Gaedes rotierende Quecksilberluftpumpe

The rotary mercury pump of Gaede Wolfgang Gaedes invention of a quickly acting high vacuum pump was induced by his studies about the Volta effect. The so far known pumps were not able to create sufficient low pressure to optain very clean surfaces. Alfred Schmidt, owner of the E. Leybold’s Nachfolger Company, Cologne, learned from the publication about the demonstration of the pump its importance. He made an agreement with Gaede to develop together the invention during 1906 and 1908 to a product for use in industrial application – first step into industrial high vacuum technology     

Wolfgang Gaede ‐ Wegbereiter der Vakuumtechnik

The inventions of Wolfgang Gaede were the beginning of the extensive industrial application of vacuum technology: the 1905 invented high vacuum mercury pump simplified the production of electric bulbs. From this time Gaede joined the company E. Leybold's Nachfolger research & development activities for 40years. Three of his inventions, the diffusion pump, the (turbo‐) molecular pump and the principle of “gas ballast” are worldwide in use even today. The most important stations of Gaede's biography are reported.     

Die patentierten Erfindungen von Wolfgang Gaede aus der Zeit von 1905 bis 1945

The Patented Inventions from Wolfgang Gaede from 1905 to 1945 The collection of Gaede's patents shows how successfully cooperation between science and industry could bee. Several up to now important inventions in vacuum technique have been made and this in sometimes hard and difficult circumstances. Even when Gaede has lost his chair at the university of Karlsruhe from illegal intrigues by the Nazis.     

Der Beginn einer Erfolgsgeschichte

The beginnings of a successful story The exciting invention of the molecular Pump by Wolfgang Gaede was followed by his new ‘Device of Producing High Vacua’ in 1913. It was announced in the second edition 1913 of E.Leybold's cataloge. Three years later Langmuir in the USA presented a similar pump called ‘condensationpump’, but with clearly better pumping speed. Another design of a pump with two stages was invented by Prof. Volmer in Berlin. Other European companies announced similar pumps. Because Gaede claimed the prinziple of evacuating gas by diffusion, he and Leybold succeeded in making all of them to ask for licences. Respective to Langmuir they exchanged licence to each other. By the time this ‘diffusion pump’ was produced from metal instead of glas, and used special mineral oil, not mercury. In the middle of the 20.century it became a most important tool for creating high vacuum, available with a few liters per second to some thousend liters of pumping speed.     

Geschichte der Vakuumtechnik. History of Vacuum Technology

The history of vacuum technology is more than 2000 years old. Over the past 400 years scientists, engineers and inventors such as Torricelli, Pascal, von Guericke and Gaede have been engaged in vacuum technology. Vacuum has become an essential instrument in science and technology and many processes could not exist without it. Furthermore vacuum technology has been developed as an individual industrially applied technology. The article describes the development of vacuum technology from ancient philosophical speculations about the mercurial glass pipe to the modern diffusion pump.     

Der Gasballast

Wolfgang Gaedes last important invention: the Gasballast Gaedes invention of the rotating Mercury‐vacuumpump made highvacuum technology available for the industrial production. A second and third impact was given by gaedes molecular‐ and diffusionpump respectively, both depending on physikal effects firstly used for vacuum generation. Vacuum technology becomes increasing importance but the common oil sealed rotating pumps for fine vacuum suffer from contamination of the oil by vapor condensation. It was another invention from Gaede that eliminated this handycap in a very elegant way: the gasballast that is up to now a very important feature of this type of pumps.     

Renaissance einer Hundertjährigen. Die Molekularpumpe von Wolfgang Gaede

New Success after 100 years: the ?Molecular Pump”? of Gaede The molecular drag pump was invented by W. Gaede in 1908. The design of the prototyp needed two years, and another two years later the first molecular pumps were 1912 ready for selling. But the sophisticated design and handling and the war 1914 limited the world wide application of the pump. Now at the end of the 20^th century the invention was successfully used as final compression stage in turbomolecular pumps.     

Tribomechanische und -chemische Vorgänge an dem Wälzlagerstahl 100 Cr 6

Tribological Processes of the Ball Bearing Steel 100 Cr 6 . Tribomechanical and tribochemical processes of the ball bearing steel 100 Cr 6 were investigated under the influence of ultra high vacuum and different gases by the pin/ring method. The conditions for adhesive wear indicated by prow formation were optimal in ultra high vacuum. Pressures of oxygen, nitrogen and air greater than 10^?6 Pa increase the lubrication by formation of thin films, measured by ellipsometry. Increasing nitrogen pressure produces a surface hardening, which can be observed by nitrided wear particles. The presence of pure oxygen creates permanently oxide films with a thickness of 10 nm. This causes abrasive wear.     

Resistivity and thermoelectric power between -100 °C and +100 °C of gold and silver thin films formed and studied in ultrahigh vacuum

A study of the size effect in the resistivity and thermoelectric power of high purity (99.999%) gold and silver films has been made in order to determine their electronic structure. The investigation was based on the ohmic and thermoelectric behaviour of gold and silver films, ranging in thickness from 100 to 3000 Å, over a temperature range of -100 °C to +100 °C in the 10^-9 torr ultrahigh vacuum enclosure where they were prepared.The experimental results obtained have enabled us to understand the behaviour of the conduction electrons in bulk gold and silver in the neighbourhood of the Fermi surface by determining (1) their mean free path as a function of temperature, and (2) the variation of the mean free path and area of the Fermi surface with energy.     

Infrared reflection absorption study of water interaction with H-terminated Si(100) surfaces

Water adsorption on clean and hydrogenated Si(100) surfaces was studied under ultra high vacuum conditions using surface infrared spectroscopy. The study shows that H-Si-Si-OH and SiH₂ species are formed on Si(100)-(2 × 1) and Si(100)-(2 × 1)-H surfaces, respectively. The reactivity behaviour of Si(100)-(3 × 1)-H and Si(100)-(1 × 1)-H is similar, both stabilizing oxygen inserted silicon dihydrides.     

锰及其硅化物在Si(100)表面的反应外延生长

采用超高真空分子束外延-扫描隧道显微镜(UHVMBE-STM)系统研究了不同温度下锰及其硅化物在Si(100)-2 ×1重构表面上的外延生长情况.实验结果表明当生长过程中衬底温度控制在室温到135℃时,生成大小基本一致的锰纳米团簇;当衬底温度达到210℃时锰与硅开始发生反应,形成硅化物,并有纳米线结构出现;当衬底温度达到330℃时,纳米线完全被棒状物或不规则的三维岛状硅化物取代.随着沉积时衬底温度升高,生成物的成核密度与生长温度的关系与经典的二维岛成核理论相符合.     

非蒸散型吸气剂泵在真空计量中的应用研究

本文简要阐述了非蒸散型吸气剂(NEG)泵的吸气机理,着重介绍了NEG泵在超高/极高真空标准、静态膨胀法真空标准等真空计量标准中的最新应用结果。结果表明:利用NEG泵在室温下获得了10-10Pa的XHV;利用NEG泵将超高/极高真空标准校准下限延伸到了10-10Pa量级;利用NEG泵将静态膨胀法真空标准的校准下限延伸到了10-7Pa量级。最后还对用NEG泵延伸固定流导法微流量标准测量下限的可行性进行了分析。     

Research on vacuum-electromagnetic casting of IN100 superalloy ingots

In order to improve the inner quality of superalloy master alloy ingots, the new technology of superalloy vacuum-electromagnetic casting, i.e. applying electromagnetic stirring (EMS) to the solidification process of superalloy vacuum casting was developed. The effect of EMS on the inner quality of IN100 superalloy ingots was studied with EPMA and optical microscope. The results show that while an EMS with 50 Hz frequency and 60 A current is imposed, the equiax crystals of IN100 superalloy ingots can be effectively refined and increased, and the central shrinkage porosity and the dendritic segregation of IN100 superalloy ingots are greatly reduced, so the inner quality of IN100 superalloy ingots is obviously improved.     

GQZ—400新型高真空油增压泵

为使油增压泵在高真空领域有较高抽速，改进了现有油增压泵的结构，其极限真空和抽速有了显著提高。扩大了它的应用范围。在真空设备中得到了成功地应用。     

真空炉高温除气工艺对降低不锈钢出气率的作用

真空炉高温除气工艺可以大大降低不锈钢出气率。通过应用实例,给出了真空炉高温除气和现场烘烤除气及二者结合除气的结果,分析了真空炉高温除气的有利因素,证明采用该工艺对于降低不锈钢出气率,从而获得超高真空具有显著的效果。     

ZHT100型1 t真空自耗电弧炉的研制

本文介绍了ZHT100型1t真空自耗电弧炉的结构、组成及工作过程。指出了调试过程中存在的问题，这种由我们自行设计、制造的1t真空自耗电弧炉已出口国外，一次试车成功并投入使用。     

Fatigue crack propagation properties of Ti–6Al–4V in vacuum environments

To determine the effects of vacuum environment on fatigue crack propagations in a Ti–6Al–4V alloy, K-decreasing tests were conducted in air and vacuum. The fatigue crack propagation rate became slower and threshold stress intensity factor range became larger with decreasing vacuum pressure. The tendency cannot be fully explained by the crack closure. Based on fracture surface observations, granular region of a few micrometer size asperities was observed on the fracture surface only in high vacuum and ultra high vacuum. The high vacuum environment is one of the necessary conditions for the formation of the granular region, and the fraction of surface coverage of adsorbed gas on fracture surfaces relates to the phenomenon. The formation of the granular region represents the difference of the crack propagation mechanism between vacuum and air environments. A new mechanism for the formation of the granular region was proposed, and that is one of the phenomena which can explain the reduction of crack propagation rate in vacuum.     

利用超低温冷冻技术改造真空溅镀产线

在连续化真空溅镀生产实践中,由于夏秋两个季节的环境湿度大,加之待镀工件和夹具携带的水蒸气,使得真空腔体达到要求的高真空时间较长。这样既延缓了生产节拍,降低了设备产能,又加大了能源消耗。在不改变原生产线设备布局的情况下,利用超低温冷冻技术对原生产线进行改造,以实现快速捕集真空腔体内的水气,使真空腔体迅速达到要求的高真空,并取得了良好效果。     

不同高阻隔复合膜在带有沟槽的真空绝热板上的适用性研究

为进一步提高真空绝热板的适用场所,从异形真空绝热板的发展趋势进行分析,重点研究了高阻隔复合膜对异形真空绝热板的影响,通过对比市面上主流的几款高阻隔复合膜,分析在带有沟槽的异形真空绝热板上使用的可行性,并通过导热系数等对比实验进一步验证,得出最佳膜材选择方案,从而为带有沟槽的真空绝热板量产化提供参考依据。