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1.
在沉积不锈钢-氮化铝(SS-AlN)金属陶瓷太阳吸收集热管的磁控溅射三靶镀膜机上,安装了UPS03反应溅射闭环控制单元,实现反应溅射Al2O3稳定反馈控制。采用国产直流电源在Al靶表面处于过渡态下,成功制备了吸收几乎为零的Al2O3薄膜。溅射功率在14kW时,反应溅射沉积Al2O3的靶电压波动可长时间稳定控制在±3 V范围内,沉积速率为5.4 nm/(min·kW),约为Al靶在无反应气体溅射下沉积Al薄膜速率的74%。采用Al2O3代替AlN作为减反射层,应用到SS-AlN太阳选择性吸收涂层中,进一步提高了复合膜的太阳光学性能,太阳吸收比由AlN作为减反射层的0.956提高到0.965,红外发射比不变,仍为0.044。 相似文献
2.
采用PLC级差法闭环控制中频电源反应溅射沉积Al2O3薄膜 总被引:3,自引:1,他引:2
本工作开发了一种靶电压反馈自动控制系统,称为可编程控制器(PLC)级差法反馈控制系统,用于旋转圆柱金属Al靶真空反应溅射沉积Al2O3陶瓷薄膜。根据反应溅射Al2O3工艺特性设计反馈控制的数学模型,再按照数学模型,采用梯形语言在PLC内进行程序编码实现。通过反馈控制参数的优化,实现较高功率26 kW下中频磁控反应溅射Al2O3工艺稳定。测试得到50 nm厚的Al2O3薄膜,其可见光吸收比和太阳光吸收比接近零。这种反应溅射反馈控制系统简易可行且经济实用。 相似文献
3.
全玻璃SS-AlN金属陶瓷真空太阳集热管 总被引:3,自引:1,他引:2
不锈钢-氮化铝(SS-AlN)金属陶瓷太阳选择性吸收涂层于1995年在实验室制备成功,采用真空磁控溅射沉积。太阳吸收复合膜采用干涉吸收型膜层结构,由不同金属含量的两层金属陶瓷层组成吸收层。金属陶瓷吸收层采用在镀膜室中SS和Al金属靶,在溅射气体Ar和反应气体N2中同时溅射运行,SS靶非反应溅射沉积SS金属组分,Al靶反应溅射沉积AlN陶瓷组分。实验室沉积的SS-AlN吸收涂层的太阳吸收比高达94%~96%,室温辐射比3.5%~4.0%。皇明公司2001年开始产业化生产全玻璃SS-AlN真空太阳集热管。我们开发了立式集热管连续镀膜线,第一条镀膜线于2007年调试成功,投入生产。集热管镀膜线真空系统长约41 m,高约3 m。每条线日产约为1.8~2.0万支。 相似文献
4.
在3.2mm厚的低铁玻璃衬底上采用金属Al靶在溅射气体Ar和反应气体N2的混合气体中,真空磁控反应溅射沉积半透明的Al-AlN金属陶瓷薄膜。再将沉积该薄膜的玻璃试样浸入沸腾的去离子水中,经一定时间氧化后,制备成表面粗糙的AlN和Al2O3的陶瓷混合物增透膜AlNxOy。在3.2 mm厚的低铁玻璃上,溅射沉积厚度为120 nm的Al-AlN金属陶瓷薄膜,沸水氧化8 min,制备的单面增透膜AlNxOy试样的太阳透射比Te达93.5%,可见光透射比Tv达95.2%。制备的双面增透膜AlNxOy试样的Te,Tv进一步提高,Te高达95.6%,与未镀膜玻璃衬底的90.4%相比,增加了5.2%;Tv高达97.0%,与玻璃衬底的91.6%相比,增加了5.4%。 相似文献
5.
射频磁控反应溅射制备Al2O3薄膜的工艺研究 总被引:4,自引:4,他引:4
采用射频磁控反应溅射法,以高纯Al为靶材,高纯O2为反应气体,在不锈钢和单晶Si基片上成功地制备了氧化铝(Al2O3)薄膜,并对氧化铝薄膜的沉积速率、结构和表面形貌进行了研究.结果表明,沉积速率随着射频功率的增大先几乎呈线性增大而后缓慢增大;随着溅射气压的增加,沉积速率先增大,在一定气压时达到峰值后继续随气压增大而减小,同时随着靶基距的增大而减小;随着氧气流量的不断增加,靶面溅射的物质从金属态过渡到氧化物态,沉积速率也随之不断降低.X射线衍射图谱表明薄膜结构为非晶态;用原子力显微镜对薄膜表面形貌观察,薄膜微结构为柱状. 相似文献
6.
利用射频磁控反应溅射法,以高纯Si为靶材,高纯N2气为反应气体,在Si衬底上制备出了Si3N4薄膜,研究了气体流量比对薄膜质量的影响.结果表明,薄膜的沉积速率主要与气体的流量比有关,随着气体流量比的增加,沉积速率下降,靶面的溅射由金属模式过渡到氮化物模式;薄膜中N/Si的原子比增加;红外吸收谱的Si-N键的振动峰向标准峰逼近. 相似文献
7.
等离子体发射监控系统参与的中频孪生反应磁控溅射沉积TiO_2薄膜的实验研究 总被引:1,自引:0,他引:1
在一个孪生靶实验装置上进行了中频反应磁控溅射沉积TiO_2薄膜的工艺实验.得到了一组真实的反应溅射TiO_2薄膜的沉积速率和真空与反应气体流量之间关系的迟滞曲线(无等离子体发射监控系统Plasma Emission Monitoring,PEM)参与.介绍了PEM参与下的反应溅射TiO_2的一些实验现象和结果,此时TiO_2的沉积速率与PEM设定值呈很好的线性关系,反应溅射可以稳定在过渡态的任一工作点.设定值是PEM控制系统最关键的参数,直接决定着控制的可靠性、反应溅射速率以及薄膜的微观结构.结果表明,为了得到标准化学配比的反应物,PEM的设定值不能超过某个极限值.要在保证化学配比也就是反应物的成分或结构的前提下提高沉积速率才有意义. 相似文献
8.
在玻璃基片上采用金属Al靶在溅射气体Ar和反应气体O2的混合气体中,真空磁控溅射半透明的Al-Al2O3金属陶瓷薄膜,再将沉积薄膜的玻璃基片浸入沸腾的去离子水中氧化,制备成陶瓷增透膜.优化镀膜工艺和沸水氧化时间,在3.2 mm厚的低铁玻璃载片上单面沉积的增透膜的太阳透射比Te由未镀膜原片的90.4%增加到93.9%,提高了3.5%,可见光透射比Tv由91.6%增加到95.5%,提高了3.9%.双面沉积增透膜玻璃载片的Te达到96.2%,增加了5.8%,Tv达到97.2%,增加了5.6%.经过400℃高温持续40 min烘烤后膜层的光学性能基本不变. 相似文献
9.
气体流量比对反应溅射Si3N4薄膜的影响 总被引:1,自引:0,他引:1
利用射频磁控反应溅射法,以高纯Si为靶材,高纯N2气为反应气体,在Si衬底上制备出了Si3N4薄膜,研究了气体流量比对薄膜质量的影响。结果表明,薄膜的沉积速率主要与气体的流量比有关,随着气体流量比的增加,沉积速率下降,靶面的溅射由金属模式过渡到氮化物模式;薄膜中N/Si的原子比增加;红外吸收谱的Si—N键的振动峰向标准峰逼近。 相似文献
10.
在N2、Ar气氛中,采用反应直流磁控溅射法在Al2O3基陶瓷及玻璃基底上制备了Ta-N薄膜,并对各样品的形貌结构、化学组分及电学特性进行了比较分析研究。结果表明,沉积于Al2O3陶瓷及玻璃基底的Ta-N薄膜分别呈团簇状生长与层状紧密堆积生长;Al2O3陶瓷基底沉积的Ta-N为单相薄膜,而玻璃基底上的Ta-N薄膜,随N2、Ar流量比增加,呈单相向多相共存转变;薄膜表面形貌和微结构与基底材料的原始形貌和微结构紧密相关,这说明基底材料对薄膜的形成有重要的影响;N2、Ar流量比相同时,玻璃基底上沉积的Ta-N薄膜电性能优于Al2O3基陶瓷基底上沉积的Ta-N薄膜。 相似文献
11.
12.
H Hamacher 《Vacuum》1982,32(6):347-350
A method is described to calculate the pressure drop in a chamber/tube system when suddenly changing the outside pressure to a lower value, taking into account the pumping line volume. Tube wall outgassing and gas generation inside the chamber are assumed to be pressure and time independent. An approximation is derived which can be used easily for practical applications. 相似文献
13.
为了促进蓄冷过程中气体水合物在换热管外的生长,对比研究了冰、THF和HCFC141b气体水合物在光管和针翅管外生长的过冷度、诱导时间和生长速度。研究表明,相对于光管,针翅管对冰、THF气体水合物和HCFC141b气体水合物的生长过程均具有良好的强化作用(减小过冷度、缩短诱导时间和加快生长速率)。对于针翅管本身来说,内外双翅式针翅管比外翅式针翅管可以更大幅度地强化生长过程。 相似文献
14.
Coated tungsten layers on stainless steel substrates were are produced by atmosphere plasma spraying. A shroud gas injection method was employed to reduce the ambient air entrainment into the plasma jets. The effects of shroud gas on the material properties of the tungsten layers were investigated by finding the dependence of oxide content, coating thickness and porosity on the injection velocity, shielding width, and mass flux of the shroud gas. The high injection velocity was more effective than thick shroud shielding in protecting the plasma jets from ambient air engulfment, and the mass flux of the shroud gas showed negligibly small effects on the suppression of air entrainment. Therefore, in order to produce a thick tungsten coating with low porosity and oxide contents, high injection velocity with a limited flow rate is a desirable operating condition for shroud gas injection in atmospheric plasma spraying. 相似文献
15.
An experimental device was set up to determine thermal resistance and conductivity of 8% yttria-stabilized zirconia deposited
by plasma spray method on cylindrical specimen. In this experimental setup, coated surface of the sample was exposed to a
high temperature environment and inner metal surface was cooled by flowing air, simulating actual gas turbine applications.
Overall heat resistance at the outside surface of thermal barrier coating was adopted to assess thermal advantage due to the
thermal barrier coating deposited on air-cooled cylindrical specimen. 28% less heat was extracted at 1000°C by applying 1.2 mm
thick thermal barrier coating. Temperatures of the outside surface of the coated samples increased with increasing coating
thickness with respect to the same furnace temperature since the sample with thicker coating was less thermally conductive
and retarded heat transfer. The overall heat resistances of samples between the outside surface of sample and the flowing
air inside the sample assembly were estimated. Then, the thermal conductivity of coating could be determined from the difference
of overall thermal resistances of two selected samples with varying coating thickness. 相似文献
16.
The Authorized Metrological Centre (AMS) working by SUJCHBO (National Institute for Nuclear, Chemical and Biological Protection) ensures for the Czech Republic the metrological traceability for devices that measure the radon concentration and the energy equivalent radon concentration connected with the radon decay products (RnDP). The evaluation and the calibration of measuring devices for radon and RnDP require the stable conditions (first of all radon and the RnDP concentrations). The new AMS radon-aerosol chamber in Kamenná consists of the walk-in testing chamber with a volume of 10 m(3) and of the handling box with a volume of 0.3 m(3). The design of the chamber allows measurement and a control of environmental parameters such as the temperature, the pressure of air inside and outside of the chamber, the relative humidity of air, the concentration and the size distribution of aerosol particles and the air velocity. 相似文献
17.
Ying Zhao 《Thin solid films》2010,518(13):3590-3594
Effects of VUV/UV radiation and oxygen radicals on low-temperature sterilization in surface-wave excited O2 plasma were studied. To examine the effect of VUV/UV radiation on the inactivation of microorganisms, a small metal chamber covered with an optical filter at the top to block the radicals and allow the VUV/UV radiation was placed inside the plasma chamber. With a LiF and a glass filter, two different emission spectra above 120 nm (LiF filter) and above 300 nm (glass filter) were examined. The spores of Geobacillus stearothermophilus with a population of 2.5 × 106 were put below the optical filter in the small chamber, which was filled with the oxygen gas at appropriate pressure or pumped down to 10− 3 Pa. The survival curve showed that the vacuum condition inside a small chamber with a LiF filter was more efficient than the same O2 gas pressure as that outside plasma chamber. From the SEM analysis of the spores, there was no obvious change in shape after plasma treatment with filter at vacuum condition. According to the present results, it is concluded that the etching effect by the oxygen radical is more efficient in inactivation process than the sterilizing effect by the VUV emission in the oxygen plasma. 相似文献
18.
Fumiyoshi Kajino Y.K. Yuan 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》1985,228(2-3):278-282
An apparatus to search for GUT magnetic monopoles has been constructed. The apparatus consists of proportional chambers, scintillation counters and iron layers. Mixed gas of helium and 10% methane flows inside the proportional chambers, utilizing ionization produced by the monopoles through the atomic induction mechanism and the Penning effect. This type of proportional chamber has been proved to work well and to be very stable. 相似文献
19.
利用流体动力学仿真软件CFX对新设计的G10超声波燃气表腔体结构的气体流动进行仿真研究和分析。在大、中、小流量点上分别仿真新设计结构内的气体流动,获得超声波燃气表的整个腔体内、腔体的YZ轴向截面上、XZ轴向截面上和XY轴向截面上的气体流速分布,并进一步获得3个截面上属于超声波测量的内流道部分的气体流速分布。对仿真结果进一步分析发现,与整个腔体气体流动和整个轴向截面上气体流动相比,超声波测量部分截面内气体流动更快,但相对更均匀和稳定,有利于超声波气体流速的准确测量。最后给出基于该设计结构的超声波燃气表样机的检测结果,检测结果也验证了用仿真来辅助表体结构设计的可行性。 相似文献
20.
M. P. SanSoucie J. R. Rogers V. Kumar J. Rodriguez X. Xiao D. M. Matson 《International Journal of Thermophysics》2016,37(7):76
The NASA Marshall Space Flight Center’s electrostatic levitation (ESL) laboratory has recently added an oxygen partial pressure controller. This system allows the oxygen partial pressure within the vacuum chamber to be measured and controlled in the range from approximately \(10^{-28}\,{\mathrm {to}}\,10^{-9}\) bar, while in a vacuum atmosphere. The oxygen control system installed in the ESL laboratory’s main chamber consists of an oxygen sensor, oxygen pump, and a control unit. The sensor is a potentiometric device that determines the difference in oxygen activity in two gas compartments (inside the chamber and the air outside of the chamber) separated by an electrolyte. The pump utilizes coulometric titration to either add or remove oxygen. The system is controlled by a desktop control unit, which can also be accessed via a computer. The controller performs temperature control for the sensor and pump, has a PID-based current loop and a control algorithm. Oxygen partial pressure has been shown to play a significant role in the surface tension of liquid metals. Oxide films or dissolved oxygen may lead to significant changes in surface tension. The effects on surface tension and viscosity by oxygen partial pressure in the surrounding environment and the melt dissolved oxygen content will be evaluated, and the results will be presented. The surface tension and viscosity will be measured at several different oxygen partial pressures while the sample is undercooled. Surface tension and viscosity will be measured using the oscillating droplet method. 相似文献