a major barrier remains in deploying rapid and reliable experiments for mechanical properties. This presentation will discuss an emerging convergence in computational, experimental and data analytic methods that offer enabling new capabilities to accelerate discovery and development of structural materials.

9:10 AM  Invited
Capturing the Mechanical Response of Three Phase Semi-solids at High Temperatures Using In Situ Synchrotron Imaging - From Superalloys to Magmas: Peter Lee1; Mohammed Azeem1; Nolwenn Le Gall1; Robert Atwood2; 1University College London; 2Diamond Light Source
    Measuring the mechanical response of three phase (solid, liquid and gas) semi-solid materials at high temperatures is particularly challenging due to the strongly non-linear temperature dependence of the properties and many of the material’s reactive nature. To help address this, we have developed a series of thermomechanical environmental rigs to measure the mechanical and rheological properties of materials in temperature ranges from -20 to 1600C whilst on a synchrotron beamline. This allows us to correlate the properties to the evolving microstructural features at the micron scale using in situ radiography, tomography and diffraction We illustrate the benefits and limitations of these techniques measuring the properties for systems ranging from aluminium alloys to cobalt-based superalloys to the flow of molten magma as it bubbles and volatilises. The insights obtained are inform and validate computational models to help design components for transport applications through to predicting volcanic eruptions.

9:40 AM  Invited
Elucidating Deformation Pathways in Refractory Multi-principal Element Alloys via In Situ Experiments: Daniel Gianola1; 1University of California-Santa Barbara
    Refractory multi-principal element alloys (MPEAs) are promising candidates for structural applications demanding mechanical robustness at temperatures exceeding the capacity of state-of-the-art superalloys. While excellent high temperature strength has been demonstrated in many refractory MPEAs, a fundamental understanding of the nature of dislocation pathways in the BCC versions of these chemically complex alloys and their ability to enable macroscopic ductility is still in its infancy. We present a study of a ternary MPEA, MoNbTi, through a combination of in situ dislocation observations, microstructural investigations, and atomistic calculations. Our results highlight multi-planar, multi-character dislocation slip in MoNbTi at low homologous temperature, encouraged by the substantial dispersion in the glide resistance for dislocation due to the atomic-scale chemical fluctuations. The ability of dislocations to choose the easy gliding direction and plane enables an excellent combination of strength and homogeneous plasticity in this alloy, traits that are not simultaneously observed in conventional metallic alloys.

10:10 AM Break

10:30 AM  
High-throughput Fatigue Testing of Nanocrystalline Al Thin Films: Alejandro Barrios1; Cody Kunka1; John Nogan1; Khalid Hattar1; Brad Boyce1; 1Sandia National Laboratories
    This work presents a small-scale high-throughput framework to characterize the mechanical behavior of nanocrystalline thin films. Using microfabrication processes, we developed a Si structure which is composed of periodic unit cells of grips with freestanding dogbone films in between, simulating a small-scale tensile test. The Si structure functions as a nanomechanical testing device in which multiple freestanding dogbones can be simultaneously tested under the same applied mechanical conditions. We used this framework to investigate the low cycle fatigue behavior of nanocrystalline Al through in-situ Scanning Electron Microscopy experiments. These experiments allow for the evaluation of the topographical evolution and crack formation across the fatigue life of several dogbones at the same time, facilitating the understanding of deformation mechanisms in nanocrystalline metals. Additionally, these high-throughput experiments allow for an extensive statistical analysis of fatigue failure in these materials. SNL is managed and operated by NTESS under DOE NNSA contract DE-NA0003525.