Article
Engineering, Mechanical
Yucong Gu, Jonathan Cappola, Jian Wang, Lin Li
Summary: This study investigates the yielding behavior of heterogeneous metallic glasses (MGs) by varying the spatial correlation and standard deviation of local shear moduli associated with clustering atoms on the nanoscale. Through computations and observations, the study proposes a Hall-Petch-like relationship where the yield stress of MGs scales inversely with the square root of the spatial correlation length. The results provide insights into the structure-property relationship of MGs and have important implications for the design of nanoscale MGs with tunable properties.
INTERNATIONAL JOURNAL OF PLASTICITY
(2023)
Article
Materials Science, Multidisciplinary
Devashish Rajpoot, R. Lakshmi Narayan, Long Zhang, Punit Kumar, Haifeng Zhang, Parag Tandaiya, Upadrasta Ramamurty
Summary: Fracture behavior of bulk metallic glass matrix composites with both transforming and non-transforming fi-Ti dendrites under shear and opening modes was examined, showing lower fracture toughness in mode II due to shear dominant stress state and considerable crack growth in this mode. Despite the ability of transforming dendrites to strain harden and enhance ductility, BMGCs reinforced with non-transforming dendrites exhibit higher toughness in both modes. Shear band patterns suggest identical fracture mechanism in BMGCs and BMGs, with differences rationalized by the effect of relaxation enthalpy and dendrites length scale.
Review
Chemistry, Physical
D. Sopu
Summary: The complex nature of shear banding and the disordered structure of metallic glasses pose challenges in understanding the mechanisms of strain localization and shear band formation. The percolation of shear transformation zones (STZs) is widely accepted as the atomic-scale mechanism for shear banding. This review provides an up-to-date assessment of the STZ-Vortex mechanism and its applications in understanding shear band dynamics and deformation mechanisms in metallic glasses. It also highlights unresolved issues where the STZ-Vortex model could be effectively applied.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Review
Chemistry, Physical
Michael Atzmon, Jong Doo Ju, Tianjiao Lei
Summary: The lack of periodicity and long-range order in metallic glasses presents significant challenges in explaining their properties. By using quasi-static anelastic relaxation, researchers have obtained relaxation-time spectra for several metallic glasses, enabling them to examine the distribution and properties of shear transformation zones in microscopic detail. The results reveal an atomically-quantized hierarchy of shear transformation zones, providing insights into structural relaxation, plasticity, and the mechanisms of alpha and beta relaxation.
Article
Nanoscience & Nanotechnology
Fu Xu, Yizhou Liu, Botao Dai, Yanhuai Ding, Celal Kursun, Meng Gao
Summary: In this study, an in-situ tensile platform coupled with a nanoindenter was used to investigate the continuous loading and creep behaviors of Cu50Zr50 metallic glass film under different pre-tensile strains. The volume, activation volume, and relaxation time spectrum of shear transformation zones were determined based on models. The results showed that all three factors increase with pre-tensile strain.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Chemistry, Physical
Yuexin Chu, Guishen Zhou, Shaoshan Wan, Yue Zhang, Fuyu Dong, Xiaoguang Yuan, Binbin Wang, Liangshun Luo, Yanqing Su, Weidong Li, Peter K. Liaw
Summary: The relationship between shear transformation zones (STZs) and serrated flow dynamics in metallic glasses (MGs) was analyzed using nanoindentation. Different plasticity MGs were studied, and two distinct types of serrated flow dynamics were identified. MGs with easily activated STZs or low loading rates exhibited a power-law distribution, indicating a self-organized critical state. In contrast, hard MGs or high loading rates showed a Gaussian distribution, indicating a chaotic state with reduced stresses required for plastic deformation.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Materials Science, Ceramics
Zhi Qiang Ren, Yu Wei Liu, Ying Liu, Jing Tao Wang
Summary: In this paper, a theoretical formulation for shear transformation zone (STZ) volume, shear band density, and plasticity is presented. The temperature dependence of these parameters is discussed. The experimental data of plasticity for Vit105 bulk metallic glass show negative temperature dependence, which is consistent with the prediction of the analytical formulation.
JOURNAL OF NON-CRYSTALLINE SOLIDS
(2023)
Article
Materials Science, Multidisciplinary
Tianbing He, Tiwen Lu, Daniel Sopu, Xiaoliang Han, Haizhou Lu, Kornelius Nielsch, Jurgen Eckert, Nevaf Ciftci, Volker Uhlenwinkel, Konrad Kosiba, Sergio Scudino
Summary: This study explores the effectiveness of powder metallurgy as an alternative method for synthesizing shape memory bulk metallic glass composites. Shape memory bulk metallic glass composites with tunable microstructures and properties are obtained by hot pressing. The results demonstrate the expanded range of shape memory bulk metallic glass composites by freely choosing the combination of glassy matrix and shape memory phase.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2022)
Article
Nanoscience & Nanotechnology
Akib Jabed, Golden Kumar
Summary: This study demonstrates that cryogenic rejuvenation promotes homogeneous-like flow and increases ductility in metallic glass samples. Conversely, annealing has the opposite effect, resulting in a smoother fracture surface.
SCRIPTA MATERIALIA
(2024)
Article
Engineering, Mechanical
A. Khmich, A. Hassani, K. Sbiaai, A. Hasnaoui
Summary: Metallic glasses exhibit high mechanical performance but are usually brittle. Reinforcement of the metallic glass matrix to form composite materials is necessary for improved ductility and toughness. Molecular dynamics simulations can provide insights into the effects of adding Ta and W monocrystalline fibers on the mechanical properties of metallic glasses.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2021)
Article
Chemistry, Physical
Yuexin Chu, Guishen Zhou, Yue Zhang, Fuyu Dong, Xiaoguang Yuan, Binbin Wang, Liangshun Luo, Yanqing Su, Weidong Li, Peter K. Liaw
Summary: This study investigates the heterogeneity of Shear Transformation Zones (STZs) in Zr-based metallic glasses (MGs) using different nanoindentation methods. The results show that the calculated volume of STZs varies depending on the method used, and is influenced by the Poisson's ratio and loading rate.
Article
Nanoscience & Nanotechnology
C. Liu, Y. Ikeda, R. Maass
Summary: This study provides strong evidence for the accumulation of structural damage in Zr-based bulk metallic glass as a result of shear strain admitted by shear bands. Analysis of shear-band structure with high-angle annular dark field transmission electron microscopy reveals scattered data with an overall trend of increasing local volume dilatation with increasing shear strain. However, locally, a variety of trends are observed, highlighting the strong heterogeneity of structural damage in shear bands in metallic glasses.
SCRIPTA MATERIALIA
(2021)
Article
Materials Science, Multidisciplinary
Huaping Sheng, Long Zhang, Haifeng Zhang, Jianbo Wang, Juergen Eckert, Christoph Gammer
Summary: The transformation-induced plasticity is a fundamental solution for improving the ductility of bulk metallic glass composites (BMGCs). The transformation redistributes the stress in the adjacent matrix, making interfacial regions potential preferential sites for shear band nucleation, which then enhance the ductility of BMGCs.
MATERIALS RESEARCH LETTERS
(2021)
Article
Materials Science, Ceramics
Srishti Mishra, Snehanshu Pal
Summary: The structural evolution of Al90Sm10 metallic glass nanowire under torsion deformation at different speeds has been investigated using molecular dynamics simulation. It was found that with increasing torsion speed, the generation of shear transformation zones becomes uneven and the width of shear bands is constrained to narrow regions. Furthermore, the improvement of Voronoi polyhedra also enhances plastic deformation.
JOURNAL OF NON-CRYSTALLINE SOLIDS
(2022)
Article
Chemistry, Multidisciplinary
Sangjun Kang, Di Wang, Arnaud Caron, Christian Minnert, Karsten Durst, Christian Kuebel, Xiaoke Mu
Summary: Scanning/transmission electron microscopy (S/TEM) techniques have been used to analyze shear bands in metallic glasses for decades in order to improve their mechanical properties. However, conventional S/TEM lacks the ability to directly characterize the local strain and atomic structure of amorphous materials. In this study, 4-dimensional-STEM (4D-STEM) is applied to directly map and correlate the local strain and atomic structure at the nanometer scale in deformed metallic glasses. The results provide a new understanding of the formation of shear bands in metallic glasses.
ADVANCED MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Landon T. Hansen, David T. Fullwood, Eric R. Homer, Robert H. Wagoner, Hojun Lim, Jay D. Carroll, Guowei Zhou, Hyuk Jong Bong
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2020)
Article
Materials Science, Multidisciplinary
D. Frazer, J. L. Bair, E. R. Homer, P. Hosemann
Article
Materials Science, Multidisciplinary
Ryan Sperry, Allan Harte, Joao Quinta da Fonseca, Eric R. Homer, Robert H. Wagoner, David T. Fullwood
Article
Nanoscience & Nanotechnology
Hunter C. Erickson, Eric R. Homer
SCRIPTA MATERIALIA
(2020)
Article
Materials Science, Multidisciplinary
Brandon D. Snow, Sterling G. Baird, Christian Kurniawan, David T. Fullwood, Eric R. Homer, Oliver K. Johnson
Summary: Historically, research on correlating grain boundary structure and properties has relied on experimental measurements and computational calculations on bicrystals. This study introduces a Bayesian framework to infer GB structure-property models from indirect polycrystal measurements and severely limited data. The findings suggest that when data is limited, polycrystals may provide more accurate results.
Article
Materials Science, Multidisciplinary
Stephen Cluff, Marko Knezevic, Michael P. Miles, David T. Fullwood, Raja K. Mishra, Anil K. Sachdev, Tyson Brown, Eric R. Homer
Summary: This study explores the influence of strain path on martensite nucleation rate in TRIP-assisted steels, as well as the unique nature of kinematic coupling between adjacent transforming regions under different paths. The research emphasizes the importance of considering strain path and kinematic coupling in understanding the transformation behavior of TRIP-assisted steels.
MECHANICS OF MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
Oliver K. Johnson, Eric R. Homer, David T. Fullwood, David E. Page, Kathryn F. Varela, Sterling G. Baird
Summary: In this work, a non-parametric Bayesian approach is used to develop structure-property models for grain boundaries (GBs) with built-in uncertainty quantification. The method is applied to infer a structure-property model for H diffusivity in [100] tilt GBs in Ni at 700 K based on molecular dynamics (MD) data. The Bayesian approach facilitates the propagation of uncertainties from the underlying structure-property model to the output predictions from mesoscale modeling, allowing for investigation of the interaction between structure-property model uncertainties and GB network structure.
Article
Materials Science, Multidisciplinary
David E. Page, Kathryn F. Varela, Oliver K. Johnson, David T. Fullwood, Eric R. Homer
Summary: This study investigates the impact of nickel grain boundaries on hydrogen diffusion through simulations of 26 different types of grain boundaries. It is found that grain boundary diffusivity is higher than bulk diffusivity within a certain temperature range, and the Borisov relationship fits well with simulated data, providing physically realistic parameter estimates.
Article
Materials Science, Multidisciplinary
Robert D. Moore, Timothy Beecroft, Gregory S. Rohrer, Christopher M. Barr, Eric R. Homer, Khalid Hattar, Brad L. Boyce, Fadi Abdeljawad
Summary: GB stiffness in Ni can be larger and more anisotropic than energy, with some boundary inclinations exhibiting negative stiffness. Results from this study are qualitatively consistent with experimental observations, providing new avenues for examining the plane normal dependency of GB properties in mesoscale treatments of GB migration and microstructural evolution.
Article
Multidisciplinary Sciences
Olivia P. Pfeiffer, Haihao Liu, Luca Montanelli, Marat Latypov, Fatih G. Sen, Vishwanath Hegadekatte, Elsa A. Olivetti, Eric R. Homer
Summary: This study provides two datasets, one containing information on the chemical compositions of aluminum alloys, and the other containing information on the mechanical properties of aluminum alloys, to help researchers accelerate the discovery of new alloys.
Article
Materials Science, Multidisciplinary
Eric R. Homer, Gus L. W. Hart, C. Braxton Owens, Derek M. Hensley, Jay C. Spendlove, Lydia Harris Serafin
Summary: This study presents a computed dataset of 7304 unique aluminum grain boundaries in the 5D crystallographic space. The dataset includes a range of atomic configurations for each structure and has great potential for understanding the relationship between grain boundary structure and properties.
Article
Chemistry, Physical
Eric R. Homer, Oliver K. Johnson, Darcey Britton, James E. Patterson, Eric T. Sevy, Gregory B. Thompson
Summary: Observations of microstructural coarsening and grain boundary motion at cryogenic temperatures have posed challenges to the expected Arrhenius behavior. However, this study demonstrates that classical equations can account for these anomalies and show that non-Arrhenius behavior can arise from thermally activated processes. The phenomenon occurs when the intrinsic barrier energies of the processes become small, allowing activation at cryogenic temperatures.
NPJ COMPUTATIONAL MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Matthew J. Patrick, Gregory S. Rohrer, Ooraphan Chirayutthanasak, Sutatch Ratanaphan, Eric R. Homer, Gus L. W. Hart, Yekaterina Epshteyn, Katayun Barmak
Summary: Grain boundary character distributions (GBCD) can be measured from microcrystalline samples using electron backscatter diffraction (EBSD) and can be used to reconstruct relative grain boundary energy distributions (GBED) based on the 3D geometry of triple lines, assuming the force balance condition is satisfied. However, for nanocrystalline thin films, the GBED cannot be extracted effectively using orientation mapping via precession enhanced electron diffraction (PED). In this study, the relative energy extraction technique was adapted to PED data and the results showed that the GBED extracted from these films do not correlate with energies calculated using molecular dynamics (MD) or with the experimentally determined GBCD. This suggests that additional geometric factors contribute to determining the triple junction geometry and boundary network structure in these films.
Article
Materials Science, Multidisciplinary
John A. Mitchell, Fadi Abdeljawad, Corbett Battaile, Cristina Garcia-Cardona, Elizabeth A. Holm, Eric R. Homer, Jon Madison, Theron M. Rodgers, Aidan P. Thompson, Veena Tikare, Ed Webb, Steven J. Plimpton
Summary: SPPARKS is an open-source simulation code that allows the development and running of various Monte Carlo models at the atomic or meso scales. It can be used to study solid-state materials and their dynamic evolution during processing. The code's modular nature allows the addition of new models and diagnostic computations without modifying its core functionality. It includes models for microstructural evolution, diffusion, thin film deposition, additive manufacturing, and can also implement grid-based algorithms.
MODELLING AND SIMULATION IN MATERIALS SCIENCE AND ENGINEERING
(2023)
Article
Multidisciplinary Sciences
Sterling G. Baird, Eric R. Homer, David T. Fullwood, Oliver K. Johnson
Summary: This paper presents a method for efficient barycentric interpolation of large grain boundary octonion point sets on the surface of a hypersphere. The method involves the removal of degenerate dimensions, determination of intersecting facets, and interpolation. It is applicable to hyperspherical point sets in various applications such as grain boundary structure-property models, robotics, and specialized neural networks.
Article
Materials Science, Multidisciplinary
Y. Liu, K. Zweiacker, C. Liu, J. T. McKeown, J. M. K. Wiezorek
Summary: The evolution of rapid solidification microstructure and solidification interface velocity of hypereutectic Al-20at.%Cu alloy after laser melting has been studied experimentally. It was found that the formation of microstructure was dominated by eutectic, alpha-cell, and banded morphology grains, and the growth modes changed with increasing interface velocity.
Article
Materials Science, Multidisciplinary
Bharat Gwalani, Julian Escobar, Miao Song, Jonova Thomas, Joshua Silverstein, Andrew Chihpin Chuang, Dileep Singh, Michael P. Brady, Yukinori Yamamoto, Thomas R. Watkins, Arun Devaraj
Summary: Castable alumina forming austenitic alloys exhibit superior creep life and oxidation resistance at high temperatures. This study reveals the mechanism behind the enhanced creep performance of these alloys by suppressing primary carbide formation and offers a promising alloy design strategy for high-temperature applications.
Article
Materials Science, Multidisciplinary
Jian Song, Qi Zhang, Songsong Yao, Kunming Yang, Houyu Ma, Jiamiao Ni, Boan Zhong, Yue Liu, Jian Wang, Tongxiang Fan
Summary: Recent studies have shown that achieving an atomically flat surface for metals can greatly improve their oxidation resistance and enhance their electronic-optical applications. Researchers have explored the use of graphene as a covering layer to achieve atomically flat surfaces. They found that high-temperature deposited graphene on copper surfaces formed mono-atomic steps, while annealed copper and transferred graphene on copper interfaces formed multi-atomic steps.
Article
Materials Science, Multidisciplinary
Jennifer A. Glerum, Jon-Erik Mogonye, David C. Dunand
Summary: Elemental powders of Al, Ti, Sc, and Zr are blended and processed via laser powder-bed fusion to create binary and ternary alloys. The microstructural analysis and mechanical testing show that the addition of Ti results in the formation of primary precipitates, while the addition of Sc and Zr leads to the formation of fine grain bands. The Al-0.25Ti-0.25Zr alloy exhibits comparable strain rates to Al-0.5Zr at low stresses, but significantly higher strain rates at higher stresses during compressive creep testing. Finite element modeling suggests that the connectivity of coarse and fine grain regions is a critical factor affecting the creep resistance of the alloys.
Article
Materials Science, Multidisciplinary
P. Jannotti, B. C. Hornbuckle, J. T. Lloyd, N. Lorenzo, M. Aniska, T. L. Luckenbaugh, A. J. Roberts, A. Giri, K. A. Darling
Summary: This work characterizes the thermo-mechanical behavior of bulk nanocrystalline Cu-Ta alloys under extreme conditions. The experiments reveal that the alloys exhibit unique mechanical properties, behaving differently from conventional nanocrystalline Cu. They do not undergo grain coarsening during extrusion and exhibit behavior similar to coarse-grained Cu.
Article
Materials Science, Multidisciplinary
Yiqing Wei, Jingwei Li, Daliang Zhang, Bin Zhang, Zizhen Zhou, Guang Han, Guoyu Wang, Carmelo Prestipino, Pierric Lemoine, Emmanuel Guilmeau, Xu Lu, Xiaoyuan Zhou
Summary: This study proposes a new strategy to modify microstructure by phase regulation, which can simultaneously enhance carrier mobility and reduce lattice thermal conductivity. The addition of Cu in layered SnSe2 induces a phase transition that leads to increased grain size and reduced stacking fault density, resulting in improved carrier mobility and lower lattice thermal conductivity.
Article
Materials Science, Multidisciplinary
Jia Chen, Zhengyu Zhang, Eitan Hershkovitz, Jonathan Poplawsky, Raja Shekar Bhupal Dandu, Chang-Yu Hung, Wenbo Wang, Yi Yao, Lin Li, Hongliang Xin, Honggyu Kim, Wenjun Cai
Summary: In this study, the structural origin of the pH-dependent repassivation mechanisms in multi-principal element alloys (MPEA) was investigated using surface characterization and computational simulations. It was found that selective oxidation in acidic to neutral solutions leads to enhanced nickel enrichment on the surface, resulting in reduced repassivation capability and corrosion resistance.
Article
Materials Science, Multidisciplinary
X. Y. Xu, C. P. Huang, H. Y. Wang, Y. Z. Li, M. X. Huang
Summary: The limited slip systems of magnesium (Mg) and its alloys hinder their wide applications. By conducting tensile straining experiments, researchers discovered a rate-dependent transition in the dislocation mechanisms of Mg alloys. At high strain rates, glissile dislocations dominate, while easy-glide dislocations dominate at low strain rates. Abundant glissile dislocations do not necessarily improve ductility.
Article
Materials Science, Multidisciplinary
M. S. Szczerba, M. J. Szczerba
Summary: Inverse temperature dependences of the detwinning stress were observed in face-centered cubic deformation twins in Cu-8at.%Al alloy. The detwinning stress increased with temperature when the pi detwinning mode was involved, but decreased when the pi/3 mode was involved. The dual effect of temperature on the detwinning stress was due to the reduction of internal stresses pre-existing within the deformation twins. The complete reduction of internal stresses at about 530 degrees C led to the equivalence of the critical stresses of different detwinning modes and a decrease in the yield stress anisotropy of the twin/matrix structure.
Article
Materials Science, Multidisciplinary
Taowen Dong, Tingting Qin, Wei Zhang, Yaowen Zhang, Zhuoran Feng, Yuxiang Gao, Zhongyu Pan, Zixiang Xia, Yan Wang, Chunming Yang, Peng Wang, Weitao Zheng
Summary: The interaction between the electrode and the electric double layer (EDL) significantly influences the energy storage mechanism. By studying the popular alpha-Fe2O3 electrode and the EDL interaction, we find that the energy storage mechanism of the electrode can be controlled by modulating the EDL.
Article
Materials Science, Multidisciplinary
Matthew R. Barnett, Jun Wang, Sitarama R. Kada, Alban de Vaucorbeil, Andrew Stevenson, Marc Fivel, Peter A. Lynch
Summary: The elastic-plastic transition in magnesium alloy Mg-4.5Zn exhibits bursts of deformation, which are characterized by sudden changes in grain orientation. These bursts occur in a coordinated manner among nearby grains, with the highest burst rate observed at the onset of full plasticity. The most significant burst events are associated with twinning, supported by the observation of twinned structures using electron microscopy. The bursts are often preceded and followed by a stasis in peak movement, indicating a certain "birth size" for twins upon formation and subsequent growth at a later stage.
Article
Materials Science, Multidisciplinary
Vaidehi Menon, Sambit Das, Vikram Gavini, Liang Qi
Summary: Understanding solute segregation thermodynamics is crucial for investigating grain boundary properties. The spectral approach and thermodynamic integration methods can be used to predict solute segregation behavior at grain boundaries and compare with experimental observations, thus aiding in alloy design and performance control.
Article
Materials Science, Multidisciplinary
Feiyu Qin, Lei Hu, Yingcai Zhu, Yuki Sakai, Shogo Kawaguchi, Akihiko Machida, Tetsu Watanuki, Yue-Wen Fang, Jun Sun, Xiangdong Ding, Masaki Azuma
Summary: This study reports on the negative and zero thermal expansion properties of Cd2Re2O7 and Cd1.95Ni0.05Re2O7 materials, along with their ultra-low thermal conductivity. Through investigations of their structures and phonon calculations, the synergistic effect of local structure distortion and soft phonons is revealed as the key to achieving these distinctive properties.
Article
Materials Science, Multidisciplinary
Thomas Beerli, Christian C. Roth, Dirk Mohr
Summary: A novel testing system for miniature specimens is designed to characterize the plastic response of materials for which conventional full-size specimens cannot be extracted. The system has an automated operation process, which reduces the damage to specimens caused by manual handling and improves the stability of the test results. The experiments show that the miniature specimens extracted from stainless steel and aluminum have high reproducibility, and the results are consistent with those of conventional-sized specimens. A correction procedure is provided to consider the influence of surface roughness and heat-affected zone caused by wire EDM.
Article
Materials Science, Multidisciplinary
Rani Mary Joy, Paulius Pobedinskas, Nina Baule, Shengyuan Bai, Daen Jannis, Nicolas Gauquelin, Marie-Amandine Pinault-Thaury, Francois Jomard, Kamatchi Jothiramalingam Sankaran, Rozita Rouzbahani, Fernando Lloret, Derese Desta, Jan D'Haen, Johan Verbeeck, Michael Frank Becker, Ken Haenen
Summary: This study investigates the influence of film microstructure and composition on the Young's modulus and residual stress in nanocrystalline diamond thin films. The results provide insights into the mechanical properties and intrinsic stress sources of these films, and demonstrate the potential for producing high-quality nanocrystalline diamond films under certain conditions.
