Article
Nanoscience & Nanotechnology
Xiangkui Liu, Tianchi Wang, Xinxiang Song, Zibo Zhang, Qipeng Wang, Shuai Feng, Yang Yang, Jian Kong
Summary: The transition in deformation mode from ductile to brittle related with glass forming ability was studied in metallic glasses through uniaxial compression tests, revealing that as GFA increases, the number and amplitude of serrated flow decrease gradually, and viscosity reduction plays a crucial role in shear deformation.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Chemistry, Physical
Y. S. Luo, J. J. Li, Z. Wang, M. Zhang, J. W. Qiao
Summary: Based on a simple mean-field model, two distinct types of slip avalanches in serrated plastic flows of bulk metallic glasses were identified to differentiate the slipping modes of shear bands under various strain rates. Small avalanches propagate progressively, while large avalanches follow a simultaneous propagation. By defining a weakening parameter and critical size, researchers were able to characterize the completely disparate shearing modes, with larger weakening and lower critical sizes indicating more activated shear transformation zones, offering a new method to explore plasticity in bulk metallic glasses.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Materials Science, Multidisciplinary
Yuanli Xu, Jiahe Song, Wenli Ma, Xinli Kou
Summary: The study investigated the serrated flow behavior of Zr61.7Al8Ni13Cu17Sn0.3 bulk metallic glass with different aspect ratios, finding that the behavior changes from uniform to nonuniform as the aspect ratio increases. Moreover, the normalized stress drop magnitude increases with increasing aspect ratios.
JOURNAL OF MATERIALS SCIENCE
(2021)
Article
Chemistry, Physical
Hu Huang, Minqiang Jiang, Jiwang Yan
Summary: Nanoindentation experiments were conducted on a Zr-based metallic glass under various loading rates, revealing that increasing the loading rate weakened the size of serrated flow but kept the number stable, while maintaining similar shear band features around residual indents. These results challenge the previous understanding derived from experiments using the Berkovich indenter.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Chemistry, Physical
H. H. Tang, X. B. Li, J. S. Zhang, D. Zhou, Z. W. Wu, S. H. Chen
Summary: Fractal analyses were conducted to unravel the relationship between serrated flows and complex shear bands in evolving bulk metallic glasses (BMGs). The increase of strains led to continuous increases in fractal dimensions of both shear-band patterns and serrated flows. Positive correlation between load-drop distributions and shear-band patterns was observed from the perspective of chaos degree. Hurst exponents less than 0.5 indicated a strong negative correlation behavior and a negative feedback mechanism in shear band development. Fractal dimensions and Weibull moduli at different strain stages indicated that load drops initially demonstrated relatively high uniformity and then stabilized at a low uniformity, which was related to regular shear-band patterns with fractal structure. These findings provide further understanding of the formation of shear bands and serrated flows in BMGs and offer a new method to uncover the plastic deformation mechanisms of BMGs using fractal analysis.
Article
Engineering, Mechanical
A. Khmich, A. Hassani, K. Sbiaai, A. Hasnaoui
Summary: Metallic glasses exhibit high mechanical performance but are usually brittle. Reinforcement of the metallic glass matrix to form composite materials is necessary for improved ductility and toughness. Molecular dynamics simulations can provide insights into the effects of adding Ta and W monocrystalline fibers on the mechanical properties of metallic glasses.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2021)
Article
Chemistry, Physical
Changshan Zhou, Hezhi Zhang, Xudong Yuan, Kaikai Song, Dan Liu
Summary: This study validates the applicability of pre-plastic deformation (PPD) on bulk metallic glasses (BMGs) with different Poisson's ratios. It is found that PPD treatment can effectively produce multiple shear bands in BMGs with high Poisson's ratios, leading to improved strength and plasticity. However, for BMGs with low Poisson's ratios, PPD treatment results in only a few shear bands and micro-cracks, leading to worsening mechanical properties. Furthermore, among the PPD-treated BMGs with similar high Poisson's ratios, Zr56Co28Al16 BMG exhibits larger plasticity due to the presence of more defective icosahedral clusters, which serve as nucleation sites for shear transformation zones (STZs) during deformation.
Article
Chemistry, Physical
A. Sharma, S. S. Hirmukhe, Sree Harsha Nandam, Horst Hahn, I. Singh, R. Lakshmi Narayan, K. Eswar Prasad
Summary: The strain rate sensitivity of a binary Cu60Zr40 nanoglass and metallic glass was studied using nanoindentation. The metallic glass exhibited noticeable displacement bursts at low loading rates, while the nanoglass showed a near homogeneous plastic flow. Both materials displayed a decrease in hardness with increasing loading rate, indicating negative strain rate sensitivity. The nanoglass had a higher strain rate sensitivity than the metallic glass.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Chemistry, Physical
Yuexin Chu, Guishen Zhou, Shaoshan Wan, Yue Zhang, Fuyu Dong, Xiaoguang Yuan, Binbin Wang, Liangshun Luo, Yanqing Su, Weidong Li, Peter K. Liaw
Summary: The relationship between shear transformation zones (STZs) and serrated flow dynamics in metallic glasses (MGs) was analyzed using nanoindentation. Different plasticity MGs were studied, and two distinct types of serrated flow dynamics were identified. MGs with easily activated STZs or low loading rates exhibited a power-law distribution, indicating a self-organized critical state. In contrast, hard MGs or high loading rates showed a Gaussian distribution, indicating a chaotic state with reduced stresses required for plastic deformation.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Multidisciplinary
Sangjun Kang, Di Wang, Arnaud Caron, Christian Minnert, Karsten Durst, Christian Kuebel, Xiaoke Mu
Summary: Scanning/transmission electron microscopy (S/TEM) techniques have been used to analyze shear bands in metallic glasses for decades in order to improve their mechanical properties. However, conventional S/TEM lacks the ability to directly characterize the local strain and atomic structure of amorphous materials. In this study, 4-dimensional-STEM (4D-STEM) is applied to directly map and correlate the local strain and atomic structure at the nanometer scale in deformed metallic glasses. The results provide a new understanding of the formation of shear bands in metallic glasses.
ADVANCED MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Wenbing Lu, Meifeng He, Dan Yu, Xiaoming Xie, Hao Wang, Shuai Wang, Chenggong Yuan, Aiying Chen
Summary: The study fabricated Mg-Zn-Yb-Ag metallic glasses by injecting into a copper roller, showing improved ductility under bending and tensile loading with the addition of trace amounts of ytterbium and precious metal silver. The amorphous alloy with 4 at% of Yb exhibited the greatest corrosion resistance due to a rare earth oxide film, indicating the potential of rare-earth element Yb in influencing alloy plasticity and corrosion resistance for better application prospects.
MATERIALS & DESIGN
(2021)
Article
Engineering, Mechanical
Yucong Gu, Jonathan Cappola, Jian Wang, Lin Li
Summary: This study investigates the yielding behavior of heterogeneous metallic glasses (MGs) by varying the spatial correlation and standard deviation of local shear moduli associated with clustering atoms on the nanoscale. Through computations and observations, the study proposes a Hall-Petch-like relationship where the yield stress of MGs scales inversely with the square root of the spatial correlation length. The results provide insights into the structure-property relationship of MGs and have important implications for the design of nanoscale MGs with tunable properties.
INTERNATIONAL JOURNAL OF PLASTICITY
(2023)
Article
Chemistry, Physical
Xiaojun Sun, Jie He, Dunbo Yu, Yang Luo, Zilong Wang, Yuanfei Yang
Summary: This work investigates the relationship between structural heterogeneity and serrated flow in nanoscale phase separated Zr-Cu-Fe-Al bulk metallic glasses with different plasticity. The results show that as the atomic ratio of Cu to Fe increases, serration dynamics transform from a chaotic state to a self-organized critical state. This transformation is attributed to the increase in structural heterogeneity, which promotes the formation of multiple shear bands.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Materials Science, Multidisciplinary
X. Yuan, D. Sopu, J. Eckert
Summary: The local stress state in metallic glasses can be modulated without affecting their structure, leading to enhanced ductility and strain hardening during loading. The stress heterogeneity in metallic glasses results in shear band multiplication, ultimately enhancing their macroscopic ductility. Additionally, residual compressive stress significantly increases the strength of the glass and contributes to observed strain hardening.
Article
Materials Science, Multidisciplinary
Devashish Rajpoot, R. Lakshmi Narayan, Long Zhang, Punit Kumar, Haifeng Zhang, Parag Tandaiya, Upadrasta Ramamurty
Summary: Fracture behavior of bulk metallic glass matrix composites with both transforming and non-transforming fi-Ti dendrites under shear and opening modes was examined, showing lower fracture toughness in mode II due to shear dominant stress state and considerable crack growth in this mode. Despite the ability of transforming dendrites to strain harden and enhance ductility, BMGCs reinforced with non-transforming dendrites exhibit higher toughness in both modes. Shear band patterns suggest identical fracture mechanism in BMGCs and BMGs, with differences rationalized by the effect of relaxation enthalpy and dendrites length scale.
Article
Chemistry, Physical
Michael I. Ojovan, Dmitri V. Louzguine-Luzgin
Summary: We utilize displacement analysis of Cu-atoms to reveal structural changes at the glass transition. The disordered congruent bond lattice of Cu loses rigidity above the glass transition temperature (T-g) due to percolation via broken Cu-Cu chemical bonds. Analysis of the first sharp diffraction minimum (FDSM) provides a more precise determination of T-g compared to classical empirical criteria.
Article
Physics, Condensed Matter
K. Pussi, D. Louzguine-Luzgin, J. Nokelaineni, B. Barbiellini, V Kothalawala, K. Ohara, H. Yamada, A. Bansil, S. Kamali
Summary: In this study, a reverse Monte Carlo technique is applied to determine the atomic structure of amorphous bulk metallic glasses. The findings contribute to the understanding of the functional properties of Fe-based metallic glasses driven by disorder effects.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2022)
Article
Nanoscience & Nanotechnology
Dmitri Louzguine-Luzgin, Jing Jiang
Summary: Low temperature relaxation and structural changes in a Cu36Zr48Al8Ag8 bulk glassy alloy were investigated using differential scanning calorimetry, X-ray diffractometry, scanning and transmission electron microscopy. The results showed that the densification of the sample occurred due to the beginning of structural relaxation, resulting in an increase in room-temperature mechanical strength and plasticity values.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Materials Science, Multidisciplinary
D. Louzguine-Luzgin, J. Jiang, G. R. Aripov, Yu P. Ivanov, V. Polkin
Summary: In this study, a Fe-Mn-Co-Al-C alloy with good tensile plasticity and high strength was obtained through standard technological operations. The high-entropy approach was utilized to form a duplex-type solid-solution structure without relying on carbide precipitates for dispersion strengthening. This approach may be applicable to other various alloys.
Article
Engineering, Mechanical
A. D. Berezner, V. A. Fedorov, M. Yu. Zadorozhnyy, I. S. Golovin, D. V. Louzguine-Luzgin
Summary: Deformation of a Cu-Pd-P amorphous alloy was studied under various frequencies of mechanical load, showing that the deformation can be interpolated using a hyperbolic function and is influenced by the combination of heating and cyclic mechanical loading.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2022)
Review
Chemistry, Physical
Alexei Vinogradov, Evgeniy Merson, Pavel Myagkikh, Mikhail Linderov, Alexandr Brilevsky, Dmitry Merson
Summary: This article provides an overview of achievements and knowledge gaps in the field of biodegradable magnesium alloys. It focuses on the popular Mg-Zn-Ca system as a representative example. The article reviews processing techniques and functional properties achieved through various processing routes. It also discusses corrosion properties, mechanical-chemical interactions, and challenges faced by researchers in this area.
Article
Chemistry, Physical
Evgeniy Merson, Vitaliy Poluyanov, Pavel Myagkikh, Dmitri Merson, Alexei Vinogradov
Summary: This study aimed to clarify the healing mechanism of Mg alloys exposed to corrosion solutions and stored in air, showing that PESCC gradually reduced and was eventually suppressed with increasing time and temperature of air storage. Recovery of elongation and complete elimination of PESCC were achieved after 24 hours of air storage at 150-200 degrees C, indicating the role of corrosion solution and hydrogen in forming specific zones on the fracture surface.
Article
Physics, Multidisciplinary
Yu-Zhang Jiao, Dmitry V. Louzguine-Luzgin, Ke-Fu Yao, Zheng-Jun Zhang, Na Chen
Summary: In this study, a magnetic semiconductor with a high Curie temperature is presented for the development of spintronic devices in next-generation computing systems. The semiconductor exhibits low resistivity and high saturation magnetization at room temperature, and forms a heterojunction with p-type silicon, showing rectifying characteristics. These findings provide design principles for high Curie temperature magnetic semiconductors with determined conduction types, which are crucial for realizing nonvolatile spin-based transistors in information technology beyond Si-based systems.
SCIENCE CHINA-PHYSICS MECHANICS & ASTRONOMY
(2023)
Article
Materials Science, Multidisciplinary
E. D. Merson, V. A. Poluyanov, A. Polunin, P. N. Myagkikh, D. L. Merson, A. Yu. Vinogradov
Summary: Preliminary immersed magnesium alloys suffer from pre-exposure stress corrosion cracking (PESCC) due to corrosion product film-induced stress (CPFIS). However, the internal residual stresses associated with corrosion product layer formation have not been investigated. In this study, the internal residual stresses of alloy ZK60 exposed to corrosion solution were evaluated using deflection and X-ray diffraction techniques. It was found that CP deposition on ZK60 alloy surface creates compressive internal stresses of both kinds - I and II. Macro residual stress of kind I does not exceed 3 MPa, while micro residual stress of kind II in the surface layer can be as high as 290 MPa.
LETTERS ON MATERIALS
(2023)
Article
Chemistry, Physical
D. V. Louzguine-Luzgin, Yu. P. Ivanov, A. L. Greer
Summary: The crystallization behavior of a Cu58Y37Sc5 metallic glassy alloy was investigated using various methods. Differential scanning and isothermal calorimetries were performed to study the phase transformations. X-ray diffractometry studies showed the simultaneous formation of Cu2Y, CuY, and CuSc crystalline phases, indicating eutectic crystallization, while the isothermal crystallization kinetics corresponded to primary crystallization. Transmission electron microscopy observations revealed a complex crystallization process involving heterogeneous nucleation on pre-existing particles.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Physical
Chandrahaasan K. Soundararajan, Dong Wang, Alexey Vinogradov
Summary: This study investigates the nanomechanical properties of Inconel 625 alloy under a hydrogen environment through in-situ electrochemical nanoindentation experiment. The hydrogen effect on various stages of the load-displacement plot is quantified, and it is found that hydrogen charging reduces the pop-in load and pop-in width, indicating hindered dislocation glide. The study also examines hydrogen-induced slip line formation and nanohardness variation using a diffusion-desorption model, and investigates the difference in plastic behavior between air and hydrogen environments through electron channeling contrast imaging.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Computer Science, Artificial Intelligence
Yu Wang, Alexey Vinogradov
Summary: This paper proposes a simple and easy-to-implement ensemble approach, the history-state ensemble (HSE) method, which leverages the "local sub-optima" of deep networks to improve the performance of deep neural networks. It is demonstrated that neural networks can naturally generate multiple diverse "local sub-optima" during training, and their combination can effectively enhance the accuracy and stability of a single network. The advantages of HSE include no additional training cost for acquiring multiple base models and applicability to any types of deep networks without tuning of network architectures.
Article
Nanoscience & Nanotechnology
D. V. Louzguine-Luzgin, E. N. Zanaeva, F. R. Pratama, T. Wada, S. Ito
Summary: The structural features of Pd42.5Cu30Ni7.5P20 and Pt42.5Cu27Ni9.5P21 metallic glasses were examined using high-resolution transmission electron microscopy. Pd42.5Cu30Ni7.5P20 exhibited true bulk glass-forming behavior without crystalline particles/nuclei, while Pt42.5Cu27Ni9.5P21 was a crystal growth-controlled bulk glass-former containing nanoparticles with a different chemical composition and an average size of about 1 nm. These structural differences influenced the mechanical properties at room temperature. Thermodynamic calculations supported the observed features.
SCRIPTA MATERIALIA
(2023)
Article
Chemistry, Physical
S. Romankov, Y. C. Park, Y. Miyauchi, D. V. Louzguine-Luzgin, S. Komarov
Summary: W-based alloyed coatings with variable W content were fabricated on Ti and steel substrates using different combinations of W milling balls. The coatings displayed heterogeneous nanocomposite structures, and the composition and microstructures could be tailored through the selection of milling balls. The hardness and wear resistance of the coatings were influenced by the W content and microstructure.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Materials Science, Multidisciplinary
D. V. Louzguine-Luzgin, K. Shinozaki
Summary: In this study, glassy oxide/metallic composite materials were produced by sintering powdered oxide glass reinforced with metallic glassy ribbons in the supercooled liquid regions. The composite samples exhibited better mechanical properties compared to single phase oxide samples.
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.
