JPS5945744B2 - Manufacturing method for fiber-reinforced composite materials - Google Patents

Description

[Detailed Description of the Invention] Composite materials in which long fibers such as graphite fibers and fine wires of W or short fibers such as whiskers are combined with metals, ceramics, or resins have become a hot topic in recent years. Almost nothing other than that has been industrialized.

The reason for this is that it is difficult to manufacture.

For example, in order to make a composite material of graphite fibers and metal, the graphite fibers are impregnated with molten metal, but at this time, if there is no wettability between the two, the molten metal will be impregnated between the graphite fibers. Do not infringe.

For this purpose, the surface of the graphite fiber is coated with, for example, Ni.

It is not easy to coat this Ni, but this Ni
The overall characteristics of the composite material are impaired due to the presence of .

This situation is exactly the same for the combination of SiC and metal and for the combination of ceramic fiber and glass.

The present invention utilizes such composite material components, namely fibers or whiskers (hereinafter referred to as fibrous materials) and matrix (
The present invention provides an extremely useful process for manufacturing composite materials regardless of the wettability problem between the matrix and the matrix.

Of course, it is not harmful that there is wettability between the two.

The present invention is a method of press-fitting a molten matrix material between fibrous materials.

This idea itself is not new.

The feature of the present invention lies in this pretreatment.

If air remains between the fibrous materials when press-fitting, naturally some parts will remain that will not be press-fitted.

Further, in many cases, the fibrous material itself contains a gas component.

If this gas component gasifies at high temperatures, this will also result in portions that cannot be press-fitted.

The gas component here refers to physically adsorbed components, chemically adsorbed components, and those present in the recesses or surfaces of the fibers in the form of hydroxides or oxides.

Heating has produced these as a function of temperature and time.

Currently, gas analysis involves first exposing a sample to a high vacuum at room temperature, then melting it in vacuum, and then quantifying the gas generated, but the gas components referred to here are close to the amount of gas determined by this gas analysis.

The previously known method for degassing and degassing as described above involves attaching a long and thin suction tube to a container filled with fibrous material, and heating the entire body while drawing a vacuum from this absorption tube. After degassing, the suction pipe is welded and sealed.

This method works well when making large items, but when making small items it becomes troublesome and expensive, making it nearly impossible to implement industrially.

The present invention is a method that is particularly characterized in that it makes small items inexpensively.

In other words, this is a method that automatically seals the gas at the end of degassing.

This method involves infiltrating a breathable material, such as a porous sintered body, with another material to block the ventilation holes.

Various combinations of breathable substances and infiltrants are possible.

Fe or Fe alloy and Cu/or Cu alloy, CO and C
u alloy, Cr and Cu alloy W and Cu alloy, W and Ni alloy,
These include Al2O3 and glass.

These are selected from the viewpoints of fiber degassing completion temperature, reactivity with fibers, etc.

Among these combinations, Fe or Fe alloy and Cu or Cu alloy are the cheapest and the easiest to operate technically.

The substance for impregnating the fibers may be placed within the container or may be part of the container.

For example, if a Ni container is used, a part of this Ni will be impregnated into the W whiskers, and the remaining Ni will serve as the container. It is also possible to use

The most preferred hot compression molding method is so-called hot static pressure molding using Ar gas or the like.

It is also possible to use a solid pressure medium such as external pyrophyllite or a liquid pressure medium such as oil.

These are determined by the required temperature and pressure.

Examples will be described below.

Example 1 A bundle of long graphite fibers with a wire diameter of 15 microns and a thickness of 0.1.
A piece with an outer diameter of about 101 m was made by winding 5 layers of copper tape with a diameter of about 101 m.

Using this as a container, the inner diameter is 10.57n7IL and the outer diameter is 13.
It was filled into a 5 mm extremely mild steel pipe.

150 meshes of less than 100 on both ends of this extremely mild steel pipe
After lightly stamping iron powder with a mesh size or larger, a porous iron sintered body with a specific gravity of 4 and a thickness of 3 m and 11 L, which was sintered at 900°C for 1 hour in a hydrogen atmosphere, was inserted, and a small piece of a Cu alloy containing 10% Mn was inserted. After it was packed on top of that, the same porous iron sintered body was fitted onto it and fixed.

The whole was placed in a vacuum furnace, heated to 1030°C, and then cooled.

When it was taken out, the outside of the porous iron sintered body used as the plug turned red and was clearly seen to have been infiltrated with Cu, and it was also completely bonded to the iron pipe.

This was put into a hot isostatic pressure molding machine that uses argon gas, and the temperature was first raised to 1150°C, and then the gas pressure was increased to 2.
The pressure rose to 000 atmospheres.

After holding for 10 minutes, the pressure was lowered by cooling.

After taking it out, the iron pipe on the surface was removed by cutting.

A graphite-Cu composite in which graphite fibers were neatly arranged in the longitudinal direction was obtained.

Chips made by cutting this material were useful as contact materials.

Example 2 AI was impregnated into graphite fibers in the same manner as in Example 1.

However, the impregnation temperature was 700°C. A graphite-AI composite in which Yabari graphite fibers were neatly arranged in the longitudinal direction was obtained.

However, in this case, instead of the Cu alloy of Example 1, an A1 alloy containing 4% Mg was used as an infiltrant.

Example 3 W whiskers were packed in a Cu container with an outer diameter of 151 m, an inner diameter of 10 mm, and a depth of 20 mm.

A W powder embossing body of several tens of microns was placed on top of this, and a small piece of Cu was further placed on top of this.

The whole was placed in a Pyrex container, which was then placed in a vacuum furnace and heated to 1150°C.

After taking it out, it was charged into a hot isostatic pressure molding machine, first heated to 1150°C, and then the gas pressure was increased to 1000 atm and held for 10 minutes.

Although Cu remained on the surface, the inside was a W-Cu composite and no pores were observed.

Claims (1)

[Scope of Claims] 1. In a method for producing a fiber-reinforced composite material, a fibrous material and a matrix metal are charged into a deformable container that partially has air permeability; Place a metal sintered body or molded body as an infiltration material in the form of blocking the vent and place it under vacuum, or heat it while vacuuming the inside of the container to remove the air and fibrous material inside the container. Most of the gas components present are removed, and the air-permeable part is sealed by infiltration by melting the matrix base material and the metal sintered body or molded body during vacuum heating, and this is further hot compression molded under high temperature and high pressure. A method for producing a fiber-reinforced composite material characterized by: 2. In the manufacturing method according to claim 1, the fiber-reinforced composite material is characterized in that the hot compression molding under high temperature and high pressure is performed by hot isostatic molding using an inert gas. Manufacturing method. 3 In the manufacturing method described in claims 1 and 2, the air permeable part is made of iron or an iron alloy, and the infiltration material therein is made of copper or a copper alloy, or an AI or A1 alloy. Characteristic manufacturing method for fiber-reinforced composite materials. 4. A method for producing a fiber-reinforced composite material according to claim 1, characterized in that a portion of the constituent elements of the container are impregnated between the fibrous materials during hot compression molding.