Experimental and statistical models of impact determination of the electron beam parameters on surface layers properties of optical elements in precision instruments building

• Main Author: I.V. Yatsenko
• Format: Article
• Language: English
• Published: Odessa National Polytechnic University 2016-05-01
• Series: Trudy Odesskogo Politehničeskogo Universiteta
• Subjects: optical element; external thermal impacts; the electron beam
• Online Access: http://pratsi.opu.ua/articles/show/6962

Modern devices with optical elements for measurement and thermal control of different physical nature objects subjected to intense external thermal actions. To prevent destruction of optical elements the electron beam methods of work surfaces finishing at the stage of manufacture has practical significance. These methods can improve the properties of the element surface layers and thus make them more resistant to external thermal and mechanical action. Aim: The aim is to determine the optimal ranges of parameters of the electron beam and the development of experimental and statistical models that will automatically generate database with improved properties of the surface layers of optical elements in real time mode after previous electron beam treatment. Materials and Methods: To study the influence of parameters of the electron beam on the properties of the surface layers of the optical elements used plates of optical glass (K8, K108, etc.) and ceramics (KO1, KO2, etc.). The strip electron beam has the following characteristics: density of heat flow Fn = 5∙10^6…9∙10^8 W/m2 and rate of displacement V = 0…0.1 m/s. Determination of the surface layers properties of the optical elements before and after electron beam treatment was carried out by known methods of physical and chemical analysis. Results: It was established that under the influence of the electron beam on the surface of the optical element there is visible clearing of various impurities take place, various micro-defects that remain on it after standard processing methods (mechanical, chemical, etc.) remove and also its smoothness significantly increases, i.e. height of residual asperities on the surface is reduced. It was also found that the processing of optical glass elements by electron beam their surface layers change their structure, which is close to the quartz. It is shown that the surface of the preprocessed electron beam elements able to withstand the critical value of external heat flows in 1.3...1.5 times higher than before treatment. Conclusions: As results of the research the experimental and statistical models to determine the impact of parameters of the electron beam on the basic properties of the surface layers of the optical elements and their resistance to thermal action have been developed. This makes it possible (with a relative error of 5 ... 9%) automatically in real time to form a managed database with improved properties that impact on the technical and operational characteristics of optical components and devices based on them.