JPH0371390B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for attaching ceramics, which are used for parts of structures or members, to metal for purposes such as heat resistance, wear resistance, and heat insulation.

Generally, it is difficult to bond ceramics and metals. In particular, it is not possible to join by welding. Therefore, conventional methods for joining metals and ceramics include depositing a special metal on the surface of the ceramic and brazing it with the metal, performing diffusion bonding via a special metal, and casting the ceramics together. Methods of mechanical attachment using bolts, studs, etc. are being considered. However, brazing and diffusion bonding methods are generally used at high temperatures, so
There are many problems such as peeling during use due to stress caused by the difference in thermal expansion between the ceramic and the metal, and cracks in the ceramic. On the other hand, mechanical attachment methods using bolts, studs, etc. are susceptible to restrictions due to the shape and dimensions of the attachment member or structure, and each method has advantages and disadvantages and is not practical.

Therefore, the extremely difficult method of attaching ceramics to metal often inhibits their use.

As mentioned above, the present invention actively utilizes ceramics as a part of a member, and thus provides a simple and reliable method for attaching ceramics to metal using an unprecedented method. That is, in the present invention, when attaching ceramics to metal, a recess is provided on the surface of the ceramic that comes into contact with the metal, a metal brazing material having a lower melting point than the metal is placed in the recess, and then the metal and the ceramic are placed in a predetermined position. This method of mounting ceramics is characterized in that the metal, the ceramic, and the brazing material are heated to a temperature higher than that at which the brazing material melts. According to the present invention, a low melting point metal brazing filler metal attached to a recess on the ceramic surface is heated to a predetermined temperature and melts and joins to the metal member, so that a part of the metal member is inserted into the recess of the ceramic. Since it has a protruding shape, separation of the ceramic from the metal member is prevented.

Specific examples of the present invention will be described below.

FIG. 1 shows a first embodiment of the present invention.
A method of attaching a cylindrical ceramic 2 to the inner surface of a cylindrical metal member 1 will be shown. After attaching a low melting point metal such as a brazing filler metal 3 to a plurality of depressions 2a formed on the outer surface of the ceramic 2, the cylindrical ceramic 2 is inserted into the cylindrical metal member 1 as shown in FIG.
When the brazing filler metal 3 is heated and cooled to a predetermined temperature, the brazing filler metal 3 melts and solidifies, the brazing filler metal 3 and the metal member 1 form a metal bond, and the solidified brazing filler metal 3
Since the shape protrudes into the recess 2a of the ceramic, both members 1 and 2 are prevented from coming off.

FIG. 2 shows a second embodiment of the present invention.
A method of attaching a ring-shaped ceramic 22 to a flat metal member 21 will be shown. 22a is a groove-shaped recess provided on the inner and outer surfaces of the ceramic 22, and after a brazing filler metal (low melting point metal) 23 is attached to this,
It is mounted in a predetermined position as shown in FIG. After that, by heating and cooling the whole, the brazing material 2
3 is melted and solidified, and the metal member 21 and the ceramic 22 are melted and solidified by the effects described in the first embodiment.
This is to prevent separation from the government.

FIG. 3 shows a third embodiment of the present invention,
A flat ceramic member 32 is attached to a flat metal member 31.
to show how to attach the two. In this case, a plurality of tapered holes 32a that penetrate the ceramic 32 in the thickness direction and open toward the surface are provided, a brazing material 33 is attached to the bottom of the hole, and heating and cooling are performed in the same manner as described above. It prevents the members 31 and 32 from coming off, and 34 is a plug for covering the tapered hole 32a.

FIG. 4 shows a fourth embodiment of the present invention.
The metal tube 41 and the ceramic tube 42 are connected to the sleeve 44.
This figure shows the case where it is installed through the In this case as well, one or more grooves 42a are provided on the outer surface of the part of the ceramic tube 42 that is inserted into the sleeve 44, and the brazing material 43 is inserted into the groove 42a.
After arranging them, they are assembled as shown in FIG. Thereafter, the joining portion is heated to a temperature higher than the melting point of the brazing material 43 to join the sleeve 44 and the brazing material 43, thereby preventing the ceramic tube 42 from separating. Since the metal tube 41 and the sleeve 44 are joined together by metals, they are joined by ordinary welding or brazing.

Although typical embodiments of the present invention have been described above, the present invention can be used in a wide range of other applications depending on the combination of metal members and ceramic members.

In the present invention, as described above, the ceramic member and the brazing material are not directly joined.
Therefore, due to the difference in thermal expansion between the two members, a slight gap will be created between the two members when used at room temperature after completion of installation. The use of is not recommended.

However, creating a slight gap between the two members is rather advantageous in terms of preventing cracking of the ceramic due to thermal stress when used at high temperatures. Moreover, depending on the usage conditions, it may not be necessary for both parts to be completely joined.
The present invention has a wide range of applications, although there are some restrictions on the conditions of use. For example, the nozzle holes of wear-resistant burner chips used in coal-fired boilers, wear-resistant rectifier plates, parts of pulverized coal conveyance piping, cylinder liners and pistons of internal combustion engines that require wear and corrosion resistance at high temperatures. Effectively used for crowns, parts of supply and exhaust valves, etc.

[Brief explanation of drawings]

Fig. 1 shows a first embodiment of the present invention, which is a sectional view showing how a cylindrical metal and a ceramic fit together, and Fig. 2 shows a second embodiment of the invention, which shows a cylindrical metal and a ring-shaped ceramic fitted together. FIG. 3 is a cross-sectional view showing the fitting, and FIG. 3 is a cross-sectional view showing a dual structure of a metal member and a ceramic member, and FIG. 4 is a fourth example of the present invention, in which a metal tube and FIG. 3 is a cross-sectional view showing how ceramic tubes are fitted through a sleeve. 1...Metal tube, 2...Ceramics tube, 2a...
...Groove-like depression provided on the outer surface of the ceramic tube, 3... Brazing metal (low melting point metal), 21... Metal plate, 22... Groove-like recess provided on the inner and outer surfaces of the ceramics, 23... Brazing filler metal, 31...metal plate,
32...Ceramics plate, 32a...Tapered hole provided in the ceramics plate and opened to the outer surface, 33...
...Brazing metal, 34...Plug, 41...Metal tube, 42...
...ceramics tube, 42a...groove-shaped recess provided on the outer surface of the ceramic tube, 43...brazing material, 44...sleeve.

Claims (1)

[Claims] 1. When attaching ceramics to metal, make a recess on the surface of the ceramic that will come into contact with the metal,
After placing a brazing filler metal of a metal with a lower melting point than the metal in the recess, the metal and the ceramic are attached to a predetermined shape, and the metal, ceramic, and brazing filler metal are heated to a temperature higher than that at which the brazing filler metal melts. A method for installing ceramics that involves heating.