Article
Materials Science, Multidisciplinary
Nicole K. Aragon, Jamie D. Gravell, Ill Ryu
Summary: Research demonstrates that grain boundaries play a crucial role in nanostructured metals, influencing plastic deformation by controlling dislocation propagation. Different samples with high angle grain boundaries and coherent twin boundaries show distinct mechanical responses in plastic deformation.
Article
Materials Science, Multidisciplinary
Xu Zhang, Songjiang Lu, Bo Zhang, Xiaobao Tian, Qianhua Kan, Guozheng Kang
Summary: This article investigates a generalized dislocation-GB interaction model and its application in nanopillars and bicrystals within a three-dimensional multiscale discrete dislocation dynamics framework. It is found that the mechanical responses of bicrystals are influenced by the GB structures and complex dislocation interactions. Furthermore, the specific events of dislocation absorption and emission, as well as the evolution of resolved shear stress and dislocation density, are found to be independent of GB misorientation angles or GB strength.
Article
Materials Science, Multidisciplinary
Alexander Bergsmo, Yilun Xu, Benjamin Poole, Fionn P. E. Dunne
Summary: The study found that non-metallic inclusions and twin boundaries are preferred locations for fatigue crack nucleation in polycrystalline Ni-based superalloys. Through a multi-scale modelling strategy, the mechanism of fatigue crack nucleation was analyzed, revealing the involvement of inclusion fracture, twin boundary slip activation, and the accumulation of local geometrically necessary dislocations. These factors ultimately lead to the formation of fatigue cracks.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2022)
Article
Engineering, Mechanical
Xiangru Guo, Chaoyang Sun, Chunhui Wang, Jun Jiang, M. W. Fu
Summary: Deformation twins play a crucial role in the plastic deformation of TWIP steels by affecting dislocation movement. A proposed dislocation-TB interaction model helps understand the strengthening effects of twins on macro deformation behaviors and dislocation reactions in TWIP steel micropillar. This research enhances the knowledge of dislocation-TB interaction mechanisms in plastic deformation of TWIP steels.
INTERNATIONAL JOURNAL OF PLASTICITY
(2021)
Article
Materials Science, Multidisciplinary
Zheyuan Xing, Haidong Fan, Guozheng Kang
Summary: As an important micro-structure, grain boundary plays a significant role in the micro-structure evolution and mechanical property of metallic materials. This study investigates the propagation mechanisms of intergranular cracks along [1100] symmetric tilt grain boundaries in magnesium bicrystals under tensile loading conditions using comprehensive molecular dynamics simulations, considering the effects of grain boundary misorientation angle, temperature, and solid solution.
COMPUTATIONAL MATERIALS SCIENCE
(2022)
Article
Nanoscience & Nanotechnology
Zhanfeng Wang, Junjie Zhang, Jinzhong Lu
Summary: This study investigates the deformation mechanisms of single crystal and bicrystal Cu workpieces under nanoindentation through experiments and molecular dynamics simulations. The results highlight the significant role of dislocation-grain boundary interactions and crystallographic orientation on the mechanical response of the materials.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Materials Science, Multidisciplinary
Xiangru Guo, Ningdong Mao, Chaoyang Sun, Chunhui Wang, Yinan Cui, Zhiping Xiong
Summary: In this study, the tension-compression asymmetry and orientation effect of dislocation-twin boundary interactions in twinned TWIP steel were investigated using discrete dislocation dynamics simulations and Schmid's law. The research advances the understanding of the asymmetric behavior of twinning and its influence on the macro hardening in plastic deformation of TWIP steels.
MATERIALS TODAY COMMUNICATIONS
(2022)
Article
Materials Science, Multidisciplinary
Jann-Erik Brandenburg, Luis A. Barrales-Mora, Sadahiro Tsurekawa, Dmitri A. Molodov
Summary: The migration behavior of grain boundaries with misorientations close to the & sigma;3 CSL orientation relationship in high purity Al bicrystals was investigated. It was found that the ability of some boundaries to move under capillary driving force depends on the initial boundary inclination. The measured migration activation enthalpy for one specific boundary was found to be the lowest among previous experiments in Al bicrystals of the same purity.
Article
Materials Science, Multidisciplinary
Jingpeng Hou, Keliang Qiu, Fengshi Li, Zhenyu Yang, Yonghai Yue, Yongjun Tian, Zhongchang Wang, Lin Guo
Summary: Twin boundary (TB) is a special and fundamental internal interface that alters the mechanical and physical properties of materials. The deformation mechanism of TB and its effect on material strength and plasticity are still under debate. This study discovered that the pseudoelastic strain of a TB can recover with decomposition and escape of pile-up dislocations, which opens up new possibilities for optimizing material properties by manipulating twin boundaries at the nanoscale.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2023)
Article
Materials Science, Multidisciplinary
N. Kvashin, A. Ostapovets, N. Anento, A. Serra
Summary: Tilt grain boundaries move conservatively under shear stress by absorbing crystal dislocations and transforming them into grain boundary dislocations (GBD). The behavior of GBDs depends on the orientation of the Burgers vector and shear stress direction, resulting in either compensated climb or nucleation of {1 1 2} twins.
COMPUTATIONAL MATERIALS SCIENCE
(2021)
Article
Materials Science, Multidisciplinary
Zhenghao Chen, Haruyuki Inui
Summary: The plastic deformation behavior of single crystals of Fe3Ge with the L1(2) structure was investigated at room temperature using micropillar compression tests. It was found that slip on (111) has occurred in Fe3Ge for the first time, and the dissociation scheme for superlattice dislocations was confirmed to be of the APB-type on both (010) and (111) faces.
Article
Multidisciplinary Sciences
Vahid Samaee, Maxime Dupraz, Thomas Pardoen, Helena Van Swygenhoven, Dominique Schryvers, Hosni Idrissi
Summary: In-situ transmission electron microscopy observations in nickel bi-crystal samples provide insights into the formation of constriction nodes at coherent twin boundaries (CTBs) by the absorption of curved screw dislocations, leading to a unique CTB sliding mechanism involving coordinated twinning dislocation pairs. The interactions between non-screw dislocations and CTBs highlight the importance of the synergy between the repulsive force of CTBs and the back stress from single arm dislocation sources (SASs) in small volumes. The findings contribute to the understanding of the mechanisms controlling the strength and ductility of metals at coherent twin boundaries.
NATURE COMMUNICATIONS
(2021)
Article
Nanoscience & Nanotechnology
Yang Su, Thanh Phan, Liming Xiong, Josh Kacher
Summary: This paper combines in situ high-resolution electron backscattered diffraction (EBSD) with concurrent atomistic-continuum (CAC) simulations to investigate the interactions between dislocation-mediated slip and grain boundaries (GBs) in Ni. The study shows that the local stress at slip-GB intersections initially increases with the pileup of dislocations and remains high, even after the nucleation of dislocations in the neighboring grain. The local stress only relaxes when the nucleated dislocations propagate away from the GB due to more incoming dislocations participating in the pileup. The relaxation of local stress is accompanied by the reconfiguration of atomic-scale GB structure, which not only affects subsequent dislocation transmission but also the configuration of dislocations away from the GB. These findings highlight the importance of incorporating local stress history in higher length scale models, such as crystal plasticity finite element.
SCRIPTA MATERIALIA
(2023)
Article
Nanoscience & Nanotechnology
Linfeng Bu, Zhao Cheng, Yin Zhang, HengAn Wu, Ting Zhu, Lei Lu
Summary: The strength-controlling dislocation mechanism in nanotwinned metals is illuminated by partitioning the flow stress into effective stress and back stress components. Recent experiments show a nearly constant saturated effective stress of about 100 MPa in nanotwinned Cu with nanotwin thicknesses less than 100 nm. This surprising result suggests that trans-twin dislocations spanning multiple nanotwin lamellae, rather than threading dislocations within individual lamellae, control the effective stress.
SCRIPTA MATERIALIA
(2023)
Article
Chemistry, Multidisciplinary
Hongbo Xie, Hucheng Pan, Junyuan Bai, Dongsheng Xie, Peijun Yang, Shanshan Li, Jianfeng Jin, Qiuyan Huang, Yuping Ren, Gaowu Qin
Summary: The study discovered three- and five-layered discontinuous segregation patterns in twin boundaries in alloys, where not all sites are occupied by solutes larger than Mg, with some larger solutes taking compression sites. Nd/Mn solutes selectively segregate at substitutional sites, generating two new types of ordered two-dimensional TB superstructures or complexions.
Article
Engineering, Mechanical
Li Ding, Chao Yu, Xu Zhang, Zefeng Wen, Qianhua Kan, Guozheng Kang
Summary: Experimental observations indicate that the torsional deformation of copper micro-wires is influenced by sample and grain size. In this study, a higher-order strain gradient constitutive model is developed based on the cyclic plastic J2 flow rule to explain the size effect in torsional deformation of copper micro-wires. A new kinematic hardening evolution rule is proposed considering the coupling effect of sample and grain sizes. Numerical implementation is accomplished using a finite element iterative algorithm, and the proposed model is validated using the finite element software ABAQUS. Simulation results show that the proposed model effectively captures the size-dependent torsional deformation of copper micro-wires. This research lays a solid foundation for the combination of strain gradient plasticity theory and cyclic plasticity constitutive model.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2023)
Article
Materials Science, Multidisciplinary
Siyao Shuang, Yanxiang Liang, Chao Yu, Qianhua Kan, Guozheng Kang, Xu Zhang
Summary: This study investigates the effect of loading orientation on the plasticity of nano-laminated DP-HEA materials using molecular dynamics simulations. The results show that a switch from strengthening to softening and back to strengthening can be achieved by adjusting the inclination angles of the nanolaminates. Lateral slip, phase transformation, and the formation of shear bands are the main mechanisms for plastic deformation under different inclination angles.
MODELLING AND SIMULATION IN MATERIALS SCIENCE AND ENGINEERING
(2023)
Article
Mechanics
Peilin Fu, Jizhong Zhao, Xu Zhang, Hongchen Miao, Zefeng Wen, Guozheng Kang, Qianhua Kan
Summary: A three-dimensional tractive rolling contact analysis is conducted on functionally graded coating-substrate systems. The surface frictional anisotropy is described by Coulomb's orthotropic friction law, and the discontinuous transmissions of stress and displacement at the coating-substrate interface are modeled by a coupled dislocation-like and force-like interfacial imperfection. A multi-layered model is used to simulate the coating with arbitrarily varying thermo-elastic properties, and numerical methods are employed to obtain the thermo-elastic responses of tractive rolling contact. The results show the effect of friction coefficients and interfacial imperfections on traction and stress distribution.
COMPOSITE STRUCTURES
(2023)
Article
Mechanics
Ni Ao, Han Zhang, Huihui Xu, Shengchuan Wu, Dong Liu, Pingguang Xu, Yuhua Su, Qianhua Kan, Guozheng Kang
Summary: This study investigated the fatigue crack growth (FCG) behavior of a structurally gradient axle steel with different pre-crack depths in air and a corrosive medium. The results showed that corrosion significantly accelerated the FCG rate in the high Delta K region, but the effect weakened as Delta K decreased. The accelerated corrosion FCG rate was influenced by anodic dissolution, hydrogen-enhanced localized plasticity and corrosion-induced crack-tip blunting. Despite the decreasing corrosion resistance with increasing pre-crack depth, the FCG rate in the corrosive medium gradually decreased due to the dominant role of fatigue loading in accelerating corrosion FCG rate.
ENGINEERING FRACTURE MECHANICS
(2023)
Article
Mechanics
Junjie Liu, Yuhong Li, Zhouhu Jiang, Qifang Zhang, Nan Hu, Guozheng Kang, Shaoxing Qu
Summary: This study presents an experimental methodology to investigate the interfacial fatigue fracture of elastomer bilayers under cyclic large deformation. The relationship between the interfacial fatigue crack propagation speed and the energy release rate is obtained, revealing three distinct regions: crack initiation, stable crack propagation, and catastrophic crack propagation regions. The findings suggest that the interfacial fatigue fracture of elastomer bilayers can be alleviated by designing the structure of the bonding interface or the bonding edge.
ENGINEERING FRACTURE MECHANICS
(2023)
Article
Mechanics
Qianhua Kan, Yong Zhang, Yangguang Xu, Guozheng Kang, Chao Yu
Summary: The functional degeneration of super-elastic NiTi shape memory alloy (SMA) rods was investigated under cyclic tension-unloading and compression-unloading experiments. The results showed that the functional degeneration exhibited a strong tension-compression asymmetry, which was caused by the initial mixed textures, polarity of martensite transformation, and the interaction between martensite transformation and dislocation slipping. Furthermore, the dependence of functional degeneration on the applied stress level was discussed.
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
(2023)
Article
Materials Science, Multidisciplinary
Weiyang Huang, Guozheng Kang, Pengyu Ma
Summary: The electro-mechanically coupled cyclic deformation of VHB 4905 dielectric elastomer is studied through experimental observation and constitutive modeling. It is found that applying a constant voltage leads to more apparent cyclic softening and ratchetting in VHB 4905 DE, indicating an electro-mechanically coupled effect. The deformation also exhibits rate-dependence and stress-level-dependence. A visco-hyperelastic constitutive model considering nonlinear viscosity and the effect of applied voltage is proposed and validated through comparison with experimental data.
JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE
(2023)
Article
Engineering, Mechanical
Yuehao Du, Jiangcheng Cai, Qianhua Kan, Qinghua Zhang, Ping Wang, Hongchen Miao, Guozheng Kang
Summary: In this study, a time-delayed layer-based piezoelectric transducer (TDLBPT) is developed for unidirectional generation and reception of pure SH0 wave. The TDLBPT can achieve a phase gradient over a wide range of frequencies, eliminating the need for additional time delays. Both simulated and experimental results demonstrate that the TDLBPT can generate pure SH0 wave and focus the wave energy along a given direction in a plate. Due to its excellent performance and easy fabrication, the proposed TDLBPT is highly useful for unidirectional excitation and reception of SH0 wave in SHM and NDT.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2023)
Article
Materials Science, Multidisciplinary
Yu Lei, Chao Yu, Ziyi Wang, Xiang Xu, Hang Li, Guozheng Kang
Summary: A multi-mechanism macroscopic phenomenological constitutive model is established to characterize the uniaxial ratchetting of extruded AZ31 magnesium alloy at room temperature. The model considers the strong basal texture and different deformation mechanisms, including dislocation slipping, twinning, and detwinning. Different yield functions and hardening rules are used to capture these different deformation mechanisms, and the interaction among them is considered in the model. The model shows good agreement with experimental results, validating its reasonability and capability.
MECHANICS OF MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Yong Zhang, Chao Yu, Di Song, Yilin Zhu, Qianhua Kan, Guozheng Kang
Summary: This study experimentally investigates the elastocaloric effect of NiTi shape memory alloy helical springs with different geometric parameters and applied loads. It is found that the elastocaloric performance can be tailored by adjusting the spring's geometric parameters and the applied load. A three-dimensional thermodynamic-consistent constitutive model is developed, and simplified analytical relations are derived to predict the cooling temperature and elastocaloric strength of the springs. The experimental data and predictions from both the finite element analysis and analytical relations are in good agreement, demonstrating the potential of developing cooling technology with high elastocaloric strength and low driving force.
MECHANICS OF MATERIALS
(2023)
Article
Polymer Science
Jian Li, Zhihong Liang, Kaijuan Chen, Xu Zhang, Guozheng Kang, Qianhua Kan
Summary: Experimental investigations on the mechanical deformations of thermo-induced shape memory polymers at different strain rates reveal the influence of loading history conditions on the glass transition temperature and shape memory effect. Temperature hysteresis is observed in stress freezing and strain recovery stages due to varied temperature rate. A logarithmic rate-based viscoelastic-viscoplastic model is established to simulate the rate-dependent mechanical deformation and shape memory effect, which is validated by comparing with experimental results.
Article
Materials Science, Multidisciplinary
Shuxin Chang, Zhiwu Zhu, Guozheng Kang, Xingmin Huang, Juan Zhang
Summary: A phase field model combined with finite element method was used to simulate the ratchetting phenomenon of medium-manganese steel under asymmetric load and discuss the effect of martensitic transformation on ratchetting. The results showed that the ratchetting strain of the steel increased with increasing stress amplitude, mean stress, and stress ratio, and the martensite content increased with increasing stress amplitude but decreased with increasing mean stress and stress ratio. The plastic strain induced by martensitic transformation played a critical role in the overall ratchetting behavior.
COMPUTATIONAL MATERIALS SCIENCE
(2023)
Article
Engineering, Mechanical
Wen-Ping Wu, Zi-Jun Ding, Yun-Li Li, Chao Yu, Guozheng Kang
Summary: The thermomechanical fatigue (TMF) properties of Ni-based single crystal superalloys are studied using molecular dynamics simulations. Two different cyclic deformation mechanisms are identified. Under Out-of-phase TMF loading, the samples exhibit a higher cyclic stress range, plastic strain energy density, and shorter fatigue life compared to In-phase TMF loading. The low-temperature tension half-cycle is found to result in earlier failure due to dislocation and stacking fault penetration into the precipitate phase, attracting more attention in actual operation.
INTERNATIONAL JOURNAL OF FATIGUE
(2023)
Article
Acoustics
Huijian Chen, Zhiqiang Feng, Ling Tao, Jian Li, Hongchen Miao, Guozheng Kang
Summary: Nonlinear ultrasonic techniques are effective in characterizing incipient defects of materials. In this study, a time domain spectral finite element method combined with the bi-potential contact theory is used to simulate contact acoustic nonlinearity (CAN) problems with prestresses. It is found that a primary shear horizontal (SH) wave can generate a second harmonic SH wave when there are tangential prestresses at the frictional interfaces or crack surfaces. This new phenomenon is explained by the asymmetric sliding mechanism induced by the tangential prestresses.
JOURNAL OF SOUND AND VIBRATION
(2023)
Article
Materials Science, Multidisciplinary
Siyao Shuang, Yanxiang Liang, Xie Zhang, Fupin Yuan, Guozheng Kang, Xu Zhang
Summary: High-entropy alloys (HEAs) are considered ideal solid solutions of multi-principal elements, but recent studies have shown that complex interactions among constituents can lead to local chemical ordering at low temperatures. In this study, the impact of chemical ordering on the deformation behaviors of CuNiCoFe HEA was investigated through molecular dynamics simulations. The results reveal that chemical ordering leads to a softening in mechanical properties and a decrease in ultimate strength due to the nucleation of dislocations.
MODELLING AND SIMULATION IN MATERIALS SCIENCE AND ENGINEERING
(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.