Article
Engineering, Multidisciplinary
Haijie Zhang, Menghuai Wu, Peter Schumacher, Christian M. G. Rodrigues, Andreas Ludwig, Abdellah Kharicha
Summary: The study investigates the phenomenon of solidification and re-melting in technical castings and their impact on structural homogeneity. A new model is proposed to address both grain nucleation and destruction, aimed at improving understanding of the solidification/melting process.
APPLIED MATHEMATICAL MODELLING
(2021)
Article
Chemistry, Multidisciplinary
Tie-Jun Li, Wei-Hua Yang, Jin-Yan Pan, Rao Huang, Gui-Fang Shao, Yu-Hua Wen
Summary: This study investigates the thermally activated microstructural evolution and resultant collapse of PtIrCu nanorings using molecular dynamics simulations. The results reveal that both the thermal and shape stabilities of these nanorings can be remarkably improved by decreasing the inner radius.
Article
Green & Sustainable Science & Technology
Mahdi Kazemi, Ali Kianifar, Hamid Niazmand
Summary: The research aimed to investigate the feasibility of using phase change material (PCM) to fabricate an air-PCM heat exchanger for buildings, showing that nano-PCMs can improve heat transfer efficiency and reduce melting and solidification time.
SUSTAINABLE ENERGY TECHNOLOGIES AND ASSESSMENTS
(2022)
Article
Chemistry, Inorganic & Nuclear
Jie Xu, Yao Cheng, Ju Xu, Hang Lin, Yuansheng Wang
Summary: The size-dependence of thermally enhanced upconversion luminescence (UCL) for UCNPs has been previously considered to be monotonous. However, this study finds that the monotonic relationship between UCL thermo-enhancement ratio and particle size is broken when the size of UCNPs goes below 7 nm. The breaking of monotonicity is accompanied by a change in the relationship between luminescence properties and particle size and supports the explanation of UCL thermo-enhancement through lattice thermal expansion-induced alleviation of surface quenching.
INORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Materials Science, Multidisciplinary
Min Zheng, Lei Wei, Jing Chen, Qiang Zhang, Guohao Zhang, Xin Lin, Weidong Huang
Summary: This study investigated the development of surface features of Inconel 718 samples fabricated by selective laser melting under different laser powers and scanning speeds. The surface tension was identified as a key factor in the SLM process, pulling melted powder into the molten pool and affecting surface morphology.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2021)
Article
Engineering, Geological
Aylin Nouri, Ali Noorzad, Jean-Michel Pereira, Anh Minh Tang
Summary: A series of 1-g physical model tests were conducted to investigate the effects of cyclic thermal loading on the response of an energy pile subjected to inclined mechanical loading. The results showed that subjecting the pile to thermal cycles after inclined mechanical loading led to irreversible settlement and horizontal displacement at the pile head, which accumulated over the cycles. The accumulation of irreversible horizontal displacement during cyclic thermal loading was found to control the long-term performance of energy pile rather than the capacity.
Article
Energy & Fuels
H. Masoumi, R. Haghighi Khoshkhoo, S. M. Mirfendereski
Summary: In this study, the melting/solidification process of nano-enhanced phase change materials (NePCM) was investigated using experimental and numerical methods. The results showed that using longitudinal fins in the heat exchanger significantly reduced the time required for melting and solidification, while adding nanoparticles had a positive effect only in the unfinned tube heat exchanger.
JOURNAL OF ENERGY STORAGE
(2022)
Article
Chemistry, Physical
Joyce Coppock, Quinn Waxter, Robert Wolle, B. E. Kane
Summary: In this study, melting and undercooling in nanoscale gold particles were investigated in a high vacuum environment. The temperature and state changes of the particles were detected and inferred through measurements of mass and direct optical measurements. The study also found a correlation between heating behavior and particle size. Undercooling, achieved through multistage laser pulses, was explored and compared to theoretical predictions.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Multidisciplinary
Fu Li, Changhao Chen, Shaoyong Lu, Xueguang Chen, Wangyu Liu, Kangkang Weng, Zhong Fu, Dan Liu, Lipeng Zhang, Hannikezi Abudukeremu, Linhan Lin, Yuanyuan Wang, Minlin Zhong, Hao Zhang, Jinghong Li
Summary: In this study, a direct patterning method based on a thermal mechanism called thermally activated ligand chemistry (TALC) is introduced. By triggering local thermal stimuli with near-infrared lasers, various nanocrystals can be patterned with high resolution and nondestructive manner. This method overcomes limitations of traditional and emerging patterning techniques and holds promise for the development of advanced optoelectronic functionalities such as transparent electronics.
Article
Materials Science, Multidisciplinary
Mathieu Opprecht, Jean-Paul Garandet, Guilhem Roux, Camille Flament
Summary: This study focuses on the effects of adding Zr or Sc elements in the laser beam melting process of hot cracking prone Al alloys, aiming to promote precipitation reactions and improve grain structure. Experimental results show that adding ZrO2 and Y2O3 particles can increase nucleant site density, affecting the threshold for Al3Zr precipitation.
Article
Engineering, Chemical
Erlei Li, Zongyan Zhou, Lin Wang, Haopeng Shen, Ruiping Zou, Aibing Yu
Summary: This study employs a validated mathematical model to assess the influence of material properties on the selective laser melting process. The results indicate that the solidification rate and mushy zone constant have a significant impact on the formation of pores and surface defects.
Article
Thermodynamics
Mohamad Hamed Hekmat, Mohamad Hosein Khaksar Haghani, Ehsan Izadpanah, Hosein Sadeghi
Summary: The main goal of this work was to understand the effects of PCM container geometry, nanoparticles, and fins on melting and solidification rates. The combination of these factors resulted in significant improvements in melting and solidification times.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2022)
Article
Chemistry, Multidisciplinary
V. M. Samsonov, I. V. Talyzin, S. A. Vasilyev, V. V. Puytov, A. A. Romanov
Summary: The melting behavior of metallic nanoparticles (Au, Ag, Cu, Ni, and Pb) was simulated using isothermal molecular dynamics and the embedded atom method. The results for Au and Ag nanoparticles were presented and analyzed. It was found that nanoparticles of about 4 and 8 nm in size exhibit continuous melting, which occurs via the surface pre-melting mechanism. The self-diffusion coefficient in the surface disordered layers of Au and Ag nanoparticles was evaluated and found to be in agreement with the values for the bulk Au and Ag melts.
JOURNAL OF NANOPARTICLE RESEARCH
(2023)
Article
Chemistry, Multidisciplinary
Zheng Tan, Yan Li, Ziying Zhang, Xin Wu, Thomas Penfold, Weimei Shi, Shiqing Yang
Summary: This article introduces an integrated framework for the effective design of thermally activated delayed fluorescence (TADF) molecules using adversarial generative models and deep learning techniques. The framework combines algorithmic synthesis, deep prediction, adversarial generation, and fine screening modules to explore the desired chemical space for use in organic light-emitting diode devices.
Article
Materials Science, Ceramics
Haijun Su, Hao Jiang, Zhuo Zhang, Di Zhao, Yuan Liu, Zhonglin Shen, Yinuo Guo, Chubin Yang, Wei Ren
Summary: This study reports on the crucible-free fabrication of ZrB2-SiC composite ceramics using laser surface zone-melting (LSZM) with Nd:YAG laser, ytterbium-doped fiber laser, and CO2 laser. The comparative investigation of the laser processed zone shows that the CO2 laser is the most suitable resource for producing highly dense and largescale ZrB2-SiC composite ceramics with maze-shaped eutectic microstructure by LSZM. The high temperature gradient achieved by CO2 laser leads to submicron-scale phase size, resulting in high relative density, Vickers hardness, and fracture toughness of the ZrB2-SiC composite ceramics.
CERAMICS INTERNATIONAL
(2023)
Article
Materials Science, Multidisciplinary
Anup Basak, Valery Levitas
Article
Materials Science, Multidisciplinary
Anup Basak, Valery Levitas
MATHEMATICS AND MECHANICS OF SOLIDS
(2020)
Article
Physics, Multidisciplinary
Hamed Babaei, Valery I. Levitas
PHYSICAL REVIEW LETTERS
(2020)
Article
Chemistry, Physical
Hao Chen, Nikolai A. Zarkevich, Valery I. Levitas, Duane D. Johnson, Xiancheng Zhang
NPJ COMPUTATIONAL MATERIALS
(2020)
Article
Materials Science, Multidisciplinary
S. Ehsan Esfahani, Iman Ghamarian, Valery I. Levitas
Article
Materials Science, Multidisciplinary
K. K. Pandey, Valery I. Levitas
Article
Materials Science, Multidisciplinary
Hao Chen, Valery Levitas, Liming Xiong, Xiancheng Zhang
Summary: The stationary motion of shuffle screw and 60 degrees dislocations in silicon under applied shear below the static Peierls stress has been proven through molecular dynamics simulations and continuum-level equation of motion. The concept of a dynamic Peierls stress below which stationary dislocation motion is impossible is established. The results suggest the potential for dynamic intensification of plastic flow and defects accumulations below the static Peierls stress.
Article
Physics, Applied
K. K. Pandey, Valery I. Levitas
Summary: A novel method using digital image correlation and ruby fluorescence microscopy has been developed to measure displacement fields in traditional diamond anvil cells and rotational DACs, providing crucial data for material property research.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
Hamed Attariani, I. Valery Levitas
Summary: Oxidation is still a significant challenge in various industrial applications due to its coupled multi-physics nature. A general large-strain mechanochemical theory was developed to model anisotropic reaction/compositional strain, introducing a kinetic relationship between deviatoric reaction deformation rate and stress. The new model showed that deviatoric stress alters the chemical equilibrium constant and reaction rate through reaction-induced deviatoric stress.
Article
Multidisciplinary Sciences
Hao Chen, Valery Levitas, Dmitry Popov, Nenad Velisavljevic
Summary: The unexpected nanostructure evolution during Si-I -> Si-II phase transformation is revealed by combining molecular dynamics, crystallographic theory, and in situ real-time Laue X-ray diffraction. This phase transformation results in twinned Si-II and unexpected nanobands, which form specific interfaces with Si-I and create self-accommodated nanostructure.
NATURE COMMUNICATIONS
(2022)
Editorial Material
Thermodynamics
Francesco Dell'Isola, Valery I. Levitas, Valery P. Matveenko
CONTINUUM MECHANICS AND THERMODYNAMICS
(2023)
Article
Multidisciplinary Sciences
Valery Levitas
Summary: This study presents a developed theory that explains the puzzles of deep-focus earthquakes, including the coupled deformation, plastic strain-induced phase transformation, transformation-induced plasticity, and self-blown-up deformation-transformation-heating process in shear bands. By considering the transformation in olivine as plastic strain-induced and finding an analytical solution for the coupled deformation-transformation-heating process in shear bands, the study provides insights into the mechanisms behind the jump in strain rates and sudden transformation of metastable olivine. The study also highlights the importance of the thermomechanochemical feedback in the severe transformation-induced plasticity and self-blown-up deformation-transformation-heating process.
NATURE COMMUNICATIONS
(2022)
Article
Thermodynamics
Anup Basak, Valery I. Levitas
Summary: This paper revisits the nanoscale multiphase phase-field model for stress and temperature-induced multivariant martensitic transformation under large strains developed by the authors. It resolves the issues related to the gradient energy and coupled kinetic equations and develops a thermodynamically consistent model. The model considers N + 1 order parameters to describe austenite and N martensitic variants, taking into account the energies of the interfaces and a kinetic relationship for the rate of the order parameters. A large strain-based finite element method is used to simulate a 3D complex twins within twins microstructure, and a comparative study is presented.
CONTINUUM MECHANICS AND THERMODYNAMICS
(2023)
Article
Multidisciplinary Sciences
Valery I. Levitas, Achyut Dhar, K. K. Pandey
Summary: This study investigates the effects of stress and plastic strain tensors on various phenomena under high pressures in diamond-anvil cells. The authors suggest a coupled experimental-analytical-computational approach to measure these tensors and friction rules in the material using synchrotron X-ray diffraction. The results are in good agreement with experiments and open opportunities for quantitative high-pressure/stress science.
NATURE COMMUNICATIONS
(2023)
Article
Materials Science, Multidisciplinary
Valery Levitas
Summary: This paper introduces a general nonlinear theory for the elasticity of prestressed single crystals, defining various elastic moduli and their relationships. It also outlines possible applications to complex nonlinear elasticity problems and illustrates them for a superdislocation. The importance of B moduli in computational algorithms and the analysis of finite rotations are highlighted.