6th International Congress on 3D Materials Science (3DMS 2022): Solidification/Phase Transformations
Program Organizers: Dorte Juul Jensen, Technical University of Denmark; Marie Charpagne, University of Illinois; Keith Knipling, Naval Research Laboratory; Klaus-Dieter Liss, University of Wollongong; Matthew Miller, Cornell University; David Rowenhorst, Naval Research Laboratory
Tuesday 1:20 PM
June 28, 2022
Room: Capitol A
Location: Hyatt Regency Washington on Capitol Hill
Session Chair: Jonathan Madison, National Science Foundation
1:20 PM Invited
Quantitative Observation of Dendritic Growth in Metallic Alloys by Time-Resolve and In-situ Tomography: Takuya Kawarasaki1; Taka Narumi1; Tomohiro Takaki2; Hideyuki Yasuda1; 1Kyoto University; 2Kyoto Institute of Technology
Time-resolved in-situ tomography, using synchrotron radiation X-rays at SPring-8, were developed to observe dendritic growth in Al-based and Fe-based alloys. The voxel size of the reconstructed image was approximately 6.5 μm × 6.5 μm × 6.5 μm. The time resolution (duration of 360-deg rotation) was as short as 0.5 s for Al-Cu alloys and 4 s for Fe-C alloys. Evolution of dendrites were clearly observed in the reconstructed 3D images. However, the contrast and the signal-to-noise-ration needed to be improved to tack the solid-liquid interface and to evaluate the area and the curvature of the solid-liquid interface. A filter procedure using Phase Field model, which are used for simulation of dendritic growth, was developed. The interfacial area and the curvatures were evaluated as a function of solidification time. Some applications using the obtained 3D dataset are also demonstrated.
1:50 PM
Eutectic Colony Evolution during Oscillatory Instability in Eutectic Solidification: Paul Chao1; Ashwin Shahani1; 1University of Michigan
A number of fundamental questions remain unanswered regarding thedynamics of eutectic patterns with anisotropic interface energies. Here, we observe experimentally the solidification behavior of an Al-Cu binary eutectic as a model system using a novel imaging approach that combines in-situ X-ray radiography and ex-situ X-ray tomography. The former allows us to trace the solid-liquid interfaces while the latter enables us to visualize the solid-solid interfaces. When put together, we can quantify the development of a highly branched and three-dimensional microstructure in the presence of an oscillatory solid-liquid interface velocity. These details provide insight into the mechanism of eutectic colony growth accommodating changes from growth velocity fluctuations. Our quasi-4D tomography approach holds broad appeal to the solidification science community, as it can temporally resolve the solidification process on the order of seconds and spatially resolves individual lamellae on the order of micrometers.
2:10 PM
Casting Design Optimization using FEA Utilizing ICME Predicted Local Properties: Jiten Shah1; 1PDA LLC
Casting process modeling simulating the mold filling, solidification and cooling for various processes and alloys using ICME tools is a very powerful and matured technology. Complex structural castings often have thick and thin cross sections and the local micro structure and mechanical properties are non-isotropic due to uneven cooling rates. The current main stream approach with design optimization assumes isotropic properties, which further can be refined using more realistic local properties. Author will present the methodology and a few case studies of the casting design optimization using FEA based structural analysis coupling the ICME predicted local properties.
2:30 PM
Investigation of Grain Boundary Precipitation in Titanium Alloys using 3D FIB/SEM Tomography and 3D Phase Field Simulation: Dian Li1; Rongpei Shi2; Yufeng Zheng1; 1University of Nevada-Reno; 2Harbin Institute of Technology (Shenzhen)
The mechanical performance of titanium alloys can be optimized by tuning the hcp structured alpha precipitates in a matrix of bcc structured beta phase. Our previous study in Ti-5Al-5Mo-5V-3Cr (wt%, Ti-5553) has shown that fine-scale alpha precipitates can nucleate from the pre-formed omega/beta interface. In this work, the grain boundary alpha precipitates in the Ti-5553 alloy were investigated using 3D FIB/SEM tomography and 3D phase field simulations. The 3D morphology of grain boundary alpha precipitates was characterized by the FIB serial sectioning using Thermo Scientific Scios 2 FIB/SEM and reconstructed using the MIPAP image analysis software. The nucleation and growth of grain boundary alpha precipitates was simulated using 3D phase field simulation. The influence of the inclination angle between the habit plane of the selected variant for grain boundary alpha and the hosting grain boundary plane in determining the morphology of grain boundary precipitates in titanium alloys will be introduced.
2:50 PM
Formation of Three-phase Eutectic Grains on Primary Phases: Observations from Correlative Imaging: George Lindemann1; Paul Chao1; Ashwin Shahani1; 1University Of Michigan
We investigate the interaction between three-phase eutectic and a primary phase during solidification of an off-eutectic Al-Ag-Cu alloy through correlative imaging. In situ synchrotron X-radiography reveals the locations and orientation of the primary Al2Cu phase, with respect to the eutectic, which strongly influence the eutectic growth velocity. By combining these results with three-dimensional (3D) focused ion beam tomography, scanning electron microscopy, and electron backscatter diffraction, we provide evidence of two-dimensional (2D) dendrites, or fingers, of Al and Ag2Al that spread along the primary Al2Cu surfaces; meanwhile, protrusions of Al2Cu grow in between pockets of the fingers and into the surrounding eutectic, preserving their crystallographic orientations in the process. We propose a competitive growth relationship between the three phases to explain these features as well as the diversity of two- and three-phase microstructures obtained at the onset of eutectic solidification.
3:10 PM Break
3:40 PM
In Situ Heating for Laboratory-Based Nanoscale X-ray Microscopy: Stephen Kelly1; Robin White1; Hrishikesh Bale1; William Harris1; William Fadgen1; Sam Kalirai2; Martin Leibowitz2; Hooman Hosseinkhannazer3; 1Carl Zeiss RMS; 2Carl Zeiss X-ray Microscopy; 3Norcada, Inc.
The mechanical and microstructural properties of many materials depend on temperature. These thermal properties dictate material behavior during thermal fluctuations, such as elevated temperature. A new device is presented to provide in situ sample heating up to 500 °C in the Xradia Ultra family of X-ray microscopes with spatial resolutions down to 50 nm. The in situ heating unit utilizes Micro-Electro-mechanical Systems (MEMS) technology whereby the heater is built directly onto a silicon and SiN windowed chip, allowing for high X-ray transmission. Various material science applications ranging from soft polymers to metal alloys are discussed and we present initial results demonstrating the utility. The in situ heater provides the ability to perform heating experiments without the need to remove or remount the sample. This allows for continuous imaging during temperature ramp, at target temperature holds, and temperature step / cycling to probe dynamic changes in the sample, in 3-dimensions.
4:00 PM
Kinetic Pathway of Order-Order Transition in Diblock Copolymer by Time-resolved 3D Electron Microscopy: Hsiaofang Wang1; Hiroshi Jinnai1; 1Institute of Multidisciplinary Research for Advanced Materials, Tohoku University
The kinetic pathway of order-order transition (OOT) from hexagonal packing cylinder (HEX) to hexagonal perforated layer (HPL) in polystyrene-block-poly(2-vinylpyridine) (PS-b-P2VP) is studied by time-resolved transmission electron microtomography (3D-TEM). Our results reveal that the OOT from HEX to HPL through a nucleation and growth process from the metastable initial state. Cylinder domains randomly form a nucleation site by thermal fluctuation. An undulation of the interface induced by the instability grows as an undulating shape to form the intermediate structure. Subsequently, the neighboring intermediate structures approach each other and coalesce into the HPL phase with ABAB…stacking sequence. Self-alignment of HPL orientation can also be visualized during thermal annealing due to entropic consideration. This work provides the first example of the real-time and real-space kinetic pathway of phase transition for soft materials.
4:20 PM
Automated Serial-sectioning Method using Electrolytic Etching and Precision Cutting for 3D Microstructure Observation of Additively Manufactured Alloy 718: Shunsaku Kawasaki1; Norio Yamashita2; Shoan Mizuno3; Shinya Morita1; Hideo Yokota2; 1Tokyo Denki University; 2Riken Center for Advanced Photonics; 3NTS Co., Ltd.
Metal additive manufacturing has been attracting attention as an innovative technology for manufacturing complex-shaped parts, especially in the aerospace industry. Alloy 718 has shown great promise as a material suitable for high-temperature applications and with excellent chemical stability. However, in metal additive manufacturing of Alloy 718, three-dimensional anisotropy in microstructure shape occurs, which affects the mechanical strength. Therefore, three-dimensional microstructure observation is required. In this study, a fully automated serial sectioning method using electrolytic etching and precision cutting was developed for Alloy 718. Using the ultrasonic elliptical vibration cutting method, we found the conditions under which the mirror surface of Alloy 718, a difficult-to-cut material, could be created. The mirror surface creation was achieved within one minute. By acquiring 50 cross-sections in less than three hours, we succeeded in acquiring the anisotropic 3D microstructure of additively manufactured Alloy 718 with a resolution of less than one micrometer.
4:40 PM
Numerical Simulation for Prediction of Gas Porosity and Microstructure in Solidifying Aluminium Alloy Using LBM-CA (Cellular Automata) Model: Wonjoo Lee1; Yuhyeong Jeong1; Howon Lee2; Seong-hoon Kang2; Jonghun Yoon1; 1Hanyang University; 2Korea Institute of Materials Science
In the current study, a three-dimensional (3D) LBM (lattice Boltzmann method)-CA model has been constructed to predict the microstructure evolution including the dendritic structure and micro porosities during the solidification process with taking into consideration of fluid flow of molten metal, which is able to demonstrate the dendrite morphologies and solute redistributions. To validate the constructed numerical model, as-casted microstructure in a casting process has been examined with experimental results in terms of the dendrite formation and texture distribution. To predict the dendrite morphology, microstructure, and porosity evolution in the solidification of molten metal, numerically, LBM-CA model has been developed by integrating the lattice Boltzmann method (LBM) to solve the mass transport by diffusion and convection during solidification and cellular automata (CA) to determine the phase transformation with respect to the solid fraction based on the local equilibrium theory.
5:00 PM
Investigation of Threshold Stress Level of Radially Reprecipitated Hydrides: A Phase-field Approach: Wooseob Shin1; Kunok Chang1; 1KyungHee University
Dry storage of the spent nuclear fuel (SNF) is an inevitable option in terms of ease and cost of SNF management. A Zr-based cladding has a strong tendency to absorb hydrogen and hydride precipitates as the cladding temperature during dry storage. The hydride in Zr-based cladding seriously degrade the mechanical integrity of the cladding, especially when it is radially oriented. We applied KKS(Kim-Kim-Suzuki) multiphase field model with elasticity to evaluate threshold applied stress level to radially precipitate δ-hydride on α-Zr affected by the temperature and dissolved hydrogen concentration. And we exhibited crystalline anisotropic interfacial energy to indicate when δ-hydride is formed in the cladding as hexagonal shape. We utilized MOOSE multiphysics framework to simulate the behavior of the hydride on the cladding materials quantitatively. Our obtained threshold applied stress level can be a meaningful guide to find safe and economic environments of the dry stored SNF.