Article
Materials Science, Multidisciplinary
Amit Acharya
Summary: An action functional is developed for nonlinear dislocation dynamics, aiming to use effective field theory to describe the macroscopic behavior of plasticity in crystalline solids. This work reveals connections between continuum mechanics, material science of defects in solids, effective field theory techniques in physics, and fracton tensor gauge theories.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2022)
Article
Chemistry, Physical
Shuwei Lu, Jun Zhang, Haiming Duan
Summary: The effects of substituting B for P on the structure and magnetic properties of FePB amorphous alloys were studied. It was found that Fe80P5B15 amorphous alloy exhibited higher local symmetry and magnetic moment.
Article
Mechanics
P. O. Kazinski, V. A. Ryakin, A. A. Sokolov
Summary: This study investigates the action functional for a linear elastic medium with dislocations and describes the forces experienced by dislocations through the derived equations of motion. The results show that the self-force on the dislocations has different expressions at different velocities.
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
(2022)
Article
Engineering, Mechanical
Yang Chen, Shuo Wang, Hui Feng, Weipeng Li, Bin Liu, Jia Li, Yong Liu, Peter K. Liaw, Qihong Fang
Summary: By conducting high-resolution transmission electron microscopy and random field theory informed discrete dislocation dynamics simulations, this study reveals the influence mechanism of heterogeneous lattice strain on the complex interaction between dislocations and dislocation loops in high entropy alloys (HEAs) under irradiation. The results show that lattice-strain-induced irradiation hardening decreases, in line with the excellent irradiation hardening resistance of HEAs observed in recent experiments. A new cross-slip mechanism is also discovered, involving the co-linear reaction between dislocations and rhombus perfect loops. This study provides insights into the mesoscopic-level irradiation damage behavior, guiding the development of advanced HEA materials for nuclear energy applications through the regulation of heterogeneous lattice strain.
INTERNATIONAL JOURNAL OF PLASTICITY
(2023)
Article
Astronomy & Astrophysics
Andrea Giusti, Stefan Zentarra, Lavinia Heisenberg, Valerio Faraoni
Summary: In this paper, the irreversible thermodynamics description is applied to the Horndeski realm, and a subclass of Horndeski theories is identified as an out-of-equilibrium state, while general relativity corresponds to an equilibrium state. By recasting the field equations, an effective heat current, "temperature of gravity," and shear viscosity are identified in the space of theories.
Article
Physics, Applied
Amran Mahfudh Yatmeidhy, Yoshihiro Gohda
Summary: We investigate the microscopic origin of strain-induced changes in the magnetocrystalline anisotropy energy of Co2FeSi, Co2MnSi, and Fe3Si Heusler alloys using first-principles electron theory. The anisotropy modulation in Co2FeSi and Co2MnSi is dominated by the quadrupole moment of Co minority-spin states under strain within the (001) plane, leading to giant magnetoelectric couplings in multiferroic heterointerfaces containing these compounds. On the other hand, the strain-induced anisotropy modulation in Fe3Si has mixed contributing factors including the anisotropy term of the orbital magnetic moment and the quadrupole term.
APPLIED PHYSICS EXPRESS
(2023)
Article
Chemistry, Physical
Ziqi Xiao, Lingfeng He, Xian-Ming Bai
Summary: Thermal annealing or radiation induced segregation of solute and impurity elements to grain boundaries in metallic alloys changes GB chemistry, affecting the cohesive strength. Solute elements show varying effects on GB strength, with C and P causing embrittlement while Cr and Ti strengthening GBs. Detailed chemical interactions between solutes and Ni atoms at GBs play a significant role in determining GB strength.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Materials Science, Multidisciplinary
Fengxian Liu, Alan C. F. Cocks, Edmund Tarleton
Summary: Diffusion plays a crucial role in dislocation motion, with lattice diffusion dominating at high temperatures and core diffusion dominating at low temperatures. However, there is currently no quantitative definition for the conditions under which each diffusion mechanism is dominant. This study combines variational principle and finite element analysis to consider the competition and synergy between core and lattice diffusion, and constructs a diffusion mechanism map to guide the evolution of dislocation loops.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2023)
Article
Materials Science, Multidisciplinary
Han Lin Mai, Xiang-Yuan Cui, Daniel Scheiber, Lorenz Romaner, Simon P. Ringer
Summary: In this study, the segregation and accumulation of hydrogen in Ni grain boundaries and their effects on cohesion and tensile mechanical strength were investigated using density functional theory simulations. The results show that the grain boundary character is the principal determinant of the likelihood of hydrogen segregation and accumulation, and hence their vulnerability to hydrogen-enhanced decohesion. This knowledge can be utilized in the design of thermomechanical processes for resistance to hydrogen embrittlement.
MATERIALS & DESIGN
(2021)
Article
Materials Science, Multidisciplinary
Chris Hardie, Rhys Thomas, Yang Liu, Philipp Frankel, Fionn Dunne
Summary: A classical crystal plasticity formulation based on dislocation slip was extended to include dislocation channelling and strain softening observed in irradiated alloys. The model's performance was evaluated using experimental data on Zircaloy-4, showing good capture of the engineering stress-strain response but sensitivity in simulating characteristic strain heterogeneity.
Article
Chemistry, Physical
Yan-Kun Dou, Han Cao, Xin-Fu He, Jin Gao, Jin-li Cao, Wen Yang
Summary: The interactions between a 1/2 <110> {111} edge dislocation and a void in Fe10Ni20Cr and Fe33Ni33Cr concentrated solid-solution alloys were studied using molecular dynamics simulation. It was found that the dislocation motion becomes more difficult in Fe33Ni33Cr alloy due to larger fluctuations in stacking fault energy compared to Fe10Ni20Cr alloy. However, Fe33Ni33Cr alloy exhibits better irradiation hardening resistance than Fe10Ni20Cr alloy, especially at high temperatures.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Chemistry, Physical
Jianbin Liu, Shinji Muraishi
Summary: This study investigated the effect of rod-shaped precipitates on misfit hardening in aluminum alloys through simulation, revealing that the evolution of dislocation microstructure is greatly influenced by local internal stress around the rod precipitate. Strong orientation dependence of misfit hardening was observed, with differences in maximum stress values amounting to 30%. The energy associated with dislocation motion was found to be affected by the internal stress of rod precipitates, leading to strong and weak hardening behaviors.
Article
Materials Science, Multidisciplinary
Xiao-Xiang Yu, Junsoo Han, John R. Scully, Laurence D. Marks
Summary: The typical defect reactions at the metal/oxide interface explaining the growth and breakdown of passive oxide films in corrosion include the creation of metal and oxygen vacancies. This study introduces a new mechanism of oxygen injection into the metal, with fast passivation in the NiCr alloy showing a significant oxygen injection at a fast growth rate. The addition of Mo promotes the formation of the corundum phase in the outer oxide layer for NiCrMo, changing the transport mechanism of oxygen through the oxide film and across the metal/oxide interface.
Article
Materials Science, Multidisciplinary
Yuhit Gupta, M. M. Sinha, S. S. Verma
Summary: First-principles calculations were used to study the structural stabilities, elastic, mechanical, and lattice dynamical properties of AlNiAs and AlNiSb half Heusler alloys. The results show that both alloys are stable in the LiAlSi-type phase, are non-magnetic, possess thermodynamic stability, and exhibit metallic properties.
MATERIALS TODAY COMMUNICATIONS
(2021)
Article
Materials Science, Multidisciplinary
Peng Wang, Yu Cao, Daoxuan Zhou, Ming Li, Kun Jiang, Haofei Zhou, Ping Qu, Hongtao Wang
Summary: In this study, molecular dynamic simulations were used to analyze the martensitic transformation and complex dislocation activities of commercial Ti80 alloy. The simulation results showed good agreement with experimental observations and provided valuable insights into the deformation mechanisms of Ti80 alloy and related Ti alloys. The findings and newly developed interatomic potential can guide the development of high-performance Ti alloys in the future.
MECHANICS OF MATERIALS
(2023)
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.