Research On The Characteristics And Measurement Methods Of Vacuum Outgassing Of Solid Materials

Vacuum outgassing measurement of solid materials is an important technical index for evaluating and selecting the performance of vacuum materials.With the demand for ultra-high vacuum in aerospace,semiconductor,high-energy physics and other application fields,around the world are committed to the research of vacuum material outgassing measurement technology.After more than half a century of development,many research institutions at home and abroad have put forward a variety of methods to measure the outgassing rate of materials.Solid materials dissolve and absorb gases in atmospheric environment.When the material is placed in a vacuum,it dissolves and dissolves.In the process of material outgassing testing,it is difficult to measure the material with small outgassing rate,the device background outgassing is large,and the material outgassing is suppressed.Therefore,the test method and test device of material outgassing rate have become a hot and difficult problem in the field of vacuum physics and have been concerned by many scholars.So far,there is no general test method and technique applicable to the test of the outgassing rate of various solid materials.In this paper,the vacuum outgassing measurement technology of solid materials is studied mainly from the perspective of improving the measurement method of vacuum outgassing of solid materials and studying the characteristics of vacuum outgassing of materials.The main tasks are as follows:?1?The principle and system composition of various methods are analyzed in depth from the measurement range and characteristics of the measurement methods of material outgassing,the existing methods and devices are summarized,the advantages and disadvantages of each method are compared,and the method of conversion gas path method was improved,a new method for measuring the outgassing of materials is proposed.?2?In this paper,the characteristics of the gas release rate and composition of titanium alloy steel,304 stainless steel and silver used in vacuum insulation vessels under the vacuum conditions of room temperature,200?and 400?were studied by using a new type of material air release rate test system based on the conversion gas path method.The results show that at room temperature,the gas release rates of the three materials are titanium alloy steel,304 stainless steel and silver successively from small to large.However,with the increase of temperature,the gas release rates of titanium alloy steel significantly increase,while that of 304 stainless steel and silver first increases and then decreases with the increase of temperature.The gas release rate at 200?is greater than that at room temperature and 400?.Meanwhile,it is found that in the vacuum degassing process,the baking temperature of 304 stainless steel and silver can be set below 400?,while the content of H₂ in titanium alloy steel is relatively high,which is difficult to remove,and the degassing process should be higher than 400?.?3?The outgassing characteristics of nickel-based alloy of electroforming cold screen material in integrated design of infrared coke plane package were studied.The gas composition of pure nickel with different roughness and pure nickel after blackening of nickel plating was detected and qualitatively analyzed by quadrupole mass spectrometer.In the test of vacuum outgassing rate,The outgassing rate of nickel base alloy can be reduced by reducing the roughness of nickel base alloy.The surface of nickel-based alloy is treated by chemical blackening of nickel plating,and the outgassing of nickel-based alloy is inhibited by blackening and coating.