JPH02258205A - How to join ceramic molded bodies - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a joining method for joining a plurality of ceramic molded bodies to each other and assembling them into a molded body of a desired shape.

[Conventional technology]

The slurry casting method, in which slurry with suspended ceramic particles is cast into a water-absorbing mold such as a plaster mold, and the slurry is deposited by the water-absorbing action of the water-absorbing mold, is the most commonly used method for forming ceramic molded bodies. It is being said. By applying rotational motion to the water-absorbing mold during slurry casting and depositing the material into the mud under the action of centrifugal force, it is also possible to obtain a highly dense ceramic molded body having a hollow cylindrical shape. The molded product is useful as a piping material that requires heat resistance, abrasion resistance, etc.

[Problem to be solved by the invention]

A hollow cylindrical ceramic molded body obtained by mud casting is useful as a piping material, but the shape of the molded body is limited to a straight cylindrical body (straight pipe) having a --like cross-sectional diameter. However, the piping structure requires flanges for connecting pipe materials, and often requires the incorporation of irregularly shaped pipes such as bent pipes such as 90'' Nirbow pipes and single-shaped and Y-shaped pipes.

In view of the above, the present invention provides a joining method for joining a plurality of ceramic molded bodies formed by plaster casting to assemble them into a member shape required for a desired use.

[Means and effects for solving the problems] The present invention provides a method of butting and joining ceramic molded bodies formed by depositing mud on a water-absorbing mold, which are in a wet state after being removed from the water-absorbing mold. The parts of each ceramic molded body that are to be joined to each other are shaped into shapes that can be butted together, and after applying a slurry of the same type as the raw material of the molded body to each of the butting surfaces, the butting surfaces are pressed together. , it is characterized by drying while maintaining the state in which pressing force is applied.

The present invention will be explained in detail below.

The present invention is for joining ceramic molded bodies that are still in a wet state after being molded in a water-absorbing mold and removed from the mold.According to the present invention, first, each ceramic molded body is bonded. A surface (butting surface) that allows mutual butting is formed at the location where the two join together. Figure 1 shows the end face (
11) and the plate surface (21) of a donut-shaped disk body (20) to assemble a flange pipe. Since is a flat surface, all you need to do to shape the abutting surfaces is to smooth each surface with a spatula to make it a smooth surface.
This is an example in which two straight hollow cylinders (30) and (40) are joined in orthogonal directions and assembled into a T-shaped tube. In this case, the body of one hollow cylinder (30) is attached to the body of the other An opening (32) that matches the inner diameter of the hollow cylinder (40), and an arcuate surface (41) that matches the outer peripheral surface of the one hollow cylinder (30) on the end face of the other hollow cylinder (40). ) with a knife or the like, and then smooth the outer surface (31) around the arcuate surface (41) and the opening (32) facing it with a spatula to achieve the shaping of the abutting surfaces. FIG. 3 shows two straight hollow cylinders (50) and (60) and a plurality of toric bodies (70, 70, . . . ) having an inclined end surface (71) (this one is a straight hollow cylinder). This is an example of forming a bent pipe such as a 90° nirbow by combining hollow cylindrical bodies (which may be cut at an angle), and in this case, the shaping of the abutting surfaces is the shape of the respective end faces (51) (
61) (71, 71,...) can be smoothed by smoothing it with a spatula.

After shaping the abutting surfaces of each ceramic molded body, plaster is applied to the abutting surfaces. The reason why plaster is applied to the abutting surfaces is to give the abutting surfaces a viscous state that enables mutual fusion and bonding. That mud is
It is sufficient to use the same type of mud as that used for casting the ceramic molded body, but the water content should be 1.
It may be as low as ~2% by weight. The plaster can be applied by brushing or the like.

The plaster is applied to the abutting surfaces of each ceramic molded body so that each ceramic molded body has a water content of approximately 15% by weight.
While maintaining the above moist state (after removing from the water absorption mold,
It is preferable to carry out the process within about 5 to 6 hours), because the moisture content of the ceramic molded body (immediately after demolding, about 18 to 6 hours) is preferred.
20% by weight and decreases over time), but about 1
If the slurry is applied when the amount is less than 5% by weight, the moisture in the applied slurry will be rapidly absorbed into the molded object, resulting in a viscous state necessary for sufficient fusion bonding of the butt surfaces. This is because it becomes difficult to do so.

After applying plaster to each abutting surface of each ceramic molded body, the abutting surfaces are immediately butted together and an appropriate pressing force is applied to dry the molded body. Pressure applied to the abutting surfaces The force is, for example, 0.3 to 2 kg
/c1a or so.

If the ceramic molded bodies to be joined are a hollow cylindrical body (10) and a disk body (20) that will serve as a flange, as shown in Fig. 1, place the disk body (20) on a horizontal table and press the disk surface (21 It is preferable to place the hollow cylinder (10) upright on a cylindrical body (10) and use the weight of the hollow cylinder (10) as a pressing force on the abutting surfaces to dry it by leaving it for a predetermined period of time. In the case of assembling the T-shaped tube shown in Figure 2, the same procedure as above is used.
One hollow cylindrical body (30) is held horizontally, and the other hollow cylindrical body (40) is placed upright thereon so that its own weight acts as a force to press the abutting surfaces. If the pressing force is insufficient due to its own weight, a load may be applied from above to compensate for the insufficiency.

In addition, when assembling the bent pipe shown in Figure 3, for example, use an appropriate outer frame member to maintain the shape of the bent pipe and bind it with a rubber band or the like to apply a pressing force to the abutting surfaces. Bye.

Drying with the abutting surfaces pressed can be done naturally in the same way as for normal ceramic molded bodies, and the drying time is approximately 1.
Drying treatment is achieved by leaving it for about 20 hours. As a result, a molded article is obtained in which the ceramic molded bodies are integrated by complete fusion bonding of the abutting surfaces. The steps including the sintering treatment after drying may be performed in the same manner as for ordinary ceramic molded bodies.

Although there is no restriction on the material of the ceramic molded body to which the present invention is applied, for example, aluminum titanate (A1, TiOS)
100 parts by weight of powder, 5 to 15 parts by weight of kaolin powder, 5 to 10 parts by weight of alumina powder, and appropriate amounts of necessary slurry conditioners (e.g., peptizers such as sodium pyrophosphate, sodium aluminate, ethylamine, piperidine, etc.) (For example 0.
3 to 0.7 parts by weight) is suitably used for joining ceramic molded bodies obtained by casting a slurry containing 3 to 0.7 parts by weight (this body is useful, for example, as a radiant tube for a steel heating furnace).

〔Example〕

(1) Molding of test ceramic molded body: 85 parts by weight of aluminum titanate powder, 1 part by weight of kaolin powder
0 parts by weight, 5 parts by weight of alumina powder, 0.5 parts by weight of deflocculant (sodium pyrophosphate), and water (solid content 100 parts by weight).
Prepare slurry (powder average particle size: 1 am) consisting of 25 parts by weight), perform centrifugal casting (centrifugal force on the circumferential surface of the water absorption mold is 7G in gravity multiple), and The hollow cylindrical body (10) shown in the figure and the disc body (
20) was molded.

Hollow cylindrical body (10) outer diameter near 0m, inner diameter: 50+ms
, body length: 500 mm, outer diameter of disc body (20): 110
m, inner diameter: 50■, wall thickness: 10IIIl.

(II) Butt joining of ceramic molded bodies: After smoothing the end face (11) of the hollow cylindrical body (lO) and the disc surface (21) of the disc body (20) with a spatula, Brush on the plaster and immediately remove the disc (
1O) and the hollow cylindrical body (20) are stacked on a horizontal table and left in the air for 120 hours to dry.The mating surfaces of each molded body are coated with slurry for about 3 hours after being removed from the water-absorbing mold. The test was carried out at a certain point in time (water content of the molded body was about 16% by weight). Further, the water content at the end of drying is about 0.4% by weight.

(III) Firing of the compact and measurement of bonding strength After the above-mentioned bonded compact was sintered in a sintering furnace at 1150°C for 10 hours, a rectangular parallelepiped was formed from the area including the joint of the sintered crystal. A test piece a (thickness direction length: 5 m2, circumferential direction length: 5011.Axial direction length: 4011I11), and a test piece having the same shape as above from the area of the hollow cylinder (lO). The pieces were cut out and the strength of each piece was measured using a three-point bending method, and the following results were obtained.

Test piece a (joint part)...500 kgf/cd Test piece b (non-joint part)...700 kgf/c4 As mentioned above, butt joints are required as structural materials such as piping materials. It has sufficient strength.

〔Effect of the invention〕

According to the method of the present invention, a plurality of ceramic molded bodies can be assembled into various shapes, and the joints thereof have sufficient strength required for various structural materials. Therefore,
The degree of freedom in designing the shape of ceramic products is increased, and a great effect can be obtained in expanding and diversifying their uses.

[Brief explanation of drawings]

1 to 3 are diagrams showing examples of joining ceramic molded bodies according to the present invention, in which FIG. 1 is a perspective view, FIG. 2 is a front view,
FIG. 3 is a side view. 10, 20.30.40.50.60. : Ceramic molded body. 11, 21.31.41.51.61.71. : Butt surface.

Claims (1)

[Claims] 1. In a method of butting and joining ceramic molded bodies formed by applying mud to a water-absorbing mold, the parts of the ceramic molded bodies that are in a wet state after being removed from the water-absorbing mold are joined to each other. , shaped into a shape that can be butted, coated each of the butt surfaces with the same type of slurry as the raw material slurry of the molded object, and then pressed the butt surfaces together and maintained the state in which pressing force was applied. A method for joining ceramic molded bodies, which is characterized by drying.