JPS6274035A - Production of ceramic whisker preform for frm - Google Patents

Abstract

PURPOSE:To obtain a preform of a complex shape with reduced unevenness in the volume content of fibers (Vf value) by mixing ceramic whiskers with an org. binder and metallic powder so as to provide fluidity to the whiskers and to regulate the Vf value, molding the mixture and degreasing the molded body. CONSTITUTION:Ceramic whiskers such a silicon carbide whiskers are mixed with an org. binder such as paraffin wax and metallic powder such as Al powder so as to provide fluidity to the whiskers and to regulate the Vf value. The mixture is injection-molded and the molded body is heated to 400 deg.C degreasing temp. at 5 deg.C/hr heating rate. The molded body is degreased by heating to form prescribed voids.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to ceramic whiskers used as a reinforcing fibrous skeleton when manufacturing FRM (fiber reinforced metal) by impregnating or impregnating a matrix material. The present invention relates to a method for mass-producing a preform, particularly a ceramic whisker preform having a predetermined desired vf value (fiber volume content) and a complex shape.

(Prior Art) Conventionally, ceramic whisker preforms for FRM have been manufactured by methods such as dispersing ceramic whiskers in an organic solvent and filtration molding, or pressure molding using a mold.

[The point where the invention attempts to solve the problem]

vfIIi of the molded preform in the above method.

The problem is that it tends to vary. In particular, when molding a preform with a complicated shape, this tendency is remarkable and the preform molding is difficult.

Also, mass production cannot be expected.

(Means for Solving the Problems) In order to solve the above-mentioned nine problems, the present invention provides an organic binder and Vf for providing fluidity to ceramic whiskers.
To adjust the value, mix the IJ Lux powder, form a P molded body by injection molding, then degrease it and F
This is a means of obtaining a ceramic whisker preform for RM.

(Function) As the organic binder, polymer thread wax, paraffin wax, etc. are used. Organic binder is 40-50
VOL% is desirable. When it is less than 40 VOL%, fluidity is poor, injection molding is difficult, and reinforcing fibers are easily damaged.

If it exceeds 50 VOL%, deformation occurs during degreasing.

As a ceramic whisker, S10 whisker, 81s
- Whiskers, mu 40m There are whiskers, etc.

SiC whiskers have a diameter of 0.2 to α5 μm and a length of 10
Beta type single crystal of 0~200μm, 5isN, whisker diameter 0.2~0.5μm, length 50~300μm
It is m. The fiber-containing lid preferably has a content of about 5 vo % to 50 vo % in consideration of various material properties when FRM is formed.

In FRM, when the Vf value is 5% or less, improvements in various strengths such as hardness are low and the effect of fiber reinforcement is not significant. Further, when the Vf value exceeds 50%, elongation and ductility such as reduction of area P are significantly reduced.

As mentioned earlier, the organic binder distribution t is 40 to 50
Since vow% is desirable, the fiber volume content 1tVf [is,
Mix and adjust the powder of the material that will become the matrix metal at the same time. This metal powder is a fine powder with a particle size of 10 μm or less.
Delicious. In particular, ultrafine powder with a particle size of 1 μm or less has good fluidity and is easy to injection mold. Coarse powder of 10 μm or more has poor fluidity and is difficult to mold. Injection pressure is 100~'2"
! 9/cm", injection m degree Fit OO-120°C is preferred.

(Example) Silicon carbide (SiC) whiskers 30 vol 1%, paraffin wax a o vo 1%, 9j=') 5
0 vow% as metal powder (in this example, aluminum powder was used), these were mixed and the injection pressure was 100
kl/cm", ttlfj temperature y 1 [10°C] to obtain a molded product. After degreasing at a degreasing temperature +100°C and a degreasing temperature increase rate of 5°C/H, scanning electron microscopy (SE
Observed with M and l.

As a result, the length of the fiber was a little short, around 100 μm, but it was in a state where it could be used sufficiently as a reinforcing fiber for FILM.

The shape of the molded body is a cylinder with a height of 5-1 and a major axis of 60IIllll.

Similarly, a silicon nitride (atsN4) whisker preform was manufactured under the above manufacturing conditions and good results were obtained.

(Effects of the Invention) By using the method for manufacturing a ceramic whisker preform for IIRM according to the present invention, the following effects can be expected.

- Fluidity is provided by an organic binder, so there is little variation in Vf Iff even in complex-shaped molded products (preforms).

■ Preforms with complex shapes can be manufactured continuously by simply changing the mold.

Sub-agent: 1) Akira Sub-agent Ryo Hagi Hara - Sub-agent Atsuo Yasunishi

Claims (1)

[Claims] A method for producing a ceramic whisker preform for FRM having predetermined voids, which comprises mixing ceramic whiskers with an organic binder and metal powder, injection molding the mixture, and then degreasing the molded body.