Advanced Real Time Imaging: Emerging Techniques
Sponsored by: TMS Functional Materials Division, TMS: Advanced Characterization, Testing, and Simulation Committee, TMS: Alloy Phases Committee
Program Organizers: Jinichiro Nakano, MatterGreen LLC; David Alman, National Energy Technology Laboratory; Il Sohn, Yonsei University; Hiroyuki Shibata, Tohoku University; Antoine Allanore, Massachusetts Institute of Technology; Candan Tamerler, University of Kansas; Noritaka Saito, Kyushu University; Neslihan Dogan, TU Delft; Zuotai Zhang, Southern University of Science and Technology; Bryan Webler, Carnegie Mellon University; Anna Nakano, US Department of Energy National Energy Technology Laboratory

Monday 8:00 AM
February 24, 2020
Room: Theater A-4
Location: San Diego Convention Ctr

Session Chair: Jinichiro Nakano, MatterGreen LLC

8:00 AM  Keynote
X-ray Phase Contrast Imaging of Dynamic Compression of Additively Manufactured High-solids-loaded Polymer Composites: Karla Wagner1; Andrew Boddorff1; Greg Kennedy1; Min Zhou1; Naresh Thadhani1; 1Georgia Institute of Technology
    X-ray phase contrast imaging (X-PCI) available at the Dynamic Compression Sector at the Advanced Photon Source is used to provide time- and spatially-resolved shock compression response of high-solids loaded polymer composite fabricated by direct-write Additive Manufacturing (AM), to determine the effects of process-inherent heterogeneities on their dynamic mechanical behavior. Dynamic compression involves complex processes due to shock wave interaction with dissimilar constituents and voids. Understanding these processes requires probing with nano-to-microsecond time and micro- to meso-scale spatial resolution, which is not possible via traditional methods that only provide volume averaged measurements of stress/strain states. In this talk we will present our observations of the shock compression response of AM-fabricated high solids filled polymer composites using X-PCI to examine the deformation and fracture processes and evaluate the equation of state of this complex material. Funding for this research is provided by DTRA Grant No. HDTRA1-18-1-0004.

8:40 AM  Invited
Ultrafast Synchrotron X-ray Imaging Studies of Ultrasonic Processing of Structural and Functional Materials: Jiawei Mi1; 1School of Engineering University of Hull
     Funded by the Royal Society and the UK Engineering and Physical Science Research Council, we have conducted a comprehensive research on ultrasonic processing of structural and functional materials. We have used ultrafast synchrotron X-ray imaging to study the highly dynamic and transient phenomena concerning the fragmentation of crystalline phases and the exfoliation of 2D functional materials under ultrasonic waves. In this paper, I present the recent findings from our research, including (1) ultrasonic bubble oscillation and implosion, and their interactions with the crystalline phases, and (2) ultrasonic bubble implosion and their effects on the exfoliation of the layer structures of Highly Ordered Pyrolytic Graphite, and Molybdenum Disulfide. The research provide unambiguous real-time evidence and quantitative understanding on how ultrasound enhances the fragmentation crystalline phases and the exfoliation of layered materials, laying a solid foundation for further optimising and upscaling ultrasound processing techniques for different materials systems.

9:00 AM  
In-situ TEM Analysis of Mechanical Behavior of the 3D Printed Alloys Exposed to High Temperature: Supriya Koul1; Le Zhou1; Yongho Sohn1; Akihiro Kushima1; 1University of Central Florida
    With the rapidly expanding interests for directly probing complex nano and atomic-scale dynamics in a broad range of materials and applications, in-situ transmission electron microscopy (TEM) is attracting much attention as a crucial tool for developing fundamental insights and formulating design parameters for advanced technologies. Here, we present a unique sample configuration that enables tensile experiment of thin TEM lamellae without undesired off-plane deformations or bending. Since the feature is implemented in the specimen itself, there is no need for special devices offering a flexibility in the material selections and preparations. The method is applied to Inconel 718 and AlSi10Mg alloy as representative selective laser melting (SLM) produced alloys to discover the relationship between the microstructure evolution after heat treatment and the associated changes in the mechanical behavior at nano scale. This analysis provides rich information that can be used to optimize the SLM-produced alloy by controlling the processing parameter.

9:20 AM  
Spatial and Time-dependent Uranium Oxidation Measurements using White-Light Interferometry: Yaakov Idell1; Mark Wall1; Wigbert Siekhaus1; Kerri Blobaum1; William McLean1; 1Lawrence Livermore National Laboratory
    Material degradation of uranium resulting from the uranium-oxygen reaction has long been of great interest to the nuclear industry, but the early stage oxidation kinetics is not well understood. Previous investigations have employed characterization techniques that include microbalance, x-ray diffraction, and spectroscopic ellipsometry in order to understand the oxide growth behavior; however, these studies have been primarily focused on thick oxide films (>1 µm). Additionally, none of these techniques provide spatial information of the oxide growth. We developed an automated and rapid surface sensitive data collection technique that provides three-dimensional spatial data of the growing oxide layer with sub-nanometer thickness resolution using white-light interferometry. Early stage oxidation kinetics and film cracking behavior of uranium heated to 90 °C under 500 torr of pure O2 will be presented. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

9:40 AM Break

10:00 AM  Cancelled
Observing the Growth of Hydrated Crystalline Calcium Carbonate by In-situ Liquid Cell Transmission Electron Microscopy: Yiping Su1; 1Southern University of Science and Technology
    Liquid-cell TEM, a new experimental platform that allows imaging through liquids at the nanoscale, has been applied to the study of nanoparticle growth mechanisms. The combined approach using STEM and EEL spectra with the in situ fluid stage for detailed investigations of solution-based minerals. Calcium carbonate(CaCO3) forms important minerals on Earth,observing the evolution of CaCO3 growth in situ under liquid conditions remains a great challenge. Recently, the newest hydrated crystal phase, hemihydrates (CaCO3•½H2O), was found in the crystallization of amorphous calcium carbonate with magnesium ions. Here, we designed a study of growing hydrated CaCO3 in mineral precursor with complex solution environments in the presence of Ba2+, Sr2+ and Mg2+. Therefore, some insights about hydrated CaCO3 may have been achieved by direct observations of nanoparticle growth processes using real-time STEM imaging and EEL spectra. This feasible strategy may have important implications for understanding mienals growth mechanisms in a natural environment.

10:20 AM  
The Mechanisms of Ultrasound Metrology in Metal Melt: Bitong Wang1; Andrew Caldwell2; Antoine Allanore2; Douglas Kelley1; 1University of Rochester; 2Massachusetts Institute of Technology
    Ultrasound metrology can enable real-time imaging and velocity measurement in a metal melt during its solidification, which could allow us to predict and control casting product quality. In a prior study, we found that the specular reflection of sound waves is the working principle of solidification-front tracking. However, the source and mechanism of bulk echoes in metal melts are still unclear. In this work, we focus on investigating the relationship between bulk echoes and oxide inclusions in the metal melt. Using novel experimental methods, we can observe the movement of oxide inclusions in the metal melt. By analyzing the echo strength, we explore the mode of acoustic scattering based on particle type and size in the melt. We also study the possibility of the existence of ultrasound induced cavitation under our experimental conditions. The experimental results presented here provide an innovative insight into the mechanisms of ultrasound in metal melt.

10:40 AM  
An Investigation of the Impact Experimental Equipment Parameters Have on Synthesis Slag Behaviors in an Oxidative Environment Using a Confocal Laser Microscope: Carlos Ortiz1; Jinichiro Nakano2; Anna Nakano2; James Bennett3; 1Oak Ridge Institute for Science and Education ; 2Leidos Research Support Team; 3U.S. Department of Energy National Energy Technology Laboratory
    Slag, as a process byproduct, is generated by many commercial processes, including gasification. During gasification of a carbon feedstock (typically coal and/or petcoke), ash impurities rapidly melt and coalesce to form a silica-rich molten oxide mixture called slag. This slag interacts with the refractory liner and can foul the syngas cooler, causing corrosive and chemical dissolution that can lead to a gasifier shutdown for cleaning or repair. During the gasification process, slag experiences rapid changes in temperature and oxygen partial pressure as it travels through the gasifier. Slag is not expected to globally attain thermodynamic equilibrium during its short residence time in the gasification chamber. In this work, the melting and crystallization behavior of gasification slag was evaluated by controlling gas flow rate, heating/cooling rates, and gas compositions using a high temperature environmental confocal laser microscope. Results of studies will be interpreted as to the expected impact on gasifier operation.