Using electron beam evaporation equipment to deposit high-quality aluminum film is a big challenge in the film process. Therefore, a method was proposed to deposit aluminum film by using a modified Al₂O₃ crucible as the lining pot, and adding materials and pre-melting them three times. The effects of different evaporation rates on the electrical resistivity, grain morphology and composition of aluminum films were studied. The results show that the convex molten aluminum liquid surface can increase the contact angle with the crucible wall, basically eliminate the aluminum oxide impurities in the aluminum film. With the increase of evaporation rate, the grain size of aluminum film increases and the average resistivity decreases. The aluminum film with purity of 99.9% and the lowest resistivity of 3.4×10^-6 Ω·cm can be prepared by adding materials for pre-melting three times.

The optical properties of multi-band thin films elements used in multispectral detection systems directly affect the detection and imagine quality of the system. In order to solve the technical problems caused by the deviation between the multi-band wavelength and the theoretical design spectrum in the process of film preparation, a wavelength error compensation design method was proposed. Combined with the development of 5-band laser film coating on multispectral ZnS optical window, the structure of the film system was designed by using the wavelength error compensation design method, and the film was prepared by vacuum evaporation technology. The experimental results were tested by spectrophotometer and infrared Fourier spectrometer. The results show that the transmittance curves of the multispectral ZnS optical window at five working bands after coating are highly consistent with the theoretical ones, which meet the technical requirements and verify the effectiveness of the wavelength error compensation design method.

Electrical insulation property of magnetron sputtered silicon oxide (SiO₂) and silicon oxide/silicon nitride (Si₃N₄)/silicon oxide (ONO) films were investigated. The insulation resistance of three batches of SiO₂ and ONO films of 4.5 cm × 3.5 cm were tested. The results show that the ratio of fully-insulative ONO films is relatively higher and more stable. Compared with SiO₂ single layer, the signal related to stretch motions of bridge oxygen (peak A) of ONO film is blue shifted, and the signal related to oxygen vacancies (peak B) or bending motions of non-bridge oxygen (peak C) is weaker than the signal related to bending motion of bridge oxygen (peak D). These structural features indicate that the atomic defects (such as oxygen vacancies and non-bridge oxygen) within ONO films are less than those within SiO₂ films. Such differences are understood in terms that the addition of Si₃N₄ interlayer chemically interrupts the continuous growth of defects in SiO₂ films. By quantifying the three parameters including position of peak A, the ratio of intensity of peak D to that of peak B, the ratio of intensity of peak D to that of peak C, the electrical insulation properties of SiO₂ and ONO films can be evaluated non-destructively.

The formula of film thickness distribution was derived mainly by the discrete mathematical integration tool, and the evaporation of array evaporation sources with non-cosine evaporation law in practical engineering project was described. The film-forming distribution law of translational substrate with different array evaporation sources was studied, and the spatial layout of evaporation sources was designed according to this law. The calculation method and distribution law of the film-forming uniformity of translational substrate with array evaporation source were mainly studied, and the influence of the open hole configuration of the evaporation source on the film thickness distribution of the upper substrate was analyzed. The results show that the overall film thickness of the substrate with array evaporation source shows intermediate periodic fluctuations, and the distribution at both ends is relatively low. It is necessary to maintain the geometric array configuration of relative dislocation and reduce the hole spacing at both ends to obtain a more reasonable and uniform film thickness distribution.

With the increasing requirement of the suction efficiency of vacuum pumping equipment in large vacuum system, the suction capacity of traditional Roots vacuum unit is obviously insufficient, which can not meet the application requirements. In this paper, the centrifugal vacuum pump with large displacement, wide pressure and high rotating speed is applied to large-scale high vacuum system, and a new type of centrifugal vacuum unit is developed, which combines centrifugal vacuum pump, Roots vacuum pump and water ring vacuum pump in series. The composition of centrifugal vacuum unit and the development process of this centrifugal vacuum pump is introduced, its extreme performance and load are tested. The results show that the pumping capacity, ultimale pressure and operational stablity of the unit meet the design requirements. This unit has the characteristics of small footprint, high operation efficiency and strong pumping capacity, and is the best pumping scheme for large-scale high vacuum system at present.

H-type reinforcing ring is widely used in vacuum vessel because of significant improvement of the critical instability pressure of the cylinder. However, the design based on GB 150-2011 standard requires repeated trial calculations and the process is cumbersome. In this paper, the simplified design calculation formula of H-type reinforcing ring for cylindrical vacuum vessel was deduced, and the accuracy of the simplified formula was verified by establishing a numerical calculation model. Finally, through the analysis of the design calculation example, the selection design of the structural parameters of H-type reinforcing ring and its influence on the stability and economy of cylindrical vacuum vessel were studied. The results show that the simplified design calculation formula of H-type reinforcing ring deduced in this paper could meet the requirements of structural stability, and the design and check of H-type reinforcing ring could be carried out quickly by the design curve at a time. Increasing the height and thickness of H-type reinforcing ring could improve the critical instability pressure of the cylinder. Compared with rectangular reinforcing ring, the use of H-type reinforcing ring could reduce the amount of material and improve the economic benefits. The research results can be used to guide the design and calculation of H-type reinforcing ring of cylindrical vacuum vessel and provide theoretical reference for structural integrity evaluation.

By studying and analyzing the vacuum pumping system and process methods, a segmented integrated vacuum pumping system and process method was proposed. A system that integrates high, medium, and low vacuum pipelines, various types of vacuum units, and process control systems to achieve batch vacuum pumping of products. The computer-controlled vacuum pumping system automatically regulates the vacuum pumping process program for individual workpiece based on data collection of the process and data analysis and identification of the process database. The control system can also improve the process database and process procedures through statistical analysis of process data, thereby automatically identifying and regulating the process, prompting process parameters one by one, and providing suggestions for abnormal handling, achieving unmanned intelligent vacuum operation management. This system and process method can reduce equipment occupancy, reasonably allocate equipment operation and maintenance, improve equipment utilization, reduce energy consumption, and improve productivity and process quality.

The sealed cabin of the spacecraft is located inside the vacuum chamber during the vacuum thermal test, and the conventional water vapor measurement methods and water removal methods cannot meet the requirements of sealed cabin. In this paper, a set of measuring device suitable for measuring the moisture content in the sealed cabin is designed to solve the problem of water removal in the vacuum thermal test of the spacecraft sealed cabin, which can meet the requirements for measuring the water vapor in vacuum environment through calibration. The as-designed sealed cabin water removal system is connected to the sealed cabin through a bidirectional sealing flange, which can complete the water removal of the sealed cabin outside the vacuum chamber. The test result shows that this water removal method can ensure that the dew point temperature of the gas in sealed cabin is below 0 ℃ during the vacuum thermal test.

Based on the characteristics of helium, the requirements of helium making device for excellent sealing performance, and the economy of liquid helium resources, taking the triple eccentric butterfly valve as the research object, the design of the sealing ring for helium making device was explored and studied from many aspects. Firstly, a variety of seal solutions were tested to explore their advantages, disadvantages, and limitations. Then, a design of metal skeleton rubber sealing ring was proposed to effectively solve the vacuum sealing problem in the structure of the triple eccentric butterfly valve. The design was experimentally and theoretically verified from the aspects of tightness, working torque and lifetime. Finally, the overall economy based on the design was described. This design of the metal skeleton rubber sealing ring provides a relatively perfect scheme for the sealing requirement of regulating butterfly valve in helium production device at room temperature.

The vacuum eletron beam welding plays an irreplaceable role in welding connections of large and thick structures. However, the size of the vacuum chamber remains a limitation for vacuum electron beam welding technology, making it a challenge to meet the welding requirements of extremely large structures. Therefore, both domestic and international researchers started working on localized vacuum electron beam welding technology, by using a smaller vacuum chamber to cover the welding structures locally to complete the ultra-large structure of the electron beam welding. This paper provides an overview of the latest advancements in localized vacuum electron beam welding technology around the world. Various forms and types of local vacuum electron beam welding equipment are introduced, and sealing structure, weld tracking, and other technical topics are discussed.

In recent years, the new generation of TiAl alloy turbine blades have been widely used in domestic and foreign aviation engines. With the increasing demand for TiAl blades, the development of the cold crucible induction skull furnace which is the key equipment for TiAl blade production, has also entered a new stage. In this context, the mainstream forms, technical characteristics and current usage status of vacuum cold crucible induction skull melting furnaces are introduced at first. Then, the differences between the vacuum cold crucible induction skull melting and levitation melting are explained, and the application scope of vacuum cold crucible induction skull melting furnace is described. Finally, the development trend and prospects of vacuum cold crucible induction skull melting furnace are analyzed.

The key technology and application of vacuum melting in the preparation of high purity metal materials are discussed. Firstly, the definition, characteristics and application fields of high purity metal materials are introduced. Then, the basic principle, classification and characteristics of vacuum melting technology are elaborated. In terms of critical technologies, the technology of vacuum environment control, equipment and process parameter control, slag and liquid separation and purification, refining and purification are discussed, respectively. The application of vacuum melting in the preparation of tungsten, titanium alloy and copper base alloy is introduced. At last, the problems that vacuum melting technology may face in the preparation of specific metals, such as pollution sources, difficulties in the optimization of process parameters and limitations of applicability are deeply analyzed.

Based on the service performance requirements of 2205 dual phase steel forgings for single-point liquid slip ring, the forging process of medium and large forgings for single-point liquid slip ring was designed. The refining technology of vacuum oxygen argon decarburization furnace (VODC) was used to ensure the purity of the ingot. The reasonable solution heat treatment process of medium and large forgings for single-point liquid slip ring was established. By finely regulating the parameters of heating and holding and cooling rate, the α + γ duplex stainless steel forgings with stable structure and uniform composition were successfully prepared, which effectively avoided the precipitation of Cr-rich σ brittle phase. The comprehensive performance test shows that the mechanical properties and corrosion resistance of the forging meet the technical requirements of the single-point liquid slip ring.

Magnetic fluid sealing technology has natural advantages such as no friction, no pollution and long life, it has broad application prospects in vacuum sealing. Combining with the practical engineering application, the principle and characteristics of magnetic fluid seal, the research status and products of MHD sealing technology at home and abroad, and the application of magnetic fluid sealing in vacuum equipment are described. The development status of the heat treatment equipment and technology of superconducting coils and the defects of existing magnetic fluid sealing structures in the sealing of superconducting coils vacuum heat treatment furnace are introduced, and a new type of water-cooled magnetic fluid sealing device for vacuum heat treatment furnace was proposed. This device can achieve gapless sealing and only enough cooling water is needed to ensure thermal balance, which can effectively reduce the cost.