Article
Nanoscience & Nanotechnology
Cheng Zhang, Huihui Zhi, Stoichko Antonov, Jun He, Hang Yu, Zihui Guo, Yanjing Su
Summary: The effect of deformation twins on the hydrogen embrittlement of TWIP steel was investigated, and the results showed that specimens with high twin volume fraction exhibited better resistance to hydrogen embrittlement.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Nanoscience & Nanotechnology
Sangmin Lee, Yong-Deok Im, Ryo Matsumoto, Hiroshi Utsunomiya
Summary: C-HSR rolling can improve the balance of mechanical properties and electrical conductivity of Cu x Al alloy by increasing dislocation density and reducing grain size.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Nanoscience & Nanotechnology
Kai Zhang, Jing-Hua Zheng, Christopher Hopper, Chaoyang Sun, Jun Jiang
Summary: The study shows that the mechanical properties of magnesium alloy (WE43) can be significantly improved at cryogenic temperatures, especially when the compression direction is perpendicular to the extrusion direction. This improvement is attributed to enhanced pyramidal slip.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Nanoscience & Nanotechnology
Frank Niessen, Azdiar A. Gazder, David R. G. Mitchell, Elena V. Pereloma
Summary: Microstructure evolution during the 3-point bending of a metastable beta Ti-10V-2Fe-3Al alloy containing 5% alpha was dominated by the formation of deformation-induced alpha '' martensite. The nucleation of alpha '' plates from {580}(alpha '') habit planes at alpha-beta interfaces, impingement with high-angle boundaries, and subsequent thickening led to a build-up of strain energy inducing {130} < 310 >(alpha '') twinning. The study also revealed the activation of {130}< 310 >(alpha '') twinning by alpha '' impingement in a metastable beta matrix.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Nanoscience & Nanotechnology
J. T. Lloyd, D. J. Magagnosc, C. S. Meredith, K. R. Limmer, D. M. Field
Summary: The mechanical properties of transformation-induced plasticity (TRIP) steels are attractive in many applications, but they lose these properties under high dynamic loading rates. However, quasi-static pre-straining can significantly improve the dynamic strength of TRIP steels while retaining high work hardening response.
SCRIPTA MATERIALIA
(2022)
Article
Materials Science, Multidisciplinary
Umer Masood Chaudry, Min-Su Lee, Tea-Sung Jun
Summary: This study systematically investigated the twin-induced dynamic recrystallization of commercially pure titanium under cryogenic and room temperature. The results showed that higher strain levels resulted in the increased evolution of twins and interactions between twins at room temperature, while cryogenic temperature led to significant grain refinement.
MATERIALS CHARACTERIZATION
(2023)
Article
Nanoscience & Nanotechnology
Shiqiu Liu, Hongsheng Ding, Ruirun Chen, Jingjie Guo, Hengzhi Fu
Summary: The microstructural refinement using deformation nanotwins can significantly improve the tensile strength of TiAl-based alloy. The generation of high-density deformation nanotwins can effectively strengthen the material by relieving stress concentration and improving the work-hardening rate during tension, thus keeping the work-hardening rate stable.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Nanoscience & Nanotechnology
Xiaoyan Wang, Shaopeng Li, Yuanfei Han, Guangfa Huang, Jianwei Mao, Weijie Lu
Summary: This study investigates the role of reinforcements in the microstructural evolution of titanium matrix composites (TMCs) during high-temperature fatigue, revealing a new phenomenon of twin nucleation. The presence of reinforcements enhances dislocation accumulation and promotes the rapid diffusion of elements, leading to an increase in local stress concentration and ultimately contributing to twin nucleation. This work contributes to a better understanding of the mechanism underlying TMC fracture during high-temperature fatigue.
SCRIPTA MATERIALIA
(2021)
Article
Nanoscience & Nanotechnology
Roopam Jain, Mirtunjay Kumar, Krishanu Biswas, N. P. Gurao
Summary: The deformation behavior of a transformative Fe50Mn30Co10Cr10 complex concentrated alloy doped with 0.2 wt% silicon was studied using experimental analysis and simulations. It was found that the addition of silicon suppresses the martensitic transformation and instead leads to the formation of nano twinning during tensile deformation. The improved strength and ductility of the alloy can be attributed to solid solution strengthening and deformation twinning, respectively. Simulations also revealed the planar nature of slip and the impact of neighboring grain orientations on the rotation path of individual grains. Deformation nano twinning was identified as a critical factor contributing to significant ductility.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Materials Science, Multidisciplinary
Min-Su Lee, Min-Ki Ji, Yong-Taek Hyun, Eun-Young Kim, Tea-Sung Jun
Summary: The study revealed the deformation anisotropy and plastic behaviors of commercial pure titanium at low temperature, twinning-induced hardening is one of the reasons for anisotropic plastic behavior, low temperature and increasing temperature gradient intensified plastic anisotropy and twinning activity, possibly increasing the activation rate of slips. Plastic anisotropy was intensified under two different crystallographic textures.
MATERIALS CHARACTERIZATION
(2021)
Article
Materials Science, Multidisciplinary
Daniel J. Savage, Rodney J. McCabe, Marko Knezevic
Summary: This paper presents a set of algorithms for automatic reconstruction of deformation twin hierarchies in heavily twinned microstructures. By addressing key issues such as twin relationships, grain grouping, and constructing twin family trees, the automation level in reconstructing twin hierarchies under large strains is significantly improved.
MATERIALS CHARACTERIZATION
(2021)
Article
Nanoscience & Nanotechnology
Jingqi Zhang, Michael Bermingham, Joseph Otte, Yingang Liu, Matthew Dargusch
Summary: This study demonstrates how to achieve uniform and enhanced tensile ductility by minimizing the in-situ intrinsic heat treatment effect. By adjusting the heating and deposition time, the tensile ductility of Ti-5Al-5Mo-5V-3Cr material was successfully improved without notable variation.
SCRIPTA MATERIALIA
(2023)
Article
Nanoscience & Nanotechnology
Jingqi Zhang, Yingang Liu, Mohamad Bayat, Qiyang Tan, Yu Yin, Zhiqi Fan, Shiyang Liu, Jesper Henri Hattel, Matthew Dargusch, Ming-Xing Zhang
Summary: This study demonstrates that in-situ grain refinement of CP-Ti can be achieved through controlling SLM parameters, with higher input energy density favoring grain refinement. Detailed microstructural characterization and multi-physics simulation were conducted to reveal the grain refinement mechanism. The refined CP-Ti showed high ductility without notable mechanical anisotropy, attributed to the intrinsic heat treatment effect resulting from the cyclic reheating in the SLM process.
SCRIPTA MATERIALIA
(2021)
Article
Materials Science, Multidisciplinary
Runrun Xu, Miaoquan Li
Summary: This study utilized transmission electron microscopy to investigate the hot deformation behavior of a beta-solidifying gamma-TiAl alloy with a duplex structure. It found that twinning is closely linked to twin intersections in gamma grains. As isothermal compression proceeded, faults evolved into twins, with dislocations aiding in promoting twinning in gamma grains.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2021)
Article
Nanoscience & Nanotechnology
Gukin Han, Yeonju Noh, Umer Masood Chaudry, Sung Hyuk Park, Kotiba Hamad, Tea-Sung Jun
Summary: The study found that Mg-0.5Ca alloy exhibits temperature-insensitive hardening behavior, while pronounced twinning activity was observed in pure Mg when deformed at low temperatures. The microstructure of Mg-0.5Ca helps reduce twinning behavior, resulting in its hardening behavior being temperature-dependent.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Materials Science, Multidisciplinary
Amit Sharma, Oz Mendelsohn, Anuj Bisht, Johann Michler, Raj Kiran Koju, Yuri Mishin, Eugen Rabkin
Summary: It is discovered that alloying pristine crystalline nickel nanoparticles with iron leads to unexpected softening due to the random distribution of solute atoms and nano-size precipitates. This softening effect is observed in particles with different compositions and orientations, and it is associated with premature dislocation nucleation caused by the randomly distributed solute atoms. The manipulation of classical hardening mechanisms in defect-free single-crystalline metal nanoparticles offers new possibilities for controlling their plastic deformation.
Article
Materials Science, Multidisciplinary
Nicolo Maria della Ventura, Peter Schweizer, Amit Sharma, Manish Jain, Thomas Edward James Edwards, J. Jakob Schwiedrzik, Cinzia Peruzzi, Roland E. Loge, Johann Michler, Xavier Maeder
Summary: The strain rate and temperature dependent mechanical response of single crystal magnesium micropillars compressed along the a-axis was investigated. It was found that extension twinning controlled the plasticity at temperatures below 423K, while prismatic dislocation mediated plasticity dominated at temperatures above 423K and strain rates below 10s-1. At higher strain rates, deformation twinning occurred again. The study also provided a detailed analysis of the transition from slip to twin and the influence of thermal and kinetic contributions on the flow stress evolution.
Article
Materials Science, Multidisciplinary
Barbara Putz, Thomas E. J. Edwards, Emese Huszar, Patric A. Gruber, Kevin-P Gradwohl, Patrice Kreiml, Daniel M. Toebbens, Johann Michler
Summary: A series of Al and Al/Al2O3 thin-film multilayer structures were fabricated on flexible polymer substrates using a unique deposition chamber combining magnetron sputtering and atomic layer deposition, and were thoroughly characterized using transmission electron microscopy. The electromechanical behavior of the multilayers and Al reference films was investigated, and it was found that all films exhibited excellent interfacial adhesion without delamination in the investigated strain range. The adhesion-promoting naturally forming amorphous interlayer was confirmed for the first time for thin films sputter deposited onto polymers under laboratory conditions.
ADVANCED ENGINEERING MATERIALS
(2023)
Article
Chemistry, Analytical
Agnieszka Priebe, Abdessalem Aribia, Jordi Sastre, Yaroslav E. Romanyuk, Johann Michler
Summary: Massive demand for Li-ion batteries drives the research of new materials for next-generation batteries, such as all-solid-state batteries. TOF-SIMS shows outstanding potential for comprehensive characterization of novel Li-rich nickel manganese cobalt oxide thin films, potential cathode materials. The investigation reveals the presence of overlithiated grains and nanoparticles in the buried part of the thin films.
ANALYTICAL CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Alexander Groetsch, Samuel Stelzl, Yannick Nagel, Tatiana Kochetkova, Nadim C. Scherrer, Aleksandr Ovsianikov, Johann Michler, Laszlo Pethoe, Gilberto Siqueira, Gustav Nystroem, Jakob Schwiedrzik
Summary: This study demonstrates the fabrication of non-cytotoxic nanocomposite ink using cellulose nanocrystals (CNCs) as reinforcement for printing and tuning complex 3D structures. It shows that the addition of CNCs significantly increases the stiffness of the composites. The insights gained from this study have implications for applications in medical, electronic, and energy fields.
Article
Materials Science, Coatings & Films
Caroline Hain, Peter Schweizer, Patrick Sturm, Aurelio Borzi, Jonathan E. Thomet, Johann Michler, Aicha Hessler-Wyser, Thomas Nelis
Summary: This study focuses on the fabrication of InN thin films at low temperature using microwave plasma-assisted reactive high power impulse magnetron sputtering (MAR-HiPIMS). The effects of microwave plasma on the HiPIMS discharge process were investigated through in situ diagnostics. InN films were deposited using both standard reactive HiPIMS and MAR-HiPIMS methods, and their properties were characterized. Results showed that the microwave plasma facilitated the dissociation/activation of nitrogen species and provided seed electrons to the plasma. The MAR-HiPIMS film exhibited stoichiometry, texturing, and desirable electrical properties.
SURFACE & COATINGS TECHNOLOGY
(2023)
Article
Chemistry, Multidisciplinary
Sebastian Bruns, Christian Minnert, Laszlo Pethoe, Johann Michler, Karsten Durst
Summary: The increasing use of oxide glasses in high-tech applications demonstrates the demand for novel engineering techniques on nano- and microscale. Shaping operations of oxide glasses at room temperature usually require high temperatures close or beyond the point of glass transition T-g. However, electron irradiation has been found to facilitate the viscous flow of amorphous silica at room temperature, offering potential for local microengineering.
Article
Materials Science, Multidisciplinary
Nicolo Maria della Ventura, Amit Sharma, Cyril Cayron, Szilvia Kalacska, Thomas E. J. Edwards, Cinzia Peruzzi, Manish Jain, Julia T. Purstl, Roland E. Loge, Johann Michler, Xavier Maeder
Summary: The strain rate sensitivity and apparent activation volume of prismatic and pyramidal slip systems in high-purity magnesium were investigated under compression and tension conditions. A new grain formation during tension was observed, which does not correspond to the well-known twin systems. The appearance of newly oriented grains was also observed during compression, suggesting a mechanism of unit cell reconstruction.
Article
Automation & Control Systems
Antoine Queguineur, Reza Asadi, Marta Ostolaza, Emilie Hordum Valente, Venkata Karthik Nadimpalli, Gaurav Mohanty, Jean-Yves Hascoet, Inigo Flores Ituarte
Summary: This study investigates the macro- and micromechanical responses of two duplex stainless steels during the wire arc additive manufacturing (WAAM) process. The results provide important insights for industrialization.
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2023)
Article
Nanoscience & Nanotechnology
Nicolo M. della Ventura, Chunhua Tian, Amit Sharma, Thomas E. J. Edwards, J. Jakob Schwiedrzik, Roland E. Loge, Johann Michler, Xavier Maeder
Summary: Single-crystal magnesium micropillars with a diameter of 5 µm were compressed along the [2110] direction at cryogenic temperature (T = 184 K) at different strain rates. The predominant twinning behavior of {1012} was observed, and the critical stress required for twinning was found to be significantly higher compared to previous reports at higher temperatures. The temperature dependence of the strain rate sensitivity and activation volume for twinning was determined to be constant and linearly dependent with T, respectively, and the activation energy (Q) for twinning was calculated to be 174 kJ mol-1 for T < 273 K and 72 kJ mol-1 above.
SCRIPTA MATERIALIA
(2023)
Article
Multidisciplinary Sciences
Dario Ferrari, Arunima Sengupta, Lyong Heo, Laszlo Pethoe, Johann Michler, Thomas Geiser, Vinicio A. de Jesus Perez, Wolfgang Soheila Zeinali, Soheila Zeinah, Olivier T. Guenat
Summary: The endothelium of blood vessels responds differently to changes in stiffness and mechanical forces of the extracellular matrix (ECM). Organs-on-chip technologies enable the investigation of the combined or unique effects of these biomechanical and biochemical stimuli. A microvasculature-on-chip model was used to study the effects of ECM stiffness and mechanical stretch on vascular development. The results showed that ECM hydrogel stiffness impacted the size and density of vasculature, while cyclic stretch led to the upregulation of specific genes involved in endothelial vasculogenesis.
Article
Nanoscience & Nanotechnology
Angelos Xomalis, Caroline Hain, Alexander Groetsch, Fedor F. Klimashin, Thomas Nelis, Johann Michler, Jakob Schwiedrzik
Summary: This study reports a resist-free and scalable method for directly structuring thin metallic films on flexible polymeric substrates via e-beam patterning. Nanostructures as small as 5 nm in height with a sub micrometer lateral resolution can be achieved by controlling e-beam dose. The resist-free lithographic tool can dramatically reduce fabrication cost and be used for different applications including biomimetic surfaces, architectured metamaterials, strain-resilient flexible electronics, and wearable devices.
ACS APPLIED NANO MATERIALS
(2023)
Article
Materials Science, Ceramics
Kimmo Kaunisto, Juha Lagerbom, Mari Honkanen, Tommi Varis, Aloshious Lambai, Gaurav Mohanty, Erkki Levanen, Paivi Kivikyto-Reponen, Erkka Frankberg
Summary: This study investigates the influence of cooling rate on the microstructural properties and phase structure of pure alumina in plasma-based processing. The phase changes in alumina particles during high-temperature plasma spheroidization and plasma sprayed alumina coatings are compared, revealing unique microstructures due to different cooling rates.
CERAMICS INTERNATIONAL
(2023)
Article
Polymer Science
P. Laurikainen, S. Bhusare, G. Mohanty, E. Sarlin
Summary: The dependence of the results on the conversion of the thermoset resin remains an issue in studies of the fibre-matrix interphase using microscale single fibre methods. The curing process of picolitre drop-on-fibre systems in the microbond method differs from macroscale resin batches due to evaporation of volatile components, potentially limiting the degree of cure. Atomistic scale modelling and experimental thermal analysis were used to understand the curing process and nanoindentation to compare mechanical performance.
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.