Vacuum最新文献 - Book学术

Synergistic effects of hydrofluoric acid on the purification of maize-derived graphite powder

IF 3.8 2区材料科学

Vacuum Pub Date : 2025-04-10 DOI: 10.1016/j.vacuum.2025.114325

V.S.S. Venkatesh , Amdadul Mahmun , Pandu Ranga Vundavilli , M.M. Mahapatra

引用次数: 0

Experimental research on pre-strike characteristics of double-break vacuum circuit breakers with grading capacitors under DC voltages

IF 3.8 2区材料科学

Vacuum Pub Date : 2025-04-05 DOI: 10.1016/j.vacuum.2025.114306

Yun Geng , Xiaofei Yao , Minju Xu , Chen Guan , Lianke Wang , Yingsan Geng , Zhiyuan Liu

{"title":"Experimental research on pre-strike characteristics of double-break vacuum circuit breakers with grading capacitors under DC voltages","authors":"Yun Geng , Xiaofei Yao , Minju Xu , Chen Guan , Lianke Wang , Yingsan Geng , Zhiyuan Liu","doi":"10.1016/j.vacuum.2025.114306","DOIUrl":"10.1016/j.vacuum.2025.114306","url":null,"abstract":"<div><div>In double-break vacuum circuit breakers (VCBs) during capacitor bank switching, uneven voltage distribution across the vacuum gaps is one of the key issues under investigation. Most existing research focuses on the interruption process, and there is a lack of studies examining the impact of voltage equalization capacitors on the pre-strike characteristics of double-break VCBs. This paper primarily conducts experimental research and comparative analysis on the impact of different equalization methods on the pre-strike characteristics of double-break VCBs under direct current (DC) voltage during closing operations. The experiments involve comparing the pre-strike characteristics of double-break VCBs without grading capacitors to those with grading capacitors. Key measurements include determining the pre-strike gap of high-voltage and low-voltage vacuum interrupters (VIs) in double-break VCBs at different levels of DC voltage, as well as analyzing the floating voltage during pre-strike. Additionally, cumulative probability distribution analysis is performed for pre-strike events. The 50 % pre-strike gap (<em>d</em><sub>50</sub>), dispersion in pre-strike gap (<em>σ</em><sub>pre</sub>), and floating voltage during pre-strike are compared and analyzed for both high-voltage and low-voltage VIs in each experimental group. Furthermore, this study discusses the underlying causes behind these results.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"238 ","pages":"Article 114306"},"PeriodicalIF":3.8,"publicationDate":"2025-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143791463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Phase, microstructure and intrinsic magnetic properties evolutions of AlNiCo5 films AlNiCo5 薄膜的相位、微观结构和固有磁性能演变

IF 3.8 2区材料科学

Vacuum Pub Date : 2025-04-04 DOI: 10.1016/j.vacuum.2025.114313

Y.P. Zeng , Z.G. Qiu , R.X. Yang , J.B. Huang , Z.G. Zheng , L. Liu , D.C. Zeng , J.P. Liu

{"title":"Phase, microstructure and intrinsic magnetic properties evolutions of AlNiCo5 films","authors":"Y.P. Zeng , Z.G. Qiu , R.X. Yang , J.B. Huang , Z.G. Zheng , L. Liu , D.C. Zeng , J.P. Liu","doi":"10.1016/j.vacuum.2025.114313","DOIUrl":"10.1016/j.vacuum.2025.114313","url":null,"abstract":"<div><div>AlNiCo permanent magnets are well-known for their remarkable thermal stability and ultra-high Curie temperatures, which are suitable for applications in high temperature micro-electromechanical systems. In this work, we systematically investigate the effects of varying annealing temperatures and sputtering parameters on the properties, phase, and microstructure of AlNiCo 5 film. We demonstrate spinodal decomposition (SD) transformation occurs in AlNiCo films after annealing. However, the microstructures of these films are markedly different from traditional SD nanostructures in bulk AlNiCo. As the annealing temperature increases, the SD transformation progress becomes more completely. Furthermore, when sputtering power is low (35 W), the coercivity of the film could reach 597.31 Oe, close to that of bulk AlNiCo, but the <strong><em>M</em></strong><sub>s</sub> was only 6.4 kGs. In contrast, at higher sputtering power (80 W), <strong><em>M</em></strong><sub>s</sub> increased to 12.5 kGs but displayed a lower coercivity of 286 Oe. The coercivity mechanism of AlNiCo films is primarily attributed to the pinning effect induced by non-magnetic amorphous phases. Additionally, the thermal stability of most AlNiCo films only slightly reduces compared to bulk AlNiCo, but remain obviously higher than rare-earth permanent magnets. This study provides valuable insights into understanding the intrinsic magnetic properties and thermal stability of AlNiCo thin films.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"238 ","pages":"Article 114313"},"PeriodicalIF":3.8,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143786128","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Achieving synergy of strength and ductility of eutectic high-entropy alloys via continuous precipitation of nano-precipitates

IF 3.8 2区材料科学

Vacuum Pub Date : 2025-04-04 DOI: 10.1016/j.vacuum.2025.114309

Yuji Cheng , Dianchun Ju , Jiahao Liu , Ning Liu , Zhanfang Wu , Jing Zhang

{"title":"Achieving synergy of strength and ductility of eutectic high-entropy alloys via continuous precipitation of nano-precipitates","authors":"Yuji Cheng , Dianchun Ju , Jiahao Liu , Ning Liu , Zhanfang Wu , Jing Zhang","doi":"10.1016/j.vacuum.2025.114309","DOIUrl":"10.1016/j.vacuum.2025.114309","url":null,"abstract":"<div><div>This study examines the impact of solid solution aging treatment on the microstructure and mechanical properties of carbon interstitial solution AlCoCrFeNi<sub>2.1</sub> eutectic high-entropy alloys (EHEAs). The results show that after solution treatment, carbon atoms are fully dissolved in the matrix. In carbon-free alloys, the body-centered cubic (BCC) phase adopts a rod-like structure, whereas carbon-doped alloys exhibit a spherical morphology. After aging at 500 °C, a small amount of precipitate appears along the phase boundary. At 600 °C, disk precipitates continuously precipitate along the phase boundary. However, at 700 °C, the disk nano-precipitates transform into coarser particles and short rod-like structures that are unevenly distributed within the BCC phase and at the phase boundaries. Mechanical testing reveals that after solution treatment at 1300 °C for 6 h and aging at 600 °C for 4 h, the alloy achieves a yield strength of 566 MPa, tensile strength of 1043 MPa, and elongation of 11.3 %, reflecting a favorable balance of strength and ductility. Strengthening is attributed to nanoscale precipitates at phase boundaries, which create significant dislocation barriers. These nano-precipitates bond strongly with the matrix, enabling coordinated dislocation movement and promoting plastic co-deformation of both phases, thereby maintaining alloy plasticity.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"238 ","pages":"Article 114309"},"PeriodicalIF":3.8,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143791462","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Carbon nanotube arrays catalyzed by NiFeSiAl in chemical vapor deposition and hybridized with silica for microwave absorption and anti-corrosion

IF 3.8 2区材料科学

Vacuum Pub Date : 2025-04-03 DOI: 10.1016/j.vacuum.2025.114312

Lingli Deng , Shengyuan Xu , Hongyan Zhang , Xinyu Mu , Yang Guo , Xiangyu Zhao , Xian Jian

{"title":"Carbon nanotube arrays catalyzed by NiFeSiAl in chemical vapor deposition and hybridized with silica for microwave absorption and anti-corrosion","authors":"Lingli Deng , Shengyuan Xu , Hongyan Zhang , Xinyu Mu , Yang Guo , Xiangyu Zhao , Xian Jian","doi":"10.1016/j.vacuum.2025.114312","DOIUrl":"10.1016/j.vacuum.2025.114312","url":null,"abstract":"<div><div>Developing microwave absorbing materials that stably operate under high humidity and salt spray while maintaining durability remains a significant challenge. A novel NiFeSiAl/carbon nanotube array/SiO<sub>2</sub> (NFSA/CNTA/S) composite with dual microwave absorption and anti-corrosion functionalities is developed via a coupled catalytic chemical vapor deposition (CCVD) and sol-gel strategy. Ball-milled NFSA flakes act as both catalyst and magnetic component, while vertically aligned CNTA grown via CCVD enhance dielectric loss and form a conductive network. Magnetic losses from NFSA (hysteresis, eddy current, natural resonance) and dielectric losses from CNTA (conductivity, interface polarization) achieve broadband absorption. SiO<sub>2</sub> coating improves impedance matching and reduces corrosion current to 2.651 × 10<sup>−7</sup> A/cm<sup>2</sup>. The composite reaches a minimum reflection loss (RL<sub>min</sub>) of −42.36 dB and effective absorption covering a substantial portion of the X and Ku bands. This coupled CCVD with sol-gel approach provides a pathway for designing novel NFSA/CNTA/SiO<sub>2</sub> hybrids with high-performance microwave absorption and anti-corrosion.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"238 ","pages":"Article 114312"},"PeriodicalIF":3.8,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143791464","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Comparative studies on irradiation effects of GaN and InxGa1-xN films induced by energetic ions

IF 3.8 2区材料科学

Vacuum Pub Date : 2025-04-03 DOI: 10.1016/j.vacuum.2025.114298

Shuang Liu , Liqing Zhang , Yang Gao , Qinwei Wang , Tingting Ma , Rui Li , Lei Zhou , Qiang Zhou , Decheng Guo , Rong Qiu

{"title":"Comparative studies on irradiation effects of GaN and InxGa1-xN films induced by energetic ions","authors":"Shuang Liu , Liqing Zhang , Yang Gao , Qinwei Wang , Tingting Ma , Rui Li , Lei Zhou , Qiang Zhou , Decheng Guo , Rong Qiu","doi":"10.1016/j.vacuum.2025.114298","DOIUrl":"10.1016/j.vacuum.2025.114298","url":null,"abstract":"<div><div>Surface morphologies, microstructures and optical properties of GaN and In<sub>x</sub>Ga<sub>1-x</sub>N films irradiated by 8-MeV Xe<sup>19+</sup> ions at different fluences were comparatively investigated by AFM, HRXRD and UV-Vis spectra, respectively. AFM observations revealed that nano-hillock defects were grown out from the irradiated GaN surfaces and their density increases obviously, accompanied by an initial reduction and then an increase, followed by a diminishment in their surface roughness, with increasing irradiation fluences. While for In<sub>x</sub>Ga<sub>1-x</sub>N films, V-shaped pits appeared on their surfaces after irradiation and the surface roughness rises generally with fluences. However, no significant changes in pit densities were observed with fluences. HRXRD analysis displayed that dislocation density and distortion parameter of both nitride films first slightly decrease and then rapidly raise with fluences, along with a gradual lattice expansion. Compared with GaN, the In<sub>x</sub>Ga<sub>1-x</sub>N films presented a notable expansion. Analyses from UV-Vis spectra showed that the Urbach energy of GaN films first slightly reduces and then significantly rises with fluences. And, their band-gap energy of both nitride films exhibited reverse trends to Urbach energy. In contrast to GaN, In<sub>x</sub>Ga<sub>1-x</sub>N films presented a sensitive change in Urbach energy and band-gap energy under the same fluences. The underlying mechanisms were discussed in detail.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"238 ","pages":"Article 114298"},"PeriodicalIF":3.8,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143783637","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

RF-driven ion source for accelerator mass spectrometry with plasma modeling and validation test stand

IF 3.8 2区材料科学

Vacuum Pub Date : 2025-04-02 DOI: 10.1016/j.vacuum.2025.114308

Sae-Hoon Park, Seung-Won Lee, Yu-Seok Kim

{"title":"RF-driven ion source for accelerator mass spectrometry with plasma modeling and validation test stand","authors":"Sae-Hoon Park, Seung-Won Lee, Yu-Seok Kim","doi":"10.1016/j.vacuum.2025.114308","DOIUrl":"10.1016/j.vacuum.2025.114308","url":null,"abstract":"<div><div>A duoplasmatron, an ion source typically used in accelerator mass spectrometry, was tested at Dongguk University, Korea, within its radiocarbon dating facility that incorporates a mini carbon dating system. The facility developed a prototype ion source for analyzing high-level <sup>14</sup>C samples. However, the duoplasmatron exhibits limitations in terms of reliability and efficiency when used for carbon counting in gas samples. To address these limitations of duoplasmatron with plasma persistence and filament lifetime, a reliable and low-maintenance RF-driven ion source was proposed, designed and fabricated. This study focuses on plasma modeling within the RF ion source to facilitate simulation studies and predict plasma conditions. An RF ion source test stand was installed, enabling the direct injection of CO<sub>2</sub> gas to verify the performance of RF components and confirm plasma ignition. RGA scanning revealed the elemental species generated during the plasma ignition, indicating an increase in the relative pressure intensity of the target elements. The results of the RF ion source plasma simulations and the test stand validation through a residual gas analysis, comparing the simulation and RGA scanning results are presented in this paper.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"238 ","pages":"Article 114308"},"PeriodicalIF":3.8,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143786129","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Interfacial segregation enables exceptional high-temperature thermal stability in magnesium alloy

IF 3.8 2区材料科学

Vacuum Pub Date : 2025-04-02 DOI: 10.1016/j.vacuum.2025.114311

Jianxin Zhou , Xiaojun Luo , Hong Yang , Yuyang Gao , Wenlong Xie , Zhihua Dong , Bin Jiang , Fusheng Pan

引用次数: 0

Revealing microstructural evolution in CrFeCoNiMoBSi HEA coatings via HVOF-induction remelting

IF 3.8 2区材料科学

Vacuum Pub Date : 2025-04-02 DOI: 10.1016/j.vacuum.2025.114307

Shengwei Wang , Jianlei Zhang , Changsheng Zhai , Hongxing Zheng

引用次数: 0

High-temperature lubrication mechanisms of laser cladding austenitic stainless steel coatings: XPS and DFT calculations

IF 3.8 2区材料科学

Vacuum Pub Date : 2025-04-01 DOI: 10.1016/j.vacuum.2025.114302

Rui Deng , Runze Wei , Chunjiang Zhao , Jianguo Liang , Qiaofeng Bai , Xiaoyu Wu , Yicha Zhang

{"title":"High-temperature lubrication mechanisms of laser cladding austenitic stainless steel coatings: XPS and DFT calculations","authors":"Rui Deng , Runze Wei , Chunjiang Zhao , Jianguo Liang , Qiaofeng Bai , Xiaoyu Wu , Yicha Zhang","doi":"10.1016/j.vacuum.2025.114302","DOIUrl":"10.1016/j.vacuum.2025.114302","url":null,"abstract":"<div><div>Austenitic stainless steels are widely utilized in engine components due to their stable crystal structure, excellent heat resistance, and relatively low cost. This study investigates the high-temperature dry sliding friction and wear behavior of laser-clad austenitic stainless steel coatings over a temperature range from room temperature to 800 °C, and further explores the wear mechanisms through X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) calculations. As the temperature increases, a series of metal oxides such as Fe<sub>3</sub>O<sub>4</sub>, Fe<sub>2</sub>O<sub>3</sub>, FeO, Cr<sub>2</sub>O<sub>3</sub>, CrO<sub>3</sub>, and NiO will be produced by friction chemical reaction during the friction process. The thickness of the oxide layer will be increased with the increase in temperature. However, when the temperature is higher than 600 °C, the internal stress condition of the oxide layer deteriorates. Peeling and fracture will occur, which will increase the wear rate of the coating slightly. The wear rate rises gradually from 1.09 mm<sup>3</sup>/(N·m) at 600 °C to 1.82 mm<sup>3</sup>/(N·m) at 800 °C. DFT calculations show that the binding energies of Fe-O bond in FeO (−6.83 eV) and Ni-O in NiO (−5.89 eV) are much lower than those of Fe-O and Cr-O bonds in Fe<sub>3</sub>O<sub>4</sub>, Fe<sub>2</sub>O<sub>3</sub> Cr<sub>2</sub>O<sub>3</sub> and CrO<sub>3</sub>. It indicates that the Fe-O and Ni-O bonds of the former are more prone to fracture during the wear process, which leads to the excellent lubrication properties of FeO and NiO, which can explain the excellent tribological properties of the coatings at high temperatures and help to reveal the high-temperature lubrication mechanism of austenitic stainless steels.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"238 ","pages":"Article 114302"},"PeriodicalIF":3.8,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143767664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0