Improvement of surface layers properties of precision engineering elements of optical ceramics by preliminary electron-beam surfacing

Trudy Odesskogo Politehničeskogo Universiteta

I.V. Yatsenko¹ 

[1] Cherkasy State Technological University;

关键词: precision engineering;    optical ceramics;    electron beam;    microstructure;    hardness;    thermal stresses;   

DOI  :  10.15276/opu.2.49.2016.13

来源: DOAJ

【 摘 要 】

To prevent destruction of the elements made of optical ceramics the practical importance has the preliminary electron-beam treatment of their surfaces during the manufacturing stage of devices based on them. This allows improving the properties of the surface layers of the elements, making them more resistant to external thermal and mechanical impacts. Aim: The aim of this research is to research the impact of parameters of preliminary electron-beam treatment of the elements made of optical ceramics to prevent their destruction, improvement of the surface layers properties and increasing of their resistance to external thermo-influences. Materials and Methods: The discs with diameter of 3∙10^(–2)…5∙10^(–2) m and thickness of 4∙10^(–3)…6∙10^(–3) m and hemispherical cowl with diameter of 4∙10^(–2)…8∙10^(–2) m were used to research the impact of electron-beam parameters on surface layers properties of the elements made of optical ceramics. Results: After researches it was established that for studied range of electron beam parameters (Fn = 10^6...1.6∙10^7 W/m^2, V = 10^(–3)...10^(–1) m/s) the microhardness of the elements surface increases from 1.2…2.9 GPa (unprocessed elements) to 5.7…6.4 GPa (processedelements). It was defined, that improvement of these properties leads to improvement of elements resistance to external thermo-influences. The critical values of external heat streams and the time of their actions are increase in 1.3...1.7 times. The excess these parameters leads to the destruction of the elements and failure of the devices for the studied range of external pressure variation 10^5...10^7 Pa. The maximum allowable values of thermal stresses in elements are raised from 50...140 to 160...370 MPa at the heating temperatures of 300...1200 K.

【 授权许可】

Unknown