SU1162770A1 - Method of obtaining vacuum-tight aluminoxide ceramics "lidar" - Google Patents

Abstract

The method of obtaining vacuum-tight alumina ceramics by forming blanks, pre-stage calcination, impregnation in Mgtf / solution, drying and final calcination, characterized in that, in order to increase the yield of suitable products, the impregnation is carried out in 33% alcohol solution for 5-7 minutes, drying is carried out at a rate of temperature rise of -3540 ° C / h to lOOilOC, kept at this temperature for 1.5-2 hours, then heated at a speed of up to 550, and the final calcination is carried out in the following mode: temperature rise at a rate of 1450 ±, all rzhka 25-35 min, temperature rise at a rate of 220 5C / h, (A holding at maximum temperature 50-60 min.

Description

J1

The invention relates to the production of non-porous ceramic products and blanks and can be used in electronic, electrical, machine-building industry, in particular in the manufacture of blanks for welding microtool for soldering (unwinding) integrated circuits,

A known method for producing vacuum-tight alumodex ceramic p.

The closest technical solution to the present invention is to obtain vacuum-tight alumina ceramics by molding blanks, pre-burning at 1200 ° C, impregnating with 10% aqueous solution of MgCtt for 60 minutes, drying with SO-IOO C and final calcination in a hydrogen furnace at 1700-20 C.D.

The disadvantage of this method in the low percentage of yield of products - 7-10%.

The aim of the invention is to increase the percentage of yield of products.

The goal is achieved by the fact that according to the method of obtaining vacuum-tight alumina ceramics by molding blanks, preliminary roasting, impregnation in MgCEi solution, drying and final roasting, impregnation is carried out in a 33% alcoholic solution of MgCj for 5-7 minutes, drying is carried out with a temperature rise rate of 35-40 C / h to 100 ± 10 C, hold at this temperature for 1.5-2 h, then heat at a rate of 55 C / C 550-10 ° C, and the final calcination is carried out according to the following mode: temperature rise with a speed of 415i5C / 4 to U50i10 C, shutter speed 25-35 min, p temperature rise at a speed of 220 ° C / h, shutter speed

with a maximum temperature of 50-60Mv (ti I

The proposed method is carried out as follows.

Molded blanks are pre-baked, then they are dipped in a 33% alcohol solution of MgCtj for 5-7 minutes. After impregnation, the billet is dried and subjected to final firing. When using a solution of MgCE. with a concentration of less than 33%, an increase in the porosity of the final products is observed.

The boundary parameters of the method and characteristics of the obtained ceramics are presented in table 1.

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Table 1

Time of holding in fQ 33% solution.

min

Heating rate

to lOOtlOC, ° С 35

40

Lead Time

at 100 ± 10 С, h 1.5 2

Speed of temperature rise up to 500 ± 10-С, С / h 55 55

Cooling with oven at speed, s / h

Lifting speed

temperature up to

1450110 С, s / h

Time out

at a temperature

1450ЯOS, min

Lifting speed

temperatures up to. 1670 ± 10С, ° С / h 215

225

50 60 325 325

0,006 0,007 45 45

As can be seen from table 1, the proposed method provides a higher

the percentage of the yield of useful products, rather than the known one, in which the obtained products have a porosity of 0.2-0.4%, and the percentage of yield of suitable ceramics (for a microtool) is 7-10%.

In this method, an increase in the porosity of ceramics and a decrease in the yield of usable products for a microtool (Tables 2–7) is observed.

The effect of exposure at 100t10C during the drying of the blanks on their poris

Note. A longer delivery at 100 ± 10 ° C makes no sense for economic reasons.

The dependence of porosity and the percentage of yield of a suitable microtool on the temperature of drying the blanks at 550 are given in Table 3.

Table 3

Table 5

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Continuation of table 6

0,008 45

V

0.03 30

The dependence of the porosity and the percentage of yield of a suitable microtool on the delivery time of blanks at 1670i, tlO.C are given in Table 7. .

Table 7

40 45

0,008

45 50 0,006.

Continued table. 7

Ceramics, obtained by the proposed method, has the following characteristics:

4.03

4100

Not changed

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Claims (1)

A method of producing vacuum-dense alumina ceramics by forming blanks, preliminary firing, impregnation in a Mgti ^ solution, drying and final firing, characterized in that, in order to increase the yield of suitable products, the impregnation is carried out in a 33% alcohol solution of MgC £ _a for 5-7 minutes, drying at a speed lead lift 'temperature 3540 ° C / h to 100 ± 10 ° C, held at this temperature for 1.5-2 hours, then heated at a rate of ⁵⁵ C / h to 550 ± * 10 ° C, and the final firing is carried out according to the following mode: temperature rise at a speed of 415 £ 5 C / hr to 1450 ± £ 10 ° C, 25-35 min exposure, recovery. temperature at a rate of 220 £ 5 ° C / h, exposure at a maximum temperature of 50-60 minutes.