JP2679160B2 - Method for manufacturing metal-based composite material member - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing a metal-based composite material member, and more specifically, to a metal-based composite material member in which only a predetermined surface portion is composite-reinforced with a reinforcing material. Related to the manufacturing method of.

As a method for producing a metal-based composite material in which a ceramic fiber or the like is used as a reinforcing material and an aluminum alloy or the like is used as a matrix metal, a molded body of the reinforcing material is placed in a mold. A conventionally known method is a pressure casting method in which a molten matrix metal is introduced into the mold and the molten matrix metal is solidified while being pressurized in the mold. According to this pressure casting method, it is possible to produce a composite material member of any shape with excellent adhesion between the matrix metal and the reinforcing material at a lower cost than the diffusion bonding method which requires a large vacuum generation device, etc. Can be manufactured.

In order to manufacture a composite material member in which only the surface part is composite-reinforced with a reinforcing material by such a pressure casting method, it is necessary to strengthen a predetermined shape having a small thickness corresponding to the shape of the surface part to be composite-reinforced. A green compact must be formed and held in place in the mold during casting.

However, since the reinforcement material with a small thickness is fragile,
It is easily damaged during handling, is easily deformed or cracked due to the pressure of the molten metal during casting, and is easily displaced in the mold. It is very difficult to manufacture reinforced composite components by conventional pressure casting methods. In order to avoid such a problem, it is possible to perform pressure casting using a reinforcing material molded body having a thickness much larger than the surface portion to be composite strengthened. Not only is it difficult to manufacture a composite material member at low cost because the area that does not need to be processed is also composite-reinforced with the reinforcing material, and it is possible to easily and efficiently process the area other than the surface part. Will be difficult to do.

In addition, Japanese Patent Application Laid-Open No.
As described in 59-23832, a mixture of a reinforcing material and a solvent is attached to a mold cavity of a mold, the mixture is dried, molten metal is poured into the mold cavity, and the molten metal is poured into the mold cavity. A method for manufacturing a composite material member that is solidified while being pressurized is already known,
According to this method, the above-mentioned various problems in the conventional general pressure casting method can be solved and alleviated.

However, in this method, since it is difficult to uniformly attach the reinforcing material to the mold cavity of the mold, it is difficult to uniformly and compositely strengthen the surface portion of the member with the reinforcing material. Since a large amount of reinforcing material cannot be attached to the above, there is a problem that the size of the range of composite strengthening by the reinforcing material is limited to a relatively small range. Further, in this method, in order to deposit a relatively large amount of the reinforcing material on the mold cavity, the binder must be added to the solvent, so that the binder remains in the composite material region of the manufactured member. It is easy to cause a decrease in strength due to that, and the process of attaching a large amount of the mixture of the reinforcing material and the solvent to the mold cavity and drying the mixture requires a troublesome manual work and a long time. It is difficult to easily and efficiently manufacture a composite material member in which only a predetermined surface portion is composite-reinforced with a reinforcing material.

The present invention relates to the case of manufacturing a composite material member in which only the surface portion is composite-reinforced with a reinforcing material by a conventional pressure casting method, and the above-described method in the method of manufacturing a composite material member according to the above-mentioned proposal. In view of the problem, it is an object of the present invention to provide a method capable of easily and inexpensively manufacturing a composite material member in which only a predetermined surface portion is reinforced by a reinforcing material.

Means for Solving the Problems According to the present invention, the above-mentioned object is to form a porous molded body having a predetermined shape with fine metal pieces, and to form the porous molded body with respect to a dispersion fluid in which a reinforcing material is dispersed. A composite molded body composed of the porous molded body and the reinforcing material molded body is formed by suction-molding the body as a filtering element and integrally forming a reinforcing material molded body on a predetermined surface of the porous molded body. Formed, the reinforcement molded body abuts the inner surface of the mold and the composite molded body is placed in the mold so as to be maintained at a predetermined position in the mold by the porous molded body, and in the mold. According to a method for producing a metal-based composite material member, which comprises introducing a molten matrix metal, infiltrating the molten matrix metal into the composite molded body, and melting the porous molded body with the molten matrix metal. Achieved.

Effects and Effects of the Invention According to the method of the present invention, a porous molded body having a predetermined shape made of fine metal pieces is used as a filtering element, and suction molding is performed, whereby a predetermined surface of the porous molded body is formed. A reinforcing material compact is formed integrally with this, and a composite is formed by infiltrating a matrix metal compact into the composite compact, and the porous compact is melted by the molten matrix metal. Disappear by.

Therefore, since the porous molded body acts as a filtering element in the suction molding step, it is possible to easily form a reinforcing material molded body having a predetermined shape corresponding to the shape of the surface portion to be composite-reinforced. Since the quality molded body acts as a carrier for holding the reinforcement molded body after the reinforcement molded body is formed, the reinforcement molded body can be prevented from being damaged or deformed, and the porous body is porous. In the process of compounding the molded body, the reinforcing material molded body is maintained at a predetermined position in a state where it is in contact with the inner surface of the mold, so that only the predetermined surface portion is composite-reinforced with the reinforcing material. A composite material member can be manufactured easily and inexpensively, and since the porous molded body disappears by being melted by the molten metal of the matrix metal, the region other than the predetermined surface portion is composed of fine metal pieces. Avoid being strengthened , It is possible to prevent this by workability in the region other than the predetermined surface portion is deteriorated.

Further, in the method of the present invention, the metal forming the porous molded body may be either a metal having the same or substantially the same composition as the matrix metal, or a metal different in composition from this. In the former case, it is possible to avoid that the metal composition of the region other than the composite material greatly differs from the composition of the matrix metal of the composite material. In the latter case described above, the composition of the constituent metal of the member is positively changed to a composition different from the composition of the matrix metal at the same time as the composite is formed by appropriately selecting the metal forming the porous molded body. Thus, various characteristics such as heat resistance and thermal conductivity can be changed.

In the method of the present invention, the porous molded body may be formed by any method, for example, the method described in JP-A-63-4032.

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

Example 1 An aluminum alloy powder (JIS standard A2024) having an average particle size of 50 μ was cold compression molded to have a diameter of 30 mm and a thickness of 10 mm as shown in FIG. 1. A disk-shaped porous molded body 12 having a volume ratio of 10 of 50% was formed.

Next, as shown in FIG. 2, the porous molded body 12 is mounted on the suction molding device 14, and the alumina-silica short fibers 16 are attached.
(Isolite Kogyo Co., Ltd. "Kao Wool") and a dispersion liquid 18 in which 10 wt% of colloidal silica is dispersed with respect to the weight of the fiber are prepared, and suction molding is performed on the dispersion liquid using the porous molded body 12 as a filtering element. , Thereby forming the porous molded body 12
On one of the circular surfaces, a reinforcing material molded body 20 made of alumina-silica short fibers was integrally formed. In this case, the reinforcement molding has a thickness of 0.7 mm and a fiber volume ratio of about 10%.
Met.

Next, a third composite molded body 22 including the porous molded body 12 thus formed and the reinforcing material molded body 20 which is not integrated with the porous molded body 12 is formed.
As shown in the figure, in the mold cavity 28 of the high-pressure casting apparatus 24, the reinforcing material molded body 20 abuts the wall surface of the mold cavity, and the reinforcing material molded body is maintained in a predetermined position by the porous molded body. It was arranged to be done.

Next, a molten metal 30 of 750 ° C aluminum alloy (JIS standard A2024) is poured into the mold cavity, and the molten metal is pressurized by the plunger 32 at about 1000 kg / cm ^2, and the molten state is completely solidified. Held up. After the molten metal is completely solidified, the solidified body in the mold is taken out by the knockout pin 34, and the solidified body is machined so that only one circular surface portion is formed, as shown in FIG. A column-shaped composite material member 38 made of an aluminum alloy composite material 36 reinforced by alumina-silica short fibers and having the other regions made of an aluminum alloy only was formed.

Next, when the composite material member 38 was cut and its cross section was observed, substantially no alumina-
It was confirmed that the short silica fibers did not exist and the adhesion between the alumina-silica short fibers and the aluminum alloy in the composite material 36 was good. It was also confirmed that the original porous compact was completely extinguished by being melted by the molten aluminum alloy as the matrix metal.

Further, a block test piece for a friction and wear test in which the portion of the composite material 36 is used as a test surface is cut out from the composite material member 38, and the block test piece is a spheroidal graphite cast iron (JIS standard FCD
60) contact the outer peripheral surface of the cylindrical test piece, and contact the contact part of these test pieces with lubricating oil (castle motor oil 5W-
30), contact surface pressure 20kg / mm ² , sliding speed 0.3m / s
A wear test was performed by rotating the cylindrical test piece for 1 hour.
Also, for comparison purposes, a block test piece in which the entire test piece was composite reinforced with the same alumina-silica short fibers as the alumina-silica short fibers used in this example was tested at high pressure using a conventional preform. A block test piece formed by the casting method and machining was also subjected to a wear test under the same conditions.

As a result, the wear scar depth of the block test piece of this example was
12 μ, the wear scar depth of the block test piece of the comparative example is 13
Therefore, it was confirmed that the wear resistance of the surface portion of the composite material member manufactured in this example was equivalent to that of the composite material member manufactured by the conventional method.

Example 2 Porous molding having a volume ratio of fibers of 15% and the same dimensions as the porous molded article of Example 1 by cold compression molding Ni fibers having an average fiber diameter of 30 μ and an average fiber length of 1 mm Formed body.

Then, using this porous molded body, in the same manner as in Example 1, a reinforcing material molded body made of alumina short fibers (ICI "Safir") is integrally formed on one circular surface of the porous molded body. Formed. The thickness of the reinforcing material molded body is 0.4 mm.
The volume ratio of the alumina short fibers was about 2%.

Then, as in the case of Example 1, the same composite molded body as the composite molded body formed in this Example was brought into contact with the inner wall surface of the mold in the reinforcing material molded body in the mold of the high pressure casting apparatus. 730 ℃ aluminum alloy (JIS
A molten metal of standard AC8A) was poured, and a composite material member was formed by the same high-pressure casting as in the case of Example 1. As a result, this composite material member was also made of an aluminum alloy composite material that was composite-reinforced with alumina short fibers. And a portion consisting essentially of an aluminum alloy only, the alumina short fibers are substantially absent in the aluminum alloy portion, and the Ni content of the aluminum alloy portion is the same as the original.
The blood was found to be higher than the Ni content.

In each of the composite material members, it was confirmed that the aluminum alloy was well filled between the individual alumina short fibers, and the adhesion between them was also good.

Although the present invention has been described in detail with reference to two embodiments, the present invention is not limited to these embodiments, and various other embodiments are possible within the scope of the present invention. Some will be apparent to those skilled in the art.

[Brief description of the drawings]

1 to 4 are process diagrams showing a series of steps in the method for manufacturing a metal-based composite material member according to the present invention. 10 …… Aluminum alloy powder, 12 …… Porous compact, 14…
… Suction molding equipment, 16 …… Alumina-silica short fibers, 18 ……
Dispersion, 20 …… Reinforcement molding, 22 …… Composite molding, 24 ……
High-pressure casting equipment, 26 …… Casting, 28 …… Mold cavity, 3
0 …… Aluminum alloy melt, 32 …… Plunger, 34…
… Knockout pin, 36 …… Composite material, 38 …… Composite material member

Claims (1)

(57) [Claims] 1. A porous molded body having a predetermined shape is formed from fine metal pieces, and suction molding is performed on a dispersion fluid in which a reinforcing material is dispersed by using the porous molded body as a filtering element. By forming a reinforcing material molded body integrally with a predetermined surface of the above, to form a composite molded body composed of the porous molded body and the reinforcing material molded body, the reinforcing material molded body abuts the inner surface of the mold. The composite molded body is placed in the mold so as to be maintained in a predetermined position in the mold by the porous molded body while contacting, and a molten metal of a matrix metal is introduced into the mold to form the composite molded body. A method for producing a metal composite material member, which comprises infiltrating the molten metal of the matrix metal and melting the porous molded body with the molten metal of the matrix metal.