DE1953891C3 - High temperature! Est putty material - Google Patents

Description

The invention relates to a cement material, in particular for use in cement connections between metal and a ceramic material, between two metals or between two ceramic materials Materials.

Such putty connections are often high in the operation of the equipment in which they are used Exposed to operating temperatures and it is desirable to manufacture them at relatively low temperatures, so that any change in the components is avoided (deformation, brittleness, etc.).

It is known for putty joints., Between a ceramic material and metal or between glass and metal to use stable types of glass that correspond to the Type belonging to the so-called "long" types of glass, d. H. Types of glass whose viscosity over a wide temperature range remains high and their silicon content is high.

The adhesion between glass and metal is brought about by a chemical bond created by the after the layer of oxide remaining between the material and the glass is obtained in the cement; a long" Type of glass that has a high viscosity at the temperature required to produce the cement joint has, makes it difficult to dissolve the oxide layer.

In connection with the wider temperature range in which the viscosity of such cement compounds changes, but becomes the maximum operating temperature of the

Tabel

Devices in which these cement compounds are used are well below the cement temperature.

In addition, the composition of a glass of this type is such that its specific resistance decreases rapidly with increasing temperature.

US Pat. No. 3,113,878 describes a cement material which is composed of devitrifiable types of glass of the "short" type with a relatively low silicon content. The composition of these types of glass described is such that the sum of the three oxides ZnO + B ₂ O ₃ + SiO _{2 is} at least 90%. However, these compositions have a high ZnO content, so that the range of expansion coefficients of the different types of gas is relatively narrow, which limits the possible uses.

The purpose of the invention is to create a new one; Kittmaierial to create that can be applied for many purposes, especially at higher temperatures, wherein the favorable mechanical and electrical properties are retained.

The invention relates to a high-temperature-resistant cement material, in particular for the production of a Connection between materials with a coefficient of expansion between about 45 and 100 · 10-VC, that of a devitrifiable glass of the "short" type based on the oxides of aluminum, boron, silicon, zinc and possibly consists of cadmium and which also contains oxides that supply network-changing ions, such as Alkaline earth oxide or magnesium, said material being characterized in that the amounts the starting components in mol% are within the following limits:

SiO ₂ 9-26 B ₂ O ₃ 9-36 AI ₂ Oj 0-16 CaO + SrO + BaO + MgO 9-56 ZnO + CdO 9-56

mi where the sum of

CaO + SrO-I- BaO + MgO + ZnO + CdO

equal to or greater than 50 mol% isL

Because of their high content of network changing

v, Ions of these types of glass only slightly attack the oxide layer that causes the adhesion between the glass and the metal. For example, various starting compositions of putty materials according to the invention are shown in the table below

■ 50 given:

Composition in mol 1 2 3 % 5 6th 7th 8th 9 10 11th 12th 13th 14th 15th 16 number 15th 15th 15th 15th 15th 35 15th 15th 15th 35 15th 15th 20th 15th 15th O 20th 20th 20th 4th 20th 20th 10 20th 20th 20th 10 20th 20th 15th 20th 15th B ₂ O ₃ 35 5 5 35 5 5 10 15th 5 SiO ₂ 10 15th 15th 10 20th 20th 25th 25th 25th 25th 45 40 55 AI ₂ O ₃ 10 40 CaO 5 20th 25th SrO 5 BaO 50 45 50 40 45 30th 35 40 35 30th 10 40 10 25th IO MgO ZnO 50 53 57 61 35 65 69 70 72 74 76 80 82 83 86 90 99 10 ' Between 20 47 64 and 32O ⁰ C

In certain cases it can be beneficial if at least part of the zinc oxide is replaced by cadmium oxide is replaced,

For example, 50% of the zinc oxide in compositions 5 and 7 can be replaced by cadmium oxide will.

These compositions correspond to devitrifiable short type glasses, borosilicate systems and Borosilico zinc aluminate systems with alkaline earth ions which, if they contain a sufficient number of network-altering ions necessary to produce a good Maintain the required oxide layer. They are made according to the well-known glass technique Temperatures between 12C0 and 1450 ° C processed.

The obtained molten glass is then put into a Converted frit, e.g. B. by having it in water is hardened, after which it is ground; it can then be used as a Kittmaierial. The cement connection is made by the usual techniques in an atmosphere that depends on the nature of the parts to be connected to each other is selected and set.

Due to the selected starting composition and the fine distribution of the ground Putty material transforms the glasses into glass ceramic products, which consist of a vitreous network exist, in which there are finely divided microcrystals of one or more crystal phases. By the The presence of the latter has a favorable effect on the mechanical properties of the connection. Of the Content of crystal phase depending on the starting composition and the temperature at which the compound is produced is dependent, but must remain low in order to achieve that the material between the ι seams of the parts to be connected can flow.

The time and temperature of manufacture of the

Putty connections are therefore not only dependent on the type of parts to be connected, but also in

ίο Dependence on their geometry, their wetting properties and chosen their river.

The mechanical properties of the obtained joints, determined by the flexural strength are given below for various ι Ί experiments in which certain compositions of the table can be used.

The initial composition is chosen so that the expansion coefficient of the cement material the body to be connected is adapted. The conditions under which dip compounds are made are determined by the duration and temperature.

example 1

^{2 r} > Using powders with compositions 0, 1, 2 , 4, 5, 6, 7 and 9 according to the table, cylindrical test tubes from Fernico are connected to one another in a nitrogen atmosphere containing 25% hydrogen and saturated with water vapor at room temperature

ίο soldered.

composition
0 t

Treatment 10 min. At ("C) 950 1100 1050 950 1050 1100 900 1050

Flexural strength in kg / mm- ² 18.1 19.1 17.5 18.1 21.9 18.2 103 8

The flexural strength is still high, even if the expansion coefficient of the connection is different from that of the material to be connected. In mechanical terms excellent results are achieved with putty materials whose expansion coefficients are from 47 to 69 · 10. ⁷

Example 2

With the help of the compositions 1, 2, 3, 5, 6 and 9, cylindrical test tubes are made of sintered Aluminum o.vyd in a non-reduced; identical atmosphere with the end faces cemented together.

composition
1 2

Treatment 10 min. At (° C) 1100 1050 1100 950 1050 1100 1050

Flexural strength in kg / mm- ² 20.9 16.8 29.3 28.0 27 ,? 27.8 19.5

In fact, the intrinsic strength of the connection is greater than in most of the performed

Tests, particularly with compositions 3, 4, 5 and 6, occurred in the alumina fracture.

Example 3

With the help of the compositions 1, 2, 3, 4, 5, 6 and 9 tend and with warning steam from room temperature

if cylindrical aluminum oxide rings were soldered to a cylindri- _b o saturated nitrogen atmosphere, Fernicöringen see a 25% hydrogen containing

Treatment temp. in ° C
Flexural strength in kg / mm

composition
I 2 1050
15.2 3 4th - 6th 9 1000
~ ² 22.0 1100
16.5 900
16.0 1050
16.3 1100
14.3 1050
13.1

The electrical properties of the connections determined by the resistivity as a function of Temperatures to be determined are given in the table below, with measurements using Fernico connections on Fernico with the help of putty materials according to the invention with some compositions the table.

In the last column, the results of the measurements of the specific resistance were compared applied from Fernico compounds to Fernico with the help of a long type glass. With these Compounds, the specific contradiction increases much faster with increasing temperature.

Measurement temperature in "C
300
350

500
550
600
o50
700

material 2 1050 5 C. 1050 Il 11.5 6th q I. HcrMelliingMempcratiir in Log. of the spec. Resistance in 5i ■ cm IA in ς 1000 11.4 9.1 9.6 1100 450 10 8.2 8.8 r \ ι
y, ι 7.4 8.1 11.2 8.2 6.9 7.5 - 10.0 7.4 _ 7.0 ! 0.7 8.9 6.9 6.0 9.8 8.0 6.5 9.0 7.3 6.2 8.3 6, b 7.7 6.0 7.2 6.1

Glass from
"Long" type

P 50

7.6

For example, some Tciic cemented together with the above-mentioned materials are in the Drawings shown. It shows

F i g. 1 connections in a high voltage bushing, namely a connection 1 between metal and metal, a compound 2 / between metal and aluminum oxide and a compound 3 between Metal;

F i g. 2 a connection 4 between a window 5 made of corundum and a Fernicorahmcn 6 and

3 shows a connection 7 between metal 8 and aluminum oxide 9, with the connections below were vacuum-tight.

I sheet of drawings

Claims (1)

Claim: High-temperature-resistant cement material made from devitrifiable glass of the "short" type based on the There is oxides of aluminum, boron, silicon, zinc and possibly cadmium and that too Contains oxides which supply network-changing ions, characterized in that the composition in mol% is within the following limits: SiO ₂ 9-26 B ₂ O ₃ 9-36 AI ₂ O ₃ 0-16 CaO + SrO + BaO + MgO 9-56 ZnO + CdO 9-56 where the sum of CaO + SrO + BaO + MgO + ZnO + CdO
is equal to or greater than 50 mole percent