Article
Materials Science, Multidisciplinary
Ci Wang, Stephan Schonecker, Wei Li, Yaochun Yang, Qing-Miao Hu, Levente Vitos
Summary: Using density-functional theory, we determined the generalized stacking fault energy for the twinning system in Fe and Fe-Cr alloys, showing that the isosceles twin boundary configuration is energetically preferred. The magnetic ordering effects and Cr content have significant influences on the twin boundary formation and migration energies in different magnetic states.
Article
Materials Science, Multidisciplinary
Qiwen Qiu, Jun Song
Summary: Comprehensive first-principles density functional theory calculations were performed to investigate the effects of solutes on the stacking fault energies in binary magnesium alloys. The solute effect was found to be mechanical and electronic in nature, which was quantified based on misfit volume and d-electrons. A predictive model of the solute effect on the stacking fault energies was developed and showed good agreement with the calculations. This study provides important mechanistic insights and predictivity for the rational design of magnesium alloys with enhanced mechanical properties.
ADVANCED ENGINEERING MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Julian Brodie, Maryam Ghazisaeidi
Summary: In this study, we calculated the Gibbs Free Energy of stacking faults relevant to (c+a) slip and the cross-slip energy barrier of (c+a) screw dislocations in Mg, Mg-Al, and Mg-Ca alloys using density functional theory and the quasiharmonic approximation. It was found that the pyramidal II stacking fault energy is lower than the pyramidal I in pure Mg for a large temperature range, while the opposite is true in alloys at all temperatures. The addition of Al and Ca significantly reduces the pyramidal I stacking fault energy at room temperature, aiding in the stabilization of pyramidal I dislocations.
SCRIPTA MATERIALIA
(2023)
Article
Metallurgy & Metallurgical Engineering
Qi Qian, Zheng-qing Liu, Yong Jiang, Yi-ren Wang, Xing-long An, Min Song
Summary: First-principles calculations were used to investigate the formation mechanism of GTBs in hcp Ti, revealing that GTBs can form from the gliding of CTBs and eventually restore CTB structures by forming twinning disconnections. The pile-up of twinning disconnections at twin boundaries can promote twin growth. Additionally, the study evaluated the possible effects of alloying elements on pinning twin boundaries in Ti alloys.
TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA
(2021)
Article
Chemistry, Physical
Yong-Qiang Wang, Chao Yuan, Y. Xiao, Xin Wen, Bing Zhang, Yi-Peng Chen, Shi-Chang Qiao, Feng-Zhen Wang
Summary: The total stacking fault energy (SFE) of GH3536 superalloy was divided into three terms for investigating the temperature dependence. The results revealed a significant temperature dependence for SFE, which explains the occurrence of twinning during plastic deformation at cryogenic temperature. The estimated SFE at ambient temperature matches well with experimental measurement, offering insights into the deformation mechanisms of fcc alloys with low SFE and paving the way for novel materials with excellent resistance to cryogenic temperature.
Article
Physics, Condensed Matter
Haiyun Huang, Lihuan Shao, Huazhu Liu
Summary: The study found that in specific slip systems of high-entropy nitrides, the stacking fault energy cannot be perfectly described by a rule of mixture, with the overall trend dominated by the behavior of TaN and NbN. Additionally, the energy fluctuation caused by atomic randomness in HENs is much smaller than the stacking fault energy barrier in all slip systems.
SOLID STATE COMMUNICATIONS
(2021)
Article
Chemistry, Physical
Hui Yu, Shuo Cao, Sabry S. Youssef, Ying-Jie Ma, Jia-Feng Lei, Yang Qi, Qing-Miao Hu, Rui Yang
Summary: The CRSS and plastic deformation of titanium with HCP structure are highly anisotropic, alloying affects the CRSS, and rational composition design can improve mechanical properties. Prediction of CRSS is challenging due to atomic randomness of the alloy, and first-principles methods are used in this study to calculate GSFEs for Ti-Al alloys and evaluate CRSS within a Peierls-Nabarro model framework. Increasing Al concentration in the alloy impacts the GSFE and CRSS, which successfully explains the measured mechanical properties of the alloy.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Chemistry, Multidisciplinary
Thillai Govindaraja Senthamaraikannan, Chang Won Yoon, Dong-Hee Lim
Summary: Active B-5-sites on Ru catalysts can be utilized for various catalytic applications, and the epitaxial formation of hexagonal planar Ru nanoparticles on hexagonal boron nitride sheets increases the number of active sites. Density functional theory calculations were conducted to investigate the adsorption energetics of Ru nanoparticles on hexagonal boron nitride. The adsorption strength of hcp Ru(0001) nanoparticles was found to be highest among the explored morphologies, and hcp-Ru60 nanoparticles exhibited the highest adsorption energy due to their perfect hexagonal match with the interacting hcp-BN(001) substrate.
NANOSCALE ADVANCES
(2023)
Article
Materials Science, Multidisciplinary
S. B. Song, Z. Wang, J. Li, R. Q. Wu
Summary: Through density-functional calculations, the exchange bias effect of the antiferromagnetic Cr(001) substrate on a single magnetic molecule CoCp2 has been systematically studied. The magnetic moment and magnetic anisotropy of CoCp2 can be greatly tuned by the charge transfer between the molecule and substrate. A large exchange energy of approximately 94 meV has been found, which essentially pins the spin orientation of CoCp2. This makes CoCp2/Cr(001) an ideal combination for quantum sensing with well-decoupled quantum spin states from the target magnetic entities.
Article
Materials Science, Multidisciplinary
Chengjun Wang, Wujie Zu, Hao Wang, Yang Wang
Summary: By performing ab initio simulations, the ground state properties and generalized stacking fault energy (GSFE) of gamma-Fe-Mn alloys with different Mn concentrations were investigated. It was found that Mn atoms have a significant short-range effect on the intrinsic stacking fault energy (ISFE), and the relationship between ISFE and Mn atom concentration of antiferromagnetic (AFM) Fe-Mn alloys can be explained by the cohesive energy and density of states (DOS) of the alloys. Additionally, AFM was shown to increase the ISFE of gamma-Fe-Mn alloys compared to non-magnetic (NM) alloys, highlighting the importance of considering magnetic interactions in ISFE calculations.
METALS AND MATERIALS INTERNATIONAL
(2021)
Article
Materials Science, Multidisciplinary
Michiel J. van Setten, Annelies Malfliet, Geoffroy Hautier, Bart Blanpain
Summary: This study demonstrates the use of first-principles density functional theory calculations to develop new metallurgical refining processes, particularly in the removal of impurities from molten host materials. The proposed methodology successfully predicts refining routes and identifies potential remover elements, which are experimentally verified to be effective in removing arsenic from lead. This approach is considered useful in accelerating the discovery of new pyrometallurgical refining processes.
Article
Materials Science, Multidisciplinary
Davide Gambino, Johan Klarbring, Bjorn Alling
Summary: This work demonstrates the feasibility and accuracy of calculating phase stability in magnetic systems using ab initio methods and thermodynamic integration. By sampling the magnetic and vibrational phase space with coupled atomistic spin dynamics-ab initio molecular dynamics simulations, energies and interatomic forces are calculated with density functional theory. The method is applied to calculate the phase stability of Fe at ambient pressure from 800 to 1800 K. The Gibbs free energy difference between fcc and bcc Fe is calculated with thermodynamic integration, and the error in transition temperature is below 150 K, with a difference of 5 meV/atom from the CALPHAD estimate. This work lays the foundation for first principles free energy calculations in magnetic materials with accuracy on the order of 1 meV/atom.
Article
Materials Science, Multidisciplinary
Cheng Tang, Lei Zhang, Yalong Jiao, Chunmei Zhang, Stefano Sanvito, Aijun Du
Summary: By combining particle swarm optimization with first-principles calculations, a stable 2D polar half-metal, quintuple layered Co2Se3 monolayer, has been predicted. This material exhibits XY magnetism and out-of-plane piezoelectricity, showing multiferroic properties and great potential in advanced multiferroic applications.
JOURNAL OF MATERIALS CHEMISTRY C
(2021)
Article
Materials Science, Multidisciplinary
Dong Huang, Yanxin Zhuang
Summary: In this study, the coherent precipitation strengthening of L1(2) phase and Face-Centered Cubic (FCC) -Hexagonal Close-Packed (HCP) type martensitic transformation were successfully combined in a single alloy, resulting in increased yield strength and uniform elongation. The presence of L1(2) phase was found to directly affect the deformation mode of the alloy.
MATERIALS & DESIGN
(2022)
Article
Chemistry, Physical
Xin Yao, Yong Mao, Ya-Fang Guo
Summary: In this study, the alloying effect on the elastic properties, stacking fault energy, yield behavior and ductility of L1(2)-Pt3Hf was investigated using first-principles methods. It was found that certain alloying elements can improve the ductility and mechanical properties of the alloy.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Materials Science, Multidisciplinary
Ci Wang, Stephan Schonecker, Wei Li, Yaochun Yang, Qing-Miao Hu, Levente Vitos
Summary: Using density-functional theory, we determined the generalized stacking fault energy for the twinning system in Fe and Fe-Cr alloys, showing that the isosceles twin boundary configuration is energetically preferred. The magnetic ordering effects and Cr content have significant influences on the twin boundary formation and migration energies in different magnetic states.
Article
Materials Science, Multidisciplinary
Shuo Cao, Shang-Zhou Zhang, Jian-Rong Liu, Shu-Jun Li, Tao Sun, Jian-Ping Li, Yang Gao, Rui Yang, Qing-Miao Hu
Summary: This study focuses on increasing the solubility of Al and inhibiting the growth of Ti3Al precipitates in high temperature titanium alloy to improve thermal strength and stability. By calculating interaction energies between Al and various alloying atoms, traps for Al in the alloy can be identified. The effects of temperature and new off-center site-occupation of alloying atoms on interaction energies were considered, with certain alloying atoms identified to benefit the strength and thermal stability of high temperature titanium alloys.
COMPUTATIONAL MATERIALS SCIENCE
(2021)
Article
Chemistry, Physical
J. X. Yan, Z. J. Zhang, H. Yu, K. Q. Li, Q. M. Hu, J. B. Yang, Z. F. Zhang
Summary: The study comprehensively investigates the effects of pressure on various aspects of FCC metals, including the GSFE, core structure of dissociated dislocations, twinning propensity, and phase stability. It demonstrates that high pressure can significantly enhance twinning propensity in Ag and the CoCrFeMnNi HEA, while the impact is minimal in Cu. Moreover, the first principles calculation reveals that the sensitivity of twinning propensity in FCC metals to pressure depends on the stacking fault energy and the relative stability of FCC and HCP phases.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Materials Science, Multidisciplinary
Wei Chen, Shuo Cao, Jinyu Zhang, You Zha, Qingmiao Hu, Jun Sun
Summary: This study systematically investigates omega-embrittlement of high misfit Ti-10Cr alloys and reveals that the lattice disordering of omega precipitates plays a key role in crack propagation. Mechanically-driven localized amorphization significantly affects the cleavage-like fracture behavior of Ti-10Cr alloys. The hydrostatic pressure, serving as the driving force for dislocations pile-up, is critical in this unusual fracture mechanism.
MATERIALS & DESIGN
(2021)
Article
Materials Science, Multidisciplinary
Shu-Ming Chen, Ze-Jun Ma, Shi Qiu, Lian-Ji Zhang, Shang-Zhou Zhang, Rui Yang, Qing-Miao Hu
Summary: Phase decomposition significantly affects the mechanical properties of high entropy alloys (HEAs). In this study, we successfully predicted the phase decomposition of the Hf-Nb-Ta-Ti-Zr alloy by combining first-principles methods and thermodynamic models. The predicted results are in good agreement with experiments and simulations, and reveal the influence of phase decomposition on the strength of the alloy.
Article
Chemistry, Physical
Yue Guan, Xiaodan Li, Qingmiao Hu, Dandan Zhao, Lin Zhang
Summary: In this paper, the thermal, mechanical, electronic and optical properties of hetemstructures composed of boron arsenide (BAs) and WX2 (X = S, Se) were systematically investigated using first principle calculations. It was found that the heterostructures are structurally, dynamically, and mechanically stable. The investigated van der Waals (vdWs) heterostructures (BAs/WS2 and BAs/WSe2) are all direct bandgap semiconductors and exhibit high carrier mobility and optical absorptivity, making them highly efficient for solar energy. The properties of BAs/WX2 hetemstructures are significantly affected by spin-orbit coupling and external electric field.
APPLIED SURFACE SCIENCE
(2022)
Article
Physics, Condensed Matter
Shuo Cao, Yang Li, Lian-Ji Zhang, Yan-Ting Yang, Jian-Rong Liu, Rui Yang, Qing-Miao Hu
Summary: Precipitation strengthening of silicides is important for improving the creep resistance of high-temperature titanium alloys. However, the oversize and concentrated silicides reduce the ductility of the alloys. It has been found that Zr and Hf stabilize Ti5Si3, promoting the nucleation and refinement of silicide particles, while beta stabilizers and simple metals destabilize Ti5Si3 and suppress its precipitation.
PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
J. X. Yan, Z. J. Zhang, P. Zhang, J. H. Liu, H. Yu, Q. M. Hu, J. B. Yang, Z. F. Zhang
Summary: The development of multi-principal element alloys (MPEAs), also known as high- or medium-entropy alloys (HEAs/MEAs), offers great possibilities for materials innovation. However, designing MPEAs with desired mechanical properties is challenging due to their vast composition space. This study provides an essential criterion to efficiently screen CoCrNi MEAs with outstanding strength-ductility combinations, combining the negative Gibbs free energy difference between face-centered cubic (FCC) and body-centered cubic (BCC) phases, enhancement of shear modulus, and decline of stacking fault energy.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2023)
Article
Materials Science, Multidisciplinary
Xue-Chun Zhang, Shuo Cao, Lian-Ji Zhang, Rui Yang, Qing-Miao Hu
Summary: In this paper, the competition between the {110}(111), {112}(111), and {123}(111) slip systems in BCC metals is determined by calculating the unstable stacking fault energy (yus) and Peierls stress (up) of these systems. It is found that yus is proportional to oB thorn G thorn =a2=3, where B, G, and a are the bulk modulus, shear modulus, and lattice constant, respectively. The calculations predict that the {110}(111) slip is prioritized, and up indicates a decrease in dislocation mobility in the order of {110}(111), {112}(111), {123}(111) for most metals. Notably, yus and up are not monotonically related.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Materials Science, Multidisciplinary
Xue-Chun Zhang, Shuo Cao, Rui Yang, Qing-Miao Hu
Summary: The Peierls stress of FCC structures calculated using the PN model is highly sensitive to various input parameters, such as shear modulus, Poisson's ratio, and generalized stacking fault energy. This sensitivity leads to significant oscillations in the predicted Peierls stress. In this study, we propose a modified model that alleviates the sensitivity of the Peierls stress on the input parameters, resulting in better agreement with experimental values.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Materials Science, Multidisciplinary
Mengmeng Yang, Jiaying Zhou, Haijun Huang, Shuo Cao, Qing-Miao Hu, Wei Li, Qingjun Chen, Yanxin Qiao, Hao Wang
Summary: By using high-throughput first-principles calculations, the segregation capacity of fifteen widely used metallic alloying elements at the grain boundary in low alloy ferritic steel was systematically investigated. The impact of strain energy minimization on segregation was found to be comparable to that of chemical energy minimization, especially for large alloying atoms. The findings suggest that the segregation of large alloy atoms on the grain boundaries can be predicted by their atomic volume, providing valuable insights for alloy development and grain boundary engineering.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Materials Science, Multidisciplinary
Shu-Ming Chen, Yang Gao, Zi-Han Yu, Bi-Ning Liang, Shuo Cao, Rui Yang, Qing-Miao Hu
Summary: According to classical metal physics theory, the substitutional solute atom in dilute metal solid solution occupies the high-symmetry lattice site without destroying the point group symmetry of the host lattice. However, recent first-principles calculations revealed that the substitutional solute atom Mo occupies a low-symmetry off-center position in dilute Ti solid solutions, which breaks the point group symmetry of the hexagonal-close-packed host lattice due to the Jahn-Teller splitting of the degenerated d orbitals of Mo. In this study, we investigated the site occupation of substitutional atom X in dilute Ti-X solid solution with X ranging from V to Zn, and found that Cr, Mn, Fe, and Co exhibit spontaneous symmetry breaking by occupying the low-symmetry off-center site, while V, Ni, Cu, and Zn tend to stay at the high-symmetry lattice site, and this off-center occupation is robust against the size of the supercell and the thermal volume expansion in first-principles calculations.
PHYSICAL REVIEW MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Jialong Tian, Gang Zhou, Wei Wang, Qingmiao Hu, Zhouhua Jiang, Ke Yang
Summary: The effect of cobalt on the precipitation hardening behavior of maraging stainless steels was investigated. It was found that cobalt addition could increase peak hardness and accelerate the aging process, as well as enhance the density of precipitates, leading to a stronger contribution to precipitation hardening.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Materials Science, Multidisciplinary
Haoran Sun, Zhigang Ding, Hao Sun, Junjun Zhou, Ji-Chang Ren, Qingmiao Hu, Wei Liu
Summary: The HCSA scheme efficiently and accurately predicts the SFEs of MPEAs by averaging SFEs from small supercells, outperforming traditional DFT calculations. It has been successfully applied to NiFe and Ni 10 Co 60 Cr 25 W 5 alloys, achieving significant error reduction and holding the potential to accelerate materials design and discovery processes.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2024)
Article
Mechanics
Sh Cao, W. Chen, R. Yang, Q-M Hu
Summary: In this study, the mechanism of omega-strengthening and embrittlement in beta-Ti alloys was investigated using density functional theory. It was found that the slip energy barriers of slip systems in the omega phase are much higher than those in the beta phase, which explains the strengthening and embrittlement effects. Aging treatment enhances the omega-strengthening and embrittlement effects by increasing the slip energy barrier of the most active slip system in the omega phase.
PHYSICAL MESOMECHANICS
(2021)
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.