JPH04312802A - Manufacture of ceramic component - Google Patents

Abstract

PURPOSE:To enable components to be manufactured which are hard to manufacture in the case of employing an ordinary mold by injection molding techniques for ceramic powder, and also enable components to be manufactured by employing an inexpensive mold, which are difficult to manufacture unless a slide core or the like is not employed. CONSTITUTION:Spherical components 1 are made by the use of brass and then set in cavities formed in a mold 3 at the movable side and formed into a rectangular parallelopiped shape. Into this cavities, a well mixed material of ceramic powder, thermoplastic as a binder, lubricant, and plasticizer is injected by means of an injection machine. After molding, cooling is effected and the mold is made open for removing a molding 5 and cutting the gate 6 to thereby obtain molded components cross-sectionally shown in the figure. The components are immersed in a nitrate solution of 10% so as to chemically solve the brass to thereby obtain components forth cross-sectionally in the figure. Thereafter, debinder and baking are effected for obtaining baked components.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing complex and precise ceramic parts using ceramic powder.

0002

BACKGROUND OF THE INVENTION In conventional injection molding technology for ceramic powder, various measures have been taken to manufacture complex and precise parts, such as adding a slide core to the mold. However, even with such efforts, there were parts whose shapes could not be molded into the desired shape. Furthermore, even in the case of parts that can be manufactured using slide cores, there are drawbacks such as the cost of the mold being very high and the manufacturing time of the mold being extremely long.

0003

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, facilitates the manufacture of molds, and reduces the cost of molds, thereby making it possible to manufacture complex or precise parts. Furthermore, it is possible to manufacture parts with shapes that could not be manufactured using conventional molds.

0004

[Means for Solving the Problems] In order to solve the above problems, the present invention provides a method for solving the above problems.
After a metal part that is easily dissolved chemically is set in the cavity of a mold, a material made of a mixture of ceramic powder and an organic binder is injected to obtain a molded body. Thereafter, the metal parts set in this molded body are chemically melted to obtain a molded body made only of the injected pellet material. By degreasing and sintering this molded body, desired shapes or precision parts are manufactured.

[0005]

[Function] The present invention makes it possible to manufacture complex and precise parts without using expensive molds, and also enables the manufacture of parts that cannot be produced with ordinary molds.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below with reference to the drawings. A spherical part 1 was made using a brass material and set in a cavity 2 formed in a rectangular parallelepiped shape in a mold 3 on the moving side. A well-mixed material of alumina powder, a thermoplastic plastic as a binder, a lubricant, and a plasticizer was injected into this cavity using an injection molding machine. At this time, the alumina powder used had an average particle size of 0.6 μm. In addition, thermoplastic materials include polystyrene,
Ethylene vinyl acetate and butyl methacrylate were used, stearic acid was used as a lubricant, and dibutyl phthalate was used as a plasticizer.

[0007] At this time, the ratio of alumina and organic binder material was set to 100:16 by weight. Also, the molding temperature is 17
The temperature was set at 5°C. After molding, the mold was cooled, the mold was opened, the molded body 5 was taken out, and the gate 6 was cut to obtain a molded part as shown in the cross-sectional view in FIG. This part was immersed in a 10% nitric acid solution to chemically dissolve the brass, yielding a part as shown in cross-section in FIG. Thereafter, organic substances were removed in a debinding furnace in an air atmosphere. The binder-removed molded body was heated in an atmospheric furnace for 1600 min.
Sintering was carried out at 0.degree. C. to produce a sintered part as shown in cross-section in FIG. The density of the sintered body is 99% of the true density of the material.
Met. The part according to this example had a shape that could not be manufactured using a normal injection mold.

Suitable materials for the parts to be set in the cavity in the present invention include aluminum, zinc, copper, and other chemically inorganic materials that are easily soluble in acids. Further, the parts to be set in the cavity can be formed by machining, lost wax method, die casting method, powder metallurgy method, etc. Further, although the embodiments have been described using alumina as an example, similar effects can be obtained with zirconia, silicon nitride, and the like.

[0009]

Effects of the Invention As described above, the present invention allows parts that are difficult to manufacture using ordinary molds to be manufactured, and also allows parts that are difficult to manufacture without using slide cores etc. to be manufactured using inexpensive molds. It has the advantage that it can be used and manufactured.

[Brief explanation of drawings]

FIG. 1 is a diagram schematically showing a cross section of a mold showing a molding state for explaining the present invention.

FIG. 2 is a diagram showing a cross section of an injection-molded molded article.

FIG. 3 is a diagram showing a state in which parts set in a cavity from an injection-molded molded body are chemically melted.

FIG. 4 is a sectional view showing a sintered state.

[Explanation of symbols]

1 Insert part formed of metal material 2 Cavity 3 Movable side mold 4 Fixed side mold 5 Molded body 6 Gate of molded body

Claims (1)

[Claims] Claim 1: Mix ceramic powder and an organic binder, pelletize the mixture, injection mold it into a mold formed into a desired shape, remove the binder from the molded body, and then sinter it to produce a ceramic part. In injection molding technology for ceramic powder, a part made of a metal material is inserted into a mold, and then a mixture of ceramic powder and a binder is injected into the mold to cover the part. A method for manufacturing ceramic parts, characterized by molding the parts, then removing metal parts from the molded body by chemical melting treatment, degreasing, and sintering.