JPH0329499B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a composite material, and more particularly to a method for manufacturing a composite material in which at least a portion of the surface portion is made of steel and the other portion is made of a fiber-reinforced metal composite material. It depends.

Fiber-reinforced metal composites, in which reinforcing fibers such as carbon fibers are used as reinforcement materials and light metals such as aluminum alloys are used as matrix metals, are metal materials with high specific strength, especially tensile strength, and are used in aircraft, automobiles, etc. made of fiber-reinforced metal composites. In various technical fields, research and development are being actively conducted on the application of fiber-reinforced metal composites to various parts, and on manufacturing methods for manufacturing fiber-reinforced metal composites at low cost and efficiently.

However, in such fiber-reinforced metal composites, light metals as matrix metals have poor wear resistance and corrosion resistance, and therefore members made only of fiber-reinforced metal composites are susceptible to severe friction and corrosion. There is a problem that it cannot be used in the environment, and in order to improve the abrasion resistance of fiber reinforced metal composites, randomly oriented short fibers with excellent abrasion resistance are used as reinforcing fibers. for,
There is a problem that the strength of the fiber reinforced metal composite cannot be improved.

In addition, methods for manufacturing fiber-reinforced metal composites include hot press method, autoclave method,
Various manufacturing methods have been proposed, such as high pressure casting. Among these, after filling a mold with reinforcing fibers, a molten matrix metal is introduced into the mold, and a plunger that engages the mold presses the molten matrix metal into the mold while solidifying the high pressure. The casting method is superior in that fiber-reinforced metal composites can be manufactured efficiently without the need for large-scale vacuum generation equipment unlike other manufacturing methods, and this high-pressure casting method has the following advantages: In order to ensure that the molten matrix metal penetrates between each reinforcing fiber, as proposed in Japanese Patent Application No. 55-107040 filed by the same applicant as the present applicant,
Preferably, the reinforcing fibers are preheated to a temperature above the melting point of the matrix metal. Thus, if the reinforcing fibers are preheated to a temperature higher than the above melting point of the matrix prior to casting, the molten matrix metal will penetrate well between each reinforcing fiber, resulting in fiber reinforcement with excellent bonding properties between the reinforcing fibers and the matrix metal. Although metal composites can be produced, preheating the reinforcing fibers to a temperature above the melting point of the matrix metal prior to casting does not improve the wear resistance or corrosion resistance of the fiber reinforced metal composites.

In view of the above-mentioned problems with conventional fiber-reinforced metal composite materials and reinforced fiber preheating high-pressure casting methods, the present invention aims to efficiently and inexpensively produce composite materials that have high specific strength and excellent wear resistance and corrosion resistance. The purpose is to provide a method that can be manufactured to

According to the present invention, at least a portion of the surface portion is made of a steel material that has been carburized or nitrided, and the other portion is made of a fiber-reinforced steel material using reinforcing fibers as a reinforcing material and a light metal as a matrix metal. A method for manufacturing a composite material made of a metal composite material, in which a combination of a carburized or nitridable steel material constituting at least a part of the surface portion and reinforcing fibers is formed, and the above-described process is performed at a temperature equal to or higher than the melting point of the matrix metal. Carburizing or nitriding the combined body,
A method for manufacturing a composite material in which the above-mentioned combination body and a molten matrix metal are combined, and at least a part of the surface part is made of precipitation hardened steel material, and the other part is made of reinforcing fiber. A method for producing a composite material comprising a fiber-reinforced metal composite material using a light metal as a matrix metal, in which a combination of solution-treated precipitation hardenable stainless steel material constituting at least a part of the surface portion and reinforcing fibers is formed. and a method for producing a composite material, in which the combination is heated to a temperature that is the quenching start temperature for the steel material and is higher than the melting point of the matrix metal, and the combination and the molten matrix metal are composited in a mold. It is achieved by doing so.

According to the above-mentioned manufacturing method (1) of the present invention, the combination of carburized or nitridable steel material and reinforcing fibers constituting at least a portion of the surface portion is carburized or nitrided at a temperature equal to or higher than the melting point of the matrix metal. The reinforcing fibers are preheated to a temperature above the melting point of the matrix metal prior to composite formation, and at the same time the steel material is surface hardened.

Therefore, since at least a part of the surface part is made of carburized or nitrided steel material, it has better wear resistance and corrosion resistance than a composite material made only of fiber-reinforced metal composite material, and the other part is made of fiber-reinforced metal composite material. This makes it possible to manufacture composite materials with higher specific strength than metal materials made only of steel, and compared to the case where the carburizing or nitriding treatment of the steel material and the preheating of the reinforcing fibers are performed separately. As mentioned above, excellent composite materials can be produced much more efficiently and at lower cost.

Further, according to the above-mentioned manufacturing method (2) of the present invention, the combination of the solution-treated precipitation hardenable stainless steel material and the reinforcing fiber, which constitutes at least a part of the surface portion, has a temperature at which the quenching start temperature for the steel material is reached. The reinforcing fibers are preheated to a temperature higher than the melting point of the matrix metal prior to compositing, and at the same time heating is performed for precipitation hardening of the steel material. In addition, during the composite process, the steel material is rapidly cooled by heat absorption by the mold.

Therefore, since at least a portion of the surface portion is made of stainless steel material hardened by a martensitic structure, it has superior wear resistance and corrosion resistance compared to composite materials made only of fiber reinforced metal composite materials,
Since the other parts are made of fiber-reinforced metal composite material, it is possible to manufacture a composite material with higher specific strength than a metal material made only of steel materials, and also to preheat the reinforcing fibers by heating for precipitation hardening of the steel materials. Compared to the case where these steps are carried out separately, the excellent composite material described above can be produced much more efficiently and at a lower cost.

According to one detailed feature of the method for producing a composite material according to the invention, the steel material constituting at least a part of the surface of the composite material to be produced is a steel pipe capable of receiving and retaining reinforcing fibers. A case made of steel is used to produce a composite material in the form of a column or rod, such as a cylinder. In this case, the steel case has the function of maintaining the reinforcing fibers at a predetermined density and orientation during preheating and casting, and also has the function of maintaining the reinforcing fibers at a predetermined density and orientation during preheating and casting.
Similar to the preheating mold in the composite material manufacturing method disclosed in No. 56-127080, it functions as a heat insulator to prevent the temperature of reinforcing fibers that have been preheated to a temperature higher than the melting point of the matrix metal from decreasing. fulfill.

According to another detailed feature of the method for manufacturing a composite material according to the invention, the compositing of the preheated combination with the molten matrix metal comprises placing the preheated combination in a mold, A high-pressure casting method in which molten matrix metal is poured into a mold, and the molten matrix metal is solidified while being pressurized within the mold.
Alternatively, the preheated assembly is loaded into a container, the interior of the container is evacuated, a part of the container is immersed in the molten matrix metal, and then the surface of the molten metal is pressurized using hydraulic pressure to cool the molten metal. This is carried out by a so-called autoclave method in which each reinforcing fiber in the container is impregnated. In this case, the reinforcing fibers are preheated to a temperature higher than the melting point of the matrix metal prior to compositing, so the molten matrix metal penetrates well between the reinforcing fibers, resulting in excellent adhesion between the reinforcing fibers and the matrix metal. A fiber reinforced metal composite is formed.

In addition, the composite material manufactured by method (1) above has sufficient wear resistance because the surface of the steel material is hardened by carburizing, etc., but it has even more wear resistance. And in order to improve the strength, the following heat treatment may be performed. That is,
The composite material is heated to 500℃ and cooled with water, thereby making the matrix metal of the fiber-reinforced metal composite material into a solution, and the surface of the steel material of the composite material is subjected to surface hardening and quenching using laser, high frequency, etc., and then further
The matrix metal is subjected to a _T6 treatment by heating at 160°C for 6 hours (the steel is tempered).

In addition, in method (2) above, the manufactured composite material is heat treated, the stainless steel material is aged or tempered, and the matrix metal of the fiber reinforced metal composite is solution treated and aged. It is preferable that

The reinforcing fibers used in the method for producing a composite material according to the present invention include long fibers such as expanded carbon fibers, alumina fibers, boron fibers, and silicon carbide fibers, whiskers such as potassium titanate, silicon carbide, silicon nitride, and boron nitride, and The matrix metal of the fiber-reinforced metal composite may be a metal such as aluminum, magnesium, copper, zinc, tin, or an alloy thereof. . The temperature at which the combination of steel and reinforcing fibers is heated is appropriately set depending on the type of steel used, the type of surface hardening heat treatment applied to it, the melting point of the matrix metal used, etc. good.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention will be explained in detail below by way of example embodiments with reference to the accompanying figures.

Example 1 Pipe 1 is a mechanical structural steel pipe (JIS standard STKM15A) with an outer diameter of 23 mm, an inner diameter of 21 mm, and a length of 75 mm.
mm alumina fiber 2 (fiber diameter 20μ, manufactured by DuPont)
The pipe 1 was filled with FP fibers oriented in the longitudinal direction so that the volume ratio was 55%. Next, the thus formed combination 3 consisting of the pipe 1 and alumina fiber 2 was carbonitrided at 920°C for 8 hours, and immediately after the carbonitriding process, the molding chamber 5 of the mold 4 for high-pressure casting was heated to 280°C. placed inside. Next, 750°C molten aluminum alloy (JIS standard AC4C) is quickly poured into the molding chamber 5 and pressurizing chamber 6 of the mold 4, and introduced into the molding chamber 5 and pressurizing chamber 6 by the plunger 8 at 160°C. The molten aluminum alloy 7 was pressurized to a pressure of 1200 Kg/cm ² . The pressurized state was maintained until the molten aluminum alloy 7 was completely solidified.

Thus, the molten aluminum alloy 7 in the mold 4
After the solidified body is completely solidified, the solidified body is taken out from the mold 4 by raising the knockout pin 9, the solidified part is removed by cutting in the pressurizing chamber 6, and the solidified body is removed into the molding chamber 5. A cylindrical body with an outer diameter of 22.5 mm and a length of 73 mm is formed by cutting the cast rough material formed by the process, and as shown in Fig. 3, the cylindrical surface part is carbonitrided. A composite material 10 was manufactured, which was made of a fiber-reinforced metal composite material made of structural steel pipes, whose interior was made of alumina fibers as a reinforcing material, and an aluminum alloy as a matrix metal.

Furthermore, the composite material 10 thus produced was heated to 500°C.
The cylindrical outer peripheral surface 11 is hardened with a laser beam, and then the composite material 10 is heated at 160° C. for 6 hours to achieve T ₆
Processed. Composite material 1 thus heat treated
Although not shown in the figure, a piston pin with an outer diameter of 22 mm and a length of 73 mm was manufactured by grinding 0.

The piston pin thus manufactured was lighter than conventional piston pins made of special steel or the like. In addition, the piston pin manufactured as described above was assembled into a 1972 c.c., 4-cylinder, 4-cycle gasoline engine, and a 200-hour durability test was conducted at a maximum rotation speed of 5200 rpm. It was confirmed that the new piston pin had the same durability as the conventional piston pin.

Example 2 Using the casting apparatus shown in FIG. 2 used in Example 1 above, a cylindrical surface was made of carbonitrided mechanical structural steel pipe, and the inside was reinforced with carbon fiber. A composite material made of a fiber-reinforced metal composite material using an aluminum alloy as a matrix metal was manufactured.

As shown in Figure 4, high elasticity carbon fiber 12 (Toray Card M40, fiber diameter 7μ)
By filament winding at ±20°, a cylindrical body 13 with an outer diameter of 21 mm, an inner diameter of 10 mm, and a length of 75 mm is formed.
21mm long, 75mm long mechanical structural steel pipe (JIS standard
STKM12B) was loaded into the pipe 14 to form an assembly 15 as shown in FIG. Next, the thus formed carbon fiber 12 and pipe 1
4 was carbonitrided at 920°C for 8 hours, and immediately after the carbonitriding process, it was placed in the molding chamber 5 of the mold 4 for high-pressure casting heated to 260°C. Then, into the molding chamber 5 and pressurizing chamber 6 of the mold 4.
The molten aluminum alloy 7 at 750°C (JIS standard AC8A) was quickly poured into the molding chamber 5 and the pressurizing chamber 6 by the 150°C plastic gear 8, and the molten aluminum alloy 7 was heated to a pressure of 1400 Kg/cm ^{2 .} Pressure was applied.
Then, the pressurized state is changed to the molten aluminum alloy 7.
was held until completely solidified.

Thus, the molten aluminum alloy 7 in the mold 4
After the solidified body is completely solidified, the solidified body is taken out from the mold 4 by raising the knockout pin 9, the solidified part is removed by cutting in the pressurizing chamber 6, and the solidified body is removed into the molding chamber 5. A cylindrical body with an outer diameter of 22.5 mm and a length of 73 mm was formed by cutting the cast rough material.The cylindrical surface part was made of carbonitrided mechanical structural steel pipe, and the inside was made of carbon fiber. A composite material consisting of a fiber-reinforced metal composite material was manufactured using aluminum alloy as a reinforcing material and an aluminum alloy as a matrix metal.

Furthermore, the composite material thus produced was heated to 520°C, cooled with water, and its cylindrical outer peripheral surface was hardened by induction hardening, and then the composite material was heated to 170°C.
_T7 treatment was performed by heating at ℃ for 16 hours. By grinding the heat-treated composite material, a hollow piston pin (not shown in the figure) having an outer diameter of 22 mm, an inner diameter of 10 mm, and a length of 73 mm was manufactured.

Example 3 As shown in FIG. 6, boron fibers 16 with a length of 119 mm and a fiber diameter of 120 μ are oriented in one direction and bundled to form a rod-shaped body with an outer diameter of 6 mm, and chromium steel ( By inserting end caps 17 and 18 made of JIS standard SCr15), the length can be adjusted.
A combination body 19 having a diameter of 122 mm and a diameter of 6 mm was formed. Next, a combination body 19 consisting of the boron fiber 16 thus formed and the end caps 17 and 18 is formed.
Carbonitriding treatment was performed at 920℃ for 8 hours, and immediately after the carbonitriding treatment, aluminum alloy (JIS standard AC4C) was impregnated between the boron fibers 16 in an autoclave.
As a result, the portion between the end caps 17 and 18 was made into a fiber-reinforced metal composite material 20 in which the boron fibers 16 were used as reinforcing fibers and the aluminum alloy was used as the matrix metal.

The thus produced composite material was then solution treated by heating to 500°C and then subjected to _T6 treatment by heating at 160°C for 6 hours. End caps 17 and 1 of the thus heat-treated composite material
By polishing the tip of No. 8 into a hemispherical shape, the seventh
A push rod 21 as shown in the figure was manufactured.

Example 4 Using a casting device similar to that used in Example 1, a cylindrical surface was made of a hardened stainless steel tube, the inside was made of carbon fiber as a reinforcing fiber, and a magnesium alloy as a matrix metal. A composite material made of fiber-reinforced metal composite material was manufactured.

First, high-strength carbon fiber (Toray T300,
A cylindrical body having an outer diameter of 21 mm, an inner diameter of 12 mm, and a length of 75 mm, similar to the cylindrical body shown in FIG. 4, was formed by filament winding the fiber diameter (7 μm) at ±20°. Next, the cylindrical body was previously subjected to solution treatment (heated to 1050°C and then rapidly cooled) with an outer diameter of 22.5 mm.
By inserting it into a stainless steel (JIS standard SUS631) pipe with an inner diameter of 21 mm and a length of 75 mm,
A combination similar to that shown in FIG. 5 was formed.

Next, the thus formed combination of carbon fiber and stainless steel tube was heated to 760°C for 90 minutes in an argon gas atmosphere, and then immediately heated to 280°C.
It was placed in a molding chamber 5 of a mold 4 for high-pressure casting heated to .degree. Next, magnesium alloy (JIS standard MC7) at 680°C is placed in the molding chamber 5 and pressurizing chamber 6 of the mold 4.
Quickly pour the molten metal 7 into the plunger 8 at 160℃.
The molten magnesium alloy 7 introduced into the molding chamber 5 and pressurizing chamber 6 was pressurized to a pressure of 1500 kg/cm ² . The pressurized state was maintained until the molten magnesium alloy 7 was completely solidified.

Thus, the molten magnesium alloy 7 in the mold 4
After the solidified body is completely solidified, the solidified body is taken out from the mold 4 by raising the knockout pin 9, and the solidified part is removed by cutting in the pressurizing chamber 6, thereby forming a cylindrical surface. A composite material was manufactured in which the inner part was made of a hardened stainless steel tube and the inner part was a fiber-reinforced metal composite material with carbon fiber as the reinforcing fiber and magnesium alloy as the matrix metal.

Furthermore, the thus produced composite material was heated at 540°C for 2 hours, forced air cooled, and then artificially aged by heating at 130°C for 48 hours.
In this case, the area approximately 0.5 mm from the surface of the cylindrical outer circumferential surface of the stainless steel pipe is heated and held at 760°C for 90 minutes, and then rapidly cooled by heat absorption by the mold during the high-pressure casting process. It became a martensitic structure and was further hardened by precipitation during the heat treatment process of heating at 540°C for 2 hours. The matrix metal of the fiber-reinforced metal composite material was solutionized during heating at 540°C for 2 hours, and age-hardened during heating at 130°C for 48 hours.

Furthermore, a hollow piston pin having an outer diameter of 22 mm, an inner diameter of 12 mm, and a length of 75 mm was manufactured by grinding the composite material thus manufactured and heat treated. The hollow piston pin manufactured in this manner was much lighter than conventional piston pins made of special steel or the like. Furthermore, when the hollow piston pin manufactured as described above was subjected to the same durability test as in Example 1, it was found to have the same durability as a conventional piston pin made of special steel and heat treated. It was recognized that there was.

Example 5 Using a casting device similar to that used in Example 1, a cylindrical surface was made of a hardened stainless steel tube, the inside was made of carbon fiber as a reinforcing fiber, and an aluminum alloy as a matrix metal. A composite material made of fiber-reinforced metal composite material was manufactured.

First, high elasticity carbon fiber (Toray M40,
A cylindrical body having an outer diameter of 21 mm, an inner diameter of 10 mm, and a length of 75 mm, similar to the cylindrical body shown in FIG. 4, was formed by filament winding a fiber (fiber diameter: 7 μm) at an angle of ±25°. The cylindrical body was then pre-solution-treated (heated to 950°C and then oil-cooled) with an outer diameter of 22.5 mm.
A combination body similar to the combination body shown in FIG. 5 was formed by inserting it into a stainless steel (JIS standard SUS420J2) pipe with a diameter of 21 mm and a length of 75 mm.

Next, the thus formed combination of carbon fiber and stainless steel tube was heated to 950°C for 90 minutes in an argon gas atmosphere, and then immediately heated to 270°C.
It was placed in a molding chamber 5 of a mold 4 for high-pressure casting heated to .degree. Next, the molding chamber 5 and pressurizing chamber 6 of the mold 4 are filled with aluminum alloy (JIS standard
A molten metal 7 of AC4C) was quickly poured into the mold, and the molten aluminum alloy 7 introduced into the molding chamber 5 and pressurizing chamber 6 by a plunger 8 at 150° C. was pressurized to a pressure of 1500 Kg/cm ² . The pressurized state was maintained until the molten magnesium alloy 7 was completely solidified.

Thus, the molten aluminum alloy 7 in the mold 4
After the solidified body is completely solidified, the solidified body is taken out from the mold 4 by raising the knockout pin 9, and the solidified part is removed by cutting in the pressurizing chamber 6, thereby forming a cylindrical surface. A composite material was manufactured in which the inner part was made of a hardened stainless steel tube and the inner part was a fiber-reinforced metal composite material with carbon fiber as the reinforcing fiber and aluminum alloy as the matrix metal.

Furthermore, the composite material thus produced was heated at 600°C for 2 hours, cooled with water, and then heated at 160°C for 6 hours to undergo artificial aging treatment. In this case, the area approximately 0.5 mm from the surface of the cylindrical outer peripheral surface of the stainless steel pipe is heated and held at 950°C for 90 minutes, and then rapidly cooled by heat absorption by the mold during the high-pressure casting process. It became a martensitic structure and was further tempered in a heat treatment process of heating at 600°C for 2 hours, resulting in a hardness of Hv=200. The matrix metal of the fiber-reinforced metal composite material was solutionized during heating at 600°C for 2 hours, and age-hardened during heating at 160°C for 6 hours.

Furthermore, a hollow piston pin having an outer diameter of 22 mm, an inner diameter of 11 mm, and a length of 75 mm was manufactured by grinding the thus manufactured and heat-treated composite material. The hollow piston pin manufactured in this manner was much lighter than conventional piston pins made of special steel or the like. Furthermore, when the hollow piston pin manufactured as described above was subjected to the same durability test as in Example 1, it was found to have the same durability as a conventional piston pin made of special steel and heat treated. It was recognized that there was.

Although the present invention has been described above in detail with reference to several embodiments, the present invention is not limited to these embodiments, and various embodiments are possible within the scope of the present invention. This will be clear to those skilled in the art. For example, in the above-described embodiments, the surface hardening treatment for the steel material is carbonitriding, but the steel material may be subjected to only carburizing or nitriding.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an assembly formed in Example 1 of the method for manufacturing a composite material according to the present invention, and FIG. 2 is a cross-sectional view showing the high pressure used in the method for manufacturing a composite material according to the present invention. FIG. 3 is a cross-sectional view showing the casting apparatus particularly during the casting process in Example 1, FIG. 3 is a perspective view showing the composite material manufactured in Example 1, and FIG.
The figure is a perspective view showing a cylindrical body of reinforcing fibers formed in Example 2, FIG. 5 is a sectional view similar to FIG. 1 showing a combination body formed in Example 2, and FIG. 7 is a cross-sectional view showing the assembly formed in Example 3, and FIG. 7 is a front view showing the push rod manufactured in Example 3. DESCRIPTION OF SYMBOLS 1... Pipe, 2... Reinforced fiber, 3... Combination body, 4... Mold, 5... Molding chamber, 6... Pressurizing chamber,
7... Molten metal, 8... Plunger, 9... Knockout pin, 10... Composite material, 11... Cylindrical outer peripheral surface, 12... Carbon fiber, 13... Cylindrical body, 14
... Pipe, 15 ... Combination body, 16 ... Boron fiber, 17, 18 ... End cap, 19 ...
Combination body, 20...Fiber-reinforced metal composite material, 21...
...Putshurotsudo.

Claims (1)

[Scope of Claims] 1. A fiber-reinforced metal composite material in which at least a portion of the surface portion is made of a steel material that has been carburized or nitrided, and the other portion is made of reinforcing fibers and a light metal as a matrix metal. A method for producing a composite material comprising: forming a combination of a carburized or nitridable steel material constituting at least a part of the surface portion and reinforcing fibers, and heating the combination at a temperature equal to or higher than the melting point of the matrix metal. A method for manufacturing a composite material, which comprises carburizing or nitriding the composite material and molten matrix metal to form a composite material. 2. A method for producing a composite material in which at least a part of the surface part is made of precipitation-hardened steel, and the other part is a fiber-reinforced metal composite material in which reinforcing fibers are used as reinforcement materials and light metals are used as matrix metals. forming a combination of a solution-treated precipitation hardenable stainless steel material constituting at least a portion of the surface portion and reinforcing fibers, and heating the combination at a quenching start temperature of the steel material and a temperature of the matrix metal. A method for manufacturing a composite material, which comprises heating the composite material to a temperature higher than its melting point and combining the composite material with a molten matrix metal in a mold.