JPS59118829A - Method for shaping composite material - Google Patents

Abstract

PURPOSE:To manufacture easily a shaped composite material of a complex shape at a low cost by laminating reinforcing fiber impregnated with a matrix on a core body made of a shape memory alloy, and shaping them after heating to a temp. above the memorized shape developing temp. CONSTITUTION:A shape memory alloy such as a Ti-Ni alloy is formed into a prescribed shape and drawn to obtain a core body. Reinforcing fiber such as glass fiber is impregnated with a matrix such as epoxy resin or polyamide, and the impregnated fiber is laminated on the core body. They are shaped after heating to a temp. above the memorized shape developing temp. A composite material of a prescribed complex shape is efficiently manufactured.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to a method of forming a composite material using a shape memory alloy as a core for forming the composite material.

The performance of glass fibers, carbon fibers, aromatic polyamide fibers, and 7-carbon carbide fibers has improved dramatically in recent years, and thermosetting resins such as epoxy resins, unsaturated polyester resins, polyimides, and phenolic resins are being used as reinforcing fibers for these fibers. , polyamide, polyester, polycarbonate,
pps, , PPO, polyetheretherketone, AB
Composite materials impregnated with thermoplastic resins such as S are not only used in sports and leisure fields such as golf shafts and fishing rods, but are also increasingly being used in industrial applications such as aircraft materials and automobile structural materials. There is.

Molding of these composite materials is relatively easy for relatively simple shapes such as flat plate shapes, cylinders, and prismatic shapes, but molded products with curved surfaces such as coil springs, tone arms, golf putter shafts, racket frames, etc. Molding is extremely difficult and is currently impossible without the creation of complex and expensive molds.

Therefore, the present inventors are currently considering developing a further improved molding method for composite materials.By using a shape memory alloy for the core mold, molded composite materials with complex shapes can be easily formed. Moreover, they discovered that it can be manufactured at low cost and completed the present invention.

The gist of the present invention is to laminate a reinforcing fiber material impregnated with a matrix on a core made of a shape memory alloy, and shape and mold the laminate by heating the core to form a memory shape. The main feature lies in the method of forming the composite material.

Specific examples of shape memory alloys used in carrying out the present invention include Ou-Zn-At alloy, Ti-Ni alloy,
Various materials (7) 4 can be used, such as CuZ n -Z n alloys, Fe-Pt alloys, etc., but in particular, it is recommended to select all those whose memory shape development is 171 degrees above room temperature and below the flow temperature of the matrix. good. An example of the shape development temperature of Ni--Tl alloy is as follows.

In addition to the above-mentioned unique performance, shape memory alloys also have excellent vibration damping properties, and are used in tone arms, golf players' shafts, and rackets that require good vibration damping properties. In racket frames and the like, the twisted core can be used as a composite molded product without removing the core.

The reinforcing fibers used in carrying out the present invention are the above-mentioned reinforcing fibers, and the matrix is 11J.
Thermosetting resins and thermoplastic resins as mentioned above are mainly used. The reinforcing fibers can be impregnated with the matrix before these materials are laminated to the core, or the reinforcing fibers are laminated to the core and then impregnated with the matrix. It can also be used in the form of prepreg impregnated with tux, scrim cloth reinforced prepreg, cloth prepreg, roving-like prepreg, sheet molding material, bulk molding material, etc.

In addition, the composite material according to the present invention can be molded by encapsulating and molding a heat-shrinkable glass or rubber tube, by using a heat-shrinkable tape, by using a mold as an auxiliary method, and by using an autoclave. It can be molded by a method such as using

The method for molding a composite material of the present invention is an extremely efficient method for molding materials having particularly complex shapes compared to conventionally developed methods.

The present invention will be explained in more detail with reference to Examples below.

Example 1 A coil spring with a diameter of 1 was made from a Ni-Ti alloy with a shape development temperature of 90C, and this was stretched to form a coil spring core.This core was reinforced with carbon fibers impregnated with epoxy resin. After the strand was wound using a filament winding method so that the thread angle was ±4 () degrees, it was wrapped in a heat-shrinkable silicone tube and heated to 90C or higher, and it returned to the memorized shape of a coil spring.

The epoxy resin at this time had sufficient fluidity. The composite material in the shape of a coil spring was inserted with an auxiliary material to hold the inner diameter, heated in an autoclave to cure the epoxy resin, and then the auxiliary material was removed and the silicone tube was removed. A carbon fiber reinforced resin coil spring with an orientation angle of ±45 degrees with respect to the spring axis was obtained.

Example 11 A hollow core body with a memory shape of a dogleg shape was made from the alloy used in Example 1, and this core body was stretched to prepare a straight cylindrical body. A prepreg made of epoxy resin-impregnated carbon fiber notebook and reinforced with glass scrim cloth is wrapped around this cylinder so that the carbon fiber axis is parallel to the cylinder, and a silicone resin tube is encapsulated. However, when it was heated to a temperature of 90C or higher, it deformed into a dogleg shape. Furthermore, this product was heated in an autoclave to cure the resin, and then the silicone resin tube was removed to obtain a dogleg-shaped bent pipe made of carbon fiber reinforced composite material.

Example ■ A flat plate having a memorized shape of a semicircular arc plate was made from the alloy used in Example 1, and a cross prepreg made of carbon fiber fabric impregnated with epoxy resin was attached to both sides of the flat plate.
9 (When heated to 1" or higher, a memorized shape was developed.

At this time, the cross prepreg followed the memorized shape well. This material was placed in a mold and heated to harden to obtain a semicircular arc-shaped plate made of carbon fiber reinforced composite material.

Patent Applicant Mitsubishi Rayon Co., Ltd. Agent Patent Attorney 1) Toshite Mura (Continuation Amendment Writing Method) April 10, 1982? Kazuo Wakasugi, Commissioner of the Japan Patent Office1, Indication of the case, Patent Application No. 226647 of 1982,2 Forming method for compound title of invention3, Person making the amendment (relationship with 'l) Patent applicant Tokyo 2-3-19 Kyobashi, Chuo-ku (603) Osamu Kanazawa, President and Director of Mitsubishi Rayon Co., Ltd., 34, Agent 2-8-1 Toranomon, Higashiito Minato-ku

Claims (1)

[Claims] A method for forming a composite material, which is characterized by laminating matrix-impregnated reinforcing fibers on a core made of a shape memory alloy, and shaping and molding the core by heating it to a temperature above the memory shape development temperature.