Calculations of thermal processes occurring in a bonded diamond tool during grinding of various materials on the surface in the zone of contact with the processed material and in the volume of the diamond tool are presented. A mathematical model of heating a bond of diamond tools as a result of frictional forces in the grinding and cooling zone by means of a cutting fluid is described.
Direct methods have shown that under the influence of surfactants included in the polishing compositions, there is a change in the deformation and strength properties of a thin surface layer of solids in the processes of fine abrasive processing. Ruby and quartz were used as samples
Within the framework of a dynamic uncoupled problem of thermoelasticity for a half-space, the effect of pulsed laser radiation on glassy and ceramic materials is considered. Analytical relations are obtained, which are the criteria for the thermal strength of materials for three temporal forms of laser pulses of nanosecond duration and make it possible to determine non-destructive annealing modes. The influence of the temporal shape of the laser pulse on the annealing regimes of materials is shown. It was found that the use of laser pulses with a steep front and a protracted falloff leads to a decrease in thermoelastic stresses in the material.
Examples of the successful application of new types of diamond tools for highly efficient processing of a wide class of materials, such as glass, ceramics, sapphire, semiconductor materials, and various metals are given. The advantages of a bonded diamond tool based on a thermally conductive polymer composite are shown.
Within the framework of a quasi-static uncoupled problem of thermoelasticity for an isotropic plate, non-destructive modes of high-temperature laser annealing of optical ceramics
KO-3 with CO2-laser radiation are determined . It is shown that non-destructive modes are provided only for a sufficiently long exposure time and a low power density of laser radiation. An experimental verification of the adequacy of the computational model has been carried out
Within the framework of the one-dimensional problem of the evaporation of an absorbing material layer at When the energy of a laser pulse was released, an analytical relationship was obtained for calculating the energy density required for punching through holes in non-metallic plates, as well as the evaporated mass of matter per unit of input energy. A method is proposed for the action of laser radiation on a plate, which makes it possible to halve energy costs and determine rational modes of punching through holes in glassy and ceramic plates.
Within the framework of the one-dimensional problem of the evaporation of an absorbing material layer at For the release of laser pulse energy, analytical relationships are obtained for calculating the required energy density at a given scribing depth. These ratios make it possible to determine energy-saving modes of scribing glassy and ceramic materials with volumetric absorption of laser radiation when exposed to one or two laser pulses. The choice of the processing mode depending on the dimensionless parameter [chi; h] makes it possible to reduce energy consumption by a maximum of 25 - 35%.
Under the action of surfactants included in the polishing compositions, due to the manifestation of the Rebinder effect, the initial crystal structure of the thinnest (tenths and hundredths of a micrometer) surface layer of the processed material (silicon) is severely destroyed and its deformation and strength properties change. The use of active additives to polishing compositions, including unconventional ones, makes it possible to reduce the thickness of the damaged layer by 1.5 - 2 times, while significantly increasing the productivity of polishing.
The paper presents the results of work on stabilizing the wall thickness of quartz tubes by external vapor-phase deposition during high-temperature hydrolysis of silicon tetrachloride. The technological parameters of the deposition of the porous layer and its sintering have been determined. Defect-free glass layers with a thickness of more than 0.2 mm were obtained with the possibility of reducing the circumferential thickness difference of pipes from 0.2 to 0.05 mm.
Within the framework of the one-dimensional problem of the evaporation of an absorbing layer of a material with an "instantaneous" release of laser pulse energy, an analytical relationship is obtained for calculating the evaporated mass of a substance per unit of input energy. This ratio makes it possible to determine the optimal processing mode for glassy and ceramic materials with volumetric absorption of laser radiation. An experimental verification of the adequacy of the computational model has been carried out.
