Article
Materials Science, Multidisciplinary
M. Longsworth, M. Fivel
Summary: The cross-slip rate of screw segments in dislocation dynamics simulations was calculated using a model based on the harmonic transition state theory and the Meyer-Neldel rule. The results were in quantitative agreement with atomistic simulations.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2021)
Article
Physics, Applied
Saurabh S. Sharma, Avinash Parashar
Summary: The safety of nuclear reactors is a major concern for designers, with helium embrittlement in nickel-based alloys presenting challenges in the nuclear industry. Studies have shown that helium bubbles have a detrimental effect on the mechanical properties of nickel, but the exact mechanism of helium-induced embrittlement is still not fully understood. Research on the effect of various configurations of helium bubbles on the mechanical properties of nickel crystals reveals that the orientation of the crack plane and direction in the crystal play a significant role in deformation mechanisms. Helium bubbles reduce the strength of nickel crystals with cracks, but increasing the number of helium atoms has a negligible effect on material toughness. Switching the spatial coordinates of helium bubbles near the crack tip can significantly affect the strength of single crystal nickel, suggesting that understanding crystal geometry and helium cluster modulation is important for studying defects in nickel crystals.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2021)
Article
Multidisciplinary Sciences
Yifan Wang, Wei Cai
Summary: This study reveals the microscopic mechanisms of cross-slip of screw dislocations in crystalline solids using molecular dynamics simulation and identifies the influence of anharmonic effects. This finding contributes to a better understanding of stress-driven thermally activated processes in solids.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2023)
Article
Materials Science, Multidisciplinary
Shujing Dong, Xiang-Yang Liu, Caizhi Zhou
Summary: This research explores the deformation mechanisms and interface misfit dislocation structures of B2-FeAl/Al nanolayered composites through atomistic simulations. It is found that there are two sets of dislocations in the interface misfit dislocation network, and the influence of layer thickness on uniaxial deformation response is investigated. The study also reveals differences in deformation behavior between weak Fe/Cu and strong FeAl/Al interfaces, with the latter triggering strain localization and void formation.
JOURNAL OF MATERIALS SCIENCE
(2021)
Article
Engineering, Geological
Richeng Liu, Xinjie Zhu, Yuanchao Zhang, Yujing Jiang, Shuchen Li
Summary: The unloading mode of shear and normal stresses and the number of shear cycles have significant effects on the unloading-induced slip of rock fractures. It is critically important to understand the slip mechanism of rock fractures disturbed by deep excavation for the exploitation of underground energy and the mitigation of seismic activity. The experimental findings suggest that the ratio of unloading rate of shear stress to that of normal stress mainly controls the slip modes of the fracture, and adjusting the unloading rate ratio during the excavation process may reduce the possibility of fracture slip-induced dynamic hazards.
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
(2023)
Review
Chemistry, Multidisciplinary
Johannes T. Margraf
Summary: Machine learning algorithms are powerful tools in science, but large well-curated databases are sparse in chemistry. This contribution reviews science-driven machine learning approaches that focus on atomistic modelling of materials and molecules. Science-driven machine learning involves starting with a scientific question and determining appropriate training data and model design choices. It emphasizes automated and purpose-driven data collection, the use of chemical and physical priors for efficient data usage, and the importance of appropriate model evaluation and error estimation.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Yeyue Xiong, Saeed Izadi, Alexey Onufriev
Summary: The article introduces a globally optimal polarizable water model, OPC3-pol, which accurately simulates water molecules at the atomic scale with minimal computational overheads. The model demonstrates improved computational efficiency and structure stability compared to existing approaches.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2022)
Article
Chemistry, Physical
Tasneem Ottallah, Sophia A. Parandian, Steven W. Rick
Summary: Two different potentials, the modified TraPPE-UA model and the modified GAFF model, are tested for temperature-dependent properties of PEO, with the TraPPE-UA model found to be more accurate in reproducing experimental properties.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2021)
Article
Nanoscience & Nanotechnology
Lei Qian, Bo Wu, Hui Fu, Wenqing Yang, Wanting Sun, Xiao-Ye Zhou, K. C. Chan, Xu-Sheng Yang
Summary: In this study, atomistic molecular dynamic simulations were conducted to investigate the creep behavior of nanograined and nanograined-nanotwinned copper at different sustained stress levels and temperatures. The results showed that the nanograined-nanotwinned structure exhibited significantly enhanced creep resistance compared to the nanograined structure. The creep parameters, as well as the formula describing the creep behavior and plastic deformation mechanisms, were determined and validated through statistical analyses and examination of atomic configurations. The study found that refining grain size had a deleterious influence on creep resistance in nanograined copper, while decreasing twin thickness effectively enhanced creep performance in nanograined-nanotwinned copper.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Chemistry, Physical
Fuchun Ge, Lina Zhang, Yi-Fan Hou, Yuxinxin Chen, Arif Ullah, Pavlo O. Dral
Summary: This article demonstrates that AI can learn atomistic systems in the four-dimensional spacetime by introducing the 4D-spacetime GICnet model. This model can predict nuclear positions and velocities as a continuous function of time up to the distant future based on given initial conditions. It provides long-time high-resolution molecular dynamics trajectories, improves efficiency and accuracy compared to traditional methods.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Editorial Material
Neurosciences
Kristine E. Zengeler, John R. Lukens
Summary: The study found that maternal immune activation promotes sex-biased activation of stress response in the developing mouse brain, leading to autism-related behaviors specifically in male offspring.
NATURE NEUROSCIENCE
(2021)
Article
Chemistry, Physical
Delin Sun, Stewart He, W. F. Drew Bennett, Camille L. Bilodeau, Olaf S. Andersen, Felice C. Lightstone, Helgi I. Ingolfsson
Summary: Research on gramicidin A (gA) subunit dimerization in lipid bilayers revealed a dimer structure with two subunits connected by six hydrogen bonds, as well as two additional dimer structures stabilized by four or two hydrogen bonds. The temporal evolution study found that the dimer can form directly with six hydrogen bonds, or through paths involving two or four hydrogen bonds.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2021)
Article
Chemistry, Physical
Yuanyuan Zheng, Gang Zheng, Kaiyu Zhang, Lili Cao, Ping Yu, Lin Zhang
Summary: In this study, it was shown that hydrogen can decrease the line energies of edge and mixed dislocations, thereby enhancing slip planarity in bcc Fe. The interaction patterns found in this study lead to an increase in the energy change in the system when edge and mixed dislocations are converted to screw dislocations. As a result, cross-slip in bcc Fe is suppressed by hydrogen, increasing the tendency toward slip planarity.
Article
Mechanics
Fatemeh Molaei, Amin Hamed Mashhadzadeh, Christos Spitas, Mohammad Reza Saeb
Summary: This study compares the fracture behavior and mechanical properties of diamond and gold in different conditions. Diamond shows brittle fracture mode while gold exhibits plastic deformation. Temperature has less impact on the fracture strength of diamond and more significant impact on gold. The mechanical properties of bicrystalline gold are lower than ideal monocrystalline gold.
ENGINEERING FRACTURE MECHANICS
(2022)
Article
Nanoscience & Nanotechnology
Yang Su, Thanh Phan, Liming Xiong, Josh Kacher
Summary: This paper combines in situ high-resolution electron backscattered diffraction (EBSD) with concurrent atomistic-continuum (CAC) simulations to investigate the interactions between dislocation-mediated slip and grain boundaries (GBs) in Ni. The study shows that the local stress at slip-GB intersections initially increases with the pileup of dislocations and remains high, even after the nucleation of dislocations in the neighboring grain. The local stress only relaxes when the nucleated dislocations propagate away from the GB due to more incoming dislocations participating in the pileup. The relaxation of local stress is accompanied by the reconfiguration of atomic-scale GB structure, which not only affects subsequent dislocation transmission but also the configuration of dislocations away from the GB. These findings highlight the importance of incorporating local stress history in higher length scale models, such as crystal plasticity finite element.
SCRIPTA MATERIALIA
(2023)
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
Qiuming Wei, K. T. Ramesh, Todd C. Hufnagel, Justin Wilkerson, Jaafar A. El-Awady, Jamie Kimberley, Babak Ravaji, Shailendra P. Joshi
Summary: This paper critically reviews the fundamental aspects of plastic deformation of Mg and Mg-alloys, as well as the history of research efforts in experiments, modeling, and simulations available in the literature. Key findings and contributions from the Materials in Extreme Dynamic Environments (MEDE) Metals Collaborative Materials Research Group (CMRG) are presented, followed by summary and future perspectives.
MECHANICS OF MATERIALS
(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
Kelvin Y. Xie, Dexin Zhao, Brandon Leu, Xiaolong Ma, Quan Jiao, Jaafar A. El-Awady, Timothy P. Weihs, Irene J. Beyerlein, M. Arul Kumar
Summary: Precession electron diffraction was used to characterize the interaction between {10 (1) over bar2} tensile twins and basal plate-like precipitates in a post-deformed, precipitate-dispersed Mg-9Al micropillar. The heterogeneous distribution of precipitates in the micropillar sample enabled the study of different stages involved in twin-precipitate interactions. It was found that twin nucleation was promoted by the precipitates, hindering twin tip propagation and growth.
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.