Article
Materials Science, Ceramics
Yichen Wang, Duo Yu, Jie Yin, Buhao Zhang, Hangfeng Zhang, Xuejian Liu, Yulong An, Michael J. Reece, Zhengren Huang
Summary: The ablation behavior of HEC-0 and the effect of SiC content on ablation resistance were investigated. The results showed that the complex oxide layer played a positive role in reducing the linear ablation rate of HEC-0. The addition of SiC significantly improved the ablation resistance of the composites.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2022)
Article
Physics, Multidisciplinary
Shuai Xu, Tao Wang, Xingang Wang, Lu Wu, Zhongqiang Fang, Fangfang Ge, Xuan Meng, Qing Liao, Jinchun Wei, Bingsheng Li
Summary: Ti0.2Zr0.2Hf0.2Nb0.2Ta0.2C-M-x C composite ceramic, with high-entropy carbide as the main phase, was prepared by hot press sintering. The oxidation behavior of the composite ceramic was examined at 923 K and 1173 K, and the morphology of the samples was observed. The oxidation characteristics of both the high-entropy carbide and the secondary phase M-x C were compared and analyzed, and nano high-entropy oxides were discovered through oxidation of the composite ceramic. This research provides a better understanding of the oxidation mechanism of high-entropy carbide and composite ceramic.
Article
Materials Science, Ceramics
Annamaria Naughton-Duszova, David Medved, Lenka Dakova, Alexandra Kovalcikova, Peter Svec, Peter Tatarko, Hakan Unsal, Pavol Hvizdos, Pavol Sajgalik, Jan Dusza
Summary: The wear characteristics of a fine-grained dual-phase high-entropy (Ti0.14Zr0.2Nb0.2Hf0.2Ta0.26)C + (Ti0.38Zr0.18Nb0.22Hf0.115Ta0.105)B-2 were studied using the ball-on-flat technique in air. The material had high density, small grain size, and high hardness. The friction coefficient increased with sliding distance, and the specific wear rate decreased with increasing sliding distance. The dominant wear mechanisms were oxidation-driven tribo-chemical reaction and tribo-layer formation in boride grains, as well as mechanical wear in carbide grains.
ADVANCES IN APPLIED CERAMICS
(2023)
Article
Multidisciplinary Sciences
Shashank Mishra, Soumyadipta Maiti, Beena Rai
Summary: Refractory high entropy alloys (R-HEAs) have gained prominence for their high strength and hardness properties in various applications. This study computationally investigates the properties of TaNbHfZr R-HEA, focusing on the role of nanostructure evolution, dislocation simulations, and the ductile to brittle transition behavior. The findings provide insights into the relationship between mechanical properties and local nanostructure, with implications for materials design and development.
SCIENTIFIC REPORTS
(2021)
Article
Materials Science, Multidisciplinary
Yichen Wang, Xincheng Wang, Suwei Li, Michael J. Reece
Summary: The oxidation behavior of high entropy carbonitrides is investigated for the first time, revealing that the oxidation onset temperature increases with nitrogen content. The high entropy carbonitrides showcase better structural stability compared to monocarbides and mononitrides.
Article
Chemistry, Inorganic & Nuclear
Pavlina Solcova, Matej Niznansky, Jiri Schulz, Petr Brazda, Petra Ecorchard, Monika Vilemova, Vaclav Tyrpekl
Summary: High-entropy ceramics, represented by metal carbides of Ti, Zr, Hf, Ta, and Nb, are materials with great potential and wide applications. A chemical route to synthesize high-entropy carbide powder at a lower temperature has been developed, allowing for ideal mixing of precursors on a molecular level without the need for milling and blending steps. The resulting phase-pure high-entropy carbide was characterized through solid-state analysis.
INORGANIC CHEMISTRY
(2021)
Article
Chemistry, Physical
Jun Wang, Liyang Fang, Xiaoning Li, Fali Liu, Xiancong He, Guanglong Xu, Yulu Zhou, Xiaoma Tao, Yifang Ouyang, Yong Du
Summary: This study systematically investigated the diffusion behaviors and mechanical properties of Zr-X (X=Nb, Ta, Hf) systems. The interdiffusion coefficients and impurity diffusion coefficients of Zr-rich alloys were evaluated and the diffusion activation energies were calculated. The hardness and Young's modulus of Zr-X were obtained through nanoindentation testing.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Materials Science, Ceramics
Jan Dusza, Tamas Csanadi, David Medved, Richard Sedlak, Marek Vojtko, Michal Ivor, Hakan Unsal, Peter Tatarko, Monika Tatarkova, Pavol Sajgalik
Summary: A (Hf-Ta-Zr-Nb-Ti)C high-entropy carbide was successfully prepared via ball milling and a two-step Spark Plasma Sintering process, achieving a single-phase ceramic sample with high relative density and hardness values. The wear mechanism of the sample was identified as mechanical wear, with an increase in specific wear rate correlated to the decrease in nanohardness on worn surfaces with increasing wear load.
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
(2021)
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
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
Materials Science, Ceramics
Yongqiang Tan, Wei Liao, Zhen Teng, Haibin Zhang
Summary: Two types of high-entropy carbides were compared and it was found that the introduction of carbon vacancy can lower the sintering temperature, unaffected the Vickers hardness, but significantly decrease the strength. The nonstoichiometric high-entropy carbide showed a 50% decrease in thermal conductivity, primarily due to the lower electrical conductivity. The oxidation resistance in high temperature water vapor was not sensitive to carbon stoichiometry.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2023)
Article
Chemistry, Physical
Guowei Zhang, Fenger Sun, Heping Liu, Xiaoyan Ren, Hong Xu, Mingjie Wang, Yizheng Fu
Summary: The structural properties, elastic anisotropy, electronic structures and work function of D0(22)-type Al3TM (TM = Sc, Ti, V, Y, Zr, Nb, La, Hf, Ta) were studied using first-principles calculations. Al3Zr was found to be the most thermodynamically stable compound, while various mechanical properties and anisotropic factors were systematically explored. Additionally, the correlation between hardness and Young's modulus was explained further through the work function analysis, with D0(22)-Al3Ta exhibiting excellent strengthening effects in experimental design.
Article
Chemistry, Physical
Mitja Krnel, Andreja Jelen, Stanislav Vrtnik, Joze Luzar, Darja Gacnik, Primoz Kozelj, Magdalena Wencka, Anton Meden, Qiang Hu, Sheng Guo, Janez Dolinsek
Summary: In this study, the scandium-containing Sc-Hf-Nb-Ta-Ti-Zr system of refractory HEAs was investigated. The addition of scandium produced a two-phase structure, with one phase being bcc and the other hcp. Superconductivity was found to originate from the bcc phase, while the hcp phase was non-superconducting. The microstructure of the alloys became very inhomogeneous due to the addition of scandium.
Article
Materials Science, Multidisciplinary
Yupeng Pan, Xiaobo He, Binjie Zhou, Denver Strong, Jian Zhang, Hai-Bin Yu, Yunfei Tan, Robert J. Cava, Yongkang Luo
Summary: In this study, the elastic properties of a hexanary high-entropy alloy superconductor were investigated at different temperatures. The results showed that the material exhibited excellent elastic performance at room temperature and even better performance at cryogenic temperature.
MATERIALS TODAY COMMUNICATIONS
(2022)
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)