Article
Engineering, Mechanical
Patxi Fernandez-Zelaia, Yousub Lee, Sebastien Dryepondt, Michael M. Kirka
Summary: Additive manufacturing has gained significant interest in recent years, but further research is needed for its widespread industrial adoption. This study presents a crystal plasticity model that includes non-Schmid effects for simulating the anisotropic creep behavior of additively manufactured materials. The model is calibrated using a probabilistic framework and an iterative sequential design strategy to determine the probability density of model parameters. As a case study, the model is used to investigate the behavior of randomly oriented equiaxed grain clusters in additively manufactured structures.
INTERNATIONAL JOURNAL OF PLASTICITY
(2022)
Article
Engineering, Manufacturing
Hui Xiao, Yanqin Li, Wenjia Xiao, Chuan Liu, Pan Xie, Lijun Song
Summary: The microstructure characteristics and solidification mechanisms of quasi-continuous-wave laser directed energy deposition (QCW-DED) under different pulse frequencies were investigated. The high pulse frequency promotes the growth of columnar dendrites and results in a high-intensity texture, while the low pulse frequency inhibits the growth of dendrites and develops a random texture. This research provides a controllable processing method for tailoring the grain structure and texture using QCW-DED.
ADDITIVE MANUFACTURING
(2023)
Article
Nanoscience & Nanotechnology
C. Paoletti, E. Santecchia, M. Cabibbo, E. Cerri, S. Spigarelli
Summary: AlSiMg alloys produced by additive manufacturing exhibit a complex microstructure, and a physically-based set of constitutive equations can predict their mechanical properties. Analysis of experimental data shows excellent correlation between model curves and experimental results.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Engineering, Manufacturing
Joseph N. Ghoussoub, Przemyslaw Klups, William J. B. Dick-Cleland, Kathryn E. Rankin, Satoshi Utada, Paul A. J. Bagot, D. Graham McCartney, Yuanbo T. Tang, Roger C. Reed
Summary: This study investigates a new class of nickel-based superalloy with high gamma ' fraction for the laser-powder bed fusion process. The results show that the (Nb+Ta)/Al ratio has a significant impact on the low-temperature strength and oxidation resistance of the alloy. The presence of defects in thin wall sections can be avoided through careful processing. Additionally, a novel sub-solvus heat treatment strategy is proposed to improve the material properties. The new superalloy exhibits superior tensile strength and oxidation resistance compared to CM247LC, but has inferior creep resistance.
ADDITIVE MANUFACTURING
(2022)
Article
Materials Science, Multidisciplinary
Christoph Kenel, Anthony De Luca, Christian Leinenbach, David C. Dunand
Summary: The effects of modifying a high-gamma' Ni-8.5Cr-5.5Al-1Ti model superalloy with 0.5 wt% Y2O3 through laser powder bed fusion are studied. The resulting oxide dispersion-strengthened (ODS) alloy exhibits significantly slower creep rates and better creep resistance compared to the base alloy. Two creep mechanisms, diffusional creep and dislocation creep, are observed. The ODS alloy shows potential for strengthening additively manufactured nickel-based superalloys.
ADVANCED ENGINEERING MATERIALS
(2022)
Article
Engineering, Manufacturing
Bojing Guo, Yashan Zhang, Zhongsheng Yang, Dingcong Cui, Feng He, Junjie Li, Zhijun Wang, Xin Lin, Jincheng Wang
Summary: Metal additive manufacturing has the potential to produce components with complex structures and outstanding properties, but the occurrence of defects such as cracking is a significant concern. This study investigated the cracking mechanism of Hastelloy X fabricated via directed energy deposition. The results revealed that thermal stress/strain, grain boundary characteristics, and micro-alloy elements were the main factors contributing to solidification cracking in Hastelloy X. Understanding these factors can guide the preparation of crack-free metals and alloys during additive manufacturing.
ADDITIVE MANUFACTURING
(2022)
Article
Nanoscience & Nanotechnology
Junmyoung Jang, Jonghyun Yim, Seung Hwan Lee
Summary: This study aimed to improve the stability of Inconel 718 against creep through induction heating during the process of laser-directed energy deposition. The induction heating dissolved the Laves phase, reduced Nb segregation, and led to the formation of directionally solidified columnar grains. The deposit produced by induction heating exhibited superior creep stability according to nanoindentation creep testing.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Materials Science, Multidisciplinary
Thaviti Naidu Palleda, Santhosh Banoth, Yen-Ling Kuo, Koji Kakehi
Summary: This study investigated the properties of the Ni-based superalloy IN718 fabricated using an electron beam melting process in as-built and heat-treated conditions, and elucidated the relationship between microstructure characteristics and creep properties. The results showed that the addition of a higher volume fraction of gamma'/gamma-strengthening precipitates within the grain and fine delta precipitates along the grain boundaries significantly improved the creep resistance of the alloy.
Article
Engineering, Mechanical
Qi Liu, Zhen Li, Sanming Du, Zhitao He, Jiesheng Han, Yongzhen Zhang
Summary: The cavitation erosion behavior of GH 4738 nickel-based superalloy was found to be better than that of Inconel 601 alloy, with selective cavitation erosion and cavitation-induced nanometer-scaled precipitates observed on the eroded surface of GH 4738. The formation of precipitates and the pinning effect of precipitates help slow down the erosion damage through absorbing the bubbles collapse energy, contributing to a better understanding of the effect of precipitates on materials cavitation erosion resistance.
TRIBOLOGY INTERNATIONAL
(2021)
Article
Chemistry, Physical
Shiwei Ci, Jingjing Liang, Jinguo Li, Haiwei Wang, Yizhou Zhou, Xiaofeng Sun, Yutian Ding
Summary: Additive manufacturing of crack-free nickel-based single-crystal superalloys using pulsed laser has shown longer stress rupture life compared to conventionally cast alloys. The improvement is attributed to the finer dendritic structure, lower inter-dendritic segregation, and evenly distributed carbides in the additive manufactured samples.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Engineering, Manufacturing
Yubei Zhang, Shan Li, Xiaodong Liu, Xin Li, Wenyan Duan, Liang Li, Bingshan Liu, Gong Wang
Summary: This research presents the successful fabrication of nickel-based superalloy Inconel 718 components using vat photopolymerization, with high-volume loading of metal powder. The process allows for the production of high precision and complex green parts, which can be debinded and sintered to obtain metal parts with specific characteristics. The microstructure evolution during sintering and the formation of oxides were comprehensively studied, providing insights into the sintering mechanism of Inconel 718.
ADDITIVE MANUFACTURING
(2023)
Article
Engineering, Manufacturing
Luciana Maria Bortoluci Ormastroni, Inmaculada Lopez-Galilea, Julian Pistor, Benjamin Ruttert, Carolin Koerner, Werner Theisen, Patrick Villechaise, Fernando Pedraza, Jonathan Cormier
Summary: This study investigated the VHCF behavior of a SX nickel-based superalloy additively manufactured by PBF-E at high temperatures. The results showed that the AM specimens had better fatigue lifetimes compared to the ones processed using traditional methods, and defect-free AM samples had very long lifetimes with surface initiation failure. The chemical stability of the superalloy played a dominant role in VHCF failure.
ADDITIVE MANUFACTURING
(2022)
Article
Crystallography
Denis Gurianov, Sergey Fortuna, Sergey Nikonov, Tatiana Kalashnikova, Andrey Chumaevskii, Veronika Utyaganova, Evgeny Kolubaev, Valery Rubtsov
Summary: Repairing damaged nickel-based superalloy products using electron-beam additive manufacturing method has been successfully achieved in this study. The repaired regions show similar structural and mechanical properties to the initial area.
Article
Materials Science, Multidisciplinary
Haohan Ni, Qi Zeng, Kai Zhang, Yingbin Chen, Jiangwei Wang
Summary: Heat treatment is an important method to adjust the properties of additive manufacturing materials. This study focuses on the microstructure and mechanical behavior of a laser powder-bed-fused superalloy and reveals the formation of laminar carbide precipitates at grain boundaries. Air cooling during heat treatment can introduce grain-boundary precipitates, leading to decreased ductility, while water quenching eliminates these precipitates and improves ductility.
Article
Engineering, Industrial
Jason C. Fox, Chris J. Evans, Jordan S. Weaver, Jesse K. Redforda
Summary: To overcome the lack of correlations between surface topography and part performance or process variables in laser powder bed fusion, this study investigated the melt pool behavior in regions where a rapid back-and-forth scan strategy occurs. The relationship between surface topography and melt pool cross section geometry on nickel superalloy 625 samples was analyzed to develop a conceptual model, and the implications for the development of strong, process-informed correlations are discussed.
CIRP ANNALS-MANUFACTURING TECHNOLOGY
(2023)
Article
Chemistry, Physical
Miaomiao Li, Meixia Xiao, Bo Wang, Zhao Li, Haiyang Song, Beibei Xiao
Summary: Inspired by the successful growth of Ti2C monolayers, the effects of Ti2CT2 anode in lithium-ion batteries were investigated using first-principles calculations. Ti2CT2 MXenes showed metallic conductivity with higher stability and strength compared to Ti2C. Among the Ti2CT2 monolayers, Ti2CS2 exhibited lower diffusion barrier, larger elastic modulus, lower open circuit voltage, and higher storage capacity. Surface sulfuration increased the interlayer spacing, enhancing Li-ion accessibility in double-layer Ti2CS2.
CHEMICAL PHYSICS LETTERS
(2023)
Article
Physics, Applied
R. N. Li, H. Y. Song, M. X. Xiao, M. R. An
Summary: The effect of HCP phase thickness, strain rate, and temperature on the interaction mechanism between screw dislocation and the HCP phase in FCC structured CoCrFeMnNi HEAs was investigated. Two interaction modes between dislocations and the HCP phase were identified: penetration mechanism and absorption mechanism. The relative ability of the HCP phase to prevent dislocation slip determined the generation of these mechanisms.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Ming Liu, Louis N. S. Chiu, Dedao Liu, Aijun Huang, Chris Davies, Xinhua Wu, Wenyi Yan
Summary: Numerical modelling is an effective tool for studying rapid temperature cycling in laser powder bed fusion. However, the high computational cost limits the modelling of part-scale components due to scale differences. In this study, a macroscale finite element thermal simulation strategy with track-scale resolution is proposed, combining a newly developed CTI model with an adaptive mesh re-mapping method. The strategy improves computational efficiency by 6 to 30 times for a Ti-6Al-4V part.
MATERIALS & DESIGN
(2023)
Article
Engineering, Mechanical
Wen Hao Kan, Huizhi Peng, Samuel Lim, Yuman Zhu, Kun Zhang, Aijun Huang
Summary: The sliding behavior of titanium alloys processed by laser powder bed fusion and conventionally-processed alloys was examined. Different microstructures were observed in these samples. When sliding against steel, oxidative, abrasive, and adhesive wear always occurred. However, wear rates were similar regardless of friction and hardness if material removal mainly occurred through abrasion or adhesion. Martensitic phases decomposed during sliding while nano-crystalline grains enhanced oxidative wear and reduced friction. By promoting oxidative wear over abrasive or adhesive wear, wear rates and friction can be substantially reduced with a stable nanocrystalline microstructure that provides ultrahigh hardness.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Metallurgy & Metallurgical Engineering
Jianan Hu, Mengmeng Yang, Wenlong Xiao, Hao Wang, Dehai Ping, Chengze Liu, Shewei Xin, Songquan Wu, Kai Zhang, Yi Yang, Lai-Chang Zhang, Aijun Huang
Summary: In this study, the thermally induced HCP to FCC phase transition in Ti35 alloy was investigated using in situ heating TEM and ab initio calculations. The observations revealed that the phase transition occurred within the matrix/twin and at the twin boundaries, leading to the formation of FCC-Ti in different morphologies. The crystallographic orientation relationship between HCP-Ti and FCC-Ti was determined, and the phase transition mechanism involved the formation of an intermediate state through the slip of partial dislocations. Moreover, the formation of FCC-Ti was found to be influenced by thermal stress, temperature, and contamination of interstitial atoms.
ACTA METALLURGICA SINICA-ENGLISH LETTERS
(2023)
Article
Engineering, Mechanical
Kai Zhang, Ying Liu, Xinni Tian, Yi Yang, Yuman Zhu, Michael Bermingham, Aijun Huang
Summary: This study investigates the high-cycle fatigue life and crack propagation rates of laser direct energy deposited Ti-6Al-4V with a trace boron addition. The refined microstructure increases crack initiation resistance and significantly improves high-cycle fatigue life. However, the crack propagation resistance, estimated from spectrum loading, is reduced due to the refined prior-beta grains and TiB particles.
INTERNATIONAL JOURNAL OF FATIGUE
(2023)
Review
Engineering, Electrical & Electronic
Jiaxuan Wang, Lei Wang, Zhao Li, Jiaying Bi, Qiong Shi, Haiyang Song
Summary: Lithium-sulfur (Li-S) batteries show great potential as the next-generation energy storage systems due to their high theoretical capacity and energy density. However, the sluggish redox kinetics of sulfur and the shuttle effect caused by lithium polysulfides (LiPSs) limit their coulombic efficiency and cycling stability. Incorporating polar catalytic materials into the cathode, particularly metal-based compounds, has been proven as an effective strategy to improve battery performance by anchoring LiPSs and accelerating the sulfur redox process. Density functional theory (DFT) calculations have played a crucial role in understanding and predicting the behavior of LiPSs on substrates, guiding the design of LiPS anchoring materials. This paper focuses on the DFT studies on metal compounds and reviews their recent progress as catalytic materials for Li-S battery cathodes, providing insights and suggestions for their wider application in the field.
JOURNAL OF ELECTRONIC MATERIALS
(2023)
Review
Materials Science, Multidisciplinary
Dina Bayoumy, Wenhao Kan, Xinhua Wu, Yuman Zhu, Aijun Huang
Summary: Laser powder bed fusion (LPBF) is a typical additive manufacturing technique that allows the fabrication of complex-shaped structures. Recent progress has been made in developing Sc-containing Al alloys specifically for LPBF production, which exhibit excellent processability and superior mechanical properties. This paper reviews the influence of Sc additions on the microstructure and properties of Al alloys when processed via LPBF, aiming to achieve remarkable material consolidation and excellent mechanical properties.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2023)
Article
Materials Science, Ceramics
L. Han, H. Y. Song, M. R. An, T. Z. Shen, Y. L. Li
Summary: The crystalline/amorphous dual-phase structure is an innovative approach to enhancing the mechanical properties of Mg alloys. The study conducted molecular dynamics simulations to investigate the influence of amorphous nanopillar size and rare earth element Y content on the interaction mechanism between prismatic dislocations and the amorphous nanopillar in Mg alloys. The results demonstrate that the strengthening effect of the amorphous nanopillar is highly dependent on its size. Furthermore, the interaction between dislocations and the amorphous nanopillar exhibits an unconventional mechanism caused by extended dislocations, distinct from the traditional shear or Orowan mechanisms with crystalline precipitates. The study also reveals that the inclusion of Y atoms increases the difficulty of basal slip, preventing the decomposition of perfect prismatic dislocations into extended dislocations on the basal plane.
JOURNAL OF NON-CRYSTALLINE SOLIDS
(2023)
Article
Materials Science, Multidisciplinary
Minghao Liu, Qi Zeng, Kai Zhang, Huawei Zhang, Wenpeng Zheng, Yuanyuan Li, Juan Hou, Jiangwei Wang, Yuman Zhu, Aijun Huang
Summary: In this study, the effects of process parameters on the defect, molten pool morphologies, microstructures, and hardness of HX were investigated. The correlation based on the Hall-Petch relationship was established. The formation mechanism of different types of defects formed by increasing energy density was systematically explained. The analysis of dendritic/cellular structure found that the dendritic arm spacing was significantly affected by varied energy densities, and higher energy input resulted in the increase of primary dendritic arm spacing (PDAS). Additionally, the grain boundaries of dendrite improved the mechanical properties, especially the hardness. The hardness test results showed a linear relationship between hardness value and decrease of PDAS, as illustrated by the Hall-Petch relationship.
Article
Materials Science, Multidisciplinary
Zuodong Zheng, Qingjun Chen, Xinyuan Peng, Hao Wang, Shoujiang Qu, Aihang Feng, Tong Xu, Kan Wang
Summary: In this study, a B2 ordered model was established using the special quasi-random structure method to simulate the real situation in high entropy alloys (HEAs). The influence of elements' occupancy and B2 structure ordering on the mechanical properties of AlTiCrVNb HEAs was explored using this model and first principles. The different effects on the mechanical properties of alloys due to the changing content of Ti or Cr were investigated using a B2-type partially ordered configuration in non-iso atomic ratio alloys, and the results were verified by experiment.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Materials Science, Multidisciplinary
Xiuhong Zhao, Yuting Ma, Shuailong Gao, Xuexiong Li, Dejun Yu, Hao Wang
Summary: This study used finite element simulations to analyze the effects of thermocouple design parameters on the thermal compression experiment of titanium alloy samples. The results showed that heat dissipation from the thermocouple caused temperature measurement deviations, and the thermal conductivity of the sample had the largest influence on measurement accuracy.
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
Shengbin Dai, Jiangqi Zhu, Xingchen Yan, Shun Wu, Yang Liu, Xiang Gao, Hamish Fraser, Peter Hodgson, Yuman Zhu, Martin Heilmaier, Aijun Huang
Summary: This study successfully combines oxide dispersion strengthened nickel-based superalloys with the laser powder bed fusion process using electrostatic self-assembly. By adding yttria oxide, the alloy's room-temperature yield strength is significantly improved due to the combined effects of yttria dispersion strengthening and dislocation strengthening within a heterogeneous microstructure.
ADVANCED MATERIALS TECHNOLOGIES
(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.