Ceramic coatings are fabricated on pure aluminium by plasma electrolytic oxidation （PEO） in three kinds of electrolyte systems [E1： 0.05M NaOH＋0.033M Na2SiO3, E2： 0.025M NaOH＋0.008M （NAPO3）6 and E3： 0.025M N...Ceramic coatings are fabricated on pure aluminium by plasma electrolytic oxidation （PEO） in three kinds of electrolyte systems [E1： 0.05M NaOH＋0.033M Na2SiO3, E2： 0.025M NaOH＋0.008M （NAPO3）6 and E3： 0.025M NaOH＋0.066M Na2SiO3＋0.008M （NAPO3）6]. The voltage-time responses show that the PEO process of E2 has the highest discharging voltage, which results in the biggest pores and heaviest cracks on the surfaces. X-ray diffraction results show that coatings produced in E1 and E3 are mainly composed of γ-Al2O3 and mullite, while coatings produced in E2 are mainly composed of a-Al2O3. After PEO treatment the corrosion resistance of aluminium is improved significantly and the coatings produced in E3 perform the best corrosion resistance.展开更多
Zirconium oxide （Zr02） thin films are deposited at room temperature by cathodic arc at substrate biases of 0 V, -60 V and -120 V, respectively. The crystal structure, composition, morphology, and deposition rate of ...Zirconium oxide （Zr02） thin films are deposited at room temperature by cathodic arc at substrate biases of 0 V, -60 V and -120 V, respectively. The crystal structure, composition, morphology, and deposition rate of the as-deposited thin films are systematically investigated by x-ray diffraction, x-ray photoelectron spectroscopy （XPS） as well as scanning electron microscopy. The results show that the crystal structure, morphology and deposition rate of the films all are dependant on substrate bias. With the increase of bias voltage from 0 V to -120 V, the zirconium oxide thin film grown on silicon wafer first exhibits monoclinic lattice and tetragonal lattice, further evolves monoclinic phase with the preferred orientation along the （-111） and （-222） directions at -60 V and finally along nearly one observed preferred （002） direction under -120 V. In addition, the variations of morphology with bias voltage are correlated to changes of the film structure. The results of XPS demonstrate that Zr elements are almost oxidized completely in the films achieved under -120 V bias.展开更多
An experimental Paschen test setup has been established to analyze the quality of ITER current lead （CL） insulation and extend the research on Paschen＇s law under various conditions. Insulation problems can destroy...An experimental Paschen test setup has been established to analyze the quality of ITER current lead （CL） insulation and extend the research on Paschen＇s law under various conditions. Insulation problems can destroy a machine if a Paschen discharge is triggered by an insulation defect that is caused by faulty manufacturing, electromagnetic force, and thermal stress load with a certain degree of vacuum helium or pipe leakage. The results show that the CL insulation mock-up worked well under normal temperature and pressure. Besides, the mock-up also worked well in helium conditions and at 80 K temperature at different pressures. One area of CL insulation was severely destroyed when the 80 K test was conducted after 5 thermal cycles, resulting in Paschen discharge phenomenon. The breakdown voltage is maintained at a relatively low level under different pressure conditions; the change of breakdown voltage was mainly due to the change of pressure, and such change was in line with the Paschen law.展开更多
Tantalum nitride （TAN） thin films are achieved on Si（111） and SS317L substrates by cathodic vacuum arc technique, which is rarely reported in the literature. The crystal structure, composition and surface morpholo...Tantalum nitride （TAN） thin films are achieved on Si（111） and SS317L substrates by cathodic vacuum arc technique, which is rarely reported in the literature. The crystal structure, composition and surface morphology of the films are characterized by x-ray diffraction （XRD）, x-ray photoelectron spectroscopy （XPS）, auger electron spectroscopy, and atomic force microscopy, respectively. The influence of substrate negative bias on crystal structure, composition, surface morphology of the TaN films is systematically studied. At the substrate bias of 0 V and -50 V, the amorphous TaN film is obtained. As the bias increases to -100 V, cubic TaN phase can be found. Stoichiometric TaN with hexagonal lattice preferred （300） orientation is prepared at a bias of -200 V. Combine the XRD and XPS results, the binding energy value of 23.6eV of Ta 4f（7/2） is contributed to hexagonal TaN. Compared to other techniques, TaN thin films fabricated by cathodic vacuum arc at various substrate biases show different microstructures.展开更多
This paper presents the evolution of the design of cold mass support for the ITER magnet feeder system. The glass fibers in the cylinder and the flanges of the normal G10 support are discontinuous in the preliminary d...This paper presents the evolution of the design of cold mass support for the ITER magnet feeder system. The glass fibers in the cylinder and the flanges of the normal G10 support are discontinuous in the preliminary design. The heat load of this support from the analysis is only 4.86 W. However, the mechanical test of the prototype showed that it can only endure 9 kN lateral force, which is significantly less than the required 20 kN. So, the configuration of the glass fibers in the cylinders and flanges of this G10 support are modified by changing it to a continuous and knitted type to reinforce the support, and then a new improved prototype is manufactured and tested. It could endure 15＇kN lateral forces this time, but still not meet the required 20 kN. Finally, the SS316LN material is chosen for the cold mass supports. The analysis results show that it is safe under 20 kN lateral forces with the heat load increased to 14.8 W. Considering the practical application, the requirements of strength is of primary importance. So, this SS316LN cold mass support is acceptable for the ITER magnet feeder system. On the other hand, the design idea of using continuous and knitted glass fibers to reinforce the strength of a G10 support is a good reference for the case with a lower heat load and not too high Lorentz force.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No 10675165.
文摘Ceramic coatings are fabricated on pure aluminium by plasma electrolytic oxidation （PEO） in three kinds of electrolyte systems [E1： 0.05M NaOH＋0.033M Na2SiO3, E2： 0.025M NaOH＋0.008M （NAPO3）6 and E3： 0.025M NaOH＋0.066M Na2SiO3＋0.008M （NAPO3）6]. The voltage-time responses show that the PEO process of E2 has the highest discharging voltage, which results in the biggest pores and heaviest cracks on the surfaces. X-ray diffraction results show that coatings produced in E1 and E3 are mainly composed of γ-Al2O3 and mullite, while coatings produced in E2 are mainly composed of a-Al2O3. After PEO treatment the corrosion resistance of aluminium is improved significantly and the coatings produced in E3 perform the best corrosion resistance.
文摘Zirconium oxide （Zr02） thin films are deposited at room temperature by cathodic arc at substrate biases of 0 V, -60 V and -120 V, respectively. The crystal structure, composition, morphology, and deposition rate of the as-deposited thin films are systematically investigated by x-ray diffraction, x-ray photoelectron spectroscopy （XPS） as well as scanning electron microscopy. The results show that the crystal structure, morphology and deposition rate of the films all are dependant on substrate bias. With the increase of bias voltage from 0 V to -120 V, the zirconium oxide thin film grown on silicon wafer first exhibits monoclinic lattice and tetragonal lattice, further evolves monoclinic phase with the preferred orientation along the （-111） and （-222） directions at -60 V and finally along nearly one observed preferred （002） direction under -120 V. In addition, the variations of morphology with bias voltage are correlated to changes of the film structure. The results of XPS demonstrate that Zr elements are almost oxidized completely in the films achieved under -120 V bias.
基金supported by ITER IO, the National "973" Program of China (No. 2007ID2006)the National ITER Special Support for R&D on Science and Technology for ITER, CN Schedule Task (No. 2008GB102000)
文摘An experimental Paschen test setup has been established to analyze the quality of ITER current lead （CL） insulation and extend the research on Paschen＇s law under various conditions. Insulation problems can destroy a machine if a Paschen discharge is triggered by an insulation defect that is caused by faulty manufacturing, electromagnetic force, and thermal stress load with a certain degree of vacuum helium or pipe leakage. The results show that the CL insulation mock-up worked well under normal temperature and pressure. Besides, the mock-up also worked well in helium conditions and at 80 K temperature at different pressures. One area of CL insulation was severely destroyed when the 80 K test was conducted after 5 thermal cycles, resulting in Paschen discharge phenomenon. The breakdown voltage is maintained at a relatively low level under different pressure conditions; the change of breakdown voltage was mainly due to the change of pressure, and such change was in line with the Paschen law.
基金Supported by the National High Technology Research and Development Programme of China under Grant No 2002AA331020, and the National Natural Science Foundation of China under Grant No 10275088.
文摘新方法说出磁性的发光弧血浆来源离子培植(MGA-PSII ) 的 A 为试管的内部表面修正被建议。在 MGA-PSII，火绒一个轴的磁场的控制，被电的卷在试管样品附近产生，进从它的二的试管的发光弧血浆行动成螺旋形结束。否定电压在试管上使用了的 A 认识到它的内部表面培植。钛氮化物(锡) 电影在直径 90 公里和长度在一个不锈钢试管的内部表面上被准备 600 公里。坚硬测试证明在试管中心的坚硬直到 20 GPa。XRD， XPS 和 AES 分析证明听电影的好质量能被完成。
文摘Tantalum nitride （TAN） thin films are achieved on Si（111） and SS317L substrates by cathodic vacuum arc technique, which is rarely reported in the literature. The crystal structure, composition and surface morphology of the films are characterized by x-ray diffraction （XRD）, x-ray photoelectron spectroscopy （XPS）, auger electron spectroscopy, and atomic force microscopy, respectively. The influence of substrate negative bias on crystal structure, composition, surface morphology of the TaN films is systematically studied. At the substrate bias of 0 V and -50 V, the amorphous TaN film is obtained. As the bias increases to -100 V, cubic TaN phase can be found. Stoichiometric TaN with hexagonal lattice preferred （300） orientation is prepared at a bias of -200 V. Combine the XRD and XPS results, the binding energy value of 23.6eV of Ta 4f（7/2） is contributed to hexagonal TaN. Compared to other techniques, TaN thin films fabricated by cathodic vacuum arc at various substrate biases show different microstructures.
基金supported by ITER IO, the National Basic Research Program of China (973 Program, No. 2008CB717906)the National Special Support for R&D on Science and Technology for ITER (No. 2008GB102000)
文摘This paper presents the evolution of the design of cold mass support for the ITER magnet feeder system. The glass fibers in the cylinder and the flanges of the normal G10 support are discontinuous in the preliminary design. The heat load of this support from the analysis is only 4.86 W. However, the mechanical test of the prototype showed that it can only endure 9 kN lateral force, which is significantly less than the required 20 kN. So, the configuration of the glass fibers in the cylinders and flanges of this G10 support are modified by changing it to a continuous and knitted type to reinforce the support, and then a new improved prototype is manufactured and tested. It could endure 15＇kN lateral forces this time, but still not meet the required 20 kN. Finally, the SS316LN material is chosen for the cold mass supports. The analysis results show that it is safe under 20 kN lateral forces with the heat load increased to 14.8 W. Considering the practical application, the requirements of strength is of primary importance. So, this SS316LN cold mass support is acceptable for the ITER magnet feeder system. On the other hand, the design idea of using continuous and knitted glass fibers to reinforce the strength of a G10 support is a good reference for the case with a lower heat load and not too high Lorentz force.
