JPH0448756B2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a method for producing a fire-resistant composite material,
This invention relates to a method for producing a composite material containing zirconia fibers that can be used as a variety of fireproof materials.

(Prior Art) Conventionally, as a method for obtaining a composite material containing refractory fibers, there have been methods in which a refractory powder is combined with a refractory fiber woven fabric or/and non-woven fabric as a matrix (see Japanese Patent Laid-Open No. 59-26982); A method in which a synthetic inorganic compound zirconia is composited with alumina-sylinker fibers and a silicon nitride coating material is further applied on the surface (see Japanese Patent Application Laid-open No. 78990/1983), ceramic fibers and ceramic powder are combined with inorganic Composite with a binding material, sintering with this composite material, and
Furthermore, there is a method of coating the surface with zirconia powder to form a coating layer (see Japanese Patent Laid-Open No. 60-215582).

(Problem to be Solved by the Invention) However, when coating the surface with a coating agent to form a coating layer, it is necessary to apply thickly to obtain sufficient strength, resulting in an increase in overall weight. There's a problem.

Furthermore, a thin plate-like refractory made of a ceramic matrix and paper-like or cross-like refractory fibers as a reinforcing material cannot be obtained by conventional methods. This is because phenomena such as warping of the thin plate occur during firing.

This invention was made in view of the above-mentioned circumstances, and its purpose is to provide a fire-resistant composite material having a thin refractory layer with sufficient strength on the surface, and a zirconia fiber reinforced with zirconia powder as a matrix. It is an object of the present invention to provide a method capable of manufacturing a composite thin plate-like refractory material as a material.

(Means for Solving the Problem) As a result of various tests and research on fire-resistant composite materials, the present inventors discovered that spraying zirconia powder is effective in achieving the object of the present invention. It was completed.

That is, the method for producing a fire-resistant composite material of the present invention is characterized by thermally spraying zirconia powder onto a zirconia fibrous molded body.

As an embodiment of the present invention, zirconia powder is thermally sprayed on both surfaces of a paper-like or cloth-like zirconia fibrous molded body to form a thin plate fireproof composite material in which the zirconia powder is used as a matrix and the zirconia fibers are used as a reinforcing material. I can do it.

Another aspect of this invention is a blanket-like
A coating layer of zirconia powder can be formed on the surface of a felt-like or board-like zirconia fibrous molded product by thermally spraying zirconia powder onto the surface of the molded product.

This invention will be explained in detail.

Zirconia fibers are used in the present invention, but when used as lightweight furnace materials for clean firing or shelf boards for manufacturing electronics elements or ceramic elements, zirconia fibers are used to prevent reactions with elements. Because it is desirable. The shape of this zirconia fiber molded body can be variously changed depending on the use of the composite material.
As such, board-like, felt-like,
There are blanket-shaped, paper-shaped, cloth-shaped, etc.

In addition to fibers, the zirconia fibrous molded article can contain various additives as necessary.
Specific examples thereof include refractory raw material powder, binder, metal powder, and metal fiber.

When attempting to produce a fire-resistant composite material using zirconia powder as a matrix and zirconia fiber as a reinforcing agent, it is desirable that the zirconia fibrous molded product is paper-like or cloth-like and thermally sprayed from both surfaces. In this case, the preferred thickness is 1~
It is 0.01mm. This is because if the thickness exceeds 1 mm, the sprayed ceramic will not be integrated with the cloth or paper, making it difficult to obtain a composite material. Further, if the thickness is less than 0.01 mm, the reinforcing effect of the fibers will not be exhibited.

The thermal spraying method used in this invention is a plasma jet thermal spraying method. When spraying zirconia with a high melting point (2700℃),
When zirconia fibers are easily altered by heating,
Plasma jet spraying is even more effective.

In the manufacturing method of the present invention, it is desirable to adjust the amount of thermal spraying so that the thickness of the thermally sprayed layer is in the range of 1.5 to 2 times the thickness of the paper or cloth.
This is because outside this range, the reinforcing effect of the zirconia fibers will not be exhibited.

Further, when thermal spraying is applied to the surface of a zirconia fibrous molded article such as a board, felt, or blanket having a thickness of over 1 mm, the thickness of the thermal spray layer is preferably 0.1 mm to 5 mm. This is because if it is less than 0.1 mm, the sprayed layer will be too thin and the product will be difficult to handle, and if it exceeds 5 mm, the sprayed layer will become too heavy and the molded product will break under its own weight.

1 to 3 of the drawings show examples of the method of the present invention, and FIG. 1 shows an example in which a zirconia powder sprayed layer 1 is formed on the surface of a fiber board 2 (Example 1 described later). has been done. Similarly, FIG. 2 shows an example in which the thermal spray layer 1 is formed on the surface of the fiber blanket 3 (Example 2), and FIG. 3 shows an example in which the thermal spray layer 1 is formed on the front and back surfaces of the fiber paper 4 (Example 3). This shows that.

(Function) In the manufacturing method of the present invention, zirconia powder is thermally sprayed. Through this thermal spraying, zirconia powder is
For example, it is heated and melted in a plasma flame, and this molten material collides with the surface of the molded product and is cooled and solidified. Therefore,
The sprayed layer on the surface of the molded product is uniform and dense, and therefore has high strength even if it is a thin layer.

Furthermore, since the zirconia powder is melted at a location away from the zirconia fibrous molded body, deterioration and damage to the zirconia fibers due to heat can be reduced.

〔Effect of the invention〕

The following effects can be obtained by the manufacturing method of the present invention.

(a) The sprayed layer is thin and dense, and has greater strength. By forming the sprayed layer on the surface of the lightweight zirconia fibrous molded body, a lightweight zirconia fibrous composite with only the surface dense and reinforced can be obtained. . Furthermore, when a sprayed layer is formed on the surface of the blanket, a unique composite is obtained which is hard only on the surface and light and flocculent on the rest.

In the conventional method of applying or impregnating a refractory powder slurry on the surface and then firing it, the surface layer deforms during firing, or if the firing temperature is increased to make the surface denser, the fiber layer may crystallize or Grain growth occurs, resulting in alteration and deterioration. This invention does not have the above problems.

(b) A thin plate composite reinforced with zirconia fiber paper or cloth obtained by thermally spraying refractory raw material powder on the front and back surfaces of zirconia fiber paper or cloth with a thickness of 1 mm or less is a thin plate that is dense and tough. The conventional method, in which paper or cloth is coated or impregnated with a slurry of refractory raw material powder and then fired, warps and deforms during firing. This invention does not have the above-mentioned problems.

(c) When a fibrous molded body is used as a ceiling material in a high-temperature furnace, falling of short fibers, a so-called raging phenomenon, occurs, but such a phenomenon can be prevented by implementing the method of the present invention. I can do it.

(d) A fibrous molded product has high air permeability, and when used as a heat insulating material, hot air may enter the product, reducing its heat insulating properties. By using the method of the present invention, such drawbacks can be overcome.

(e) Therefore, a fireproof composite material having sufficient strength and a thin refractory layer on the surface by the production method of the present invention, and a thin plate-like fireproof material made of a composite of zirconia powder as a matrix and zirconia fiber as a reinforcing material. can be manufactured.

(Example) Hereinafter, the present invention will be specifically explained using examples according to the present invention and comparative examples according to a conventional method.

Example 1 A zirconia fiber was prepared by adding zirconium acetate as a binder, vacuum forming it, and then heat-treating it at 300°C. Zirconia powder of 0.3 mm or less is sprayed on the surface of the obtained 30 mm thick zirconia fiber board by plasma jet spraying, and only the surface layer has a bending strength of about 1 mm and an apparent porosity of 8% of zirconia.
A zirconia fibrous refractory composite with a dense layer of 100 Kg/cm ² could be created.

Comparative Example 1 A refractory composite material was manufactured using the conventional method, that is, impregnated with zirconia powder slurry of 0.3 mm or less to a thickness of 1 mm, and then fired at 1750°. This surface layer had a porosity of 20% and a bending strength of 20 kg/cm ² .

Example 2 Zirconia powder of 0.3 mm or less was sprayed on the surface of a 50 mm thick zirconia fiber blanket by plasma jet spraying, and only the surface layer was coated with a hard dense layer of zirconia with an apparent porosity of 5% and a bending strength of 150 Kg/cm ² and a thickness of 2 mm.
was formed. This zirconia fibrous fireproof composite was hard only in the surface layer of 2 mm, and the rest maintained the cotton-like state characteristic of fibers.

Example 3 Zirconia powder of 0.1 mm or less was sprayed on the front and back surfaces of a 0.5 mm thick zirconia fiber paper by plasma jet to produce a 0.7 mm thick composite material in which the zirconia fiber paper and the zirconia powder were integrated. The physical properties of the obtained zirconia fiber-reinforced thin plate are as follows: Bending strength: 100 Kg/cm ² Apparent porosity: 9% Maximum deflection: 20 mm (Maximum deflection at failure when measuring bending strength with a span of 100 mm: m/m Comparative example 2 As a conventional method, a 0.5 mm thick zirconia fiber paper was impregnated with a zirconia powder slurry of 0.1 mm or less and then fired at 1800℃ to produce a 0.7 mm thick composite.After firing, the prototype was concave upward. It was warped and it was not possible to obtain a smooth thin plate.
Its physical properties were as follows: bending strength: 20 kg/cm ² apparent porosity: 18% maximum deflection: 5 mm, and was completely different from the composite material obtained in Example 3.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view schematically showing a composite material obtained from Example 1, FIG. 2 is a cross-sectional view schematically showing a composite material obtained from Example 2, and FIG. 3 is a cross-sectional view schematically showing a composite material obtained from Example 3. FIG. 2 is a cross-sectional view schematically showing the obtained composite material. 1... thermal spray layer, 2... fiber board, 3...
... Blanket, 4... Paper-like fibrous molded article.

Claims (1)

[Claims] 1. A fire-resistant composite in which zirconia powder is melted and sprayed with plasma flame on both surfaces of a paper-like or cloth-like zirconia fibrous molded body, and the zirconia powder is used as a matrix and the zirconia fibers are used as a reinforcing material. Method of manufacturing fire-resistant composite materials forming materials. 2. Production of a fire-resistant composite material by melting and spraying zirconia powder on the surface of a zirconia fibrous molded body in the form of a blanket, felt, or board using a plasma flame to form a coating layer of zirconia powder on the surface of the molded body. Law.