Article
Nanoscience & Nanotechnology
K. N. Chaithanya Kumar, Atharva Pagare, H-G Brokmeier, M. Sankar, Nobert Schell, K. S. Suresh
Summary: The in-situ deformation of Ni rich NiTi shape memory alloy was characterized using synchrotron diffraction. The study found that applied stress affects the texture of material and restricts the stress induced martensitic transformation. A strong lattice correspondence between the austenite and martensite phases along with a strong variant selection was observed.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Mechanics
William S. LePage, John A. Shaw, Samantha H. Daly
Summary: The study revealed that crystallographic texture significantly affects the fatigue performance of NiTi sheet, with strong orientation-dependent mechanisms of plasticity, transformation, and twinning on both functional and structural fatigue. Under stress-controlled cycling, tension along textures similar to that of the TD demonstrated better fatigue performance.
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
(2021)
Article
Nanoscience & Nanotechnology
Xiaohui Bian, Ludek Heller, Ondrej Tyc, Lukas Kaderavek, Petr Sittner
Summary: This study addresses the unanswered questions regarding superelastic deformation of NiTi wires, including the texture and microstructure of stress induced martensite, the transformation process of austenite to martensite, and the deformation mechanisms at different temperatures. Experimental results reveal distinct differences in superelasticity and plastic deformation mechanisms at different temperatures.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Chemistry, Physical
Kangjie Chu, Bing Wang, Qiao Li, Yusuke Onuki, Fuzeng Ren
Summary: The effect of grain size on temperature-dependent elastic modulus (TDEM) of polycrystalline NiTi was investigated. It was found that the TDEM decreased rapidly with smaller grain size. In-situ neutron diffraction and molecular dynamics simulation revealed that the reduction in grain size led to an increase in the volume fraction and thermal stability of the austenite phase at low temperature, resulting in two-phase coexistence during cooling. The compensation of the intrinsic opposite TDEM of austenite and martensite contributed to the overall reduced TDEM in nanocrystalline NiTi. This study suggests that the TDEM of shape memory alloy can be controlled by grain size.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Materials Science, Multidisciplinary
Xiaohui Bian, Ludek Heller, Lukas Kaderavek, Petr Sittner
Summary: The tensile deformation behavior of nanocrystalline NiTi wire in the martensite state was investigated, revealing its superelasticity and plastic deformation capability. The wire also exhibited the ability to refine the austenitic microstructure during the deformation process.
APPLIED MATERIALS TODAY
(2022)
Article
Chemistry, Physical
A. Shuitcev, R. N. Vasin, A. M. Balagurov, L. Li, I. A. Bobrikov, S. Sumnikov, Y. X. Tong
Summary: The thermoelastic martensitic transformation in the polycrystalline Ti29.7Ni50.3Hf10Zr10 alloy was studied using high-resolution and in situ neutron diffraction. The study found that the B19' martensite and austenite have different thermal expansion behaviors. Some disordered austenite does not participate in the martensitic transformation. The addition of Hf and Zr atoms leads to the deterioration of the crystallographic compatibility between martensite and austenite, causing large thermal hysteresis and volume changes upon transformation.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Engineering, Manufacturing
Ze Pu, Dong Du, Kaiming Wang, Guan Liu, Dongqi Zhang, Haoyu Zhang, Rui Xi, Xiebin Wang, Baohua Chang
Summary: In this study, NiTi shape memory alloys were successfully in-situ synthesized using dual-wire-feed electron beam additive manufacturing. The as-built NiTi alloys exhibited continuous coarse columnar grains and uniform composition distribution, and showed good static compressive property and shape memory response.
ADDITIVE MANUFACTURING
(2022)
Review
Materials Science, Multidisciplinary
Fuzhen Sun, Xinxin Feng, Haizhen Wang, Xinjian Cao, Xiao Liu, Yang Liu, Yan Li, Zhongli Liu, Xiaoyang Yi
Summary: Shape memory alloys are smart materials that have superior properties and are widely used in aerospace, naval, automobile, and biomedicine industries. Functionally graded shape memory alloys are created to achieve accurate controllability for progressive movement. This review paper discusses the classification, fabrications, microstructural features, and performances of functionally graded shape memory alloys. Creating various gradients in shape memory alloys can widen the transformation temperature intervals and transformation stress intervals, leading to excellent performances and wider application range.
ADVANCED ENGINEERING MATERIALS
(2023)
Article
Engineering, Electrical & Electronic
A. Sibirev, S. Belyaev, N. Resnina
Summary: The study investigates the influence of counter-body stiffness on the recovery stress, recoverable strain, and work output during thermal cycling of NiTi cylindrical samples in the actuator regime. Results show a nonlinear relationship between stiffness values and shape memory effect/recovery stress, and a gradual decrease in recovery stress, work output values during thermal cycling.
SENSORS AND ACTUATORS A-PHYSICAL
(2021)
Article
Materials Science, Multidisciplinary
Hongjia Li, Zhaolong Yang, Huahai Shen, Yuanhua Xia, Jian Li, Zhijian Fan, Chaoqiang Huang, Guangai Sun, Jian Gong
Summary: A combined experimental and computational effort was conducted to investigate the microscopic deformation behavior of B19' martensitic NiTi during compressive loading-unloading. In situ neutron diffraction experiment and an elastic-viscoplastic self-consistent (EVPSC) model incorporating a domino detwinning scheme were used to interpret the experimental data and elucidate the deformation mechanisms. The model predictions showed good agreement with the in situ load-unload stress-strain curve and lattice strains, and were further validated against deformed texture and individual microstrains from published work. The effects of domino detwinning on intergranular stresses and the various deformation mechanisms during compressive load and unload processes were thoroughly discussed by comparing simulations and experiments.
Article
Chemistry, Physical
Jan Dittrich, Gergely Farkas, Daria Drozdenko, Michal Knapek, Kristian Mathis, Peter Minarik
Summary: A combination of advanced in-situ experimental techniques, including neutron diffraction, acoustic emission, and electron backscattered diffraction, was used to investigate the deformation behavior of magnesium alloys. The potential and limitations of these techniques were demonstrated in a study on the influence of crystallographic texture on deformation mechanisms in a hot-rolled sheet of the AZ31 alloy. The results showed the twinning activity and its evolution, as well as the deformed microstructure, providing valuable insights into the deformation mechanisms of the alloy.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Nanoscience & Nanotechnology
Jiao Luo, Kengfeng Xu, Chaojun Li, Miaoquan Li, Yingying Lin
Summary: Isothermal compression tests, EBSD observations, and quantitative analysis were conducted to investigate the effect of process parameters on microstructure variables during isothermal compression of NiTi shape memory alloy. The results showed that dynamic recovery is the dominant softening mechanism at lower strains, while dynamic recrystallization plays a significant role in softening the alloy at higher strains, leading to a steady state of flow behavior. Additionally, the occurrence of dynamic recrystallization during deformation promotes the formation of a strong gamma-fiber texture in the alloy.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Engineering, Electrical & Electronic
A. Sibirev, S. Belyaev, N. Resnina
Summary: The influence of fraction of the forward and reverse martensitic transformations on the variations in the recoverable strain, recovery stress, work output and irreversible strain was studied. The equiatomic NiTi alloy was subjected to thermal cycling under torque stress and pre-deformed by various strain. The results showed that thermal cycling at different strains caused changes in these characteristic parameters.
SENSORS AND ACTUATORS A-PHYSICAL
(2023)
Article
Engineering, Manufacturing
Keyvan Safaei, Mohammadreza Nematollahi, Parisa Bayati, Fatemeh Kordizadeh, Mohsen Taheri Andani, Hossein Abedi, Behrang Poorganji, Mohammad Elahinia
Summary: There is a growing interest in additive manufacturing (AM) techniques for producing complex-shaped parts and tailoring the microstructure and properties. NiTi-based shape memory alloys (SMA) have a poor machinability and require additional treatments. The build orientation approach is used to control the crystallographic texture of LPBF-processed NiTi specimens. The study shows the significant effect of building orientation on the crystallographic texture and discusses the mechanism of this approach. The thermomechanical properties of the printed samples are assessed and correlated to the crystallographic textures.
ADDITIVE MANUFACTURING
(2022)
Article
Materials Science, Multidisciplinary
A. Sibirev, E. Ubyivovk, S. Belyaev, N. Resnina
Summary: This study examined the peculiarities of the movement of martensite interfaces in a NiTi alloy during the forward and reverse transformations using in situ transmission electron microscopy. The results showed that the sequence of martensite shrinking on heating was not the opposite of the sequence of martensite formation on previous cooling, and the formation sequence during the second cooling was different from the first cooling. Additionally, dislocations did not hinder martensite formation nor aid in nucleation and growth.
Article
Engineering, Biomedical
Chia-Chen Hsu, Julian H. George, Sharlayne Waller, Cyril Besnard, David A. Nagel, Eric J. Hill, Michael D. Coleman, Alexander M. Korsunsky, Zhanfeng Cui, Hua Ye
Summary: The study successfully supported 3D hiPSC-derived neural networks using granular hydrogel-based scaffolds, resulting in improved cell viability and longer neurite extensions. This method is simple, rapid, and efficient, achieving tissue-relevant granular structures in hydrogel cultures.
BIOACTIVE MATERIALS
(2022)
Article
Computer Science, Information Systems
Mehmet C. Kulan, Nick J. Baker, Konstantinos A. Liogas, Oliver Davis, John Taylor, Alexander M. Korsunsky
Summary: Finite element analysis is crucial in accurately predicting losses in magnetic materials and is important in designing electromagnetic devices. Soft magnetic composites, an alternative to silicon steel laminations, have unique microstructures that require different modeling approaches. This study evaluates the trends in modeling soft magnetic composite core losses and discusses the challenges in estimating and using Steinmetz core loss coefficients.
Article
Engineering, Mechanical
Jingwei Chen, Zifan Wang, Alexander M. Korsunsky
Summary: In this study, the inhomogeneity of multiscale stresses and strains in polycrystalline metals was investigated using a rate-independent crystal plasticity formulation. The statistical distribution of stress and strain at macro-, meso- and micro-scales were explored through multiple realizations of a cubic representative volume element (RVE). The findings reveal that the dispersion of local stress and strain is much larger than that of the macroscopic average, providing new guidance for determining the minimum RVE size.
INTERNATIONAL JOURNAL OF PLASTICITY
(2022)
Article
Materials Science, Multidisciplinary
Zifan Wang, Jingwei Chen, Oxana V. Magdysyuk, Fatih Uzun, Alexander M. Korsunsky
Summary: This paper introduces a new method to extract texture information from single shot diffraction patterns and demonstrates another texture analysis method based on single shot X-ray diffraction. The effectiveness of both methods is proven through evaluation on polycrystalline nickel-based superalloy samples. Additionally, a new metric is proposed to quantify the matching quality of pole figures.
MATERIALS CHARACTERIZATION
(2022)
Article
Nanoscience & Nanotechnology
Zifan Wang, Jingwei Chen, Radim Kocich, Samuel Tardif, Igor P. Dolbnya, Lenka Kuncicka, Jean-Sebastien Micha, Konstantinos Liogas, Oxana Magdysyuk, Ivo Szurman, Alexander M. Korsunsky
Summary: An effective route of customizing the superelasticity (SE) of NiTi shape memory alloys via modifying the grain structure was explored. It was found that the smaller the grain size, the higher the phase transformation nucleation kinetics, and the lower the propagation kinetics. Stress concentration happens near high-angle grain boundaries, while no obvious stress concentration can be observed in low-angle grain boundary structures. The statistical distribution of strain becomes asymmetric during loading.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Review
Engineering, Industrial
Hitoshi Soyama, Alexander M. Korsunsky
Summary: Mechanical surface modification techniques, such as shot peening, can improve the fatigue properties of metals and other materials. Cavitation peening is a special variation of shot peening that offers the advantage of lower surface roughness and no solid collisions. Understanding both fluid dynamics and materials science is necessary for grasping the mechanisms of cavitation peening. This comparative review presents key insights and achievements, comparing water jet, pulsed laser, and ultrasonic cavitation peening with traditional shot peening.
JOURNAL OF MATERIALS PROCESSING TECHNOLOGY
(2022)
Article
Materials Science, Multidisciplinary
Cyril Besnard, Ali Marie, Petr Bucek, Sisini Sasidharan, Robert A. Harper, Shashidhara Marathe, Kaz Wanelik, Gabriel Landini, Richard M. Shelton, Alexander M. Korsunsky
Summary: This study investigates the nanoscale structural changes within dental carious lesions and establishes dental 3D nano-histology as an advanced platform for quantitatively evaluating caries-induced structural modification.
MATERIALS & DESIGN
(2022)
Article
Materials Science, Multidisciplinary
Patrick Aggrey, Igor A. Salimon, Alexey I. Salimon, Pavel Somov, Eugene Statnik, Dmitry Zherebtsov, Alexander M. Korsunsky
Summary: Effective light scattering, transmission, and absorption are crucial for optical devices. This study presents a facile and eco-friendly method for fabricating a textured Si/a-C film nanocomposite with high broadband absorption. The combination of surface texturing techniques and photo-friendly thin film coatings has shown significant progress in this field.
Article
Multidisciplinary Sciences
Yanan Hu, Shengchuan Wu, Yi Guo, Zhao Shen, Alexander M. Korsunsky, Yukuang Yu, Xu Zhang, Yanan Fu, Zhigang Che, Tiqiao Xiao, Sergio Lozano-Perez, Qingxi Yuan, Xiangli Zhong, Xiaoqin Zeng, Guozheng Kang, Philip J. Withers
Summary: In this study, the authors quantified the softening mechanisms in the fine equiaxed zone (FQZ) and proposed a hybrid welding strategy to mitigate the intergranular failure and increase weld strength in 7000 series aluminum alloys.
NATURE COMMUNICATIONS
(2022)
Article
Multidisciplinary Sciences
Vedat Durmaz, Katharina Koechl, Andreas Krassnigg, Lena Parigger, Michael Hetmann, Amit Singh, Daniel Nutz, Alexander Korsunsky, Ursula Kahler, Centina Koenig, Lee Chang, Marius Krebs, Riccardo Bassetto, Tea Pavkov-Keller, Verena Resch, Karl Gruber, Georg Steinkellner, Christian C. Gruber
Summary: This study used bioinformatics analysis to investigate the impact of SARS-CoV-2 variants on the affinity to the human receptor hACE2, with the latest Omicron variant showing the largest impact on the RBD binding interface compared to other variants. Omicron exhibited a higher ACE2 binding affinity than the wild type and requires special attention and monitoring.
SCIENTIFIC REPORTS
(2022)
Article
Chemistry, Physical
A. Salimon, E. S. Statnik, Yu Kan, O. O. Yanushevich, V. N. Tsarev, M. S. Podporin, S. D. Arutyunov, P. Yu Skripnichenko, M. S. Galstyan, A. M. Korsunsky
Summary: The decontamination of medical tools using sub- and supercritical fluids provides a sustainable alternative to disposable items. However, it is essential to assess the extent of material surface degradation, as CO2 can corrode metals and dissolve in polymers.
JOURNAL OF SUPERCRITICAL FLUIDS
(2022)
Article
Nanoscience & Nanotechnology
Zifan Wang, Yunlan Zhang, Konstantinos Liogas, Jingwei Chen, Gavin B. M. Vaughan, Radim Kocich, Lenka Kuncicka, Fatih Uzun, Zhong You, Alexander M. Korsunsky
Summary: Despite the challenges caused by the lack of a training methodology and understanding of its mechanisms, a novel training routine and device have been developed for the effective application of the Two-Way Shape Memory Effect (TWSME) in Shape Memory Alloys. Through experiments and analysis, it has been revealed that the training process has negligible influence on the parent phase's texture, the preferred variant of the B19' phase exhibits tension/compression asymmetry, and lattice defects are rearranged after training. These findings have important implications for the practical use of TWSME.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Engineering, Manufacturing
Konstantinos A. Liogas, Kwang Boon Lau, Zifan Wang, David N. Brown, Efthymios Polatidis, Pei Wang, Alexander M. Korsunsky
Summary: Equiatomic Co-Fe alloy with controlled slow cooling through thermal post-processing has shown excellent soft magnetic properties, making it suitable for manufacturing three-dimensional complex-shaped electromagnetic cores using Laser Powder Bed Fusion technique.
ADDITIVE MANUFACTURING
(2023)
Article
Chemistry, Physical
Julijana Cvjetinovic, Anastasiia A. Merdalimova, Maria A. Kirsanova, Pavel A. Somov, Daniil Nozdriukhin, Alexey Salimon, Alexander M. Korsunsky, Dmitry A. Gorin
Summary: Siliceous diatom frustules are a promising platform for bio-assisted nanofabrication processes. By modifying diatomite with gold nanoparticles, composite structures with highly porous properties have been obtained, which can be used for various applications such as SERS.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
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.