JPH02213458A - Method for sealing thermally sprayed ceramic material - Google Patents

Abstract

PURPOSE:To perfectly seal the pores of a thermally sprayed ceramic material by heating the material under reduced pressure to dry the material, sucking a monomer into the pores under reduced pressure, then impregnating a polymerization catalyst-monomer mixed soln. into the pores and polymerizing the monomer. CONSTITUTION:The thermal sprayed ceramic material is heated under reduced pressure and dried to perfectly remove the water. The material is then cooled under reduced pressure, and a monomer (e.g. styrene) is flushed and sucked into the pores of the material. The material is then dipped under pressure into a mixed soln. contg. the monomer and about 3wt.% of the polymerization catalyst (e.g. benzoyl peroxide) to impregnate the soln. into the pores, and the monomer in the pores is polymerized under the partial pressure of the monomer vapor equilibrated with the temp. and pressure. By this method, a thermally sprayed ceramic material having excellent resistance to corrosion and wear is obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for sealing a product to which ceramic spraying is applied, and in particular to the production of a funnel for a movable vane pump such as an axial fan blade or a V-shape blade. Concerning a method that can be advantageously applied to.

[Conventional technology]

Cefmic's thermal spray material has excellent wear resistance and has recently been used in various products.

For example, movable vane pumps have recently come into widespread use due to their ability to easily perform load fluctuation follow-up control operations for fluid transport. In transportation, the problem of severe wear of movable wings often arises. For this reason, it has been strongly desired to select materials with excellent wear resistance and corrosion resistance.However, materials with excellent wear resistance do not necessarily satisfy corrosion resistance, and conversely, materials with excellent corrosion resistance have high wear resistance. There are many environments where the wear resistance is not satisfied, and the current situation is that the problems of corrosion and wear have not been solved. A method of thermal spraying to improve wear resistance has been proposed.

However, currently developed thermal spraying techniques cannot produce pore-free coatings, which prevents them from being applied to products that require corrosion resistance. To solve this problem, conventional thermal sprayed layers [K
A so-called pore sealing treatment method has been proposed to seal the generated pores.

Conventionally, proposed pore sealing methods include applying emulsions of thermosetting resins such as epoxy resins, polyester resins, and silicone resins, acrylic resins, and vinyl acetate resins, or applying diluted solutions of these resins. There is a method of soaking and impregnating.

[Problem to be solved by the invention]

In the conventional method of applying or impregnating a resin solution, if the dilution rate of the resin is reduced, the viscosity of the solution increases, so it may not penetrate into the pores of the sprayed coating, and may not cover the very surface layer of the sprayed layer. On the other hand, if the dilution rate is increased, it becomes easier to penetrate deep into the pores, but after the solvent evaporates due to drying, holes are formed in the pores again, There are problems such as it being difficult to fill the entire hole with resin, and even with conventionally sealed ceramic sprayed materials, the interface between the sprayed ceramic and the base material corrodes in an environment where it comes into contact with an aqueous solution. Therefore, it is difficult to apply it to products that require long-term durability.

In view of the above-mentioned state of the art, the present invention eliminates the conventional drawbacks in the pore sealing method for Cefmic thermal spraying materials, completely seals the pores of Cefmic thermal spraying materials with resin, and provides excellent corrosion resistance that prevents the penetration of corrosive liquids. The present invention attempts to provide a method for sealing.

[Means to solve the problem]

When performing pore sealing treatment on ceramic sprayed materials, the present invention involves the first step of drying the cefmic sprayed material under reduced pressure while heating it, and the monomer is flashed into the pores of the sprayed material while maintaining reduced pressure and in good condition. A second step of adsorbing the monomer; A third step of impregnating the pores of the thermal spray material with a solution of a mixture of monomers and a polymerization catalyst while maintaining a reduced pressure state; Impregnating the monomer with a solution of a mixture of a polymerization catalyst. This is a method for sealing a ceramic thermal sprayed material, which comprises a fourth step of polymerizing the monomer of the thermal sprayed material under a partial pressure in which the chemical vapor is in equilibrium with the temperature and pressure.

The ceramic spraying material in the present invention includes alumina,
Any highly wear-resistant ceramic material can be used, including tungsten carbide, zirconia, titania, and many others. Furthermore, many compounds such as styrene and methyl methacrylate can be used as the chemical compound, and many organic peroxides such as benzoyl peroxide and bark mill peroxide can be used as the polymerization catalyst. The mixing amount of the polymerization catalyst can be arbitrarily selected depending on the type of product, but preferably 15~! L.

Used in amounts ranging from vtl.

[Effect]

In the present invention, in order to completely fill the resin deep into the fine pores, in the first step, the resin is heated and dried under reduced pressure from the surface in order to completely remove the moisture adsorbed in the pores. If moisture remains, it will not only prevent the monomer from filling all the pores in the monomer impregnation process, but also inhibit wetting of the ceramic and the monomer, so if the monomer is impregnated and polymerized, It is difficult for the ceramic and resin to form an adhesive state.

The second step is a treatment to facilitate the impregnation of the chemical into the pores.The monomer is flashed under reduced pressure and the monomer vapor is introduced into the pores. This is the process of wetting the surface with soap. This step not only serves to complete the monomer impregnation in the next step, but also strengthens the adhesion between the polymerized resin and the ceramic, thereby completely sealing the pores.

The third step is a step of impregnating a polymer mixed with a polymerization catalyst. By completely immersing the ceramic spray material in a 7-mer solution containing a polymerization catalyst and reducing the pressure,
The pores of the ceramic thermal spray material can be impregnated with a monomer mixed with a polymerization catalyst.

The fourth step is a step in which all of the monomer impregnated into the pores of the ceramic thermal spray material is polymerized without evaporation or diffusion. In order to prevent the impregnated polymer from evaporating and evaporating, it is preferable to transfer the monomer vapor into a container whose partial pressure is adjusted to equilibrium at the temperature and pressure at which the monomer is polymerized, and to hold the container until the polymerization is completed.

By carrying out the continuous treatment from the first step to the fourth step as described above, the pores of the ceramic sprayed material can be completely sealed, and a ceramic sprayed material with excellent corrosion resistance can be provided.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail with reference to FIGS. 1 to 8.

Figures 1 and 2 are views showing one aspect of the runner vane of a movable vane pump. Figure 1 is a front view of the shaft attached to the pump body, and Figure 2 is a view of the shaft from above. This is a diagram. Figure 5 shows a 500mm coating on the entire surface of the runner vane excluding the shaft.
FIG. 4 is an enlarged view of a cross section taken in the direction of the arrow A- in FIG.

Figures 5 to 8 are diagrams showing how runner vanes sprayed with alumina are sealed using styrene monomer; Figure 5 is a diagram showing how the sprayed runner vanes are dried under reduced pressure; Figure 7 shows a method of adsorbing hemotsma in the pores of an alumina thermal spray coating film using a flash of hastyrene monomer. Figure 8 shows an embodiment in which the styrene monomer containing benzoyl peroxide is impregnated in a reduced pressure state by immersion, and Figure 8 shows an embodiment in which the monomer impregnated into the pores of the coating membrane of an alumina thermal spray runner vane is polymerized in styrene monomer vapor. It is.

1 to 8, 1 is the runner vane body of the movable vane pump (Japanese AS141Ell), 2 is the alumina spray coating film sprayed on the tip of the runner vane, 3
is a vacuum container with a lid, 4 is a monomer injector with a cock, 5 is a cock, 6 is a vacuum pump, 7 is a styrene monomer i-liquid containing benzoyl peroxide, 8 is a styrene monomer vapor, 9 is a styrene monomer evaporation container It is.

A runner vane was prepared by thermally spraying alumina to a thickness of 500 μm on the tip of the runner vane with a length of 400 mm at the longest part, and after heating the runner vane to 100 °C, it was vacuum bonded to 6
The sample was placed in a container 3 capable of being depressurized, and dried under reduced pressure of 1 tor for 10 minutes while heating to 100°C. (5th
Figure) Next, while maintaining the reduced pressure, the temperature was lowered to room temperature, and then the cock 5 of the styrene monomer injector 4, which had been set in advance on the top of the container 3, was opened to prevent the styrene monomer from coming into contact with the surface of the thermally sprayed coating film. After that, the cock 5 connected to the vacuum pump 6 was closed and held for 10 minutes. (Fig. 6) Next, styrene monomer containing benzoyl peroxide 3wt4 is put into the monomer injector 4, and while the cock 5 connected to the vacuum bonder 6 is opened to reduce the pressure inside the container, the cock 5 of the styrene monomer injector 4 is opened. Open the test runner vane and add 3 yt of benzoyl peroxide until the entire alumina spray coating part of the test runner vane is completely immersed.
A styrene monomer containing 4 was injected, and after 9 hours, the mixture was held for 10 minutes under reduced pressure. (Fig. 7) Next, after releasing the reduced pressure, the runner vane was taken out and transferred to a lidded container 3 equipped with an evaporation container 9 containing styrene monomer.
It was kept at 0C for 24 hours. (Fig. 8) Attach the Amu Mina thermal sprayed runner vane that has undergone the above treatment, the alumina thermal sprayed runner vane that has not been subjected to the sealing treatment, and the alumina thermal sprayed runner vane whose surface is coated with room temperature curing epoxy resin to a movable vane pump. As a result of conducting a durability evaluation test for 6 months while circulating a sulfuric acid solution, no abnormality was observed on the adhesive surface of the runner vane that had undergone the above sealing treatment, whereas the runner vane that had not undergone the sealing treatment And those coated with epoxy resin peeled off from the adhesive surface of the coating and base material.

[Example ■]

A sample ceramic sprayed material was prepared in the same manner as in Example I except that the styrene monomer was replaced with methyl methacrylate monomer and the pores were sealed. This was subjected to a corrosion test under the same conditions as in Example (2), and as a result, it showed good corrosion resistance (1), similar to that obtained by sealing with styrene monomer.

〔Effect of the invention〕

The present invention enables ceramic spraying materials to be applied to corrosive environments where conventional ceramic spraying materials could not be applied, and has the industrial effect of making ceramic spraying materials applicable to all products that require wear resistance. is big.

[Brief explanation of the drawing]

Figures 1 and 2 are diagrams showing aspects of the movable blade runner vane;
Fig. 5 is a diagram showing a state in which ceramic spraying is applied to a part of the runner vane, Fig. 4 is an enlarged view of a cross section taken along arrow A-A' in Fig. 3, and Figs. 5 to 8 are sealing holes. Figure 5 is a diagram showing an aspect of the treatment method, Figure 5 is a diagram showing an aspect of the vacuum drying process of the thermally sprayed runner vane, and Figure 6 is a diagram showing the aspect of the vacuum drying process of the thermally sprayed runner vane, and Figure 6 is the adsorption of hemotsma in the pores of the alumina thermally sprayed coating film by flashing styrene monomer. A diagram showing an embodiment, Figure 7 shows the addition of Pencil Peroxide S to styrene monomer as a polymerization catalyst.
Figure 8 shows the coating film pores of the alumina sprayed runner vane in the styrene monomer vapor by immersing the alumina sprayed runner vane in a solution containing wt4 and impregnating it with styrene monomer containing pencil peroxide under reduced pressure. It is a figure which shows the aspect which polymerizes the monomer impregnated in the inside. Figure 1

Claims (1)

[Claims] When sealing the ceramic sprayed material, the first step is to dry the ceramic sprayed material under reduced pressure while heating it, and while the reduced pressure is maintained, the monomer is flashed to close the pores of the sprayed material. a second step in which the monomer is adsorbed on the thermal spray material; a third step in which the pores of the thermal spray material are impregnated with a solution in which the monomer is mixed with a polymerization catalyst while maintaining a reduced pressure state; A method for sealing a ceramic thermal spray material, comprising a fourth step of polymerizing the impregnated monomer of the thermal spray material under a partial pressure where the monomer vapor is in equilibrium with temperature and pressure.