Vacuum最新文献

{"title":"Measurements of PSD and photoelectrons on NEG coated vacuum chambers exposed to synchrotron radiation at the Taiwan Light Source beamline","authors":"Gao-Yu Hsiung ,&nbsp;Chin Shueh ,&nbsp;Chia-Mu Cheng ,&nbsp;Che-Kai Chan ,&nbsp;Reza Valizadeh","doi":"10.1016/j.vacuum.2025.114112","DOIUrl":"10.1016/j.vacuum.2025.114112","url":null,"abstract":"<div><div>A 1.5 GeV Taiwan Light Source (TLS) BL19B beamline was built to measure the photon stimulated desorption (PSD)-yield (η_PSD) and the associated photoelectron yield (PEY, η_e). Three stainless steel vacuum tubes 0.5 m in length were installed in the beamline for synchrotron radiation exposure. They were coated with non-evaporable getter (NEG) films with different structures, including conductive NEG (TiZrVAg) to reduce RF surface resistance, dual NEG (dense-TiZrV/columnar-TiZrV) for higher pumping performance, and triple-layer NEG (TiZrVN/dense-TiZrV/columnar-TiZrV) in which the nitride-layer (TiZrVN) acted as a hydrogen barrier in the chamber. Both η_PSD and η_e were measured simultaneously under two conditions, namely, “non-activated NEG”, baking only the tube at 80 °C without NEG-activation and “activated NEG” where the NEG was activated after at 180 °C. The intrinsic η_PSD comprises two parts, the η_c is measured via the throughput or conductance method for non-activated NEG, hydrocarbons, and noble gases with a sticking probability of α = 0; and the η_α for the activated NEG which absorbs the gases with α &gt; 0. The results of PSD reveal a much lower intrinsic η_PSD for activated NEG than that of the non-activated NEG by a factor of 10–100 for most of the gases including H₂, CO, CO₂, CH₄, H₂O, and C₂H₆. The PEY (η_e) measurements for the NEG-tube showed higher values (&gt;0.033 electrons/photon) for the non-activated NEG and lower values (&lt;0.022 electrons/photon) for the activated NEG. Comparison showed that the triple-layer NEG tube possessed both the lowest η_PSD and η_e of all the NEG tubes. The η_e was also lower after activation of the conductive NEG tube. The simultaneous measurements of both η_PSD and η_e for the NEG-coated tubes at the beamline in this experiment are reproducible and practically convincing.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"234 ","pages":"Article 114112"},"PeriodicalIF":3.8,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143369861","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}

{"title":"Controllable preparation of flaky CoxNiy for designing and fabricating a multilayer absorber with broadwidth microwave absorption at thin thickness","authors":"Peng Wang","doi":"10.1016/j.vacuum.2025.114108","DOIUrl":"10.1016/j.vacuum.2025.114108","url":null,"abstract":"<div><div>Magnetic materials, as the microwave absorber, have huge advantages due to high microwave permeability and large microwave magnetic loss. To achieve a broadband microwave absorption, magnetic Co_xNi_y alloy particles were prepared in this paper by a simple co-precipitation method of H₂C₂O₄ and a quick thermal decomposition process in vacuum, then deformed into micro-flakes by planetary ball milling method. Based on the Co_xNi_y alloy particles before and after ball milling, a three-layer absorber was designed and fabricated, with an effective absorption band of 5.4–18 GHz at a total thickness of 3.3 mm. It is found that the Co_xNi_y alloy particles show high coercive force and large microwave magnetic loss after ball milling, capable of greatly attenuating electro-magnetic (EM) waves, as a wave absorbing layer of the three-layer absorber. However, they are soft magnetic with relatively low coercive force and high microwave permeability before ball milling, allowing the incident EM waves to enter the absorbing layer when employed as an impedance matching layer. Through this study, the strategy combining the magnetic alloys before and after ball milling as well as the multilayer structure design, is feasible to achieve a broadband microwave absorption at a thin thickness, providing a simple and effective method for the broadband microwave absorption research and application.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"234 ","pages":"Article 114108"},"PeriodicalIF":3.8,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143369863","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}

{"title":"Investigation of the interface deformation behavior of SiCp/Al composites via TEM in-situ tensile test","authors":"Pengru Liu ,&nbsp;Shiming Hao ,&nbsp;Haozhan Wu ,&nbsp;Sitong Cai ,&nbsp;Aiqiong Pan ,&nbsp;Jingpei Xie","doi":"10.1016/j.vacuum.2025.114106","DOIUrl":"10.1016/j.vacuum.2025.114106","url":null,"abstract":"<div><div>As a “bridge” between the matrix and reinforcement, the interface plays a crucial role in the deformation behavior of SiCp/Al composites. It is of great significance to investigate the dynamic changes of dislocations and microcracks in the deformation process of the composite interface microzone. In situ tensile specimens with special interfaces containing different thicknesses of MgAl₂O₄ reaction layers were selected. In situ tensile tests were performed using field emission transmission electron microscopy. The effect of the interface layer thickness on the tensile deformation of the composites was revealed based on the crack initiation to propagation fracture. The results showed that the cracks first emerged at the SiC/Al interface, and then extend along the MgAl₂O₄/Al interface to the interface region of the MgAl₂O₄ reaction layer with a thickness of about 40 nm, eventually fracture occurs at the interface region with 70 nm thick MgAl₂O₄ reaction layer. Suitable thickness of MgAl₂O₄ reaction layer can effectively delay the crack propagation and improve the interface bonding strength between SiC and Al. The regulation of the thickness of the MgAl₂O₄ reaction layer is crucial for the mechanical properties of SiCp/Al composites.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"234 ","pages":"Article 114106"},"PeriodicalIF":3.8,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143349788","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}

{"title":"Corrosion and fretting wear behavior of Cr-based composite coatings on zirconium alloy","authors":"Jian-guo Yu ,&nbsp;Zheng-yang Li ,&nbsp;Quan-yao Ren ,&nbsp;Yong-jun Jiao ,&nbsp;Zhen-bing Cai","doi":"10.1016/j.vacuum.2025.114104","DOIUrl":"10.1016/j.vacuum.2025.114104","url":null,"abstract":"<div><div>The accident tolerant fuel (ATF) was developed to improve nuclear safety and economic benefits of nuclear power after the Fukushima nuclear accident. The coatings prepared on zirconium (Zr) alloy fuel cladding is one of the primary research directions for ATF. In this research, Cr, CrN, Cr/CrN/CrAlN (Multi-1), and Cr/CrN/CrAlN/CrAlSiN (Multi-2) coatings were prepared on Zr alloy using magnetron sputtering technology. The characteristics, corrosion, and fretting wear behavior of different coatings were investigated. The results show that different coatings can improve the corrosion resistance of Zr alloy, and Cr coating has the best corrosion resistance in high-temperature pressurized steam condition because a very thin Cr₂O₃ layer is formed on the surface after corrosion, effectively preventing the penetration of oxygen ions. Zr alloy exhibits the significant wear damage, primarily including adhesive wear, abrasive wear, and oxidative wear. The CrN coating presents the best wear resistance compared with other coatings. The wear depth, wear area, and wear rate of CrN coating are 1/4, 1/3, and 1/8 of Zr alloy, respectively. The wear mechanisms of different coatings predominantly involve abrasive wear and oxidative wear. Based on the above results, CrN coating has both the best wear resistance and good corrosion resistance.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"234 ","pages":"Article 114104"},"PeriodicalIF":3.8,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143387769","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}

{"title":"Wear properties, corrosion behaviors, and TEM structures of CrSiN/CrSi multilayer coatings on oxynitriding-treated Unimax tool steel using the direct current magnetron sputtering system","authors":"Kuo-Tsung Huang ,&nbsp;Shih-Hsien Chang ,&nbsp;Min-Zhe Wu ,&nbsp;Hao-Yu Wu ,&nbsp;Hsin-Chih Lin","doi":"10.1016/j.vacuum.2025.114109","DOIUrl":"10.1016/j.vacuum.2025.114109","url":null,"abstract":"<div><div>This study employed the direct current magnetron sputtering process of physical vapor deposition to deposit CrSiN and CrSiN/CrSi multilayer coatings onto Unimax tool steel post oxynitriding treatment. Experimental parameters included various deposition times (1.5, 2, 2.5, and 3 h), a gas flow rate of 45/30 (Ar/N₂) sccm, a power of 100 W, a voltage of 400 V, a substrate bias of −50 V, and a deposition temperature of 250 °C. The results indicate that when deposited for 2.5 h, the CrSiN coatings exhibited a distinct columnar crystal structure and possessed the highest hardness (14.0 GPa) and elastic modulus (241 GPa). When the deposition times were 10 min for CrSi and 2 h and 20 min for CrSiN, the CrSiN/CrSi multilayer coatings demonstrated the best wear resistance (with a wear loss volume of 1.5 × 10⁻⁴ mm³ and a specific wear rate of 5.2 × 10⁻⁸ mm³·m⁻¹ N⁻¹ under a 5 N load) and strong corrosion resistance (with a corrosion current of 5.2 × 10⁻⁶ A·cm⁻² and polarization resistance of 783 Ω cm² in a 3 wt% NaCl solution). Transmission electron microscopy observations reveal that the CrSiN/CrSi multilayer coatings exhibited a stable CrN crystal structure alongside Si₃N₄ amorphous structures.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"234 ","pages":"Article 114109"},"PeriodicalIF":3.8,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143377376","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}

{"title":"Non-enzymatic photoelectrochemical sensors based on rGO/TiO2/Cu-MOFs nanostructures for simultaneous detection of glucose and lactic acid","authors":"Bairui Tao ,&nbsp;Huihui Guo ,&nbsp;XiaoQin Li ,&nbsp;Fengjuan Miao,&nbsp;Hui Li","doi":"10.1016/j.vacuum.2025.114105","DOIUrl":"10.1016/j.vacuum.2025.114105","url":null,"abstract":"<div><div>This study reports the preparation of a high-performance rGO/TiO₂/Cu-MOFs sensitive electrode through a two-step hydrothermal method. This electrode exhibits low detection limits, high sensitivity, and a straightforward fabrication process. The nanomaterials are uniformly grown on a 1 × 1 cm² nickel foam substrate, with rGO first coated and then followed by the growth of rod-shaped TiO₂ and Cu-MOFs metal particles, forming a three-dimensional spatial structure. The micromorphology, chemical composition, and state of the electrode were characterized using TEM, SEM, and other techniques. Its electrochemical performance was tested using an electrochemical workstation. Experimental results indicate that the copper ions in this electrode, due to their different valence states, can achieve highly sensitive detection of glucose and lactic acid, with sensitivities reaching as high as 1195.13 μA mM⁻¹ cm⁻² and 1157.77 μA mM⁻¹ cm⁻², respectively. Additionally, it possesses excellent anti-interference ability, stability, and reproducibility, making it a promising dual-function photoelectrochemical sensor.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"234 ","pages":"Article 114105"},"PeriodicalIF":3.8,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143265943","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}

{"title":"Regulation in mechanical properties and structural morphology of M2B-type borides in Fe-B-C alloy","authors":"Jin Fengshuo ,&nbsp;Xie Tianjin ,&nbsp;Gao Guihong ,&nbsp;Qin Jiaqing ,&nbsp;Han Juan ,&nbsp;Lei Naiyi ,&nbsp;Du Wei ,&nbsp;Pan hongbo ,&nbsp;Xiao peng ,&nbsp;Yi Yanliang","doi":"10.1016/j.vacuum.2025.114086","DOIUrl":"10.1016/j.vacuum.2025.114086","url":null,"abstract":"<div><div>Fe₂B in Fe-B-C alloy has the characteristics of inherent brittleness and continuous and coarse morphology. When stress is concentrated, cracks will be easily formed, resulting in failure of the alloy, which limits its application and development. In this paper, theoretical calculations and experiments are combined, Fe₂B is toughened by atomic doping firstly, then the morphology of Fe₂B is regulated by heterogeneous nucleation, and finally the service performance of the alloy is greatly improved. The results of first principle calculation show that compared to Mn, Co and Ni elements, Cr element exhibits the best toughening effect, which is because the addition of Cr weakens the directional covalent bonding of Fe₂B. Compared to the lattice mismatch between TiN, TiC, α-MnS and M₂B, the lattice mismatch between α-MnS and (110)M₂B is low and less than 6 %, and the interface energy of α-MnS(100)//M₂B(002) is greater than 0, indicating that α-MnS is an effective heterogeneous core of M₂B. After adding K₂SO₄ to Fe-B-C alloy, α-MnS is formed in the alloy. During the solidification process, M₂B grows around the effective heterocore α-MnS, forming isolated blocks in the alloy, and the shape factor of M₂B increases from 0.067 to 0.353. Meanwhile, the impact toughness of Fe-B-C alloy increases from 5.9 J cm⁻² to 14.2 J cm⁻², demonstrating the improving mechanical property of Fe-B-C alloy.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"234 ","pages":"Article 114086"},"PeriodicalIF":3.8,"publicationDate":"2025-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143377375","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}

{"title":"High-strength nanostructured copper alloys via mechanical consolidation of pure copper and Fe-Si-B glassy powers","authors":"Hongbo Zhou ,&nbsp;Haihong Jiang ,&nbsp;Li Yu ,&nbsp;Gan Ding ,&nbsp;Songlin Cai ,&nbsp;Depeng Shen ,&nbsp;Minqiang Jiang ,&nbsp;Gerhard Wilde","doi":"10.1016/j.vacuum.2025.114101","DOIUrl":"10.1016/j.vacuum.2025.114101","url":null,"abstract":"<div><div>High-strength nanostructured copper alloys were fabricated through the mechanical consolidation of pure copper and Fe-Si-B glassy powders using a two-step high-pressure torsion (HPT) process. Structural characterization by transmission electron microscopy and electron backscatter diffraction revealed that, after overall 20 HPT revolutions, 1 wt% Fe₇₈Si₉B₁₃ glassy powders can be fully decomposed and homogeneously supersaturated into the copper matrix. The resulting Cu-1 wt.% FeSiB alloy exhibited a compositionally uniform nanostructure with an average grain size of 63.3 nm and a high proportion of low-angle grain boundaries (54.2 %), achieving an ultimate tensile strength of 1246 MPa. In contrast, the addition of 5 wt% Fe₇₈Si₉B₁₃ glassy powder under the identical HPT conditions resulted in a crystal-glass composite structure with an ultimate tensile strength of 895.8 MPa. This work advances a hybrid method that integrates bottom-up particle bonding with top-down grain refinement to fabricate high-performance alloys.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"234 ","pages":"Article 114101"},"PeriodicalIF":3.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143206202","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}

{"title":"Editorial Board and Vacuum units","authors":"","doi":"10.1016/S0042-207X(24)00966-7","DOIUrl":"10.1016/S0042-207X(24)00966-7","url":null,"abstract":"","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"232 ","pages":"Article 113920"},"PeriodicalIF":3.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143182754","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}

{"title":"Design and characteristic analysis of micro-cathode arc thruster using liquid metal as working medium","authors":"Tiance Liang ,&nbsp;Tianyuan Ji ,&nbsp;Haochen Ma ,&nbsp;Lu Wang ,&nbsp;Liqiu Wei","doi":"10.1016/j.vacuum.2025.114083","DOIUrl":"10.1016/j.vacuum.2025.114083","url":null,"abstract":"<div><div>The limitation associated with the application of titanium micro-cathode arc thruster (Ti-μCAT) is that the cathode working medium carried in a single space mission is insufficient. To address this issue, a μCAT using liquid metal as the working medium (LM-μCAT) was designed. The discharge characteristics and performance parameters of the LM-μCAT and Ti-μCAT were examined. The experimental results show that the LM-μCAT has higher elementary impulse, lower ion velocity, higher plasma ionization degree, and lower power consumption. Theoretical analysis indicates that the differences are caused by the surface structure and physical property parameters of the two working media. The reason for the change of elementary impulse and ion velocity is the larger average atomic mass of liquid metal. The discrepancies in plasma ionization degree and power consumption are caused by the difference between the energy proportion of metal into metal vapour and ionized metal vapour to form plasma. The change in the energy proportion is caused by the physical characteristics of the cathode and the roughness of its surface.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"234 ","pages":"Article 114083"},"PeriodicalIF":3.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143265944","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}