At the period of science and technical evolution the modern machine-building is facing a lot of diversity problems. One of them - reliable guarantee of production’s technical characteristics for desired conditions. The fundamental index of machinery is reliability and coefficient of efficiency, which are determined by parts and combina-tions working abilities. In turn their working abilities predetermine state of productions blanket, which are generated by mechanical treatment. Often for production is impos-sible or not rational to use metals.

Now in the world the tendency of manufacture of products from nonmetallic and composite materials is observed. This tendency is connected with decrease of the cost production price, increase of their service term, reliability and ecological cleanliness. Physicomechanical properties of constructional ceramics (including sitall) in compari-son with all kinds of metals, have such distinctive characteristics, as high melting tem-perature, hardness, wear resistance, etc. These factors caused wide interest for studying properties sitall.

1. Definition of a kinematic error of processing of such blankets as paraboloids of rotation by periphery of a grinding circle method of direct copying.
2. Designing nonbacklash drive of rotary grinding stock.
3. Reception of dependences of a defective layer formation of processable sitall from temperature of diamond grinding.

Development of management technique by processing of such blankets paraboloids of rotation, which is based on the research results of influence of temperature of dia-mond grinding on structure of a defective layer of products from sitall. Adaptive management of position of a grinding circle from a condition of achievement of the maximal area of contact of a working surface of a circle and processable preparation.

Picture 1 - The grinding imitation
(size of animation - 50 kb, consist of 7 slide, 6 cycle)

On the basis of researches of formation of a sitalls superficial layer deficiency at diamond processing dependences between a thermal stream in a zone of cutting and formation of defects in a superficial layer have been found. By means of the found de-pendences it is possible to control process of grinding for creation of homogeneous structure.

In 1950th director of branch of basic researches in chemistry of the company «Daw Corning» in New York Donald Stukej invented a way of process stimulating a glass crystallization with the purpose of new valuable materials reception. A new material was called "piroceram". A method of reception: mixture with nukleator, was exposed to melting, then manufacture and cooling. Then updatings of piroceram under named " piroflume", "centure", "fotoceram" have been prodused, etc. In the USSR it called "sitalls".

Sitalls density - 2400-2950 kg / m3, durability at a bend - 70-350 MPa, time resis-tance - 112-161 MPa, resistance to compression - 7000-2000 MPa, the module of elasticity 84 - 141 GPa. Hardness - 7000-10500 MPa. Thermostability - 500-9000 С.

The sitalls technology includes stages of heating a glass, forming products and special thermal processing.

Technical sitalls receive on the basis of artificial mixtures with the special additives, serving as catalysts and the centers of crystallization of glasses.

As the last are applied: metal Au, Ag, Cu, Pt, Pd; oxide TiO₂, P₂O₅, Cr₂O₃, ZrO₂, ZnO, fluorides Na₃AlF₆, Na₂SiF₆, CaF₂, etc.

Today they are widely used in aviation, electronic, chemical, by-product-coking industry and a petroleum-refining industry, in hydraulic engineering construction, in everyday life.

Formation of a defective layer except for power influence is attected also with a thermal stream from a zone of contact. It forms thermoelastic pressure in blanks which can cause growth of a crack. It occurs at the limiting size of a thermal stream dependent from K_1c, thermalphysic properties of a processable material (factor of heat conductivity , the size of defect l_c and his orientation

Limiting value of normal making force of cutting of the width of a unit circle can be determined on the following dependence:

where – Poisson factor;

       – Factor of temperature linear expansion of a material;

       - Factor of heat conductivity of a processable material

Using the received dependence, it is possible to define values of radial making force, at which thermal stream from a zone of contact does not result in development of defects. As calculations show, from 70 up to 85 % of heat from a zone of contact at deep flat longitudinal grinding ceramics leaves in preparation. The increase in modes of proc-essing results in reduction of limiting value of normal making force of cutting. With increase in an operating time of a circle the factor of abrasive cutting decreases, it also leads at constant modes of processing to reduction of limiting value of normal making cutting force at which does not lead to development of defects under the thermal factor.

List

1. Справочник технолога - машиностроителя/ Под ред. А. Г. Косиловой, Р. К. Мещерякова. - М.: Машиностроение. 1972. - Т1 и Т2

2. Моделирование систем с распределёнными параметрами: Монография/ А.В. Усов, А.Н. Дубров, Д.В. Дмитришин. - Одесса: Астропринт, 2002. - 664 с.

3. http://home.nestor.minsk.by/build/press/2006/09/1212.html