Editorial Material
Nanoscience & Nanotechnology
Jeno Gubicza
Summary: This commentary points out potential issues with the methodology used in a study for determining dislocation density from X-ray diffraction peak breadth, cautioning against relying solely on values obtained from diffraction profiles.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Engineering, Mechanical
X. X. Zhang, P. -p. Bauer, A. Lutz, C. Wielenberg, F. Palm, W. M. Gan, E. Maawad
Summary: Understanding and controlling the performance of additively manufactured aluminum alloys with scandium and zirconium elements requires knowledge of their microplasticity and macroplasticity behavior, which has received little attention. This study uses in-situ synchrotron X-ray diffraction and full-field crystal plasticity modeling to quantitatively assess the transitions from elasticity to microplasticity and then to macroplasticity, and analyze the development of the initial microstructure. The findings provide deeper insights into controlling the performance of these alloys and pave the way for predicting the behavior of various metallic materials.
INTERNATIONAL JOURNAL OF PLASTICITY
(2023)
Article
Nanoscience & Nanotechnology
Andras Borbely
Summary: This study numerically calculated diffraction peak profiles for dislocation ensembles with different spatial arrangements and correlations between the Burgers vector signs. The results showed that the arrangement parameter M and the square root of the dislocation density play key roles in determining the relationship between peak breadth and the magnitude of the diffraction vector in the modified Williamson-Hall (mWH) plot. The mWH plot is found to be very useful in practice, indicating a consistent asymptotic line-profile analysis.
SCRIPTA MATERIALIA
(2022)
Article
Engineering, Mechanical
Y. Z. Li, Z. Y. Liang, M. X. Huang
Summary: This study investigates the effect of warm rolling on the deformation mechanisms of TWIP steel. It is found that while dislocation multiplication always controls the maximum flow stress, deformation twinning becomes increasingly important for steels with larger warm rolling reductions. The twinning kinetics is enhanced by the high dislocation densities caused by warm rolling, leading to an enhancement of twinning-induced hardening.
INTERNATIONAL JOURNAL OF PLASTICITY
(2022)
Article
Materials Science, Multidisciplinary
Sven E. Gustafson, Wolfgang Ludwig, Raquel Rodriguez-Lamas, Can Yildirim, Katherine S. Shanks, Carsten Detlefs, Michael D. Sangid
Summary: Triple junctions in polycrystalline solids are known for their potential stress concentration and strain localization. This study measures the intragranular lattice curvatures and elastic strains at triple junctions using a novel zoom-in style combination of synchrotron X-ray techniques. Additionally, the impact of including elastic strain gradients while calculating dislocation density within embedded grains is revisited.
Article
Multidisciplinary Sciences
Ulrich Burkhardt, Aimo Winkelmann, Horst Borrmann, Andreea Dumitriu, Markus Koenig, Grzegorz Cios, Yuri Grin
Summary: This study investigates the assignment of enantiomorphs using diffraction methods for X-rays and electrons. By comparing experimental and simulated Kikuchi patterns, enantiomorphs in polycrystalline materials of beta-Mn and Pt2Cu3B can be accurately determined.
Article
Physics, Applied
Akio Ogura, Shota Nogawa, Masahiro Kawano, Ryo Minematsu, Koshiro Kubo, Mitsuru Imaizumi, Hidetoshi Suzuki
Summary: Using synchrotron X-ray diffraction, a study found that a low open-circuit voltage (V-oc) solar cell exhibits inhomogeneous distribution of different preferential glide planes compared to high-V-oc cells. Understanding the changes in preferential glide planes within a cell can help improve the uniformity of cell properties over the entire wafer.
APPLIED PHYSICS EXPRESS
(2021)
Article
Metallurgy & Metallurgical Engineering
Apu Sarkar, Ajay Kumar, Saurabh Mukherjee
Summary: This article investigates the microstructural changes and mechanical property degradation of zirconium alloys used in nuclear reactors during high-energy neutron irradiation, and simulates the radiation damage using ion irradiation. The density of point defects and dislocations in the irradiated samples were characterized, and their relationship with the mechanical properties was determined.
TRANSACTIONS OF THE INDIAN INSTITUTE OF METALS
(2022)
Article
Nanoscience & Nanotechnology
Leyun Wang, Ziliang Lu, Hancheng Li, Zhijie Zheng, Gaoming Zhu, Jun-Sang Park, Xiaoqin Zeng, Thomas R. Bieler
Summary: High energy X-ray diffraction microscopy (HEDM) was used to index nearly 1000 grains in a poly-crystalline Ti specimen and characterize their deformation during an incremental tensile test. The positions of diffraction peaks were analyzed for evolving crystal orientation and stress tensor of each grain. The study evaluated the Taylor hardening model for each grain, showing a correlation between yield stress, hardening, and grain properties.
SCRIPTA MATERIALIA
(2021)
Article
Materials Science, Multidisciplinary
Jai Tiwari, Padma Pratheesh, O. B. Bembalge, Hariharan Krishnaswamy, Murugaiyan Amirthalingam, S. K. Panigrahi
Summary: This research investigates the electroplastic mechanism in AA 6063 alloy and its nanocomposites, revealing that SiC particles suppress the electroplastic effect. By analyzing the trend of flow stress reduction, decoupling Joule heating effects, and hypothesizing a magnetic depinning mechanism, the role of electron-dislocation interactions in plastic deformation is elucidated. The reduction in dislocation density quantified using X-ray diffraction aligns with the inferred mechanism.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2021)
Article
Engineering, Mechanical
X. X. Zhang, A. Lutz, H. Andrae, M. Lahres, W. M. Gan, E. Maawad, C. Emmelmann
Summary: This study investigates the microstructure, crystal lattice strains, and elastoplastic properties of LPBF AlSi10Mg alloy using high energy synchrotron X-ray diffraction technology. Average phase stresses are calculated to quantify load distribution, while the dislocation density and its evolution during plastic deformation are determined based on modified methods. The Al matrix exhibits a multistage strain hardening behavior associated with interactions between dislocations and cell boundary networks.
INTERNATIONAL JOURNAL OF PLASTICITY
(2021)
Article
Chemistry, Multidisciplinary
Shuo Feng, Rajesh Kumar Singh, Yucheng Fu, Zhuo Li, Yulong Wang, Jie Bao, Zhijie Xu, Guosheng Li, Cassidy Anderson, Lili Shi, Yuehe Lin, Peter G. Khalifah, Wei Wang, Jun Liu, Jie Xiao, Dongping Lu
Summary: In this study, a simple strategy was demonstrated for constructing low-tortuosity through-pores in both vertical and planar directions of electrodes by casting large particles into single-particle-layer electrodes. Through multi-scale characterizations and simulations, correlations between material/electrode structures, electrolyte permeability, polysulfide migration, and sulfur reactions were elucidated. The high-loading and dense sulfur cathode fabricated by this method delivers a high specific capacity at a very low electrolyte/sulfur ratio.
ENERGY & ENVIRONMENTAL SCIENCE
(2022)
Article
Chemistry, Physical
M. Moran, M. Vicente Alvarez, P. Vizcaino, D. W. Brown, J. Santisteban
Summary: Diffraction line profile analysis was used to investigate the change in dislocation density during the processing of a Zr-2.5%Nb pressure tube. The results showed a gradual decrease in dislocation density over time, with a significant decrease after post-annealing. The study proposed a model to estimate the expected dislocation density for different soaking conditions.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Nanoscience & Nanotechnology
S. R. Agnew, N. E. Peterson, J. J. Bhattacharyya, H. Macdonald, M. A. Wischhusen, Z. Harris, J. T. Burns, M. Webster
Summary: Prior studies have shown that the rate of sensitization in 5xxx-series Al-Mg alloys is influenced by the dislocation content, with lower dislocation densities resulting in higher rates of sensitization. This study used X-ray line profile analysis (LPA) to evaluate the dislocation density in 5083 and 5456 alloys samples with different tempers and thermomechanical processing states. The results demonstrated that LPA can distinguish between samples with different tempers, but not within a given temper. The technique, combined with a constitutive model, accurately predicted the mechanical strength of the alloys. However, the use of a more monochromatic X-ray source may enhance the technique's application for structural health monitoring of sensitization-prone 5xxx alloys.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Nanoscience & Nanotechnology
P. H. F. Oliveira, D. C. C. Magalhaes, M. T. Izumi, O. M. Cintho, A. M. Kliauga, V. L. Sordi
Summary: This study investigated the microstructure evolution and flow behavior of a Cu-0.7Cr-0.07Zr alloy through tensile tests at different temperatures, supported by in-situ X-ray diffraction experiments. Results showed that at 298 K, dislocation glide controlled the strain-hardening rate, while at 123 K, simultaneous strength and ductility enhancement was achieved due to the TWIP effect.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Chemistry, Physical
Samuel A. Hevia, Joseba Orive, Fernando Guzman, Eduardo Cisternas, Fabian Dietrich, Roberto Villarroel, Judit Lisoni
Summary: The study demonstrates that the performance of vanadium pentoxide thin films as cathodes for lithium-ion batteries can be optimized by specific production routes and fabrication parameters, with factors such as film thickness and microstructure, influenced by oxidation temperature, playing a key role. In addition, first-principles calculations using density functional theory (DFT) were conducted to explain the relationship between the remarkable performance and film microstructure.
APPLIED SURFACE SCIENCE
(2022)
Article
Energy & Fuels
Adriana Blanco, Josefina Caroca, Rocio Tamayo, Marcos Flores, Manuel Romero-Saez, Rodrigo Espinoza-Gonzalez, Francisco Gracia
Summary: Nickel-doped CaTiO3 (Ni@CTO) perovskites prepared by sol-gel synthesis showed high catalytic activity and selectivity in the CO2 methanation reaction. The catalysts with particle sizes below 10 nm exhibited the highest activity. The doped catalysts exhibited activity at lower temperatures, possibly due to enhanced CO2 adsorption sites and higher specific surface area resulting from the formation of oxygen vacancies in the perovskite. The 10Ni@CTO catalyst demonstrated high stability over 40 hours of reaction.
Article
Nanoscience & Nanotechnology
Vicente Salinas, Claudio Aguilar, Rodrigo Espinoza-Gonzalez, Javiera Gonzalez, Javier Henriquez, Fernando Lund, Nicolas Mujica
Summary: This study monitors the dislocation density of 304L steel in a tension test by measuring acoustic wave velocities. The results show that the measured velocities are consistent with theoretical predictions. XRD measurements and C-J analysis also indicate the presence of twins at high strains. Additionally, the study investigates the differences in plastic behavior during different loading and unloading cycles.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Energy & Fuels
Dario F. Zambrano-Mera, Rodrigo Espinoza-Gonzalez, Roberto Villarroel, Andreas Rosenkranz, Nicolas Carvajal, Maria I. Pintor-Monroy, A. Gabriela Montano-Figueroa, Maria J. Arellano-Jimenez, Manuel Quevedo-Lopez, Paulina Valenzuela, William Gacitua
Summary: Multi-layer TiO2/SiO2 coatings doped with Zr-oxides were investigated to enhance their crystalline structure and density/compactness, and to form Si-Zr-O bonds. The doping of Zr-oxides improved the optical and mechanical properties of the coatings, with the sample annealed at 400 C and doped with 1 at.-% Zr showing the best anti-reflective behavior and mechanical performance.
SOLAR ENERGY MATERIALS AND SOLAR CELLS
(2022)
Article
Materials Science, Multidisciplinary
B. V. Bhaskara Rao, Maheswar Jena, Radhamanohar Aepuru, R. Udayabhaskar, Mangalaraja Ramalinga Viswanathan, Rodrigo Espinoza Gonzalez, Sangeeta N. Kale
Summary: By optimizing the use of mGAPC pigment in epoxy paint, lightweight electromagnetic absorbers based on PE foam were successfully fabricated. The absorption of electromagnetic waves in the hybrid foam was significantly improved after multiple coating cycles.
MATERIALS CHEMISTRY AND PHYSICS
(2022)
Article
Chemistry, Physical
Roberto Villarroel, Dario Zambrano-Mera, Rodrigo Espinoza-Gonzalez, Katherine Paredes-Gil, Stefano Pantaleone, Luis Ballesteros, Gerko Oskam, Jose A. Garcia-Merino, Samuel A. Hevia, Guillermo Gonzalez-Moraga
Summary: This study investigated the hydrogenation process and photoactivity improvement of anatase TiO2 thin films produced by direct-current reactive magnetron sputtering. The structural changes and enhanced photoactivity were found to be related to the formation of defects at the surface of the hydrogenated films.
APPLIED SURFACE SCIENCE
(2023)
Article
Energy & Fuels
Dario F. Zambrano-Mera, Rodrigo Espinoza-Gonzalez, Andreas Rosenkranz, Terry J. Harvey, Tomas Polcar, Paulina Valenzuela, William Gacitua
Summary: The study explores the possibility of enhancing erosion resistance in antireflective coatings through Zr-oxide doping and thermal annealing, and demonstrates that this method can improve the longevity and efficiency of solar panels.
SOLAR ENERGY MATERIALS AND SOLAR CELLS
(2023)
Article
Materials Science, Multidisciplinary
Santhosh Kumar Adpa, S. Shanmukharao Samatham, Radhamanohar Aepuru, Kalyani Date, Ravi Prakash Magisetty, Suwarna Datar, S. N. Kale, Rodrigo Espinoza Gonzalez, Vijaya Bhaskara Rao Bhaviripudi
Summary: Nanocrystalline Ni3Al thin films were deposited using DC magnetron sputtering and their electron transport mechanism and electromagnetic shielding properties were studied. STM was used to study the electron transport mechanism and barrier heights of the films. The barrier height of Ni3Al thin films decreased with sputtering power and the entire tunneling current appeared to come from Schottky emission. The electromagnetic shielding properties of the films were studied in the X-band region and showed increased shielding effectiveness with sputtering power.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2023)
Article
Nanoscience & Nanotechnology
Carolina Espinoza, Vicente Salinas, Makarena Osorio, Edgar Pio, Claudio Aguilar, Fernando Lund, Nicolas Mujica
Summary: Knowledge of the state of plastic deformation in metallic structures is crucial for failure prevention. Non-destructive acoustic tests based on first order elastic constants have limitations when plastic deformations are heterogeneous or have small variations in elastic constants. Digital image correlation techniques combined with finite element modeling provide information about plastic deformation in the sample interior. This study demonstrates that the nonlinear Second Harmonic Generation method (SHG) can detect von Mises stress zones and plastic strain in aluminum pieces, indicating sensitivity to dislocation density. Experimental results align with Finite Element Method (FEM) modeling and are supported by X-ray Diffraction measurements (XRD).
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Chemistry, Physical
Rodrigo Espinoza-Gonzalez, Josefa Caamano, Ximena Castillo, Marcelo O. Orlandi, Anderson A. Felix, Marcos Flores, Adriana Blanco, Carmen Castro-Castillo, Francisco Gracia
Summary: The structural and gas sensing properties of CaCu3Ti4O12 compound prepared by sol-gel technique were studied. The compound exhibited pseudo-cubic phase with less than 4 wt% of secondary phases. Microstructural analysis was performed using scanning electron microscopy, while elemental composition was determined by X-ray energy dispersive spectroscopy. Gas sensing response of the samples showed selectivity for NO2, with the highest sensor signal at 250 ?.
Article
Physics, Fluids & Plasmas
Camila Sandivari, Jacob Egge, Belen Barraza, Leonardo Gordillo, Nicolas Mujica
Summary: We conducted an experimental study on a new type of dual drop-wave entity in a localized structure in a water Faraday-wave system. By analyzing the trajectories of the drops, we observed several regimes including periodic bouncing, period doubling, period tripling, a sawtooth state, and chaotic/erratic trajectories. We found that the most stable cases resulted from the synchronization between the drop self-oscillations and the soliton's sloshing motion. This synchronization ensures stability and longer lifetimes. We also analyzed the lifetime of the drops and found that they follow a Weibull distribution.
PHYSICAL REVIEW FLUIDS
(2023)
Article
Engineering, Electrical & Electronic
B. V. Bhaskararao, Durga Prasad Pabba, Radhamanohar Aepuru, Ali Akbari-Fakhrabadi, Prasad Lokhande, R. Udayabhaskar, Marco Rosales-Vera, Rodrigo Espinoza-Gonzalez
Summary: The rapidly increasing demand for electronic devices and electric vehicles has led to the need for efficient and high power and energy density storage devices. This study successfully synthesized and optimized Fe3O4 nanoparticles intercalated with rGO nanosheets, and evaluated their performance for supercapacitors and lithium-ion batteries.
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2023)
Article
Physics, Fluids & Plasmas
Nicolas Mujica, Scott Waitukaitis
Summary: Experiments have shown that charge distributions of granular materials are non-Gaussian, indicating the presence of many highly charged particles. Measurement uncertainties account for the previously observed tail broadening, as distributions measured at different electric fields have different tail sizes. By accounting for uncertainties, the true charge distribution without broadening is found to be non-Gaussian, with fewer highly charged particles. These findings have implications for granular behavior in natural settings where electrostatic interactions play a role.
Article
Energy & Fuels
Vijayabhaskara Rao Bhaviripudi, Pravin K. Dwivedi, Durga Prasad Pabba, Radhamanohar Aepuru, Umesh T. Nakate, Rodrigo Espinoza-Gonzalez, Manjusha Shelke
Summary: In this study, Fe3O4 nanoparticles and acid functionalized multi-wall carbon nanotubes (FMWCNT) were synthesized and used as electrodes for solid-state symmetric capacitors. The results showed that the Fe3O4-FMWCNT electrodes had high areal specific capacitance and good cycle stability, indicating their potential for high-performance energy storage devices.
JOURNAL OF ENERGY STORAGE
(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.
