Article
Nanoscience & Nanotechnology
Junichiro Yamabe, Jean-Gabriel Sezgin, Kentaro Wada
Summary: The study found that hydrogen-induced ductility loss in two precipitation-hardened, martensitic stainless steels was more significant with higher hydrogen content or tensile strength. Lower hydrogen content and tensile strength resulted in quasi-cleavage fracture and significant plastic strain, suggesting that hydrogen-dislocation interaction contributed to the loss in ductility. Increase in either hydrogen content or tensile strength led to intergranular and cleavage surfaces being incorporated into the quasi-cleavage surface, attributed to hydrogen-induced reduction of cohesive strength. Subsequent impact tests at cryogenic temperatures confirmed this reduction, indicating underlying mechanisms responsible for the loss in ductility.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Nanoscience & Nanotechnology
Meichao Lin, Haiyang Yu, Yu Ding, Gang Wang, Vigdis Olden, Antonio Alvaro, Jianying He, Zhiliang Zhang
Summary: The detrimental effect of hydrogen on metals, causing a transition from ductile to brittle failure mode, has been incorporated into a unified predictive framework. This model can accurately predict the embrittlement level and surface morphology changes in metals under hydrogen environment.
SCRIPTA MATERIALIA
(2022)
Article
Materials Science, Multidisciplinary
Dong-Han Kim, Mohammad Moallemi, Kyung-Shik Kim, Sung-Joon Kim
Summary: In this study, the hydrogen embrittlement micromechanisms in Fe40Mn40Ni10Cr10 and Fe38Mn41Ni10Cr10C1 medium entropy alloy, as well as the effect of carbon interstitial on hydrogen distribution, were characterized. Ex-situ microstructural observations revealed that the segregation of carbon on grain boundaries suppressed the trapping of hydrogen in the grain boundaries for the carbon-doped alloy before deformation. However, the distribution of hydrogen was similar for both alloys after plastic strain, with a large fraction of hydrogen being trapped in the grain boundaries during deformation. The fully intergranular fracture mode in the hydrogen-affected area of both alloys was explained by the synergy of grain boundary dislocation reactions and hydrogen-enhanced grain boundary decohesion effects.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2022)
Article
Chemistry, Physical
Xiu Ran, Songrong Qian, Ji Zhou, Zhengyun Xu
Summary: We introduced a coupled peridynamic hydrogen diffusion and fracture model to solve the hydrogen embrittlement fracture of low alloy steel AISI 4340. The model considers the influence of temperature on hydrogen diffusion coefficient and uses a new peridynamic constitutive analysis method to simulate the crack propagation of hydrogen embrittlement. The model was verified through experimental tests and can numerically simulate the entire process of hydrogen atom diffusion and crack growth.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Materials Science, Multidisciplinary
Yunlong Li, Keshi Zhang
Summary: This study proposes a methodology for hydrogen-assisted fracture analysis that takes into account deformation and hydrogen transport. The proposed method uses a phase-field-based formulation and models the effect of hydrogen enhanced decohesion. Numerical and experimental investigations on 45CrNiMoVA steel validate the feasibility and predictive capabilities of the proposed method.
Article
Materials Science, Multidisciplinary
Tingshu Chen, Takahiro Chiba, Motomichi Koyama, Akinobu Shibata, Eiji Akiyama, Kenichi Takai
Summary: The study focused on investigating the local plastic strain evolution associated with crack growth in hydrogen-assisted quasi-cleavage fracture using tempered lath martensitic steels. The quasi-cleavage crack growth involved sharp crack initiation and growth, crack deflection/branching, crack tip blunting, and subsequent crack coalescence. Specific correlations were found between hydrogen-assisted cracking behavior and local plastic strain evolution at different spatial scales, with the largest plastic strain evolution occurring in the region where crack coalescence was observed.
METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE
(2021)
Article
Nanoscience & Nanotechnology
Chengshuang Zhou, Dan Tang, Kaiyu Zhang, Fangyue Wu, Ping Lin, Yan Jin, Lin Zhang, Jinyang Zheng
Summary: The hydrogen embrittlement behavior of two stabilized austenitic TWIP steels under high-pressure thermal hydrogen charging and hydrogen environment were investigated. It was found that both TWIP steels showed a certain susceptibility to hydrogen embrittlement after hydrogen charging, with the TWIP steel with higher Mn content showing weaker hydrogen embrittlement.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Chemistry, Physical
Thanh Tuan Nguyen, Kyung-Oh Bae, Park Jaeyeong, Seung Hoon Nahm, Un Bong Baek
Summary: There is no common standard for blended hydrogen use in the natural gas grid. The need for quantitative evaluation of hydrogen-natural gas mixtures to ensure the mechanical performance of pipeline structures is becoming increasingly evident. This study provides experimental data on the effect of H-2 concentration in a methane/hydrogen gas mixture and compares the mechanical performance of three pipeline steels.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Materials Science, Multidisciplinary
Kyung-Shik Kim, Jee-Hyun Kang, Sung-Joon Kim
Summary: The study revealed that carbon can alleviate the impact of hydrogen on the tensile properties of stainless steel, but increasing the carbon content does not significantly affect hydrogen diffusivity. Cracks induced by hydrogen mainly occur at grain boundaries and propagate inside grains, but are suppressed by grain boundaries.
Article
Nanoscience & Nanotechnology
Mitsuhiro Okayasu, Takafumi Fujiwara
Summary: Experimental and numerical studies revealed that severe hydrogen embrittlement occurred in the DS sample, while weak hydrogen embrittlement was detected in the AS and FS samples. Hydrogen trapping occurred in the low atomic density zones in the boundaries between alpha and gamma phases in the DS sample.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Materials Science, Multidisciplinary
Benjamin T. Wilson, Joseph D. Robson, Pratheek Shanthraj, Christopher P. Race
Summary: Materials modelling at the atomistic scale is used to investigate the fundamental mechanisms of hydrogen embrittlement in materials like aluminium alloys. This study focuses on understanding the hydrogen enhanced decohesion mechanism (HEDE) through density functional theory based tensile tests of grain boundaries. The results demonstrate that hydrogen weakens the grain boundaries and increases the embrittlement effect, which can be simulated using the proposed methods.
MODELLING AND SIMULATION IN MATERIALS SCIENCE AND ENGINEERING
(2022)
Article
Nanoscience & Nanotechnology
Futao Dong, Jeffrey Venezuela, Huixing Li, Zhiming Shi, Qingjun Zhou, Liansheng Chen, Jun Chen, Linxiu Du, Andrej Atrens
Summary: The temper embrittlement and hydrogen embrittlement of dual-phase steels were studied. It was found that an increased phosphorus content intensified hydrogen embrittlement and weakened the temper embrittlement. Hydrogen had little effect on strength but significantly decreased ductility. Hydrogen-induced cracks mainly initiated at the specimen surface and were predominantly martensite related. The increased phosphorus content enhanced hydrogen embrittlement susceptibility through interface weakening and ferrite ductility loss mechanisms.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Chemistry, Multidisciplinary
Kejun Shi, Xinyu Meng, Shu Xiao, Guohua Chen, Hao Wu, Chilou Zhou, Saihua Jiang, Paul K. Chu
Summary: MXene coatings on pipe steel exhibit excellent hydrogen resistance and corrosion protection by forming a barrier against diffusion, with hydrogen permeability of one third of the substrate and decreased diffusion coefficient. The concentration of the d-MXene colloidal suspension determines the thickness of a single coating, while surface damage caused by the suspension may limit improvements in hydrogen resistance.
Article
Nanoscience & Nanotechnology
Heena Khanchandani, Baptiste Gault
Summary: High strength twinning induced plasticity (TWIP) steels have potential for applications in the automotive industry, but they are susceptible to hydrogen embrittlement (HE) and galvanic corrosion. This study investigates the susceptibility towards HE and oxidation of a model Fe 27Mn 0.3C (wt%) TWIP steel using atom probe tomography. The segregation of hydrogen and oxygen at grain boundaries, correlated with manganese depletion, is measured. The study suggests a correlation between HE and oxidation mechanisms in TWIP steels, which can contribute to hydrogen enhanced decohesion of grain boundaries.
SCRIPTA MATERIALIA
(2023)
Article
Metallurgy & Metallurgical Engineering
Jun Zhang, Jie Su, Boning Zhang, Yi Zong, Zhigang Yang, Chi Zhang, Hao Chen
Summary: Hydrogen embrittlement of steels is directly correlated to hydrogen diffusion and trapping in the microstructure, which is difficult to measure accurately with modern experimental techniques. A phase-field model introducing a chemical potential well of hydrogen in the grain boundaries was proposed to simulate hydrogen diffusion and trapping in polycrystalline iron. Interestingly, it was found that grain boundaries act as connected trap sites, having a complex influence on the effective diffusivity of hydrogen, which is strongly associated with grain boundary diffusivity and binding energy.
ACTA METALLURGICA SINICA-ENGLISH LETTERS
(2021)
Article
Metallurgy & Metallurgical Engineering
Xu Lu, Dong Wang, Di Wan, Xiaofei Guo, Roy Johnsen
Summary: In this study, the effect of hydrogen on dislocation and twinning behavior in various grain boundaries of a high-manganese twinning-induced plasticity steel was investigated. The research found that the presence of hydrogen increased the compressive stress in both elastic and plastic regimes. Further investigation showed that hydrogen promoted dislocation multiplication and twin formation, leading to stress concentration at twin-twin and twin-grain boundary intersections.
ACTA METALLURGICA SINICA-ENGLISH LETTERS
(2023)
Article
Engineering, Multidisciplinary
Dengshan Zhou, Xiuzhen Zhang, Ali Tehranchi, Junhua Hou, Wenjun Lu, Tilmann Hickel, Dirk Ponge, Dierk Raabe, Deliang Zhang
Summary: Stacking faults (SFs) can be used to increase the strength and ductility of metal matrix composites. However, SFs are rarely observed in Al alloy matrix composites. In this study, SFs are introduced into an ultrafine-grained Al(Mg)-Al3Mg2 composite, resulting in improved yield strength and tensile elongation.
COMPOSITES PART B-ENGINEERING
(2022)
Article
Materials Science, Multidisciplinary
Zhuang Li, Pengcheng Zhao, Tiwen Lu, Kai Feng, Yonggang Tong, Binhan Sun, Ning Yao, Yu Xie, Bolun Han, Xiancheng Zhang, Shantung Tu
Summary: This study investigates the microstructural evolution, mechanical properties, and deformation mechanisms of a multi-principal element alloy prepared via laser powder bed fusion. The results show that the annealing temperature significantly affects the grain size, dislocation density, and precipitates, which in turn influence the strain hardening behavior and mechanical properties of the alloy.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2023)
Article
Materials Science, Multidisciplinary
Xu Lu, Yan Ma, Ding Peng, Roy Johnsen, Dong Wang
Summary: The effect of hydrogen on the surface morphology and nanomechanical properties of Ni-based Alloy 725 under different conditions was investigated. The results showed distinctive effects of hydrogen on the pop-in and hardness, with different mechanisms involved in each condition.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2023)
Article
Materials Science, Multidisciplinary
K. N. Sasidhar, Heena Khanchandani, Siyuan Zhang, Alisson Kwiatkowski da Silva, C. Scheu, Baptiste Gault, Dirk Ponge, Dierk Raabe
Summary: We conducted high-resolution structural and chemical characterization of the oxide films on a ferritic Fe-13 at% Cr alloy at different growth stages. The protective oxide film was found to be 5-6 nm thick, epitaxially grown with a cubic spinel-structure, and had a Baker-Nutting orientation-relationship with the alloy. The composition evolution within the oxide was explained by the low solid-state mobility of Cr3+ cations, suggesting the miscibility gap in the Fe-Cr spinel oxide solid-solution as a cause for the reduced driving force for oxide-layer thickening over time.
Review
Materials Science, Multidisciplinary
Binhan Sun, Alisson Kwiatkowski da Silva, Yuxiang Wu, Yan Ma, Hao Chen, Colin Scott, Dirk Ponge, Dierk Raabe
Summary: This review critically discusses the microstructure and mechanical responses of steels with medium manganese content, highlighting the differences from established steel grades. It addresses the phase transformation phenomena and mechanical behavior of these steels, covering the whole inelastic deformation regime. The relationships between processing, microstructure, and mechanical properties are assessed and open questions and challenges are identified for future research efforts.
INTERNATIONAL MATERIALS REVIEWS
(2023)
Article
Engineering, Multidisciplinary
H. M. Shodja, A. Ordookhani, A. Tehranchi
Summary: This paper investigates the scattering of SH-waves by a heterogeneous magneto-electro-elastic (MEE) scatterer embedded in an unbounded medium. The scatterer consists of a core and encapsulator with distinct MEE properties. The study employs fully coupled partial differential equations and Green's function equations to describe the fields in different regions. A rigorous analytical method called the dynamic magneto-electro-mechanical equivalent inclusion method (DMEMEIM) is developed to solve the problem. The results show that the magnetic field has a significant effect on the scattering cross-section and the interfacial stresses are influenced by both eccentricity and magnetic parameters.
JOURNAL OF ELASTICITY
(2023)
Article
Metallurgy & Metallurgical Engineering
Jun Zhang, Binhan Sun, Zhigang Yang, Chi Zhang, Hao Chen
Summary: This study proposes a microstructure architecting strategy based on a core-shell compositional distribution to enhance the hydrogen embrittlement resistance in advanced high-strength steels. By accurately designing the distribution of components within the austenite phase, it is possible to inhibit the formation and growth of hydrogen embrittlement while maintaining the mechanical performance of the material.
ACTA METALLURGICA SINICA-ENGLISH LETTERS
(2023)
Article
Materials Science, Multidisciplinary
T. S. Prithiv, Baptiste Gault, Yujiao Li, Dustin Andersen, Nathalie Valle, Santhana Eswara, Dirk Ponge, Dierk Raabe
Summary: The addition of boron (B) to steels significantly suppresses the austenite to ferrite phase transformation, increasing their hardenability. The mechanisms of B segregation and how exactly B suppresses the ferrite nucleation remain elusive.
Article
Materials Science, Multidisciplinary
Erik Koren, Catalina M. H. Hagen, Dong Wang, Xu Lu, Roy Johnsen, Junichiro Yamabe
Summary: This study investigated the hydrogen uptake and diffusivity in X65 pipeline steel using the permeation technique under various hydrogen charging conditions. Hydrogen charging was conducted using hydrogen gas at different pressures and electrochemical charging at different cathodic current densities. The results demonstrated that both the sub-surface hydrogen concentration in lattice and reversible trap sites and the effective hydrogen diffusivity were influenced by the charging conditions. Additionally, the relationship between equivalent hydrogen fugacity and overpotential was determined.
Article
Nanoscience & Nanotechnology
Xu Lu, Andres Diaz, Jun Ma, Dong Wang, Jianying He, Zhiliang Zhang, Roy Johnsen
Summary: Recently, hydrogen-assisted failures have been observed on nickel alloys used in the subsea oil and gas industries. This study investigates the hydrogen diffusion behavior in a nickel Alloy 625 under various pre-strain levels. The results show that while an increase in strain levels reduces hydrogen diffusivity, there is an acceleration in hydrogen diffusion when the strain exceeds a certain level, likely due to hydrogen-enhanced strain-induced vacancy formation at grain boundaries and reduced hydrogen trapping by fractured carbides.
SCRIPTA MATERIALIA
(2023)
Article
Materials Science, Multidisciplinary
Huijie Cheng, Xu Lu, Jingjing Zhou, Tiwen Lu, Binhan Sun, Xian-Cheng Zhang, Shan -Tung Tu
Summary: Multicomponent alloys have gained global attention due to their excellent mechanical and functional properties. However, concerns about hydrogen embrittlement (HE) arise due to their high strength level. This study investigates the effect of ordered precipitates on HE resistance in CoCrNi-based medium entropy alloys (MEA). It demonstrates that the presence of ordered precipitates reduces the tendency of H-induced intergranular cracking, leading to improved HE resistance.
Article
Materials Science, Multidisciplinary
Wei Peng, Jianbao Gao, Tiwen Lu, Binhan Sun, Xiancheng Zhang, Lijun Zhang, Shantung Tu
Summary: In this paper, a multi-order-parameter phase-field model was developed to study the abnormal grain growth (AGG) mechanism in copper thin films. The model was coupled with elastic mechanics and finite element framework to achieve a quantitative simulation of microstructure evolution during AGG. The simulation was further combined with the Mayadas-Shatzkes model to predict the evolution of electrical resistivities, leading to the proposal of feasible strategies for preparing high-performance copper thin films.
Article
Materials Science, Multidisciplinary
Xinren Chen, Jaber Rezaei Mianroodi, Chuanlai Liu, Xuyang Zhou, Dirk Ponge, Baptiste Gault, Bob Svendsen, Dierk Raabe
Summary: In aluminum alloys, solute atoms often trap excess vacancies, resulting in a change in the number of mobile vacancies and affecting solute diffusion and precipitate formation. This study investigates vacancy trapping indirectly in the Al-Sn binary alloy and reveals that the addition of Sn reduces the density of quenched-in Frank loops. Modeling of vacancy trapping by solutes during quenching shows the influence of vacancy-solute binding energy, solute concentration, and temperature on the trapping process.
Article
Nanoscience & Nanotechnology
Yu Xie, Tiwen Lu, Pengcheng Zhao, Binhan Sun, Ning Yao, Xiyu Chen, Jianping Tan, Xian-Cheng Zhang, Shan-Tung Tu
Summary: A hierarchical twin architecture was developed in coarse grained CoCrNi MEA through a new technique and annealing process, which improved the strength and ductility at cryogenic temperature. The material exhibited exceptional fatigue strength and showed the ability to suppress crack initiation. The unique substructure played a crucial role in achieving such performance.
SCRIPTA MATERIALIA
(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.