JPH01219076A - Production of ceramic sliding material - 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 method of manufacturing a ceramic sliding material used as a bearing or the like.

(Prior art) Sliding members such as bearings generally use soft metals such as copper alloy, lead alloy, zinc alloy, or aluminum alloy, and sintered bodies of carbon powder or metal powder.
It is also known to use a porous body of silicon carbide as disclosed in No.

(Problem to be solved by the invention) In the case of soft metals, sufficient load carrying capacity and wear resistance cannot be exhibited under severe usage conditions, and bearings made of porous bodies simply made of ceramic (silicon carbide) cannot be used. In this case, the bearing surface cannot be machined smoothly and the mating material may be damaged.

(Means for Solving the Problems) In order to solve the above problems, the present invention mixes ceramic powder, foamed resin beads, and a true solvent to form a slurry,
This slurry is injected into the mold, and while the slurry dries, the resin beads are aggregated in the center, and the resin beads are fused together using a true solvent.The resin beads are then scattered, making the center porous. A calcined body was prepared, and after forming pores on the sliding surface of the calcined body, wood firing was performed.

(Function) When the slurry solidifies in the mold, the foamed resin beads are pushed inward as the ceramic powder forms a skin layer, and also moved inward due to the difference in surface tension. The resin beads stick to each other due to the action of the solvent and move inward, resulting in agglomeration of the resin beads in the center of the molded body, which is then scattered during pre-firing to form a porous part.

(Example) Embodiments of the present invention will be described below based on the accompanying drawings.

In the present invention, first, as shown in FIG. 1, a slurry 1 containing ceramic powder, foamed resin beads, and a true solvent such as acetone or methyl acetate is poured into a mold 2.

Here, as the ceramic powder constituting the ceramic slurry 1, Si3N4. SiC.

A sentence 203, Z ro2. Mullite, cordierite, etc. are used, and examples of the resin beads include styrene beads, melamine beads, acrylic beads, and polyamide beads. These are mixed with water or a solution (about 3%) of an organic solvent such as ammonium polyacrylate, water-soluble phenol, or ammonium alginate, and the viscosity is 1 to 100c.
Adjust the slurry to about p.

Then, when the slurry 1 is filled into the mold 2 and left to stand, the slurry starts to solidify from the part that comes into contact with the inner surface of the mold 2, and this solidification causes the resin beads 3 to form inside the mold 2, as shown in FIG. A compacted body 4 is obtained by being pushed by the agglomerates.

This aggregation is more effective if the mold temperature is heated to about 50°C.

Furthermore, the surfaces of the resin beads 3 that were in contact with each other in agglomerated form are melted by the true solvent, and the pieces 3 become continuous with each other.

Next, the molded body 4 is released from the mold, and a true solvent is sprayed onto the molded body 4 from the outside or the molded body 4 is permeated into the true solvent to dissolve the resin component. Then, in order to remove the remaining resin,
After drying at ~150°C for 1-2 hours, drying at 200-300°C for 2-3 hours to degrease and burn and scatter the resin beads 3.
Heat for an hour. Here, since the resin beads 3 are welded at the contacting portions by the true solvent, by burning and scattering the resin beads 3, the inside of the molded body 4 has a three-dimensional network structure in which many pores communicate with each other. It becomes a porous part.

Then, after scattering the resin beads 3, the molded body 4 is
Preliminary firing is performed at 50° C. for 1 hour and then at 1200° C. for 2 hours in an N2 atmosphere. This calcining yields a calcined body that is porous on the inside and dense on the outside.

Thereafter, as shown in FIG. 3, the surface 5a of the surface of the pre-fired body 5 that will become the bearing surface is exposed, and the other surface is covered with a resin film f of polyethylene, polyvinyl, vinyl acetate, etc. HC observed at ~60°C.

Cleaning is performed by immersing in HNO3 or water. Through this cleaning, fine particles and impurities are eluted and the surface 5 that will become the bearing surface is cleaned.
Fine pores of 10 to 30 IL are formed in a, and the internal porous portion and the outside communicate with each other through these pores.

FIG. 4 shows an example in which the sliding material manufactured by the above method is used as a fluid bearing.
Fine pores are formed in the portion 6b in contact with the shaft surface, and fluid is supplied to the shaft surface through the pores.

In addition, in the example, a sliding material made only of ceramic is shown, but after the main firing, molten metal is filled into the pores of the fired body and solidified to form a composite sliding material of ceramic and metal. It is also possible. In this case, a small gap is formed between the metal and the ceramic pores, so this gap can be used for supplying fluid.

(Effects of the Invention) As explained above, according to the present invention, a ceramic material with excellent load-bearing properties and wear resistance, which has a porous interior and a necessary minimum number of holes on the surface (sliding surface). It is possible to obtain a sliding material with high properties.

In addition, in the present invention, since the main firing is performed after the skin layer is formed by preliminary firing, it is easy to secure the shape, the temperature of the main firing can be increased, and a product with excellent strength can be obtained. It will be done.

[Brief explanation of the drawing]

Figure 1 shows the state in which ceramic slurry is injected into the mold, Figure 2 is a cross-sectional view of the molded body, Figure 3 shows the state of cleaning, and Figure 4 shows an example of use. This is a diagram. In the drawings, 1 is ceramic slurry, 12 is a mold, and 3 is a ceramic slurry.
4 is a resin bead, and 4 is a molded body. Patent applicant: Agent for Honda Motor Co., Ltd.
Patent Attorney Part 2 1) Part 1 Patent Attorney
Kuni Ohashi, Patent Attorney, Department
Yama Yu Diagram 2 O

Claims (1)

[Claims] A slurry is created by mixing ceramic powder, foamed resin beads, and a true solvent with water or a solvent, and this slurry is poured into a mold so that the resin beads aggregate in the center and are fused together. After creating a body, the resin beads inside the molded body are burned and scattered, and the central part is calcined to become a porous part with many connected pores, and then the surface that will become the sliding surface is cleaned. A method for manufacturing a ceramic sliding material, characterized in that the internal porous part and the outside are communicated with each other through fine communication holes, and then main firing is performed.