SU1353728A1 - Method of roasting fine-grained carbon specimens - Google Patents

Abstract

This invention relates to a technology for burning carbon blanks used in semiconductor industry. The method of firing fine-grained billets based on uncaptured coke and pitch involves heating to a temperature of no more than 2–50 ° C / h, followed by cooling, and when cooled to 750–800 s, the billet is reheated for 30–50 s, followed by decreasing the temperature to the initial temperature before heating at a rate of 1.0-1.5 ° C / h and continuing cooling with the indicated reheating and lowering the temperature every 250-300 ° C lowering the temperature. The properties of the obtained carbon blanks after graphitization: tffla tensile strength at: compression - 128-131, bending - 72-78, thickness - 40-44, density 1910 - 1950 kg / m, porosity 9.5–9.9%, electrical resistivity 10.4 - 10.8 10 0mm. 1 hp f-ly, 1 tab. i SL

Description

The invention relates to a process for burning carbon shaped moldings based on non-calcined coke and pitch, used after graphing in semiconductor and other engineering fields.

The purpose of the invention is to reduce the electrical resistivity and improve the physicomechanical characteristics of carbon blanks after their graphitization.

Example 1. Blanks SHG-6 on the basis of non-calcined coke (60 wt.%) And pitch (40 wt.%) With a diameter of 150 and a height of 170 mm are installed in a crucible made of material GMZ, having a height of 500 mm, an internal diameter of 210 mm, wall thickness 20 mm. The workpiece is set on a layer of transfer material 30 mm thick. On top of this, another billet is installed, with the transfer layer between the billets — 10 mm. Installed blanks to the top of the crucible are filled with overfilling, which is a dried coke breeze of the fraction - 5-16 mm with a fraction of 5-0.16 mm no more than 16%. A crucible with billets is installed in an electric furnace with graphite heaters. The working volume of the furnace: height 600 mm, internal diameter 260 mm. The distance of the crucible from the wall of the frame is 5 mm. The firing mode and cooling are carried out by thermocouples (HA), which are evenly spaced along the height of the furnace chamber at a distance of 5 mm from the surface of the blanks. The blanks are heated to 1000 ° C at a rate of 3.0 ° C / h. After heating, the billet is cooled in an oven to 780 ° C and heated at 40 ° C at a rate of 20 ° C / h, followed by cooling at a rate of 1.2 ° C / h to the initial temperature (780 ° C). Then the blanks are heated twice more and

Primary heating temperature during cooling, ° С

Reheat interval, s

270

250

0

five

0

five

cooled again at identical speeds with a 270 ° C cooling interval starting from 780 ° C.

After firing, billets graphitize at a rate of 10 ° C / h in conventional industrial furnaces up to 2400 ° C in chlorine,

The table presents data on the properties of carbon blanks obtained under different firing conditions by the proposed and known methods.

These tables show that the fine-grained carbon blanks obtained by the proposed method have lower porosity, electrical resistivity and better physicomechanical indicators of compressive strength, bending, breaking.

Claims (2)

1. A method of roasting fine-grained carbon blanks based on non-calcined coke and pitch by heating to a temperature of no more, followed by cooling. 1300 ° C characterized in that, in order to reduce the electrical resistivity and improve the physicomechanical characteristics of the baked blanks after graphitization, when cooled to 750-800 ° C, the blanks are reheated to 30-50 ° C, followed by a decrease in temperature to the initial one before heating at a rate of 1, 0-1.5 ° C / h and continue cooling with the indicated repeated heating and a decrease in temperature every 250-300 ° C decrease in temperature, 2. The method according to claim I, about tl and h and h- and and so that the initial heating to the maximum temperature and cooling of the workpieces is carried out with a speed of 2-50 ° C / h, 800 721 824 300 242 311 Indicators, Method of roasting blanks Proposed The value of temperature repeated heating, C40 Cooling rate with repeated heating, ° C / h 1.2 Strength at compression bend thin Density, kg / mz 1950 1910 1920 1900 1890 1810 Porosity,% 9.5 9.9 9.7 Electrical resistivity 10, Ohm 10.4 10.8 10.6 11.2 11.7 14.4 Note: The arithmetic average results of 8-10 measurements are given. Compiled by N. Dergunov. Editor N. Yegorov. Tehred I. Veres. Corrector A.T. Order 5662/20 Circulation 456 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, st. Design, 4. Table continuation Famous thirty 50 25 58 1.0 1.5 0.5 2.1 129 72 40 122 119 71 -65 39 34 110 64 33 10.4 11.0 14.3