Article
Materials Science, Multidisciplinary
Konstantin D. Molodov, Talal Al-Samman, Dmitri A. Molodov
Summary: Single crystals of pure Mg and Mg-0.8 wt% Gd alloy were compressed at room and elevated temperatures to study the activation of prismatic and pyramidal (c+a) slip. The addition of Gd did not increase (c+a) slip activity, but had a significant impact on continuous dynamic recrystallization in Mg-Gd alloy. The improved formability in polycrystalline Mg-Gd alloys is mainly attributed to changes in recrystallization behavior and its effect on texture.
Article
Materials Science, Multidisciplinary
Konstantin D. Molodov, Talal Al-Samman, Dmitri A. Molodov
Summary: This study provides an overview of the mechanical response and microstructure evolution of pure magnesium single crystals under plane strain compression at room temperature. The deformation behavior varies depending on the crystal orientations, with different activation of slip and twinning mechanisms. The presence of high angle grain boundaries and certain twin boundaries is crucial for the activation of contraction twinning. Two-stage work hardening is observed in crystals aligned for basal slip, with the second stage attributed to microstructural changes.
Article
Engineering, Mechanical
Xin Hu, Yanzhou Ji, Lei Chen, Ricardo A. Lebensohn, Long-Qing Chen, Xiangyang Cui
Summary: The study introduces a spectral phase-field method model of deformation twinning and plasticity, verified through studying the twinning morphology evolution and plastic deformation of Mg single crystals. Furthermore, the model is applied to investigate heterogeneous twinning nucleation, growth, and propagation behaviors, providing valuable insights into morphological evolution of deformation twinning and its effects on elasto-plastic responses of polycrystalline materials.
INTERNATIONAL JOURNAL OF PLASTICITY
(2021)
Article
Nanoscience & Nanotechnology
Zhe Chen, Mohammadreza Yaghoobi, Veera Sundararaghavan, John Allison, Samantha Daly
Summary: The interplay between microstructure and deformation twinning in a WE43-T6 Mg alloy under uniaxial compression was investigated. The study found a strong correlation between the nominal Schmid Factor and twin activation and variant selection, but it was not fully deterministic. The deformation twinning was also affected by existing slip and twinning in the neighboring grain and the m' value. The statistical analysis of CPFE simulations captured the effect of the nominal Schmid Factor.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Chemistry, Physical
Dong Sun, Shuyong Jiang, Yanqiu Zhang, Bingyao Yan, Junbo Yu
Summary: Equiatomic NiTi shape memory alloy subjected to severe plastic deformation through local canning compression exhibits different twin structures after solution treatment and subsequent annealing, which significantly influence the phase transformation behavior of the alloy.
JOURNAL OF ALLOYS AND COMPOUNDS
(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
Chemistry, Physical
Junyu Zhu, Fabien Briffod, Takayuki Shiraiwa, Manabu Enoki, Satoshi Emura
Summary: A combination of experimental and numerical studies was conducted to understand the microstructure and formation mechanism of kink bands in alpha/beta two-phase titanium alloys. Deformation kink bands were introduced in a Ti-9Cr alloy, and the strength changes of the alpha and beta phases inside and outside the kink band were evaluated. Microstructural examination and crystallographic analysis revealed the presence of prismatic slip during compression, and a crystal plasticity finite element model was developed to reproduce the {110}beta-rotation-type kink bands.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Materials Science, Multidisciplinary
Ning Guo, Bingtao Tang, Jiyuan Liu, Zongan Luo
Summary: The stepwise strain hardening behavior of copper single crystals is influenced by the competition and collaboration between dislocation slip and deformation twinning. A crystal plasticity-based model is proposed to study the strain hardening characteristics associated with slip and twinning interactions, providing insight into the evolution of hardening mechanisms. By incorporating accumulated twin volume fraction and investigating the effects of crystal orientation and twinning, a deeper understanding of stress fluctuation and large plastic deformation evolution can be achieved.
PHILOSOPHICAL MAGAZINE
(2021)
Article
Materials Science, Multidisciplinary
Mohsen Rezaee-Hajidehi, Przemyslaw Sadowski, Stanislaw Stupkiewicz
Summary: A finite-strain phase-field model is proposed to study the coupled deformation twinning and crystal plasticity. Twinning is treated as a volume-preserving stretch and a micromorphic formulation is employed. In the model, each pair of conjugate twinning systems is represented by a single twin deformation variant, and a single order parameter is used to consistently describe the two conjugate twinning systems.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2022)
Article
Nanoscience & Nanotechnology
Jianping Xu, Chengze Liu, Jinping Wu, Boyi Qi, Yusheng Zhang, Yongqing Zhao, Lian Zhou
Summary: The microstructure and texture evolution of Ti35 alloy during plastic deformation at various temperatures were systematically investigated. Different stages of fragmentation, elongation, and recrystallization were observed. The study revealed that the compressive twinning during hot rolling significantly improved the mechanical properties of Ti35 alloy.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Materials Science, Multidisciplinary
Xuexu Xu, Zhiyong Liu, Tianliang Zhao, Qiaoqi Cui, Tianyi Zhang, Xiaogang Li
Summary: The study investigated the corrosion fatigue of TWIP steel in a simulated seawater environment and found that TWIP steel is highly susceptible to corrosion fatigue due to anodic dissolution at grain boundaries and twin boundaries. However, uniform plastic deformation can inhibit corrosion fatigue. Research also revealed that improving grain boundary strength through plastic deformation or metallurgical design can enhance the resistance of TWIP steel to corrosion fatigue.
Article
Nanoscience & Nanotechnology
Ting-Chun Lin, Chien-Lung Liang, Shan-Bo Wang, Yung-Sheng Lin, Chin-Li Kao, David Tarng, Kwang-Lung Lin
Summary: The introduction of highly (111)-oriented nanotwinned Cu effectively inhibits detrimental Cu protrusion in TSV technology, reducing protrusion height during thermal annealing and strengthening TSV by impeding dislocation glide. The electrodeposited nanotwinned Cu TSV shows great thermal stability and slight micro-hardness loss under thermal annealing.
SCRIPTA MATERIALIA
(2021)
Article
Nanoscience & Nanotechnology
P. C. Han, N. R. Tao
Summary: Deformation and annealing were combined to optimize the mechanical properties of metallic materials. The study found that there were differences in the strength-ductility trade-off between the dynamic plastic deformation-induced structures and annealed structures in Cu and Cu-4.5Al alloy. It was suggested that high performance metallic materials can be obtained by just one-step plastic deformation without subsequent annealing treatment.
SCRIPTA MATERIALIA
(2022)
Article
Materials Science, Multidisciplinary
Krishna Yaddanapudi, Brandon Leu, M. Arul Kumar, Xin Wang, Julie M. Schoenung, Enrique J. Lavernia, Timothy J. Rupert, Irene J. Beyerlein, Subhash Mahajan
Summary: This study investigated {(1) over bar 012} tensile twins terminating inside the grains of a deformed Mg-Y alloy using transmission electron microscopy. Crystallographic features of the terminating twins and associated slip structures were quantified and analyzed, with local stresses computed using crystal plasticity simulations. Basal < a > and < c + a > matrix glide were found to accommodate the plastic stresses near the terminating twins, with defect contrast consistent with lattice dislocations and twinning partials observed along the twin boundary. A dislocation reaction was proposed to establish the interrelationship between matrix glide and {(1) over bar 012} twinning in Mg-Y alloys.
Article
Materials Science, Multidisciplinary
Jinghui Li, Renhai Yu, Jintong Chen, Fuguo Li, Shan Liang, Mingya Zhang
Summary: A three-dimensional Voronoi polycrystal model was utilized to analyze heterogeneous phenomena and microplasticity in polycrystalline solids using crystal plasticity and finite element method. The study investigated the impact of various load modes on severe plastic deformation response characteristics, with simple shear determined to be the optimal fine grain mode in the SPD process based on maximum cumulative plastic strain and minimum damage principles.
JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE
(2021)
Article
Materials Science, Multidisciplinary
Qianqian Jin, Xiaohong Shao, Shijian Zheng, Yangtao Zhou, Bo Zhang, Xiuliang Ma
Summary: Understanding the interface structure between strengthening precipitates and matrix in alloys at the atomic level is crucial for tailoring the mechanical properties. High-resolution scanning transmission electron microscopy was used to study the semi-coherent interfaces in Mg-Zn-Y alloys, revealing unique features such as Shockley partial dislocations and dissociated structures. The interaction between dislocation arrays and solute atoms plays a key role in the stability and morphology of these interfaces, influencing the lateral growth of LPSO phases in Mg alloys.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2021)
Article
Nanoscience & Nanotechnology
Siyuan Wei, Zhiyu Zhao, Shijian Zheng, Hua Wei, Jiangwei Wang
Summary: Cu/V nanoscale metallic multilayers exhibit interface-controlled fatigue deformation, resulting in nanoscale intrusions/extrusions on the bimetal interface, without the presence of persistent slip bands or crack formations. This study provides insights into the fatigue damage mechanisms in metallic multilayers at nanoscale and suggests the potential for enhancing damage tolerance in heterostructures through interface engineering.
SCRIPTA MATERIALIA
(2021)
Review
Energy & Fuels
Lihua Zhu, Xueni Shang, Kaixiang Lei, Cuncun Wu, Shijian Zheng, Cong Chen, Hongwei Song
Summary: From the perspective of perovskite solar cells device structure, the electron transport layer is crucial for carrier recombination suppression. Doping new ions is an effective method to improve electron mobility, but the fundamental mechanism of doping is still lacking in most cases.
Article
Materials Science, Multidisciplinary
Huhu Su, Xinzhe Zhou, Mengmeng Zhang, Shijian Zheng, Hengqiang Ye, Zhiqing Yang
Summary: In this study, reactions of {10 (1) over bar1} twin boundaries (TBs) with slip dislocations in a Mg alloy were investigated and modeled based on atomic-resolution observations and interfacial defect theory. The reactions were found to produce asymmetric tilt grain boundaries and various types of residual dislocations, leading to modifications in local atomic structures of steps at {10 (1) over bar1} TBs. These experimental results provide insights for understanding the plastic relaxation mechanisms at {10 (1) over bar1} TBs.
Article
Materials Science, Multidisciplinary
Y. T. Zhou, X. H. Shao, S. J. Zheng, X. L. Ma
Summary: This study investigated the atomic structures of cementite/ferrite interfaces in cold-drawn pearlitic steel wire using transmission electron microscopy. The findings revealed that the deformation-induced partial decomposition of cementite plays a crucial role in interface reconstruction, while the amorphization of cementite layers effectively eliminates interfacial dislocations and reduces interfacial stress.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2022)
Article
Nanoscience & Nanotechnology
Huhu Su, Xinzhe Zhou, Shijian Zheng, Hengqiang Ye, Zhiqing Yang
Summary: The formation and evolution of basal-prismatic/prismatic-basal (BP/PB) interfaces in a Mg alloy under cyclic deformation were studied and modeled based on atomic-resolution experimental observations and interfacial defects theory. It was found that BP/PB interfaces could be formed by emission of specific dislocations and twinning disconnections, and could transform into twin boundaries. The experimental results offer insights into the dislocation-assisted mechanisms of formation and evolution of BP/PB interfaces in hexagonal-close-packed materials.
SCRIPTA MATERIALIA
(2022)
Article
Materials Science, Multidisciplinary
Rodney J. McCabe, Thomas J. Nizolek, Nan Li, Yifan Zhang, Daniel R. Coughlin, Cody Miller, John S. Carpenter
Summary: The evolution of microstructures and properties of bi-metallic laminates during cold accumulative roll bonding is influenced by both material properties and layer locations. Layer instabilities occur when there is a significant difference in hardness between Fe and fcc metals, signaling the need for processing changes once the strength ratio approaches two.
MATERIALS & DESIGN
(2021)
Article
Nanoscience & Nanotechnology
Joseph Indeck, David Cereceda, Jason R. Mayeur, Kavan Hazeli
Summary: The use of machine learning techniques in mechanics and materials research can enhance the understanding of microstructure-property relationships. In this study, various machine learning techniques were employed to analyze mesoscopic deformation mechanisms and gain insights into void nucleation in polycrystalline metals. The results showed that unsupervised clustering analysis combined with a K-nearest neighbor classifier accurately characterized slip transmission and identified grains with fatigue-induced voids. It was also discovered that the inclusion of partially-active slip systems was more appropriate for predicting slip activity than the binary classification. The study concluded that grains containing fatigue-induced voids were more likely to be surrounded by grains with orientations that inhibited slip transmission according to the Lee Robertson-Birnbaum criteria. Furthermore, it was demonstrated that smaller datasets using limited simulation results could yield similar outcomes when additional physical descriptors for the slip system activity were incorporated.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Multidisciplinary Sciences
Kaisheng Ming, Zhengwang Zhu, Wenqing Zhu, Ben Fang, Bingqiang Wei, Peter K. Liaw, Xiaoding Wei, Jian Wang, Shijian Zheng
Summary: Crystalline-amorphous composites have the potential to achieve high strength and high ductility. Researchers fabricate a TiZr-based alloy with micrometer-size equiaxed grains that are made up of three-dimensional bicontinuous crystalline-amorphous nanoarchitectures. In situ tension and compression tests reveal enhanced ductility and strain hardening capability, providing ultra-high yield strength, ultimate tensile strength, and large uniform ductility to the alloy. Experiments combined with simulations reveal the synergetic deformation mechanisms, resulting in an effective combination of strength, ductility, and strain hardening.
Article
Engineering, Manufacturing
Behzad Bahrami Babamiri, Jason R. Mayeur, Kavan Hazeli
Summary: This article presents a methodical approach to optimize both microstructure and topology of additively manufactured metallic lattice structures (AMLS) in order to improve their mechanical properties. By calibrating crystal plasticity model parameters and considering different microstructures and topologies, the structural integrity of AMLS can be significantly enhanced.
ADDITIVE MANUFACTURING
(2022)
Article
Materials Science, Multidisciplinary
Xiaolong Ma, Bharat Gwalani, Jinhui Tao, Mert Efe, Matthew Olszta, Miao Song, Sakshi Yadav, Anqi Yu, Thomas J. Nizolek, John S. Carpenter, Bo Zhou, Arun Devaraj, Suveen Mathaudhu, Aashish Rohatgi
Summary: Disentangling the contribution of intragranular and interfacial plasticity is crucial for understanding the overall strain accommodation in nanoscale materials. Researchers introduced shear strain gradients to Cu/Nb nanolaminates and found that intragranular slip dominates deformation in thick laminates, while it contributes significantly to plasticity in thin laminates. Additionally, forced chemical mixing was observed in the top region of the thin laminates.
Article
Materials Science, Multidisciplinary
Yifan Zhang, Jonathan G. Gigax, Thomas J. Nizolek, John S. Carpenter, Matthew M. Schneider, Nan Li, Laurent Capolungo, Rodney J. McCabe
Summary: Nano metallic laminates (NMLs) show exceptional strengths, but limited ductility under tension. By conducting mesoscale tension tests, it is found that annealing at 800 degrees C significantly enhances the ductility and work hardenability of NMLs.
Article
Materials Science, Multidisciplinary
Yifan Zhang, Nan Li, Matthew M. Schneider, Thomas J. Nizolek, Laurent Capolungo, Rodney J. McCabe
Summary: This study investigates the formation process and mechanism of kink band (KB) in Cu/Nb nano metallic laminates (NMLs). It is found that the inhomogeneous microstructure plays a key role in the formation of KB, leading to the accumulation of geometrically necessary dislocations (GNDs) and the formation of tilt geometrically necessary boundaries (GNBs) near KB boundaries (KBBs). Furthermore, once the layer-parallel slip systems are activated, preexisting lattice dislocations and dislocations nucleating from interfaces will accumulate as GNDs near KBBs, promoting the evolution of KB.
Article
Materials Science, Multidisciplinary
Yifan Zhang, Miroslav Zecevic, Aritra Chakraborty, Rodney J. McCabe, Thomas J. Nizolek, Ricardo A. Lebensohn, John S. Carpenter, Nan Li, Laurent Capolungo
Summary: This study investigates the dependence of kinking on microstructural attributes in NMLs through in situ micropillar compression, microstructure characterization, simulations, and modeling. The development of internal stresses during loading activates local layer-parallel glide triggering kinking in NMLs. The effect of key microstructural features on kink band formation in NMLs is also revealed.
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.
