Article
Chemistry, Multidisciplinary
Yuki Mitsuta, Toshio Asada
Summary: The nudged elastic band (NEB) method is widely used for reaction path (RP) finding, but some NEB calculations fail to converge to the minimum energy paths (MEPs) due to the occurrence of kinks caused by free bending of the bands. Therefore, we propose an extension of the NEB method called the nudged elastic stiffness band (NESB) method, which incorporates stiffness stress using a beam theory. The results from three examples demonstrate that the NESB method has three advantages: reducing the number of iterations, shortening the pathway length by reducing unnecessary fluctuations, and finding transition state (TS) structures by converging to paths close to the MEPs for systems with sharp curves on the MEPs.
JOURNAL OF COMPUTATIONAL CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Qiyuan Zhao, Dylan M. Anstine, Olexandr Isayev, Brett M. Savoie
Summary: The emergence of & UDelta;-learning models provides a versatile route to accelerate high-level energy evaluations. However, these models are unable to predict reaction properties that require both high-level geometry and energy evaluation. This study introduces a & UDelta;(2)-learning model that predicts high-level activation energies based on low-level critical-point geometries. The model demonstrates excellent performance on unseen reactions and shows near chemical accuracy, making it an efficient strategy for accelerating chemical reaction characterization.
Article
Biochemistry & Molecular Biology
Merve Demirtas, Hande Ustunel, Daniele Toffoli
Summary: The catalytic activity of gold can be enhanced by introducing other metals to its surface. In this study, the effect of Pt doping on the catalytic activity of a Au(111) surface for methanol dehydrogenation was investigated using first-principles density functional theory. It was found that Pt surface doping significantly decreases the activation energy barrier of this reaction.
Article
Chemistry, Medicinal
Ziad Fakhoury, Gabriele C. Sosso, Scott Habershon
Summary: Recent advances in machine learning methods have made progress in protein structure prediction, but accurately generating and characterizing protein-folding pathways is still challenging. In this study, a directed walk strategy using the residue-level contact-map space was employed to generate protein folding trajectories. The strategy considers protein folding as transitions between connected minima on the potential energy surface. The generated folding paths were validated against direct molecular dynamics simulations, demonstrating the potential of this approach for studying protein folding.
JOURNAL OF CHEMICAL INFORMATION AND MODELING
(2023)
Article
Multidisciplinary Sciences
Nadav Snir, Maytal Caspary Toroker
Summary: In this study, the inner sphere component of the reorganization energy that contributed to the activation energies was calculated using a novel algorithm based on Marcus theory combined with the climbing image nudged elastic band method. The new method was tested in both acidic and basic conditions with explicit and implicit solvation. It was found that the reaction involving the transition of the *O intermediate into *OOH had the highest activation energy, which explained the high coverage of the *O intermediate found in experiments.
ADVANCED THEORY AND SIMULATIONS
(2023)
Article
Chemistry, Multidisciplinary
Yuki Mitsuta, Toshio Asada
Summary: In this study, a new method for calculating the curvature of reaction paths and weighting the spring constant of NEB calculations with curvature is proposed. The efficiency of this method is demonstrated by comparing it with other methods.
JOURNAL OF COMPUTATIONAL CHEMISTRY
(2023)
Article
Chemistry, Physical
Christopher Robertson, Ross Hyland, Andrew J. D. Lacey, Sebastian Havens, Scott Habershon
Summary: This article addresses the challenge of identifying multistep reaction mechanisms in complex chemical environments. By using a discrete optimization approach and screening autogenerated mechanisms, several barrierless reaction mechanisms for benzene formation in the interstellar medium are identified, which could supplement existing microkinetic models and operate in low temperature environments.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2021)
Article
Chemistry, Physical
Qiyuan Zhao, Hsuan-Hao Hsu, Brett M. Savoie
Summary: In this study, a classifier was trained to learn the features of reaction conformers that lead to successful transition state searches, enabling the down-selection of optimal conformers before incurring the cost of a high-level transition state search. The results showed that neglecting conformer contributions can lead to qualitatively incorrect activation energy estimations, while machine learning classifiers reliably down-select low-barrier reaction conformers.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2022)
Article
Multidisciplinary Sciences
Fei Shuang, Penghao Xiao, Liming Xiong, Wei Gao
Summary: In this study, a computational investigation was conducted on the solid-solid phase transition of a model two-dimensional system from a hexagonal phase to a square phase under pressure. The atomistic mechanism and propagation method of the phase transition were determined using solid-state Dimer and nudged elastic band (NEB) methods. It was found that the phase nucleation was triggered by localized shear deformation caused by the relative shift between two adjacent atomic layers. Additionally, a defect-assisted low barrier propagation path was identified in the hexagonal to square phase transition. This study highlights the significance of using the Dimer method to explore unknown transition paths and provides insights into phase transition mechanisms of other solid-state and colloidal systems.
PROCEEDINGS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES
(2022)
Article
Materials Science, Multidisciplinary
Fei Shuang, Rigelesaiyin Ji, Liming Xiong, Wei Gao
Summary: In this work, the effect of periodic image interactions on the calculation of activation barriers or formation energies of kink pair of screw dislocation in BCC metals is quantified through combined nudged elastic band (NEB) simulations and theoretical analysis based on dislocation mechanics. The NEB calculation result shows a significant size dependence on the activation barrier at zero and low stresses. The theoretical analysis provides a practical approach to quantify this size effect without the need for time-consuming NEB simulations. In addition, a simple relationship between kink activation barrier and dislocation line length is derived at zero stress, offering a new approach to compute kink pair formation energy based on NEB simulation results.
COMPUTATIONAL MATERIALS SCIENCE
(2023)
Article
Materials Science, Multidisciplinary
Sweta Kumari, Amlan Dutta
Summary: This study investigates the nucleation of twinning dislocation loops in metals with fcc crystal structure using a combination of atomistic computations and continuum modeling. It explores both the conventional layer-by-layer model and the newly proposed alternate-shear mechanism for twin nucleation, finding differences in nucleation stress between the two mechanisms. The research also highlights the non-uniform variations in critical loop size and fractional Burgers vector with applied shear load.
MECHANICS OF MATERIALS
(2021)
Article
Physics, Multidisciplinary
Trinh Le Huyen, Chi-Hsuan Lee, Shun-Jen Cheng, Chih-Kai Yang
Summary: First-principles density functional theory (DFT) is used to study the interaction between peptide molecules and a two-dimensional (2-D) monolayer of molybdenum disulfide (MoS2) with a nanopore. The results show bonding between some molecules and the hole edge of MoS2, and the potential energy surface can be used to predict the reaction outcome. These findings suggest that 2-D MoS2 nanopores have a wide range of biological applications and should be further investigated experimentally.
CHINESE JOURNAL OF PHYSICS
(2023)
Article
Chemistry, Physical
Yanhui Zhang, Stefano Sanvito
Summary: Understanding surface reactivity is crucial in various fields, and the surface reactions of ZrB2 exposed to harsh aerospace environments were studied using density functional theory and nudged elastic band methods. It was found that dissociative adsorption of O-2 dominates the reactivity of ZrB2 surfaces, while the reactions of H2O and CO are less active on Zr-surfaces and even less on B-terminated ones. Additionally, the reaction of O-2 and CO was shown to induce strong surface reconstruction at B-surfaces.
APPLIED SURFACE SCIENCE
(2021)
Article
Materials Science, Multidisciplinary
Raghasudha Pooja, Raghasudha Mucherla, Ravinder Pawar
Summary: Diamonds have the potential to revolutionize next-generation technologies with their unique properties, but the presence of hydrogen as a prevalent impurity in synthetic diamonds significantly affects their mechanical properties. This study aims to understand the effect of hydrogen at an electronic level on the stability of the σ5 (100) grain boundary in diamond. The results show that the concentration of hydrogen greatly influences the deformation of the grain boundary, and the dissociation of hydrogen molecules occurs without any activation energy, further explained by attractive orbital interactions with dangling bonds within the void of the σ5 (100) grain boundary. Examination of the mechanical properties reveals a change in elasticity as the hydrogen concentration increases, while grain boundary energy calculations indicate that the studied σ5 (100) grain boundary is stable.
DIAMOND AND RELATED MATERIALS
(2023)
Article
Engineering, Mechanical
Li Li, Lijun Liu, Yoji Shibutani
Summary: The interactions between edge dislocations and <112>-axis symmetric tilt grain boundaries in copper were investigated through atomistic simulations. The results showed that the leading partial dislocation was absorbed into the grain boundary upon impact, while the trailing partial dislocation played a crucial role in determining the threshold reaction stress. The reaction energy barriers exhibited a linear relationship with the resolved shear stress or strain state, and the corresponding strain rate sensitivities obtained through activation volumes matched well with experimental data.
INTERNATIONAL JOURNAL OF PLASTICITY
(2022)
Article
Engineering, Mechanical
Yejun Gu, Jean Charles Stinville, Patrick G. Callahan, McLean P. Echlin, Tresa M. Pollock, Jaafar A. El-Awady
Summary: Fatigue crack initiation at high temperatures in polycrystalline nickel-base superalloys occurs at microscopic fatigue shear bands near twin boundaries with minimal metallurgical defects. Formation of fine-scale carbide precipitates along these fatigue shear bands during fatigue above 650 degrees C is observed, with pipe diffusion critical to their formation coincident with delocalization of slip during fatigue.
INTERNATIONAL JOURNAL OF FATIGUE
(2021)
Article
Materials Science, Multidisciplinary
Yejun Gu, David W. Eastman, Kevin J. Hemker, Jaafar A. El-Awady
Summary: The proposed unified statistical dislocation-mediated crystal plasticity model considers the randomness of pre-existing dislocation network, grain orientation, and grain size to predict the strength of metals in different crystal systems. The model rigorously captures the effect of size on strength across all three crystal systems and shows good agreement with experimental results, providing an accurate and efficient approach to predict yield strength in metals.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2021)
Article
Materials Science, Multidisciplinary
Quan Jiao, Jiahao Cheng, Gi-Dong Sim, Somnath Ghosh, Jaafar A. El-Awady
Summary: The thermo-mechanical response of micro-architectured tungsten coatings was characterized in a temperature range of 293 to 673 K using in situ micro-compression experiments and image-based crystal plasticity finite element method simulations. The study found that the material exhibited different strain hardening responses at different temperatures, with simulations showing the strong influence of local crystallographic anisotropy and microstructure inhomogeneity on material behavior.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2021)
Article
Multidisciplinary Sciences
Haidong Fan, Qingyuan Wang, Jaafar A. El-Awady, Dierk Raabe, Michael Zaiser
Summary: The study explores the relationship between material strength, strain rate, and dislocation density using discrete dislocation dynamics and molecular dynamics simulations. It suggests that a coupling parameter between dislocation density and strain rate can control phenomena such as plasticity localization. The research provides a better understanding of the micro-scale deformation in metals.
NATURE COMMUNICATIONS
(2021)
Article
Materials Science, Multidisciplinary
Wei Li, Xianghe Peng, Alfonso H. W. Ngan, Jaafar A. El-Awady
Summary: This study presents first principles calculations of the energies and relaxation of unreconstructed low-index surfaces in multi-principal element alloys. The calculated surface energies agree well with thermodynamic modeling and a bond-cutting model. The calculations also reveal an important surface structure, and provide insights into surface-controlled phenomena in these alloys.
MODELLING AND SIMULATION IN MATERIALS SCIENCE AND ENGINEERING
(2022)
Article
Materials Science, Multidisciplinary
Divya Singh, Satish I. Rao, Jaafar A. El-Awady
Summary: This study investigates the dislocation core structure, critical resolved shear stress (CRSS), and mobility of screw and edge dislocations in BCC Ta-8%W alloy. Molecular statics and dynamics simulations are used at different temperatures to obtain the results. The study finds that the Chen potential provides accurate estimations of dislocation mobility and CRSS in Ta-8%W alloy. Furthermore, the asymmetry in CRSS of edge dislocations is attributed to the atomic disregistry and dislocation misfit across the glide plane. The simulation results are in good agreement with analytical models in terms of CRSS values.
Article
Materials Science, Multidisciplinary
Yin Zhang, Kunqing Ding, Yejun Gu, Wen Chen, Y. Morris Wang, Jaafar El-Awady, David L. McDowell, Ting Zhu
Summary: We developed models to understand the microscale internal stresses in additively manufactured stainless steel, focusing on their back stress components. By considering printing and deformation-induced back stresses, as well as deformation-induced back stresses associated with grain boundaries, we were able to accurately simulate and measure the microscale back stresses in the material. These results provide important insights into the origins and evolution of microscale internal stresses in additively manufactured metallic materials.
MODELLING AND SIMULATION IN MATERIALS SCIENCE AND ENGINEERING
(2022)
Article
Engineering, Manufacturing
Markus Sudmanns, Andrew J. Birnbaum, Yejun Gu, Athanasios P. Iliopoulos, Patrick G. Callahan, John G. Michopoulos, Jaafar A. El-Awady
Summary: Additive manufacturing of metallic components offers advantages in design flexibility, precision, and mechanical properties. However, understanding the relationship between microstructure and mechanical properties remains a challenge. This study combines experimental and simulation methods to uncover the mechanisms behind the formation of heterogeneous defect structures in additively manufactured metals, providing insights for predicting mechanical properties.
ADDITIVE MANUFACTURING
(2022)
Article
Materials Science, Multidisciplinary
Ali Rida, Satish Rao, Jaafar A. El-Awady
Summary: Molecular statics and dynamics simulations were conducted to investigate the core structure and critical resolved shear stress of a screw dislocation in pure α-Ti. The results obtained using the modified embedded atom method potential showed good agreement with experimental data, providing insight into the slip behavior of the crystal.
Editorial Material
Multidisciplinary Sciences
Mostafa M. Omar, Jaafar A. El-Awady
Article
Chemistry, Multidisciplinary
Lucas Frerot, Alexia Crespo, Jaafar A. El-Awady, Mark O. Robbins, Juliette Cayer-Barrioz, Denis Mazuyer
Summary: The required tangential force for slip across a frictional interface can increase due to aging processes, including creep, chemical, or structural changes. In this study, the interplay between surface roughness and molecular motion within adsorbed monolayers explains the macroscopic friction response. Contact junctions and their dynamics are studied experimentally and computationally to understand their role in structural aging.
Review
Chemistry, Physical
Dhriti Nepal, Saewon Kang, Katarina M. Adstedt, Krishan Kanhaiya, Michael R. Bockstaller, L. Catherine Brinson, Markus J. Buehler, Peter Coveney, Kaushik Dayal, Jaafar A. El-Awady, Luke C. Henderson, David L. Kaplan, Sinan Keten, Nicholas A. Kotov, George C. Schatz, Silvia Vignolini, Fritz Vollrath, Yusu Wang, Boris Yakobson, Vladimir V. Tsukruk, Hendrik Heinz
Summary: This Review discusses recent advancements in bioinspired nanocomposite design, focusing on the role of hierarchical structuring at different length scales in creating multifunctional, lightweight, and robust structural materials. By manipulating the architecture, interphases, and confinement, dynamic and synergistic responses have been achieved. The study highlights the significance of hierarchical structures across multiple length scales for achieving multifunctionality and robustness.
Article
Nanoscience & Nanotechnology
Khalid A. El-Awady, Steven Lavenstein, Jaafar A. El-Awady
Summary: We propose a method for tracking the 3D surface displacements of a material undergoing mechanical testing in a scanning electron microscope. Our approach estimates the in-plane and out-of-plane surface motion by analyzing multiple views of the sample and propagating the displacements backwards in time using reverse optical flow. This method offers advantages over the commonly used digital image correlation (DIC) technique as it enables reconstruction of the 3D surface morphology and requires no speckle pattern on the material surface.
SCRIPTA MATERIALIA
(2023)
Article
Materials Science, Multidisciplinary
Junjie Yang, Ali Rida, Yejun Gu, Daniel Magagnosc, Tamer A. Zaki, Jaafar A. El-Awady
Summary: An analytical solution for the displacement field of non-uniformly moving Volterra dislocations is derived using the Green's function approach. The strain and stress fields can be evaluated by numerically differentiating the displacement field. The analytical solution captures features including the plane waves during the injection process of dislocations.
Article
Materials Science, Multidisciplinary
Markus Sudmanns, Athanasios P. Iliopoulos, Andrew J. Birnbaum, John G. Michopoulos, Jaafar A. El-Awady
Summary: Mesoscale simulations of discrete defects in metals provide an ideal framework to investigate the micro-scale mechanisms governing plastic deformation under high thermal and mechanical loading conditions. This study focuses on the representation of heterogeneous dislocation structure formation in simulation volumes by using large-scale three-dimensional discrete dislocation dynamics simulations and thermo-mechanical finite element modeling. The results highlight the significance of simulation domain constraints for predicting mechanical properties and provide a basis for future investigations of heterogeneous microstructure formation in mesoscale simulations.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2023)
Article
Materials Science, Multidisciplinary
Y. Liu, K. Zweiacker, C. Liu, J. T. McKeown, J. M. K. Wiezorek
Summary: The evolution of rapid solidification microstructure and solidification interface velocity of hypereutectic Al-20at.%Cu alloy after laser melting has been studied experimentally. It was found that the formation of microstructure was dominated by eutectic, alpha-cell, and banded morphology grains, and the growth modes changed with increasing interface velocity.
Article
Materials Science, Multidisciplinary
Bharat Gwalani, Julian Escobar, Miao Song, Jonova Thomas, Joshua Silverstein, Andrew Chihpin Chuang, Dileep Singh, Michael P. Brady, Yukinori Yamamoto, Thomas R. Watkins, Arun Devaraj
Summary: Castable alumina forming austenitic alloys exhibit superior creep life and oxidation resistance at high temperatures. This study reveals the mechanism behind the enhanced creep performance of these alloys by suppressing primary carbide formation and offers a promising alloy design strategy for high-temperature applications.
Article
Materials Science, Multidisciplinary
Jian Song, Qi Zhang, Songsong Yao, Kunming Yang, Houyu Ma, Jiamiao Ni, Boan Zhong, Yue Liu, Jian Wang, Tongxiang Fan
Summary: Recent studies have shown that achieving an atomically flat surface for metals can greatly improve their oxidation resistance and enhance their electronic-optical applications. Researchers have explored the use of graphene as a covering layer to achieve atomically flat surfaces. They found that high-temperature deposited graphene on copper surfaces formed mono-atomic steps, while annealed copper and transferred graphene on copper interfaces formed multi-atomic steps.
Article
Materials Science, Multidisciplinary
Jennifer A. Glerum, Jon-Erik Mogonye, David C. Dunand
Summary: Elemental powders of Al, Ti, Sc, and Zr are blended and processed via laser powder-bed fusion to create binary and ternary alloys. The microstructural analysis and mechanical testing show that the addition of Ti results in the formation of primary precipitates, while the addition of Sc and Zr leads to the formation of fine grain bands. The Al-0.25Ti-0.25Zr alloy exhibits comparable strain rates to Al-0.5Zr at low stresses, but significantly higher strain rates at higher stresses during compressive creep testing. Finite element modeling suggests that the connectivity of coarse and fine grain regions is a critical factor affecting the creep resistance of the alloys.
Article
Materials Science, Multidisciplinary
P. Jannotti, B. C. Hornbuckle, J. T. Lloyd, N. Lorenzo, M. Aniska, T. L. Luckenbaugh, A. J. Roberts, A. Giri, K. A. Darling
Summary: This work characterizes the thermo-mechanical behavior of bulk nanocrystalline Cu-Ta alloys under extreme conditions. The experiments reveal that the alloys exhibit unique mechanical properties, behaving differently from conventional nanocrystalline Cu. They do not undergo grain coarsening during extrusion and exhibit behavior similar to coarse-grained Cu.
Article
Materials Science, Multidisciplinary
Yiqing Wei, Jingwei Li, Daliang Zhang, Bin Zhang, Zizhen Zhou, Guang Han, Guoyu Wang, Carmelo Prestipino, Pierric Lemoine, Emmanuel Guilmeau, Xu Lu, Xiaoyuan Zhou
Summary: This study proposes a new strategy to modify microstructure by phase regulation, which can simultaneously enhance carrier mobility and reduce lattice thermal conductivity. The addition of Cu in layered SnSe2 induces a phase transition that leads to increased grain size and reduced stacking fault density, resulting in improved carrier mobility and lower lattice thermal conductivity.
Article
Materials Science, Multidisciplinary
Jia Chen, Zhengyu Zhang, Eitan Hershkovitz, Jonathan Poplawsky, Raja Shekar Bhupal Dandu, Chang-Yu Hung, Wenbo Wang, Yi Yao, Lin Li, Hongliang Xin, Honggyu Kim, Wenjun Cai
Summary: In this study, the structural origin of the pH-dependent repassivation mechanisms in multi-principal element alloys (MPEA) was investigated using surface characterization and computational simulations. It was found that selective oxidation in acidic to neutral solutions leads to enhanced nickel enrichment on the surface, resulting in reduced repassivation capability and corrosion resistance.
Article
Materials Science, Multidisciplinary
X. Y. Xu, C. P. Huang, H. Y. Wang, Y. Z. Li, M. X. Huang
Summary: The limited slip systems of magnesium (Mg) and its alloys hinder their wide applications. By conducting tensile straining experiments, researchers discovered a rate-dependent transition in the dislocation mechanisms of Mg alloys. At high strain rates, glissile dislocations dominate, while easy-glide dislocations dominate at low strain rates. Abundant glissile dislocations do not necessarily improve ductility.
Article
Materials Science, Multidisciplinary
M. S. Szczerba, M. J. Szczerba
Summary: Inverse temperature dependences of the detwinning stress were observed in face-centered cubic deformation twins in Cu-8at.%Al alloy. The detwinning stress increased with temperature when the pi detwinning mode was involved, but decreased when the pi/3 mode was involved. The dual effect of temperature on the detwinning stress was due to the reduction of internal stresses pre-existing within the deformation twins. The complete reduction of internal stresses at about 530 degrees C led to the equivalence of the critical stresses of different detwinning modes and a decrease in the yield stress anisotropy of the twin/matrix structure.
Article
Materials Science, Multidisciplinary
Taowen Dong, Tingting Qin, Wei Zhang, Yaowen Zhang, Zhuoran Feng, Yuxiang Gao, Zhongyu Pan, Zixiang Xia, Yan Wang, Chunming Yang, Peng Wang, Weitao Zheng
Summary: The interaction between the electrode and the electric double layer (EDL) significantly influences the energy storage mechanism. By studying the popular alpha-Fe2O3 electrode and the EDL interaction, we find that the energy storage mechanism of the electrode can be controlled by modulating the EDL.
Article
Materials Science, Multidisciplinary
Matthew R. Barnett, Jun Wang, Sitarama R. Kada, Alban de Vaucorbeil, Andrew Stevenson, Marc Fivel, Peter A. Lynch
Summary: The elastic-plastic transition in magnesium alloy Mg-4.5Zn exhibits bursts of deformation, which are characterized by sudden changes in grain orientation. These bursts occur in a coordinated manner among nearby grains, with the highest burst rate observed at the onset of full plasticity. The most significant burst events are associated with twinning, supported by the observation of twinned structures using electron microscopy. The bursts are often preceded and followed by a stasis in peak movement, indicating a certain "birth size" for twins upon formation and subsequent growth at a later stage.
Article
Materials Science, Multidisciplinary
Vaidehi Menon, Sambit Das, Vikram Gavini, Liang Qi
Summary: Understanding solute segregation thermodynamics is crucial for investigating grain boundary properties. The spectral approach and thermodynamic integration methods can be used to predict solute segregation behavior at grain boundaries and compare with experimental observations, thus aiding in alloy design and performance control.
Article
Materials Science, Multidisciplinary
Feiyu Qin, Lei Hu, Yingcai Zhu, Yuki Sakai, Shogo Kawaguchi, Akihiko Machida, Tetsu Watanuki, Yue-Wen Fang, Jun Sun, Xiangdong Ding, Masaki Azuma
Summary: This study reports on the negative and zero thermal expansion properties of Cd2Re2O7 and Cd1.95Ni0.05Re2O7 materials, along with their ultra-low thermal conductivity. Through investigations of their structures and phonon calculations, the synergistic effect of local structure distortion and soft phonons is revealed as the key to achieving these distinctive properties.
Article
Materials Science, Multidisciplinary
Thomas Beerli, Christian C. Roth, Dirk Mohr
Summary: A novel testing system for miniature specimens is designed to characterize the plastic response of materials for which conventional full-size specimens cannot be extracted. The system has an automated operation process, which reduces the damage to specimens caused by manual handling and improves the stability of the test results. The experiments show that the miniature specimens extracted from stainless steel and aluminum have high reproducibility, and the results are consistent with those of conventional-sized specimens. A correction procedure is provided to consider the influence of surface roughness and heat-affected zone caused by wire EDM.
Article
Materials Science, Multidisciplinary
Rani Mary Joy, Paulius Pobedinskas, Nina Baule, Shengyuan Bai, Daen Jannis, Nicolas Gauquelin, Marie-Amandine Pinault-Thaury, Francois Jomard, Kamatchi Jothiramalingam Sankaran, Rozita Rouzbahani, Fernando Lloret, Derese Desta, Jan D'Haen, Johan Verbeeck, Michael Frank Becker, Ken Haenen
Summary: This study investigates the influence of film microstructure and composition on the Young's modulus and residual stress in nanocrystalline diamond thin films. The results provide insights into the mechanical properties and intrinsic stress sources of these films, and demonstrate the potential for producing high-quality nanocrystalline diamond films under certain conditions.