Article
Construction & Building Technology
Ngoc-Vinh Nguyen, Chao Chang, Seung-Eock Kim
Summary: The study aims to investigate the size-dependent strain rate sensitivity in structural steel using the continuous stiffness measurement (CSM) indentation method. Experimental results showed size-dependent behavior in indentation hardness, strain rate, and flow stress. The dependence on indentation size can be attributed to the transition of dislocation nucleation rate and dislocation behaviors during indentation. The findings can be used in structural analysis, deformation mechanism understanding, and stress-state assessment during indentation testing.
STEEL AND COMPOSITE STRUCTURES
(2023)
Article
Chemistry, Multidisciplinary
Kyuyeon Won, Chanwoo Lee, Jaehyuck Jung, Sanghyuk Kwon, Yisehak Gebredingle, Jang Gyun Lim, Moon Ki Kim, Mun Seok Jeong, Changgu Lee
Summary: Graphene, a superstiff and extremely strong material, has been challenging to measure its physical properties under high strains. This research reports a successful measurement of suspended graphene under a biaxial strain as large as 6.1% using AFM-Raman spectroscopy. The Raman signals of graphene's G and 2D bands redshifted significantly, providing an effective methodology to measure variations in the physical properties of atomically thin materials under superhigh strain.
ADVANCED MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Hendrik Holz, Benoit Merle
Summary: We introduce a new nanoindentation method that allows continuous measurement of hardness across different orders of magnitudes of strain rates within a single experiment. The method demonstrates applications on various materials and shows some discrepancy with reference measurements but seems to be primarily affected by the nanoindentation size effect.
MATERIALS & DESIGN
(2023)
Article
Chemistry, Physical
Anna Sophie Ebner, Ernst Plesiutschnig, Helmut Clemens, Reinhard Pippan, Verena Maier-Kiener
Summary: Through strain rate jump tests, it was found that the influence of hydrogen can lead to an increase in hardness, an increase in strain rate sensitivity, a decrease in activation volume, and a change in the formation of plastically deformed zone in nickel-based alloy 725, further study contributes to understanding hydrogen-induced localized plasticity.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Materials Science, Multidisciplinary
Patrick Feldner, Benoit Merle, Mathias Goeken
Summary: The study analyzed the deformation behavior of ultrafine-grained, heterogeneous superplastic alloy at small scales and found new characteristics of strain rate sensitivity, emphasizing the importance of controlling grain boundary sliding by dislocation creep.
MATERIALS RESEARCH LETTERS
(2021)
Article
Engineering, Geological
Truong Le, Jamie Standing, David Potts
Summary: High-quality rotary core samples of natural London Clay were taken during the construction of Crossrail tunnels in Hyde Park, London. Advanced triaxial tests were performed on the samples, providing new insights into the stiffness variations at small- and medium-strain levels. The findings explain significant discrepancies in small-strain stiffness values reported in recent years, improving triaxial testing techniques and data interpretation.
Article
Materials Science, Multidisciplinary
Xu Long, Qipu Jia, Ziyi Shen, Ming Liu, Cao Guan
Summary: This study investigates the stress-strain relationships of silver nanoparticles reinforced by SiC particles at different strain rates using nanoindentation technique, aiming to bridge the strain rate gap between nanoindentation and uniaxial tests. The proposed rate factors enable the evaluation of constitutive responses of sintered AgNP materials at different uniaxial strain rates, demonstrating the advantages of assessing the strain rate sensitivity using a Berkovich indenter.
MECHANICS OF MATERIALS
(2021)
Article
Chemistry, Physical
Amina Turki, Bruno Guelorget, Virgil Optasanu, Manuel Francois, Frederic Herbst, Nabil Njah
Summary: This study aims to produce a highly twinned microstructure in a Cu-6 wt % Zn alloy with a moderate stacking fault energy (SFE) using equal channel angular pressing (ECAP). The results show that a high density of defects is stored after 2 passes of ECAP, followed by recovery. EBSD imaging reveals a high density of twins and a fibrous microstructure.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Physical
Shilun Yu, Yingchun Wan, Chuming Liu, Zhiyong Chen, Xiangyang Zhou
Summary: Nanocrystalline Mg-Gd-Y-Zr alloy exhibits negative strain rate sensitivity and negative rate dependence in creep behavior at room temperature, with reduced hardness and creep displacements as loading strain rate increases, mainly due to enhanced twinning activities. The dominant creep mechanism of this alloy is discussed based on a work-of-indentation theory.
Review
Materials Science, Multidisciplinary
P. Sudharshan Phani, B. L. Hackett, C. C. Walker, W. C. Oliver, G. M. Pharr
Summary: Recent advancements in electronics have led to renewed interest in high strain rate nanoindentation testing, resulting in the development of new equipment and methodologies. This review critically examines the current state-of-the-art in high strain rate nanoindentation testing, focusing on the equipment's dynamic mechanical and electronic response, test methodology, and post-processing of raw data. The challenges in hardware design and data analysis are discussed, along with the optimal strain rate range for accurate measurements.
CURRENT OPINION IN SOLID STATE & MATERIALS SCIENCE
(2023)
Article
Materials Science, Ceramics
Wei Hang, Lanqing Wei, Tekalign Terfa Debela, Hongyu Chen, Libo Zhou, Julong Yuan, Yi Ma
Summary: This study investigated the relationship between the polishing responses of lithium tantalite single crystal and its crystallographic orientation and rotation speed. The results showed that crystallographic orientation had little effect on surface quality, but rotation speed had a linearly increasing effect on material removal rate (MRR). The study also found that the X-112 degrees plane had better mechanical properties and a lower MRR value due to its plastic removal mechanism.
CERAMICS INTERNATIONAL
(2022)
Article
Materials Science, Ceramics
M. S. Z. Zhao, Z. L. Long, L. Peng
Summary: Nanoindentation tests were conducted on different bulk metallic glasses to determine their strain rate sensitivities of hardness, which were found to be negative. The variations in strain rate sensitivity values along with different factors were observed and discussed to understand the reasons for this negative strain rate sensitivity and its dependence on the composition and other factors of metallic glasses.
JOURNAL OF NON-CRYSTALLINE SOLIDS
(2021)
Article
Materials Science, Multidisciplinary
Diana Avadanii, Anna Kareer, Lars Hansen, Angus Wilkinson
Summary: Instrumented spherical nanoindentation is increasingly popular in microphysical investigations. This study tests and integrates strategies for tip and machine-stiffness calibration for spherical tips. A routine for independently calibrating effective tip radius and machine stiffness is proposed, and its validity is confirmed through benchmarks and application to different materials. The impact of machine stiffness on yield stress identification methods is also evaluated.
JOURNAL OF MATERIALS RESEARCH
(2023)
Article
Materials Science, Multidisciplinary
Yuanli Xu, Jiahe Song, Wenli Ma, Xinli Kou
Summary: The study investigated the serrated flow behavior of Zr61.7Al8Ni13Cu17Sn0.3 bulk metallic glass with different aspect ratios, finding that the behavior changes from uniform to nonuniform as the aspect ratio increases. Moreover, the normalized stress drop magnitude increases with increasing aspect ratios.
JOURNAL OF MATERIALS SCIENCE
(2021)
Article
Chemistry, Physical
Zhaoqi Hou, Wanchang Sun, Yaqiang Wang, Jinyu Zhang, Kai Wu
Summary: Nanostructured Ti/Ta and Tigr multilayers with different layer thicknesses were prepared and their rate dependent deformation behaviors were investigated. The strain rate sensitivity of Ti/Ta multilayers changed from positive to negative at a critical thickness, while the sensitivity of Tigr multilayers decreased with decreasing thickness. The deformation morphologies after nanoindentation were observed to examine the plastic deformation and dislocation activities of the multilayers.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Nanoscience & Nanotechnology
David D. Gebhart, Anna Krapf, Christoph Gammer, Benoit Merle, Megan J. Cordill
Summary: Measurements of electrical resistance have been commonly used as a failure criterion for cyclically loaded conductive films. However, there is limited research on extracting additional information from resistance data sets. This study demonstrates that an increased peak width indicates a transition from cracks bridging to through-thickness crack formation. The method is applicable to various material systems and offers a time-efficient and non-destructive alternative to traditional inspection methods.
SCRIPTA MATERIALIA
(2022)
Article
Materials Science, Multidisciplinary
Jedrzej Winczewski, Manuel Herrera, Clement Cabriel, Ignacio Izeddin, Stefan Gabel, Benoit Merle, Arturo Susarrey Arce, Han Gardeniers
Summary: This study develops a tailor-made organo-metallic resin suitable for two-photon lithography, which enables the additive manufacturing of 3D luminescent microarchitectures emitting light in the visible range. Through thermal treatment in an oxygen-rich atmosphere, silicon-free ZrO2 structures can be created using this resin, which is compatible with a luminescent activator and allows for tuning of the optical properties.
ADVANCED OPTICAL MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
S. Gabel, B. Merle, E. Bitzek, M. Goeken
Summary: An advanced method for determining cyclic crack growth on the microscale is introduced using a nanoindenter and fabricated microcantilevers. The method has been validated and shown to be reliable and comparable with macroscopic setups. The characteristics of metallic glass are also discussed.
JOURNAL OF MATERIALS RESEARCH
(2022)
Article
Materials Science, Ceramics
Zerong Yang, Hongcai Wang, Sebastian KrauB, Florian Huber, Benoit Merle, Michael Schmidt, Matthias Markl, Carolin Koerner
Summary: This study provides a better understanding of the evolution of microstructure, composition, and corresponding micromechanical property changes during multiple laser beam melting. The Zr-based BMG material demonstrates good thermal and compositional stability. Crystallization leads to an increase in hardness and Young's modulus.
JOURNAL OF NON-CRYSTALLINE SOLIDS
(2022)
Article
Engineering, Mechanical
Sebastian Krauss, Armin Seynstahl, Stephan Tremmel, Bernd Meyer, Erik Bitzek, Mathias Goken, Tadahiro Yokosawa, Benjamin Apeleo Zubiri, Erdmann Spiecker, Benoit Merle
Summary: Industrial upscaling often leads to a different coating microstructure compared to laboratory prototypes. In this study, we observed a crystallographic reorientation towards a basal texture in physical vapor deposited MoS2 coatings after wear testing. This favorable reorientation can improve the friction properties of the coatings, making them comparable to ideal chemical vapor deposited MoS2 single crystals.
Article
Chemistry, Physical
Elena Bykova, Erik Johansson, Maxim Bykov, Stella Chariton, Hongzhan Fei, Sergey V. Ovsyannikov, Alena Aslandukova, Stefan Gabel, Hendrik Holz, Benoit Merle, Bjorn Alling, Igor A. Abrikosov, Jesse S. Smith, Vitali B. Prakapenka, Tomoo Katsura, Natalia Dubrovinskaia, Alexander F. Goncharov, Leonid Dubrovinsky
Summary: A new class of rhenium borides with attractive mechanical, electronic, and other properties was identified. These compounds have a unique structural organization and potential for synthesizing new compounds with similar properties.
CHEMISTRY OF MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Luis Angel Morales, Andreas Bezold, Andreas Foerner, Hendrik Holz, Benoit Merle, Steffen Neumeier, Carolin Koerner, Christopher H. Zenk
Summary: Introducing Cu nanoparticles effectively strengthens and toughens Fe-based materials. This study investigates the effect of Cu on the mechanical properties of a novel Fe-based superalloy. Cu-containing alloy exhibits slightly higher strength, but heat treatment has a more significant impact. The presence of Cu also leads to a higher creep rate and faster-coarsening kinetics.
ADVANCED ENGINEERING MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Benedict Rothammer, Michael Schwendner, Marcel Bartz, Sandro Wartzack, Thomas Boehm, Sebastian Krauss, Benoit Merle, Stefan Schroeder, Maximilian Uhler, Jan Philippe Kretzer, Volker Weihnacht, Max Marian
Summary: This study investigates the biocompatibility, mechanical properties, adhesion, and wear resistance of tetrahedral amorphous carbon (ta-C) coatings on different materials. The coatings exhibit satisfactory cytocompatibility, excellent adhesion, and significantly increased hardness. In sliding experiments, the wear rates of the coated materials are reduced compared to uncoated pairings. However, there are some wear mechanisms observed, which need further attention.
ADVANCED MATERIALS INTERFACES
(2023)
Article
Materials Science, Coatings & Films
David D. Gebhart, Anna Krapf, Benoit Merle, Christoph Gammer, Megan J. Cordill
Summary: The fatigue properties of metallizations used in flexible electronic devices have been extensively studied. In situ electrical resistance measurements, along with other characterization methods, are often used to assess mechanical damage. However, a comprehensive analysis of the resistance data is usually missing. This study demonstrates the potential for analyzing gold films on polyimide using resistance data alone to determine grain growth, cracking, and fatigue behavior, emphasizing the importance of utilizing easily obtained data to expedite experiment evaluation.
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A
(2023)
Article
Materials Science, Ceramics
Zerong Yang, Florian Huber, Anna Krapf, Benoit Merle, Matthias Markl, Michael Schmidt, Carolin Koerner
Summary: This article combines experimental and numerical methods to study the crystallization behavior of bulk metallic glass (BMG) during laser powder bed fusion (PBF-LB/M). It reveals that BMG crystallization in PBF-LB/M is a localized phenomenon mainly caused by short-range in situ heat treatment. This work provides important insights into the crystallization kinetics of BMGs during PBF-LB/M and demonstrates the usefulness of simulation software in guiding the process development for BMGs and BMG composites.
JOURNAL OF NON-CRYSTALLINE SOLIDS
(2023)
Article
Nanoscience & Nanotechnology
Anna Krapf, David D. Gebhart, Christoph Gammer, Megan J. Cordill, Benoit Merle
Summary: The high-cycle fatigue properties of metallic thin films, especially their relation to creep behavior, were investigated. Cyclic testing on gold thin films showed that the lifetime decreases with increasing stress amplitude and temperature. Strain accumulation is mainly attributed to cyclic creep, and creep becomes more pronounced at higher temperatures. The study suggests that the fatigue lifetime of gold thin films is closely connected to their creep properties.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Materials Science, Multidisciplinary
Hendrik Holz, Benoit Merle
Summary: We introduce a new nanoindentation method that allows continuous measurement of hardness across different orders of magnitudes of strain rates within a single experiment. The method demonstrates applications on various materials and shows some discrepancy with reference measurements but seems to be primarily affected by the nanoindentation size effect.
MATERIALS & DESIGN
(2023)
Article
Chemistry, Physical
Elena Bykova, Sergey Ovsyannikov, Maxim Bykov, Yuqing Yin, Timofey Fedotenko, Hendrik Holz, Stefan Gabel, Benoit Merle, Stella Chariton, Vitali B. Prakapenka, Natalia Dubrovinskaia, Alexander F. Goncharov, Leonid Dubrovinsky
Summary: This study reported the successful synthesis of single crystals of the stoichiometric WB4 phase under high-pressure high-temperature conditions, with a hardness reaching the level of superhard materials.
JOURNAL OF MATERIALS CHEMISTRY A
(2022)
Correction
Materials Science, Multidisciplinary
David Wallis, Joe Harris, Corinna F. Bohm, Di Wang, Pablo Zavattieri, Patrick Feldner, Benoit Merle, Vitaliy Pipich, Katrin Hurle, Simon Leupold, Lars N. Hansen, Frederic Marin, Stephan E. Wolf
MATERIALS ADVANCES
(2022)
Article
Materials Science, Multidisciplinary
David Wallis, Joe Harris, Corinna F. Bohm, Di Wang, Pablo Zavattieri, Patrick Feldner, Benoit Merle, Vitaliy Pipich, Katrin Hurle, Simon Leupold, Lars N. Hansen, Frederic Marin, Stephan E. Wolf
Summary: Biomineralizing organisms have the ability to generate structural materials with exceptional crystallographic control, and the nacro-prismatic pearl oyster demonstrates systematic textural changes in its biogenic ceramic. The textured gradients in the shell result in variations in Young's modulus, providing intrinsic toughening properties similar to those of compositionally-graded synthetic materials. This unique concept of gradation based on elastic anisotropy makes oyster shells potential blueprints for future bioinspired functional materials and damage-resistant ceramics.
MATERIALS ADVANCES
(2022)
