Pub Date : 2025-02-24DOI: 10.1016/j.vacuum.2025.114149
H. Saadi , H. Kerrai , E.M. Jalal , M. El Bouziani
The structural stability, optical, electronic, and thermoelectric properties of NaInCu(F/Cl) double perovskites have been investigated using density functional theory (DFT) with the Tran–Blaha modified Becke–Johnson potential and spin–orbit coupling (TB-mBJ + SOC). The structural analysis confirms the stability of the cubic phase for both compounds, with lattice parameters of 8.47 Å for NaInCuF and 10.07 Å for NaInCuCl. The electronic properties reveal semiconducting behavior with a direct band gap for both materials. Optical parameters, including absorption coefficients, refractive index, and reflectivity, are calculated and analyzed. The band gaps, along with favorable optical properties such as high absorption coefficients, indicate the potential of these compounds for solar cell and optoelectronic applications. Thermoelectric properties, including electrical conductivity, thermal conductivity, and the Seebeck coefficient, are evaluated to determine their contribution to the figure of merit (ZT). The room-temperature ZT values highlight the suitability of NaInCu(F/Cl) for thermoelectric applications.
{"title":"First-principles investigation of optical and thermoelectric properties of Na2InCu(F/Cl)6 double perovskites for energy harvesting devices","authors":"H. Saadi , H. Kerrai , E.M. Jalal , M. El Bouziani","doi":"10.1016/j.vacuum.2025.114149","DOIUrl":"10.1016/j.vacuum.2025.114149","url":null,"abstract":"<div><div>The structural stability, optical, electronic, and thermoelectric properties of Na<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>InCu(F/Cl)<span><math><msub><mrow></mrow><mrow><mn>6</mn></mrow></msub></math></span> double perovskites have been investigated using density functional theory (DFT) with the Tran–Blaha modified Becke–Johnson potential and spin–orbit coupling (TB-mBJ + SOC). The structural analysis confirms the stability of the cubic phase for both compounds, with lattice parameters of 8.47 Å for Na<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>InCuF<span><math><msub><mrow></mrow><mrow><mn>6</mn></mrow></msub></math></span> and 10.07 Å for Na<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>InCuCl<span><math><msub><mrow></mrow><mrow><mn>6</mn></mrow></msub></math></span>. The electronic properties reveal semiconducting behavior with a direct band gap for both materials. Optical parameters, including absorption coefficients, refractive index, and reflectivity, are calculated and analyzed. The band gaps, along with favorable optical properties such as high absorption coefficients, indicate the potential of these compounds for solar cell and optoelectronic applications. Thermoelectric properties, including electrical conductivity, thermal conductivity, and the Seebeck coefficient, are evaluated to determine their contribution to the figure of merit (ZT). The room-temperature ZT values highlight the suitability of Na<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>InCu(F/Cl)<span><math><msub><mrow></mrow><mrow><mn>6</mn></mrow></msub></math></span> for thermoelectric applications.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"236 ","pages":"Article 114149"},"PeriodicalIF":3.8,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143488141","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}
In this paper, we analyze the possibility of measuring the electron energy distribution function (EEDF) in a discharge plasma in a wide energy range using a digital method for recording the current-voltage characteristic (IVC) of a Langmuir probe. The analysis is performed using the example of measurements in hollow cathode discharge plasma in helium. The distribution function is determined by double differentiation of the IVC using the Savitzky-Golay or Blackman smoothing filters. It is shown that the capabilities of these filters are comparable. In particular, none of them allows to correctly retrieve the EEDF in the entire energy range considered in the experiment with a fixed value of the parameters of each of the filters. A method for retrieving the EEDF with separate determination of its low-and high-energy parts and their subsequent stitching is proposed. To determine each part, specially selected filter parameter values are used. For the experimental conditions, criteria for selecting the values of filter parameters for the correct determination of the specified parts of the distribution function are proposed. The EEDF obtained in this way is compared with the theoretical one calculated for experimental conditions using the Monte Carlo technique.
{"title":"On the choice of filters and their parameters in the determination of EEDF in gas discharge plasma from the current-voltage characteristic of the Langmuir probe","authors":"A.V. Bernatskiy , I.I. Draganov , N.A. Dyatko , I.V. Kochetov , V.V. Lagunov , V.N. Ochkin","doi":"10.1016/j.vacuum.2025.114162","DOIUrl":"10.1016/j.vacuum.2025.114162","url":null,"abstract":"<div><div>In this paper, we analyze the possibility of measuring the electron energy distribution function (EEDF) in a discharge plasma in a wide energy range using a digital method for recording the current-voltage characteristic (IVC) of a Langmuir probe. The analysis is performed using the example of measurements in hollow cathode discharge plasma in helium. The distribution function is determined by double differentiation of the IVC using the Savitzky-Golay or Blackman smoothing filters. It is shown that the capabilities of these filters are comparable. In particular, none of them allows to correctly retrieve the EEDF in the entire energy range considered in the experiment with a fixed value of the parameters of each of the filters. A method for retrieving the EEDF with separate determination of its low-and high-energy parts and their subsequent stitching is proposed. To determine each part, specially selected filter parameter values are used. For the experimental conditions, criteria for selecting the values of filter parameters for the correct determination of the specified parts of the distribution function are proposed. The EEDF obtained in this way is compared with the theoretical one calculated for experimental conditions using the Monte Carlo technique.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"235 ","pages":"Article 114162"},"PeriodicalIF":3.8,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143473979","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}
The energy storage performance of transition metal oxides (TMO) as electrode materials for supercapacitors exhibit a strongly morphology-dependent due to changes in the local electronic and microscopic geometric structure of the interface. Herein, MoO3 with morphology in nanoprisms (NP), nanostrips (NS), and nanobulks (NB) were prepared by different synthesis routes. The morphology and structural characteristics of the three obtained MoO3 were characterized by scanning electron microscopy, the high resolution transmission electron microscopy, Brunauer–Emmett–Teller techniques, X-ray diffraction, and X-ray photoelectron spectroscopy. And then, the significant effects of the morphologies of MoO3 on the electrochemical activity were assessed using cyclic voltammetry and galvanostatic charge-discharge measurements. The supercapacitors using MoO3-NP as electrode achieved the largest specific capacitance of 254.0 F g−1 at a current density of 0.3 A g−1 as compared to 123.3 F g−1 of MoO3-NS, and 8.7 F g−1 of MoO3-NB in 1 mol L−1 Na2SO4 electrolyte. Among them, the MoO3-NP electrode has the highest pseudo-supercapacitive response and excellent cycling stability than the other electrodes, which is attributed to the morphology-dependent to enhance the electrical conductivity and promote the generation of active reaction sites. Therefore, the MoO3-NP electrode can be significantly applied to supercapacitors for cost reduction and energy conversion efficiency improvement.
{"title":"The morphology-dependent on the electrochemical performance of molybdenum trioxide in supercapacitors","authors":"Hui Zhao, Ziwei Chen, Yuanhao Li, Shuhui Liu, Bei Ruan, Mingxing Wu, Ping Li, Kezhong Wu","doi":"10.1016/j.vacuum.2025.114179","DOIUrl":"10.1016/j.vacuum.2025.114179","url":null,"abstract":"<div><div>The energy storage performance of transition metal oxides (TMO) as electrode materials for supercapacitors exhibit a strongly morphology-dependent due to changes in the local electronic and microscopic geometric structure of the interface. Herein, MoO<sub>3</sub> with morphology in nanoprisms (NP), nanostrips (NS), and nanobulks (NB) were prepared by different synthesis routes. The morphology and structural characteristics of the three obtained MoO<sub>3</sub> were characterized by scanning electron microscopy, the high resolution transmission electron microscopy, Brunauer–Emmett–Teller techniques, X-ray diffraction, and X-ray photoelectron spectroscopy. And then, the significant effects of the morphologies of MoO<sub>3</sub> on the electrochemical activity were assessed using cyclic voltammetry and galvanostatic charge-discharge measurements. The supercapacitors using MoO<sub>3</sub>-NP as electrode achieved the largest specific capacitance of 254.0 F g<sup>−1</sup> at a current density of 0.3 A g<sup>−1</sup> as compared to 123.3 F g<sup>−1</sup> of MoO<sub>3</sub>-NS, and 8.7 F g<sup>−1</sup> of MoO<sub>3</sub>-NB in 1 mol L<sup>−1</sup> Na<sub>2</sub>SO<sub>4</sub> electrolyte. Among them, the MoO<sub>3</sub>-NP electrode has the highest pseudo-supercapacitive response and excellent cycling stability than the other electrodes, which is attributed to the morphology-dependent to enhance the electrical conductivity and promote the generation of active reaction sites. Therefore, the MoO<sub>3</sub>-NP electrode can be significantly applied to supercapacitors for cost reduction and energy conversion efficiency improvement.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"236 ","pages":"Article 114179"},"PeriodicalIF":3.8,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143488163","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}
Pub Date : 2025-02-22DOI: 10.1016/j.vacuum.2025.114155
Ailing Ran , Ali Afshar , Shirin Mehmet , Yusuf Kemal
The relative rollers rotation during roll-bonding affects the effective strain applied to composite layers. In this paper, the differential speed accumulative roll bonding (DSARB) and conventional accumulative roll bonding (CARB) methods were incorporated to fabricate Cu/St/Cu multi-laminated composites. Based on the observation of microstructures, the evolution of microstructure of composites contained necking and rupturing of St layers. In the composite fabricated by DSARB, the St layers showed more irregularities and better distribution in Cu matrix compared to CARB. Based on the observation of grain structures, both methods resulted in ultra-fine-grained structure in layers. However, the DSARB method led to a more pronounced decrement in grain size. The lowest grain size of St and Cu were 2.9 μm and 1.4 μm, respectively, in the DSARB method. Similarly, this method could result in a higher hardness of 401 HV for St and 232 HV for Cu. Also, compared to composite processed by CARB, higher yield and ultimate strength values of 488 MPa and 798 MPa were seen in composite fabricated by DSARB, after seven passes. Furthermore, the fracture surface showed shallower and more sheared dimples in the composite fabricated by DSARB.
{"title":"Obtaining ultrafine-grained structure in copper/steel/copper multi-laminated composite by different accumulative roll bonding methods","authors":"Ailing Ran , Ali Afshar , Shirin Mehmet , Yusuf Kemal","doi":"10.1016/j.vacuum.2025.114155","DOIUrl":"10.1016/j.vacuum.2025.114155","url":null,"abstract":"<div><div>The relative rollers rotation during roll-bonding affects the effective strain applied to composite layers. In this paper, the differential speed accumulative roll bonding (DSARB) and conventional accumulative roll bonding (CARB) methods were incorporated to fabricate Cu/St/Cu multi-laminated composites. Based on the observation of microstructures, the evolution of microstructure of composites contained necking and rupturing of St layers. In the composite fabricated by DSARB, the St layers showed more irregularities and better distribution in Cu matrix compared to CARB. Based on the observation of grain structures, both methods resulted in ultra-fine-grained structure in layers. However, the DSARB method led to a more pronounced decrement in grain size. The lowest grain size of St and Cu were 2.9 μm and 1.4 μm, respectively, in the DSARB method. Similarly, this method could result in a higher hardness of 401 HV for St and 232 HV for Cu. Also, compared to composite processed by CARB, higher yield and ultimate strength values of 488 MPa and 798 MPa were seen in composite fabricated by DSARB, after seven passes. Furthermore, the fracture surface showed shallower and more sheared dimples in the composite fabricated by DSARB.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"236 ","pages":"Article 114155"},"PeriodicalIF":3.8,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143488139","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}
Pub Date : 2025-02-21DOI: 10.1016/j.vacuum.2025.114172
Jilei Zhang , Dekun Si , Zhenlu Cui , Wenzhe Zhao , Xuhao Wang , Zhijie Liang , Xuran Gong , Xiaoliang Han , Jianhong Gong , Kaikai Song , Zhijie Yan , Laichang Zhang
Gradient heterostructure design effectively balances strength and ductility, yet its precise control remains challenging. By applying electron beam surface melting (EBSM) to a cold-rolled CoCrNi multicomponent alloy, three distinct microstructural zones, i.e., coarse columnar grains, fine equiaxed grains, and deformed structures, are artificially regulated. The hardness varies continuously from the surface to the center, and the EBSM-treated sample achieves an optimal balance between strength and ductility under controlled conditions. The underlying strengthening mechanisms can be attributed to the rule of mixtures and hetero-deformation-induced (HDI) strengthening. This work provides valuable insights into the artificial regulation of gradient heterostructures for high-performance alloys.
{"title":"Artificial regulation of gradient heterostructures in CoCrNi multicomponent alloys via electron beam surface melting","authors":"Jilei Zhang , Dekun Si , Zhenlu Cui , Wenzhe Zhao , Xuhao Wang , Zhijie Liang , Xuran Gong , Xiaoliang Han , Jianhong Gong , Kaikai Song , Zhijie Yan , Laichang Zhang","doi":"10.1016/j.vacuum.2025.114172","DOIUrl":"10.1016/j.vacuum.2025.114172","url":null,"abstract":"<div><div>Gradient heterostructure design effectively balances strength and ductility, yet its precise control remains challenging. By applying electron beam surface melting (EBSM) to a cold-rolled CoCrNi multicomponent alloy, three distinct microstructural zones, i.e., coarse columnar grains, fine equiaxed grains, and deformed structures, are artificially regulated. The hardness varies continuously from the surface to the center, and the EBSM-treated sample achieves an optimal balance between strength and ductility under controlled conditions. The underlying strengthening mechanisms can be attributed to the rule of mixtures and hetero-deformation-induced (HDI) strengthening. This work provides valuable insights into the artificial regulation of gradient heterostructures for high-performance alloys.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"236 ","pages":"Article 114172"},"PeriodicalIF":3.8,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143488137","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}
Pub Date : 2025-02-21DOI: 10.1016/j.vacuum.2025.114173
Yongqi Wang, Zhihao Bai, Pengyu Wang, Wanting Du, Rui Huang, Zhengwei Tang, Jiangnan Xia, Dongshuai Zhou, Jian Wang
The influence of anisotropy on dissimilar aluminum alloy FSW joints were studied by changing the welding direction and advancing side materials. The results show the significant differences in both mechanical properties and microstructure of the welded joints. The 0°7AS joint has the highest tensile strength (414 MPa), reaching 87 % of the 2A12 aluminum alloys strength. The 0°7AS joint has the smallest average grain size in the weld nugget, and the best recovery and recrystallization ability. In the HAZ, the strongest texture types of the 0°7AS and 45°7AS joints are different. The 0°7AS joint has the highest texture strength, with a prominent {011} <211> brass texture. This paper provides the guidance for aluminum alloys welding.
{"title":"Study of anisotropy impact of 2A12 and 7075 dissimilar aluminum alloys FSW joints","authors":"Yongqi Wang, Zhihao Bai, Pengyu Wang, Wanting Du, Rui Huang, Zhengwei Tang, Jiangnan Xia, Dongshuai Zhou, Jian Wang","doi":"10.1016/j.vacuum.2025.114173","DOIUrl":"10.1016/j.vacuum.2025.114173","url":null,"abstract":"<div><div>The influence of anisotropy on dissimilar aluminum alloy FSW joints were studied by changing the welding direction and advancing side materials. The results show the significant differences in both mechanical properties and microstructure of the welded joints. The 0°7AS joint has the highest tensile strength (414 MPa), reaching 87 % of the 2A12 aluminum alloys strength. The 0°7AS joint has the smallest average grain size in the weld nugget, and the best recovery and recrystallization ability. In the HAZ, the strongest texture types of the 0°7AS and 45°7AS joints are different. The 0°7AS joint has the highest texture strength, with a prominent {011} <211> brass texture. This paper provides the guidance for aluminum alloys welding.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"236 ","pages":"Article 114173"},"PeriodicalIF":3.8,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143488138","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}
Pub Date : 2025-02-21DOI: 10.1016/j.vacuum.2025.114136
Zhenggang Li , Xiaoxue Tan , M.A. Yarmolenko , Keneshbekova A , Ao Wang , Xin Liu , Xiaohong Jiang
In this study, an EC-based dual drug-carrying composite film with ethyl cellulose (EC): silver nitrate = 1: 1 as the upper layer and EC: fluconazole (FCZ) = 1: 1 as the lower layer was prepared using the low-energy electron beam dispersion (EBD) technique. The film molecular structure, chemical composition and morphology were studied by FT-IR, XPS, and SEM methods. The results showed that the EC powder and FCZ powder used had excellent film-forming ability and the prepared films retained the majority of the molecular structure of the original powder. The films exhibited no obvious defects on the surface and their thickness reached the micrometer scale. The contact angle test confirmed good hydrophilicity of the films. With immersion in phosphate buffered saline (PBS), the porous structure formed on the surface of the films facilitated drug release. The kinetic properties of FCZ release from the composite layer into the aqueous environment were investigated, and a long-lasting release of FCZ in the composite layer for about 9 days was tailed. The performance of the films was characterized and the results showed that the EC-based dual drug-carrying composite film exhibited optimal inhibition of Candida albicans.
{"title":"Deposition of ethyl cellulose-based drug-carrying coating by low-energy electron beam dispersion and its antifungal properties","authors":"Zhenggang Li , Xiaoxue Tan , M.A. Yarmolenko , Keneshbekova A , Ao Wang , Xin Liu , Xiaohong Jiang","doi":"10.1016/j.vacuum.2025.114136","DOIUrl":"10.1016/j.vacuum.2025.114136","url":null,"abstract":"<div><div>In this study, an EC-based dual drug-carrying composite film with ethyl cellulose (EC): silver nitrate = 1: 1 as the upper layer and EC: fluconazole (FCZ) = 1: 1 as the lower layer was prepared using the low-energy electron beam dispersion (EBD) technique. The film molecular structure, chemical composition and morphology were studied by FT-IR, XPS, and SEM methods. The results showed that the EC powder and FCZ powder used had excellent film-forming ability and the prepared films retained the majority of the molecular structure of the original powder. The films exhibited no obvious defects on the surface and their thickness reached the micrometer scale. The contact angle test confirmed good hydrophilicity of the films. With immersion in phosphate buffered saline (PBS), the porous structure formed on the surface of the films facilitated drug release. The kinetic properties of FCZ release from the composite layer into the aqueous environment were investigated, and a long-lasting release of FCZ in the composite layer for about 9 days was tailed. The performance of the films was characterized and the results showed that the EC-based dual drug-carrying composite film exhibited optimal inhibition of <em>Candida albicans</em>.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"236 ","pages":"Article 114136"},"PeriodicalIF":3.8,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143488125","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}
Pub Date : 2025-02-20DOI: 10.1016/j.vacuum.2025.114161
Li Zuo , Qi Gao , Yi-Cun Xu , Zuo-Ming Xie , Lin-Chao Zhang , Rui Liu , Li-Long Pang , Zhi-Guang Wang , Gai-Ling Lu , Jun-Feng Yang
In this work, FeCrAlTiSi high-entropy alloy coatings (HEACs) were prepared using magnetron sputtering (MS) under various substrate biases with a Ti interlayer pre-deposited through multiarc ion plating (M-AIP) to enhance the coating/substrate adhesion strength. The morphology, microstructure, elemental and phase composition, nanohardness, Young's modulus, adhesion strength and corrosion resistance were characterized using SEM, XRD, TEM, XPS, nanoindenter, scratch tester and electrochemical workstation. Results indicated that all FeCrAlTiSi coatings were in an amorphous state. Nanohardness and Young's modulus had a strong substrate bias dependence, reaching the maximum of 16.04 GPa and 241.3 GPa, respectively, at −100 V bias. Meanwhile, FeCrAlSiTi coatings at −100 V exhibited superior corrosion resistance to that of 316L in 3.5 wt% NaCl aqueous solution, about 60 times improvement in terms of corrosion current density owing to the combined effect of homogeneous composition distribution, amorphous structure, and chemically stable oxide film predominantly composed of Al2O3, TiO2 and SiO2.
{"title":"Preparation, microstructure and properties of FeCrAlTiSi high entropy alloy coatings using the combined technique of magnetron sputtering with multiarc ion plating","authors":"Li Zuo , Qi Gao , Yi-Cun Xu , Zuo-Ming Xie , Lin-Chao Zhang , Rui Liu , Li-Long Pang , Zhi-Guang Wang , Gai-Ling Lu , Jun-Feng Yang","doi":"10.1016/j.vacuum.2025.114161","DOIUrl":"10.1016/j.vacuum.2025.114161","url":null,"abstract":"<div><div>In this work, FeCrAlTiSi high-entropy alloy coatings (HEACs) were prepared using magnetron sputtering (MS) under various substrate biases with a Ti interlayer pre-deposited through multiarc ion plating (M-AIP) to enhance the coating/substrate adhesion strength. The morphology, microstructure, elemental and phase composition, nanohardness, Young's modulus, adhesion strength and corrosion resistance were characterized using SEM, XRD, TEM, XPS, nanoindenter, scratch tester and electrochemical workstation. Results indicated that all FeCrAlTiSi coatings were in an amorphous state. Nanohardness and Young's modulus had a strong substrate bias dependence, reaching the maximum of 16.04 GPa and 241.3 GPa, respectively, at −100 V bias. Meanwhile, FeCrAlSiTi coatings at −100 V exhibited superior corrosion resistance to that of 316L in 3.5 wt% NaCl aqueous solution, about 60 times improvement in terms of corrosion current density owing to the combined effect of homogeneous composition distribution, amorphous structure, and chemically stable oxide film predominantly composed of Al<sub>2</sub>O<sub>3</sub>, TiO<sub>2</sub> and SiO<sub>2</sub>.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"236 ","pages":"Article 114161"},"PeriodicalIF":3.8,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143488142","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}
Pub Date : 2025-02-20DOI: 10.1016/j.vacuum.2025.114137
Xiujie Yue , Ping Zhang , Yajie Sun , Xiaomin Jiang , Youqiang Wang
This study aims to explore the influence of the divergence angle of a nozzle on the flow field structure of a water jet. Based on the traditional conical nozzle structure, two types of nozzles were designed: angular nozzles with divergence angles ranging from 0° to 30° and abrupt expansion nozzles with divergence angles ranging from 60° to 180°. A numerical model was established to analyze the relationship between the nozzle divergence angle and the nozzle exit velocity. The model was validated using Fluent simulations, and the impact of the nozzle divergence angle on the water jet flow field structure was investigated.The research findings indicate that the numerical model provides a good fit to the nozzle exit jet velocity with a maximum error of only 14.1 % when compared to the simulation model. This suggests that the model has practical implications for predicting the exit jet velocity of conical nozzles, allowing for rapid assessment of jet velocities under different nozzle exit divergence angles. Furthermore, as the divergence angle increases, the nozzle exit jet velocity exhibits a trend of initially decreasing, then increasing, and finally decreasing again. When the nozzle divergence angle is 60°, the exit jet velocity is the lowest, measuring 171 m/s, while an increase in the divergence angle to 90° results in a 7 % velocity increase. At a 60° divergence angle, the axial velocity decreases most rapidly, leading to jet deflection.Under the same operating conditions, a 90° divergence angle nozzle yields the highest exit dynamic pressure at 11.646 MPa, an increase of 19 % compared to the 60° divergence angle nozzle. Additionally, at the water jet exit, dynamic pressure exceeding 2 MPa is considered effective impact pressure. At a 60° divergence angle, the effective impact diameter is approximately six times larger than that at 30°, with a 2–3 mm greater effective impact diameter compared to other divergence angles, making it more suitable for surface strengthening operations on metals.Finally, different divergence angle nozzle exit velocities, obtained through fitting, were used to validate the residual stress in 7075 aluminum alloy after water jet impact using ABAQUS simulations and experiments. After water jet impact, 7075 aluminum alloy exhibits primarily residual compressive stress, and the distribution of residual stress resembles a “spoon.” When comparing experimental and simulation values, residual stress changes along the depth direction are generally consistent, with errors ranging from 3.7 % to 39.6 %.
{"title":"Study on cavitation flow field of cavitation nozzle and strengthening mechanism of cavitation jet of 7075 aluminum alloy","authors":"Xiujie Yue , Ping Zhang , Yajie Sun , Xiaomin Jiang , Youqiang Wang","doi":"10.1016/j.vacuum.2025.114137","DOIUrl":"10.1016/j.vacuum.2025.114137","url":null,"abstract":"<div><div>This study aims to explore the influence of the divergence angle of a nozzle on the flow field structure of a water jet. Based on the traditional conical nozzle structure, two types of nozzles were designed: angular nozzles with divergence angles ranging from 0° to 30° and abrupt expansion nozzles with divergence angles ranging from 60° to 180°. A numerical model was established to analyze the relationship between the nozzle divergence angle and the nozzle exit velocity. The model was validated using Fluent simulations, and the impact of the nozzle divergence angle on the water jet flow field structure was investigated.The research findings indicate that the numerical model provides a good fit to the nozzle exit jet velocity with a maximum error of only 14.1 % when compared to the simulation model. This suggests that the model has practical implications for predicting the exit jet velocity of conical nozzles, allowing for rapid assessment of jet velocities under different nozzle exit divergence angles. Furthermore, as the divergence angle increases, the nozzle exit jet velocity exhibits a trend of initially decreasing, then increasing, and finally decreasing again. When the nozzle divergence angle is 60°, the exit jet velocity is the lowest, measuring 171 m/s, while an increase in the divergence angle to 90° results in a 7 % velocity increase. At a 60° divergence angle, the axial velocity decreases most rapidly, leading to jet deflection.Under the same operating conditions, a 90° divergence angle nozzle yields the highest exit dynamic pressure at 11.646 MPa, an increase of 19 % compared to the 60° divergence angle nozzle. Additionally, at the water jet exit, dynamic pressure exceeding 2 MPa is considered effective impact pressure. At a 60° divergence angle, the effective impact diameter is approximately six times larger than that at 30°, with a 2–3 mm greater effective impact diameter compared to other divergence angles, making it more suitable for surface strengthening operations on metals.Finally, different divergence angle nozzle exit velocities, obtained through fitting, were used to validate the residual stress in 7075 aluminum alloy after water jet impact using ABAQUS simulations and experiments. After water jet impact, 7075 aluminum alloy exhibits primarily residual compressive stress, and the distribution of residual stress resembles a “spoon.” When comparing experimental and simulation values, residual stress changes along the depth direction are generally consistent, with errors ranging from 3.7 % to 39.6 %.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"236 ","pages":"Article 114137"},"PeriodicalIF":3.8,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143488140","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}
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