Article
Materials Science, Coatings & Films
Bih-Show Lou, Chaur-Jeng Wang, Yen-Yu Chen, Sheng-Bo Hung, Yu-Chen Lin, Jyh-Wei Lee
Summary: This study fabricated refractory MEA thin films of W-Nb-Ta-Ti and W-Nb-Ta-Ti-N, and demonstrated how the structure and microstructure of the films can be controlled by adjusting the nitrogen concentration. The films exhibited varying hardness, adhesion properties, friction coefficients, and corrosion resistance.
SURFACE & COATINGS TECHNOLOGY
(2022)
Article
Materials Science, Multidisciplinary
Enkuan Zhang, Ying Tang, Mingwen Wen, Abdulmonem Obaied, Irina Roslyakova, Lijun Zhang
Summary: Refractory high entropy alloys (RHEAs) have great potential for ultrahigh-temperature applications. In this paper, the authors evaluated the Gibbs energy expressions for pure Mo, Nb, Ta and W, and developed a thermodynamic database for the Mo-Nb-Ta-W quaternary system. The calculated results showed good agreement with experimental and theoretical data. Additionally, experimental investigation and high-throughput mapping were performed to further verify the reliability of the database.
INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS
(2022)
Article
Nanoscience & Nanotechnology
Marta Pozuelo, Jaime Marian
Summary: In this study, the direct link between the strength of micron-sized specimens of high-entropy alloys and deviations from equiatomic stoichiometry was established. The compositional fluctuations near the micropillar tip were found to be the best quantitative predictor of yield strength.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Materials Science, Ceramics
Shan Li, Lairong Xiao, Sainan Liu, Yafang Zhang, Jiawei Xu, Xiaojun Zhou, Gang Zhao, Zhenyang Cai, Xiaojun Zhao
Summary: A novel composite ceramic coating was prepared on tantalum substrate using a three-step method to address the challenge of recyclability in high temperature oxidation environments. The coating exhibited superior performance and effective protection, possibly due to the formation of a composite oxide film with low oxygen permeability, moderate viscosity, thermal expansion coefficient, and good self-healing ability. The presence of an Nb interlayer mitigated thermal mismatch and reduced coating cracking.
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
(2022)
Article
Nanoscience & Nanotechnology
Minhyung Ahn, Yongmo Park, Seung Hwan Lee, Sieun Chae, Jihang Lee, John T. Heron, Emmanouil Kioupakis, Wei D. Lu, Jamie D. Phillips
Summary: High-entropy-oxide-based memristors composed of Zr, Hf, Nb, Ta, Mo, and W oxides demonstrate uniform distribution of vacancies and low stochastic behavior in resistive switching, showing promise for neuromorphic applications. These memristors exhibit forming-free operation, low device and cycle variability, gradual conductance modulation, 6-bit operation, and long retention.
ADVANCED ELECTRONIC MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
Sicong He, Xinran Zhou, Dan Mordehai, Jaime Marian
Summary: The refractory multi-element alloys (RMEA) with body-centered cubic (bcc) structure have attracted much attention as potential high-temperature materials. Recent research on Nb-Mo-Ta-W alloys suggests that the role of edge dislocations, caused by atomic-level chemical fluctuations, plays a key role in their remarkable strength above 1000℃. This study proposes a strengthening mechanism based on thermal super-jogs in edge dislocations, which act as strong obstacles to dislocation motion, and explains the strength plateau observed in these alloys.
Article
Chemistry, Physical
Xinran Zhou, Sicong He, Jaime Marian
Summary: In this study, vacancy energetics in the equiatomic Nb-Mo-Ta-W alloy were investigated using molecular statics calculations. The results demonstrate a wide distribution of vacancy formation and migration energies, which are influenced by short-range order.
Article
Nanoscience & Nanotechnology
Xinran Zhou, Sicong He, Jaime Marian
Summary: The Nb-Mo-Ta-W system, a model alloy of the refractory multi-principal element alloy family, exhibits exceptional mechanical properties at high temperature due to its highly twisted screw dislocations with a high concentration of kinks and cross-kinks. This study quantifies the contribution of the 'self-pinning' effect to the total strength using a kinetic Monte Carlo model, and reveals that the self-pinning stress remains even at high temperatures.
SCRIPTA MATERIALIA
(2023)
Article
Materials Science, Ceramics
David Medved', Michal Ivor, Alexandra Kovalcikova, Erika Mudra, Tamas Csanadi, Richard Sedlak, Hakan Unsal, Peter Tatarko, Monika Tatarkova, Pavol Sajgalik, Jan Dusza
Summary: The wear characteristics of a high-entropy carbide were studied using a ball-on-flat technique. The wear behavior showed that the friction coefficient and specific wear rate increased with increasing load, and the dominant wear mechanism was identified as mechanical wear.
INTERNATIONAL JOURNAL OF APPLIED CERAMIC TECHNOLOGY
(2022)
Article
Chemistry, Physical
Nestor Garcia-Romeral, Angel Morales-Garcia, Francesc Vines, Iberio de P. R. Moreira, Francesc Illas
Summary: A systematic computational study was conducted to investigate the electronic ground state nature and properties of M2C MXenes. The results revealed diverse conductivity and spin configurations for different MXenes, providing valuable insights for understanding and designing MXene materials.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Nengbin Hua, Wenjie Wang, Qianting Wang, Youxiong Ye, Sihan Lin, Lei Zhang, Qiaohang Guo, Jamieson Brechtl, Peter K. Liaw
Summary: The study on TixZrNbTaMo high entropy alloys revealed excellent properties in hardness, corrosion resistance, and wear resistance, with improvement in wear resistance in phosphate buffer saline solution as the titanium content decreases. The Ti0.5ZrNbTaMo alloy showed the highest corrosive wear resistance among the four HEAs due to its superior mechanical properties and chemical stability.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Energy & Fuels
Jack A. Wilson, Lee J. Evitts, Alberto Fraile, Roy E. Wilson, Michael J. D. Rushton, David T. Goddard, William E. Lee, Simon C. Middleburgh
Summary: In this study, the thermal expansion behavior of equiatomic alloys in the Mo-Nb-Ta-Ti-W system was investigated using atomic-scale modeling techniques. The results showed that these techniques can reliably predict the thermal expansion behavior of high entropy alloys and concentrated solid solutions.
JOURNAL OF PHYSICS-ENERGY
(2022)
Article
Chemistry, Physical
A. R. Akhmadeev, V. A. Eremin, M. V. Ananyev, B. V. Voloshin, M. P. Popov, I. L. Ivanov, A. V. Fetisov
Summary: This study investigates the oxygen exchange kinetics and diffusivity in Ba0.5Sr0.5Co0.8Fe0.2O3-delta oxides doped with high-charged cations (M = Ta, Nb, Mo or W). Factors influencing oxygen vacancy mobility and surface exchange activity were examined. The effects of oxygen pressure and temperature on the oxygen content in Nb-doped oxide were studied using quasi-equilibrium oxygen release method. The composition and morphology of the oxide surfaces were analyzed using XPS and SEM. The results provide insights into the factors governing oxygen diffusion and surface exchange mechanism.
APPLIED SURFACE SCIENCE
(2023)
Article
Materials Science, Multidisciplinary
Yuuka Iijima, Takeshi Nagase, Aira Matsugaki, Pan Wang, Kei Ameyama, Takayoshi Nakano
Summary: By applying empirical alloy parameters and thermodynamic calculations, new noble nonequiatomic Ti-Zr-Hf-Nb-Ta-Mo high-entropy alloys for metallic biomaterials were designed. The Mo equivalent and valence electron concentration parameters were found to be useful for alloy design, including BCC structure formation in bio medium-entropy alloys and BioHEAs.
MATERIALS & DESIGN
(2021)
Article
Materials Science, Ceramics
Yu-Zhang Zhou, Kun-Heng Huang, Guang-Xu Bo, Si-Chun Luo, Wei-Ming Guo, Shi-Kuan Sun, Hua-Tay Lin
Summary: High hardness and high toughness (Ti,Nb,Ta,Mo,W)(C,N)-based ceramics were prepared using pre-synthesized high-entropy carbonitride (HECN) powder and high-entropy alloy (HEA) via spark plasma sintering, and the fracture toughness of the ceramics was significantly improved.
CERAMICS INTERNATIONAL
(2023)
Article
Engineering, Electrical & Electronic
Weidong Ding, Jiachen Wang, Zhenbo Wan, Fangfei Su, Kaisheng Mei, Yuchang Qiu
Summary: This paper presents the design and analysis of two step pulse generators with different output voltages for calibrating the performance of non-contact sensors. The experimental results show that the designed step pulse generators have fast response time and high precision pulse width adjustment.
IEEE TRANSACTIONS ON POWER DELIVERY
(2022)
Article
Physics, Applied
Linyuan Ren, Yanan Wang, Weidong Ding, Anbang Sun, Burak Karadag, Zichen Deng, Jinyue Geng
Summary: This article experimentally studied the discharge characteristics and mode transition phenomenon of the ring-cusp magnetically confined plasma bridge neutralizer (RCM-PBN). Two distinct discharge modes, high oscillation mode and low oscillation mode, were observed. The RCM-PBN can transition into the low oscillation mode by adjusting certain parameters.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Instruments & Instrumentation
Yang Meng, Meng Yuan Tang, Haruki Xue, Weidong Ding, Youngman Zhang, Yana Wang
Summary: Electrical wire explosions have various applications, and optical diagnosis is an effective method to understand their evolution. This study established an experimental platform to diagnose the optical radiation of copper and tantalum wire explosions. The results revealed the characteristics and spectral changes during the explosions.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2022)
Article
Engineering, Electrical & Electronic
Guoxiang Sun, Xia Wang, Weidong Ding, Jiaqi Yan, Saikang Shen, Shaohao Nie
Summary: The influence of laser energy, irradiation position, photoelectric material, and anode voltage on the trigger characteristics of a pseudospark switch triggered by a 532-nm nanosecond focused laser is studied. It is found that the increase of laser energy and anode voltage can increase the current density of seed electrons, reduce the time of electrons diffusion to the cathode hole, and thus reduce the trigger delay.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Engineering, Mechanical
Chen Chen, Tianning Chen, Wei Ding, Fuyi Yang, Jian Zhu, Jie Yao
Summary: This article investigates and demonstrates the capability of impurities to control and switch valley Hall edge modes in acoustic systems. The acoustic transmission spectrum is found to be sensitive to the rotation angle of the impurity, providing a potential platform for switchable acoustic devices or filters.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2023)
Article
Acoustics
Wei Ding, Tianning Chen, Chen Chen, Dimitrios Chronopoulos, Jian Zhu
Summary: This work presents the design, manufacture, and experimental testing of a three-dimensional twisted phononic crystal made of a single-phase material. The research comprehensively explains the mechanism of bandgap formation in the crystal and the methods for tuning the bandgap.
JOURNAL OF SOUND AND VIBRATION
(2022)
Article
Instruments & Instrumentation
Zichen Deng, Qi Yuan, Ran Chang, Zhenjie Ding, Weidong Ding, Linyuan Ren, Yanan Wang
Summary: With the advancement of technology, low-temperature plasma has become increasingly important in industrial applications. The industrial application of low-temperature plasma requires high electron energy, low macroscopic temperature, and uniformity. Compared to direct current plasma and alternating current plasma, low-temperature plasma driven by nanosecond pulses has significant advantages in these aspects. This paper proposes a simple topology based on the pseudospark switch and the diode opening switch. A pulse generator is developed, which can output pulses with an amplitude of 106 kV, a rise time of 15.5 ns, a pulse width of 46 ns, and a maximum repetition rate of 1 kHz on a 260 omega resistive load. The proposed topology and pulse generator have potential applications in various industries.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2023)
Article
Engineering, Electrical & Electronic
Yang Meng, Zhichuang Li, Haorui Xue, Weidong Ding, Zichen Deng, Wen Liu
Summary: This article investigates the surface flashover characteristics of a 252-kV conical insulator in a C4F7N/CO2 mixture, an alternative to SF6. The study shows that adding small amounts of C4F7N to CO2 can increase the surface flashover voltage. The experiment also observes four types of discharge traces, most of which are on the concave side under both ac and LI voltage. The polarity effect is noticed in C4F7N/CO2 gas mixtures, and a formula is fitted to predict the flashover voltage.
IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION
(2023)
Article
Engineering, Multidisciplinary
Jiaqi Yan, Saikang Shen, Weidong Ding, Guoxiang Sun, Weizong Wang
Summary: This article presents the development and comprehensive testing of a miniaturized sealed-off pseudospark switch, which exhibits superior performances including high hold-off voltage, low jitter, high repetition rate, high peak current, long lifetime, and miniaturized size.
IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS
(2023)
Article
Engineering, Mechanical
Wei Ding, Tianning Chen, Chen Chen, Dimitrios Chronopoulos, Jian Zhu, Badreddine Assouar
Summary: We report a planar chiral phononic crystal based on Thomson scattering that can open a broadband gap by discarding the local resonant sub-structure. By simplifying the material components, we lower the starting frequency while maintaining the width of the bandgap. This finding provides a new way to manipulate broadband elastic waves and validates Thomson scattering as a promising alternative approach for bandgap formation.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2022)
Article
Physics, Fluids & Plasmas
Yongsheng Wang, Yang Meng, Wenyong Jin, Mingbin Peng, Weidong Ding
Summary: This study analyzes the formation and development process of positive streamers in water under microsecond voltage, as well as the effects of voltage amplitude, liquid conductivity, and the presence of bubbles on underwater discharge characteristics. The simulation results show that the electron density of the streamer in water can reach 10(23) m(-3), and its development speed increases with higher voltage amplitude and conductivity, while the presence of bubbles causes multiple bifurcations in the discharge channel.
PHYSICS OF PLASMAS
(2023)
Article
Physics, Fluids & Plasmas
Guoxiang Sun, Xia Wang, Weidong Ding, Jiaqi Yan, Saikang Shen
Summary: The conduction loss of the pseudospark switch can be reduced by connecting the magnetic switch and pseudospark switch in series to form the magnetically delayed pseudospark switch. In this study, a 2D electrostatic Particle in Cell/Monte Carlo Collision simulation model of the magnetically delayed pseudospark switch coupled with the external circuit is established to investigate the discharge process and characteristics. It is found that the forward conduction process of the magnetically delayed pseudospark switch can be divided into four stages.
PHYSICS OF PLASMAS
(2023)
Review
Environmental Sciences
Shuran Zheng, Jinling Wang, Chris Rizos, Weidong Ding, Ahmed El-Mowafy
Summary: The Simultaneous Localization and Mapping (SLAM) technique has made significant progress in recent decades and has attracted considerable attention in the autonomous driving community. This study provides an overview of different SLAM implementation approaches and discusses the applications, challenges, and solutions in the context of autonomous driving. It also presents a real-world road test showcasing a multi-sensor-based SLAM procedure for autonomous driving.
Article
Nuclear Science & Technology
Weidong Ding, Hongguang Yang, Qin Zhan
Summary: The aim of this study is to derive mathematical equations for the thermodynamics and kinetics of hydrogen absorption by Zr0.8Ti0.2Co. The results showed that the hydrogen absorption process can be divided into two stages, and the JMAK model fits well for both stages. The obtained mathematical equations can be used to investigate the performance and guide the design of metal hydride beds.
FUSION SCIENCE AND TECHNOLOGY
(2023)
Article
Instruments & Instrumentation
Zhenbo Wan, Weidong Ding, Fengju Sun, Xiwen Zhang, Qi Yuan
Summary: Linear transformer drivers (LTDs) are considered the most promising technological approach for future pulsed-power accelerators. This paper establishes a mathematical model of the magnetic core based on experimental results, and couples it with the LTD circuit model in simulations. The results show good agreement with experiments and provide insights into the influence of magnetic core characteristics on fault waveforms and the magnetization process under prefire conditions.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2023)