JPS6015132A - Manufacture of composite material reinforced with fiber - Google Patents

Abstract

PURPOSE:To obtain the titled composite material with good productivity that is excellent in orientation and strength, by mixing magnetic reinforcing short fibers (FR) with a plastic or the like followed by heating to melt the plastic or the like, injecting the mixture into a mold place in a magnetic field, and orientating the FR in a desired direcion by the magnetic force. CONSTITUTION:FR (e.g. silicon carbide short fibers) is magnetized by a process of forming a metal film of iron, nickel or the like wherein for example sputtering, electroless plating is used, and is mixed with a plastic 4 or a metal such as aluminium in a desired ratio followed by heating to melt the plastic or the like. Then the melt is injected into a mold 1 placed in a magnetic field and magnetic lines of force are generated in parallel with the direction wherein the FR3 are orientated.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for manufacturing a fiber reinforced composite material used as a strength member.

(Prior art) Fiber reinforced resin (FRP) and fiber reinforced metal (F') LM
) is used in various industrial fields, and special K F RM 7
7. Development is progressing as engine parts such as piston heads.

By the way, FRP-? The strength properties of PRM are extremely dependent on the fiber arrangement direction. For example, in FRM, if the tensile direction is shifted by 10 degrees from the fiber axis, the tensile strength decreases significantly, and if the tensile strength is shifted by 3σ, the matrix It is known that the strength decreases and the effect of fiber reinforcement disappears.

FRM is generally manufactured by hot rolling method.
Extrusion methods and welding methods have been attempted as methods for improving the degree of fiber orientation, but have not yet achieved sufficient effects. That is, to explain a composite material made of aluminum and silicon carbide (8iC) short fibers as an example, the extrusion method uses a mixture of aluminum and 8iC short fibers e 400 to 500
In the method of hot extrusion molding at ℃, the 8iC short fibers are further cut into lengths of 1 to 10% while passing through the die, and variations occur in the arrangement direction of the SiC short fibers when viewed in cross section, especially from the center to the periphery. It is recognized that the orientation is poor in some parts. It is clear that these phenomena have an adverse effect when the composite material is used as a part subjected to bending. The extrusion method also has the disadvantage that the direction in which the fibers are arranged is limited to the extrusion direction.

Next, the welding method is a method in which SiC short fiber slurry is poured onto an aluminum metal foil or sheet that moves on a heated roll and heated to form a melt layer, and the fibers are oriented in the flow direction of the slurry, that is, in the rotational direction of the roll. The looseness of the foil produced by this method involves manual work such as cutting and stacking the sheets, which poses a problem in productivity, and the orientation is insufficient compared to the above-mentioned extrusion method.

(Objective of the Invention) The object of the present invention is to solve these problems and provide a method for producing a fiber-reinforced foam material in which the fibers in the matrix can be oriented in any direction.

(Structure of the Invention) That is, the method for producing a fiber reinforced composite material of the present invention is to mix reinforcing short fibers with a property with metals or plastics at a predetermined ratio, heat and melt the mixture, and then place the mold in a magnetic field. Among these, the entire feature is that the reinforcing fibers mentioned above are oriented in the direction of magnetic force.

Fibers that are inherently non-magnetic, such as λ, StC'p At203
Magnetism can be imparted to the fiber surface by forming a broken film of a third substance, for example λ, a metal such as iron or nickel, by means such as sputtering, electroless plating or thermal spraying. Furthermore, since the cut pieces produced when cutting a round iron bar are short fibers, they can be used as they are in the method of the present invention.

Hereinafter, the present invention will be described in detail with reference to the drawings.

(Example) A short SiC fiber having a diameter of 0.2 μm and a length of 40 to 60 μm is placed in a vacuum, and a nickel coating is formed on the entire surface of the fiber by sputtering using a nickel cathode.

The above-mentioned fibers are mixed with aluminum alloy powder (2 to 3 tI) by volume, heated to 700° C. to form a molten metal, and then poured into a mold 1 shown in FIG. 1. Next, this mold 1
is placed in magnetic field generator #2, and lines of magnetic force are generated parallel to the direction in which the SiC short fibers 3 are desired to be oriented (in the direction of the arrow). In the device cast into the mold 1, the S r C short fibers 3, which were randomly dispersed as shown in FIG. 2, are arranged in a desired direction in the magnetic field as shown in No. 31\1. After the matrix aluminum alloy 4 is cooled and solidified, a test piece A (diameter 20I x length 30m+) is taken out from the mold 1, and a predetermined strength test is carried out to obtain a test piece obtained by the conventional extrusion method. ) and a test piece (C) which was simply cast and not subjected to a magnetic field, and the following results were obtained.

AB C Tensile strength 197m 64 56 42 Tarnishing rate Ir
P/m” 18,300 16,200 11.800
That is, in the test piece A according to the method of the present invention, the test piece C
Compared to this, the tensile strength increased by 52 inches and the Young's modulus increased by 55 inches, and the tensile strength and Young's modulus increased by 14 factors and 13 inches with respect to test piece H.

It is clear that the same effect as above can be obtained by applying a coating of a third substance to the fibers, which are themselves magnetic, and oriented in a magnetic field. It is also not true that the method of the present invention can be applied to F It P.

(Effect of the invention) As is clear from the above description, according to the method of the present invention,
The reinforcing fibers in IJ Lux can be easily oriented in any direction, resulting in an overall uniform and high-strength FIE.
tM, FI-LP f can be produced. It should be noted that the method of the present invention can be carried out using a simple device, so it is suitable for mass production, and has a large effect on improving productivity.

[Brief explanation of drawings]

FIG. 1 shows an explanatory diagram of an embodiment, FIG. 2 shows a partial cross-sectional view of test piece A according to the example, FIG. 3 shows a partial cross-sectional view of test piece C according to a comparative example. In the diagram, 1...Mold 2...Magnetic field generator

Claims (1)

[Claims] Mixing magnetic reinforcing short fibers with metals or plastics at a predetermined ratio, heating and melting them, and then orienting the reinforcing fibers in the direction of magnetic force in a mold placed in a magnetic field. A method for producing a fiber-reinforced composite material characterized by: