Article
Nanoscience & Nanotechnology
Divya Singh, Vladyslav Turlo, Daniel S. Gianola, Timothy J. Rupert
Summary: Linear complexions are defect phases that form in the presence of dislocations and have the potential to control plasticity directly. This study uses atomistic simulations to demonstrate that linear complexions have unique behaviors compared to classical dislocation glide mechanisms. Different types of linear complexions have different levels of strengthening effects on the resistance to dislocation motion. The study also shows that linear complexions can be a tool for microstructure engineering to create alloys with new plastic deformation mechanisms and extreme strength.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Physics, Fluids & Plasmas
Jozismar Rodrigues Alves, Vera Bohomoletz Henriques
Summary: The main focus of this paper is to address the question of thermodynamic stability in phase-separating systems at equilibrium. By introducing the thermodynamics of the interface between coexisting phases, the authors provide an alternative interpretation for the unstable regions observed in numerical simulations and restore the proper convexity of the true potentials. Additionally, they successfully calculate the surface tension in accordance with Onsager's analytic prediction.
Article
Nanoscience & Nanotechnology
Wangjun Cheng, Dongdong Cui, Yaoning Sun, Wei Liu, Yifei Xu, Bin Liu
Summary: An experimental study was conducted to analyze the undulated work-hardening behavior of S30408 metastable austenitic stainless steel at liquid nitrogen temperature. The effects of cryogenic temperature and deformation degree on the dislocation evolution, phase transformation, slip behavior, and hardening behavior were analyzed. The high strength during cryogenic deformation was mainly attributed to the martensitic transformation and dislocation strengthening.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Materials Science, Multidisciplinary
Divya Singh, Daniel S. Gianola, Timothy J. Rupert
Summary: This study investigates the influence of linear complexions formed by nanoparticle arrays on dislocation mechanics in a Ni-Al alloy through atomistic modeling. A new strength scaling law is discovered, and a mechanism involving both bowing and progressive unpinning is uncovered.
Article
Materials Science, Multidisciplinary
Boris Straumal, Kristina Tsoy, Aleksandr Druzhinin, Valery Orlov, Natalya Khrapova, Gregory Davdian, Gregory Gerstein, Alexander Straumal
Summary: Magnesium-based alloys are highly sought after in the industry due to their lightweight and reliable strength. By alloying magnesium with elements like zirconium, zinc, and rare earth metals, the anisotropy caused by the hexagonal crystal structure of magnesium is effectively addressed. However, the formation of intermetallic phases within the microstructure can weaken the material by providing easy pathways for crack propagation. The study of GB wetting phase transition and controlling GB layers of IP phases becomes crucial to enhance the alloy's mechanical properties and structural integrity. Rating: 9/10.
Article
Chemistry, Physical
J. F. Xiao, B. B. He, C. W. Tan
Summary: {332}(beta) twinning and stress-induced martensite transformation are two important deformation mechanisms in metastable beta titanium alloys. By studying a model alloy, the correlation between {332}(beta) twinning and stress-induced martensite was revealed. The mechanism leads to a strong relationship between {332} twinning and stress-induced martensite in the alloy.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Nanoscience & Nanotechnology
I. Gordeev, L. Kolotova, S. Starikov
Summary: The mechanism of crystallization of Al-Si alloy from an amorphous state is still unclear. This study investigates the properties of aluminum silicide Al2Si structure and reveals the existence of several crystal structures with similar geometry and low formation energies. The chemical ordering in these structures is similar to that in Si-Al melt.
SCRIPTA MATERIALIA
(2022)
Article
Chemistry, Physical
Wenqiang Fang, Wenyan Zhu, Yaoming Shao, Pingping Zheng, Jianxiao Si
Summary: In this study, Mg3Bi2 thin films were prepared at different temperatures using magnetron co-sputtering technique, and their microstructure and thermoelectric properties were investigated. It was found that the film undergoes a structural phase transition as the temperature increases, and different structural films exhibit different electrical properties. Among them, the textured hexagonal Mg3Bi2 thin film showed the highest power factor at 393K.
APPLIED SURFACE SCIENCE
(2022)
Article
Nanoscience & Nanotechnology
Zhouchangwan Yu, Balreen Saini, Yunzhi Liu, Fei Huang, Apurva Mehta, John D. Baniecki, H. -S. Philip Wong, Wilman Tsai, Paul C. McIntyre
Summary: This study systematically investigates the effects of deposition and annealing processes on Hafnia-based ferroelectric thin films. Crystallites consistent with the polar orthorhombic phase were observed in films deposited at elevated ALD temperature, and high-polarization ferroelectric switching was achieved after low-temperature rapid annealing.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Multidisciplinary Sciences
Daniel T. Sneed, G. Alexander Smith, John S. C. Kearney, Christian Childs, Changyong Park, Keith V. Lawler, Ashkan Salamat, Dean Smith
Summary: In this study, SnO2 was analyzed using a combination of synchrotron X-ray diffraction and X-ray absorption spectroscopy across a pressure range of 0 to 82.9 GPa. By utilizing thermal annealing with a CO2 laser, access to all known high-density polymorphs of SnO2 was achieved and their crystallographic information was reported. The metastability of the post-rutile α-PbO2 and PdF2 structures in SnO2 was investigated through experiments and PW-DFT simulations, revealing a complex energetic landscape and suggesting a significant dependence on the pressure-temperature pathway taken in the experiment.
PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES
(2023)
Article
Materials Science, Multidisciplinary
Ruifeng Dong, Hongchao Kou, Yuhong Zhao, Xiaoyang Zhang, Ling Yang, Hua Hou
Summary: The research highlights the evolution of alpha precipitates from dot-like to lath-like, V-shaped clusters, or triangular ones during aging treatment. The study also confirms that variant selection of alpha precipitates induced by the transformation strain and the interplay between alpha variants and the dislocations are key factors for the formation of these morphologies.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2021)
Article
Chemistry, Multidisciplinary
Jiang Luo, Guodong Ren, Brandon M. Campbell, Dongyan Zhang, Tengfei Cao, Rohan Mishra, Bryce Sadtler
Summary: The electrochemical growth of bismuth selenide microcrystals in the metastable orthorhombic phase at room temperature in aqueous solution is reported in this study. The spontaneous formation of a seed layer containing nanocrystals of cubic BiSe enforces the metastable phase, allowing for the growth on a variety of substrates. This method broadens the range of applications for this semiconductor in optoelectronic and electrochemical devices.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Materials Science, Multidisciplinary
Charlette M. Grigorian, Timothy J. Rupert
Summary: In this study, the stability of amorphous complexions in Cu-based alloys was investigated, showing enhanced stability of the amorphous complexion structure in the Cu-Zr-Hf alloy compared to the Cu-Zr alloy. Time-temperature-transformation diagrams were constructed for amorphous-to-ordered complexion transition, revealing a critical cooling rate three orders of magnitude slower in the ternary alloy compared to the binary alloy.
Article
Materials Science, Multidisciplinary
Paul Junge, Moritz Greinacher, Delf Kober, Patrick Stargardt, Christian Rupprecht
Summary: The need for new solutions for electrical insulation is increasing due to the growing electrification in industrial sectors. In this study, alumina coatings with different spray distances were prepared and analyzed to investigate their dielectric properties. The results show that decreasing spray distance reduces resistivity and enhances the formation of the metastable phase.
Article
Chemistry, Multidisciplinary
Eamonn T. Hughes, Mario Dumont, Yingtao Hu, Di Liang, Raymond G. Beausoleil, John E. Bowers, Kunal Mukherjee
Summary: A process has been developed for regrowing thick III-As layers on a thin GaAs template on Si, with a focus on controlling threading dislocation formation. The use of compressively strained dislocation blocking layers leads to a significant reduction in threading dislocation densities by as much as 30x.
CRYSTAL GROWTH & DESIGN
(2022)
Article
Materials Science, Multidisciplinary
Zhifeng Huang, Vladyslav Turlo, Xin Wang, Fei Chen, Qiang Shen, Lianmeng Zhang, Irene J. Beyerlein, Timothy J. Rupert
Summary: In this study, the segregation behavior of Y at basal-prismatic interfaces in Mg alloys was investigated using atomistic simulations. It was found that interfaces with disconnections and dislocations are more energetically stable and have lower segregation energy, indicating the importance of local defects and atomic hydrostatic stress in segregation behavior at complex interfaces in Mg alloys.
COMPUTATIONAL MATERIALS SCIENCE
(2021)
Article
Nanoscience & Nanotechnology
Jiaxiang Wang, Xin Wang, Kehang Yu, Timothy J. Rupert, Subhash Mahajan, Enrique J. Lavernia, Julie M. Schoenung, Irene J. Beyerlein
Summary: The study investigates the effect of Y concentration on slip and twinning mechanisms in binary Mg-Y alloys. Increasing Y concentration reduces the intensities of the initial and deformation textures, as well as plastic anisotropy, tension-compression asymmetry, and twinning. The model suggests that increased Y concentration increases the critical resolved shear stress for basal slip and reduces plastic anisotropy, leading to enhanced non-basal activity in Mg-Y alloys.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Materials Science, Multidisciplinary
Charlette M. Grigorian, Timothy J. Rupert
Summary: It has been demonstrated that increasing the chemical complexity of grain boundaries can enhance the ductility and stability of nanocrystalline alloys. In this study, significant boundary segregation was observed in the Cu-Zr-Hf-Nb-Ti alloy, resulting in a thicker amorphous complexion and high thermal stability. The complex grain boundary chemistry and multi-component segregation contributed to the thicker amorphous complexion and the enhanced stability.
JOURNAL OF MATERIALS RESEARCH
(2022)
Article
Nanoscience & Nanotechnology
Yann L. Mueller, Lars P. H. Jeurgens, Andrej Antusek, Vladyslav Turlo
Summary: This study investigates the phase stability and atomic mobility of confined metals in Cu/AlN nanomultilayers using molecular dynamics simulations, revealing promising engineering tools for enhancing reaction kinetics at low temperatures.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Materials Science, Multidisciplinary
Javier Troncoso, Vladyslav Turlo
Summary: Magnesium (Mg) is a metallic element with attractive mechanical properties, but its potential is hindered by its low ductility. This study investigates the applicability of available Mg potentials for modeling the properties of metastable bcc polymorph of Mg. The results suggest that the modified embedded atom method (MEAM) potentials are suitable for studying bcc Mg in Mg/Nb nano-composites, while neural network interatomic potentials may be better for modeling high-pressure bcc Mg.
MODELLING AND SIMULATION IN MATERIALS SCIENCE AND ENGINEERING
(2022)
Article
Nanoscience & Nanotechnology
Xin Wang, Yang Hu, Kehang Yu, Subhash Mahajan, Irene J. Beyerlein, Enrique J. Lavernia, Timothy J. Rupert, Julie M. Schoenung
Summary: The study investigates deformation-induced solute segregation in a Mg-Y alloy at room temperature. High concentrations of Y were observed at dislocation cores, and the segregation arrangement minimizes lattice distortion and is supported kinetically by dynamic interactions between solute atoms, crystallographic defects, and slip-twin interactions during plastic deformation.
SCRIPTA MATERIALIA
(2022)
Article
Nanoscience & Nanotechnology
Tianjiao Lei, Mingjie Xu, Jungho Shin, Daniel S. Gianola, Timothy J. Rupert
Summary: Unique nanorod precipitates with a core-shell structure are found to nucleate from the grain boundaries of a bulk nanocrystalline Al-Ni-Y alloy. The local structure and chemistry of these features during annealing are studied. As annealing time increases, more nanorods transform to an ordered structure while the shell chemistry transitions from Y-rich to Ni-rich. The correlation between the nanorods and amorphous complexions is observed.
SCRIPTA MATERIALIA
(2022)
Article
Materials Science, Multidisciplinary
Tianjiao Lei, Esther C. Hessong, Jungho Shin, Daniel S. Gianola, Timothy J. Rupert
Summary: The mechanical behavior of two nanocrystalline Al alloys, Al-Mg-Y and Al-Fe-Y, was investigated through in-situ micropillar compression testing. The alloys exhibited hierarchical microstructures and high yield strengths, but also showed issues such as plastic softening and grain growth.
Article
Materials Science, Multidisciplinary
Pulkit Garg, Timothy J. Rupert
Summary: Amorphous grain boundary complexions lack long-range crystalline order, but distinct gradients in structural short-range order have been observed. This study tests the hypothesis that the distribution of short-range order is determined by the confining crystals using atomistic simulations. The results show that the density of ordered structural motifs in the amorphous-crystalline transition region is inversely related to grain incompatibility.
Article
Physics, Applied
Doruk Aksoy, Megan J. McCarthy, Ian Geiger, Diran Apelian, Horst Hahn, Enrique J. Lavernia, Jian Luo, Huolin Xin, Timothy J. Rupert
Summary: This study uses atomistic modeling to simulate a high-temperature alloy and investigates the influence of interfacial segregation and chemical short-range ordering on grain boundary behavior. The results show that there are extended segregation zones near the boundaries, exhibiting chemical patterning and structural transitions. The widths of these regions are affected by grain size and temperature. Additionally, the analysis of chemical short-range order reveals that only certain elemental clustering types are more likely to be present near specific boundaries, emphasizing the increased chemical complexity in these near-boundary segregation zones.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Physics, Applied
Ian Geiger, Jian Luo, Enrique J. Lavernia, Penghui Cao, Diran Apelian, Timothy J. Rupert
Summary: Refractory multi-principal element alloys with excellent mechanical properties at elevated temperatures have attracted increasing attention. This study investigates the segregation trends and underlying structural and chemical driving factors in the grain boundaries of NbMoTaW alloys using atomistic simulations. The complex interplay between local grain boundary structure and chemical short-range ordering is highlighted, suggesting tunable segregation and chemical ordering by tailoring the grain boundary structure in multi-principal element alloys.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Engineering, Manufacturing
Viktor Lindstrom, Giandomenico Lupo, Jian Yang, Vladyslav Turlo, Christian Leinenbach
Summary: This study proposes a simple thermal scaling model for predicting the transition from balling mode to conduction mode in laser powder bed fusion. The model's accuracy and reliability are verified through experiments and simulations, and it suggests viable strategies for adjusting the operating parameters to achieve defect-free 3D printed parts.
ADDITIVE MANUFACTURING
(2023)
Article
Nanoscience & Nanotechnology
Divya Singh, Vladyslav Turlo, Daniel S. Gianola, Timothy J. Rupert
Summary: Linear complexions are defect phases that form in the presence of dislocations and have the potential to control plasticity directly. This study uses atomistic simulations to demonstrate that linear complexions have unique behaviors compared to classical dislocation glide mechanisms. Different types of linear complexions have different levels of strengthening effects on the resistance to dislocation motion. The study also shows that linear complexions can be a tool for microstructure engineering to create alloys with new plastic deformation mechanisms and extreme strength.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Materials Science, Multidisciplinary
Javier F. Troncoso, Yang Hu, Nicolo M. della Ventura, Amit Sharma, Xavier Maeder, Vladyslav Turlo
Summary: Twinning is an important deformation mode in hexagonal close-packed materials. Atomistic simulations are used to investigate the role of twin/matrix interfaces in twin growth kinetics. However, there is currently no framework for automatically differentiating these interfaces. This study explores the use of machine learning to analyze local stress field distribution as an indicator for the presence and types of interfaces in Mg-10 at.% Al alloys.
COMPUTATIONAL MATERIALS SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Florence Baras, Olivier Politano, Yuwei Li, Vladyslav Turlo, Sergey Zharkov
Summary: Using molecular dynamics simulations, nanometric multilayers composed of immiscible silver (Ag) and nickel (Ni) metals were studied. The results showed that at high temperatures, there was enhanced mobility and partial dissolution of Ni within the amorphous Ag at the interface. The study also examined the grooving phenomenon at grain boundaries in polycrystalline layers.
