JPS59153876A - Composite material coated with sprayed film containing needlelike ceramic fiber - Google Patents

Abstract

PURPOSE:To prevent the resulting titled composite material from causing carcking and stripping due to aging by spraying a powdered spraying material contg. dispersed needlelike ceramic fibers on the surface of the base of an article to form a film. CONSTITUTION:Needlelike ceramic fibers such as SiC or Si3N4 whiskers are dispersed in a powdered spraying material. The spraying material contg. the dispersed fibers is sprayed on the surface of the base of an article by plasma or flame spraying to form a sprayed film. The adhesive strength of the sprayed film to the surface of the base is very high, so the resulting composite material does not cause cracking and stripping due to aging.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a composite material coated with a thermally sprayed coating in which acicular fibers of 1311Vi ceramic are dispersed.

BACKGROUND ART Thermal spraying methods, in which a thermal spraying material is melted and sprayed onto the target substrate surface for coating, have been widely used industrially.

However, the adhesion of thermal sprayed coatings obtained by spraying and coating various thermal sprayed materials onto the substrate surface of the intended article is not necessarily strong, often causing cracking and peeling over time. Also, high-temperature or ultra-high-temperature materials manufactured using high-melting-point metals, ceramics, cermets, etc. as thermal spray materials have not been able to fully demonstrate their properties. On the other hand, similar defects are likely to occur when a low melting point resin is coated on the surface of a substrate such as gold 14.

The adhesion between the article substrate surface and the coating depends on various factors such as the material of the article substrate, thermal spraying pretreatment, and the type of thermal spraying material. It has been extremely difficult to completely avoid crack peeling over time.

The present invention has been achieved in view of the above points, and aims to provide a composite material that has extremely high adhesion between the thermal sprayed coating and the substrate of the article, and does not cause cracks or peeling over time.

The present invention will be explained in detail below.

In other words, the gist of the present invention is as follows.

It is a composite material that is coated with a thermally sprayed coating in which ceramic acicular fibers are dispersed and mixed in a thermally sprayed powder material.

Powder spray materials such as aluminum, cobalt, nickel, copper, and tac-X-ten are used here.

Wire mesh such as molybdenum and its low alloys, AllOs.

ZrO,, MgOl Cr, Of MgO-
8iO*, 2Mg0”2Aj嘗 On”8i0
．． .

26g0@S 1Ox ZrSiO,, MgTi0. Town #go, MgZr0.
, Mg, Alx Os 71 which heat resistance, low expansion,
Ceramics with electric axis properties and magnetic properties, an additional 40%
Co+'lro@mixture.

4096Ni+Al5Os mixture, 12%Co
+ Resins that can be replaced with cerments such as wc mixtures, epoxies, polyamides, etc.

Ceramic acicular fibers are made of silicon nitride and silicon carbide, which have many properties such as thermal shock resistance, low thermal expansion, heat resistance, and chemical resistance, and are acicular single crystals with a very large aspect ratio. Ceramic couskers are most suitable, and other suitable materials include alumina couskers and short fibers obtained by shredding other ceramic continuum fibers such as alumina couskers, other ceramic couscars, silicon carbide fibers, carbon fibers, and glass fibers. It is possible.

As for the silicon nitride or silicon carbide in the shaft, for example, the ceramic Weisker is disclosed in Japanese Patent Application No. 56-88095 (III Box 57-196), which the applicant has already filed.
711! > It is preferable to use silicon nitride whiskers or silicon carbide whiskers obtained from Japanese Patent Application No. 118878/1987, Japanese Patent Application No. 551969/1982, 4I Application No. 96791/1982, and Japanese Patent Application No. 288849/1985. .

Further, the blending ratio of the powder sprayed material and the ceramic needle fiber is 1 to 50 wt%, preferably 8 to 2 wt% of the ceramic needle edge # to the powder spray material (100wt96).
5 wt%, but at this time, this powder thermal spray material and ceramic needle fibers are mixed with carboxymethyl cellulose (
CMc ) Y In short, the axiality of the sprayed material changes when it exceeds 50vvt%.

As mentioned above, the content of ceramic fiber is 1~
5Q wt%, preferably ha~25 wt%,
A combined effect is achieved without sacrificing both the adhesion of the thermal spray material and the properties of the ceramic acicular fibers.

CMC binder can be granulated, and one particle size may be 10μ to 500μ, preferably 50μ to 10μ.
If you adjust it to around 0μ, it will be easier to spray.

Then, as mentioned above, the powder spray material and ceramic acicular fiber granules mixed in a predetermined ratio are sprayed and coated on the surface of the target article by a thermal spraying method. The material composing is sI
C,,sl,N4. siβ.

f 47 o, / ZrO, Alyu 03. Heat-resistant shock-resistant and low thermal expansion ceramics such as cordierite and mullite porcelain.

Fireproof materials, fireproof insulation materials using ceramic fibers, and sound materials such as iron, stainless steel, and aluminum can be used. When the surface condition of the thermally sprayed coating of the resulting composite material of the present invention was observed using a scanning electron microscope, it was confirmed that ceramic acicular fibers were uniformly dispersed in the coating in no direction. The surface of both the powder sprayed material and the ceramic quisker is melted and welded, and the shape of the mink quisker does not change substantially due to the aging force of the mink quisker, resulting in breakage and cranking. Since no cracks were observed, it is recognized that the reinforcing effect of the whisker composite, such as improved mechanical strength, is significant.

The reason for the formation of such a strong thermal spray coating is firstly the FRC, FRM and FRP effect due to fiber reinforcement.

The second effect is the adjustment effect of the difference in thermal expansion between the substrate and the film. especially! ? ! In consideration of the difference in expansion, two layers and eight layers of undercoat are used, but with the great invention, it is possible to omit the undercoat in some cases.

Next, wheat is shown as an example of a composite material obtained through experiments.

Claims (3)

[Claims] (1) A composite material coated with a sprayed coating consisting of a dispersed mixture of ceramic acicular fibers in powder sprayed material. (2) @Tt In the composite material according to claim 1, the ceramic acicular am is characterized in that it is a nitrogen (U) silicon whisker, a silicon carbide whisker, a Cefmin whisker such as a lumina whisker, or a Cefmin whisker. Composite material 0 (3) In the composite material according to claim 1, the ceramic acicular fibers are charcoal, silicon, wI. Composite material 0 characterized by being short fibers obtained by shredding other ceramic continuous fibers such as fibers, carbon fibers, glass fibers, etc.