International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

Existing experimental researches show that in order to prevent the destruction of optical elements of modern opto-electronic devices (discs as the light filter linings for IR devices, the input protective windows of laser sighting systems for observation in IR areas of the spectrum, semispherical fairings of IR devices for homing and observation of objects, lightguides for laser medical devices, etc.), electron beam method becomes promising, as it provides cleaning of surfaces, increases their microhardness, makes them more resistant to external influences. The results of experimental studies to improve the properties of the surface layers of elements from optical ceramics after their processing with a moving electron beam with a heat density Fn = 106…1.6∙107 W/m2 and moving speed V = 10-3…10-1 m/s (increase in the surface microhardness from 1.2 … 2.9 GPa (raw elements) to 5.7 … 6.4 GPa (processed elements), the occurrence of hardened layers with a thickness of 210… 230 microns). It has been established that the improvement of these properties leads to an increase in the resistance of elements to external thermal effects: an increase of 1.3…1.7 times the critical values of external heat flows and their exposure times, exceeding which leads to the destruction of elements and the failure of devices for the studied range of change of external pressure is 105…107 Pa; increasing the maximum allowable values of thermoelastic stresses in elements from 50…140 MPa to 160…370 MPa at heating temperatures of 300…1200 K.

Given are the results of a comparative design analysis of the operating cycle and thermal stressed state of a piston in diesel engine 2F10,5/12 under rated power conditions. To reduce the thermoelastic stresses in the piston, the paper suggests using the modern method of managing the operating cycle – homogeneous mixing and combustion. Such an operating cycle reduces the maximum local temperature in the combustion chamber and the temperature gradients, thereby reducing the thermal load on the piston.