JPH1147914A - Metal group composite casting article and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metal group composite casting article and its manufacturing method which is excellent in the workability of a metal group composite material. SOLUTION: A metal group composite casting article 5 comprises a working member 1 which is inserted into a metal group composite material 3 and its working part 30 and a working part 2 of a prescribed shape provided at the working part. The working member 1 is installed in a cavity of a casting die in advance and after the inside of the cavity is charged with a dispersant material for improving the characteristic, the metal is poured into the cavity by a pressure casting method. The metal group composite material 3 is Al-SiC, etc. The working part 2 can be formed by removing the whole or a part of the working member 1 from the working part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal-based composite casting in which particles or fibers such as ceramics, short fibers, whiskers and the like are dispersed, and a method for producing the same.

[0002]

2. Description of the Related Art A metal matrix composite is a material in which a metal is used as a base material and a dispersion material for improving properties such as particles and fibers coexists. As the metal matrix composite, for example, there is one in which ceramic particles are dispersed in an aluminum base material. Such an Al-based composite material is prepared by placing a formed body of ceramic particles prepared in advance in a casting mold and compounding it by a die casting method.

[0003] Al-based composite materials are used as components such as heat sinks for power modules. Al-SiC is generally used as a metal matrix composite for a heat sink. Since the heat sink needs to be provided with an IC substrate, it is necessary to perform secondary processing such as surface processing and drilling.

[0004]

[Problem to be solved] However, Al-SiC
The composite material has a problem that it is very hard and difficult to process, and the cost is high. Therefore, conventionally, an Al-SiC substrate is manufactured by utilizing an Al layer formed on a surface portion thereof.
A method of processing the surface of a SiC plate has been proposed (Japanese Patent Publication No. 5-508350). However, in this method, since the formed Al layer is thin, it is also difficult to process due to the influence of the underlying metal matrix composite.

[0005] Therefore, a pre-drilling process is performed on a formed body of ceramic particles or the like, and this is set in a casting mold.
It is conceivable that the metal is cast. However, in this method, there are cases where holes formed in the molded body during casting are broken, and there are problems such as an increase in cost due to drilling. Furthermore, it may be difficult to form a hole in a formed body.

The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide a metal-based composite casting having excellent workability of a metal-based composite material and a method of manufacturing the same.

[0007]

According to a first aspect of the present invention, there is provided a metal-based composite material, a processed member formed by casting a processed portion of the metal-based composite material, and a processed portion having a predetermined shape provided on the processed member. It is a metal matrix composite casting characterized by comprising.

The operation and effect of the present invention will be described.
In the present invention, a processed member is inserted into a processed portion of the metal matrix composite. Therefore, by a simple operation of removing the processed member, a processed portion having substantially the same or similar shape as the processed member can be formed at the processed portion.
Also, the processed part is not destroyed.

Further, a part of the processed member is left. Thus, the processed portion can be easily formed into a desired shape in order to process the processed member by a method such as cutting. That is,
The periphery of the processed part is preferably covered with the processed member. The reason for this is that even when trying to form a machined part such as a bolt hole in a machined part, the metal matrix composite is hard and difficult to machine, but the part around the machined part is machined around the machined part, leaving a part of the machined member in the machined part. This is because, by coating with a member, a processed portion having a desired shape can be easily formed in the processed portion, and workability of the processed portion is improved. That is, a processed portion having a complicated shape such as a thread can be easily formed at the processed portion.

[0010] The processed portion is, for example, a hole. Such a hole can be used, for example, as a bolt fastening hole. In addition, the processed portion may be, for example, tapered, or may be a curved surface or a flat surface.

According to a second aspect of the present invention, the difference in the coefficient of thermal expansion between the processed member and the metal matrix composite is 10 × 10 ^-6 /
It is preferably at most K. Accordingly, the metal matrix composite or the processing member around the processing portion does not peel off from the processing portion due to thermal fatigue of the processing portion, and can be kept at the processing portion. On the other hand, if the difference in thermal expansion coefficient between the processed member and the metal-based composite exceeds 10 × 10 ⁻⁶ / K, thermal fatigue occurs in the processed portion, and the metal-based composite or the processed member around the processed portion. May peel off.

Preferably, the processed member is cast iron and the metal-based composite is a SiC / Al composite. As a result, the difference in the thermal expansion coefficient between the processed member and the metal matrix composite is reduced, and the thermal fatigue of the processed portion during casting is reduced. For this reason, it is possible to suppress the peeling of the member around the processed portion, that is, the processed member. In addition to these combinations, the processed member and the metal matrix composite include those described later.

Next, as a method of manufacturing a metal-based composite casting, for example, a step of setting a processing member in a cavity of a mold in advance and dispersing the inside of the cavity for improving characteristics in the mold are provided. Filling a metal into the cavity by a pressure casting method to form a metal matrix composite comprising a dispersant for improving properties and the metal, and processing the processed member into a predetermined shape And a step of forming a portion.

In the present manufacturing method, after a working member is placed in a cavity of a mold in advance, a dispersing material for improving properties is filled in the cavity, and a metal is injected. Therefore, the metal matrix composite is cast in a state where the dispersion material for property improvement is dispersed using the metal as a base material,
In the metal-based composite material, a processing member set in a molding die in advance is cast. Accordingly, a metal-based composite casting obtained by casting a processed member with the metal-based composite material is obtained.

In addition, a processed member is inserted into a processed portion of the metal matrix composite. Therefore, by a simple operation of removing the processing member such as punching or screwing, a processing portion having substantially the same or similar shape as the processing member can be formed at the processing position at the trace. Also, the processed part is not destroyed. Therefore, the manufacturing method of the present invention is excellent in workability.

Next, the details of the manufacturing method will be described. The processed member is a member having the same or similar shape as the shape of the processed portion, and is a member that is previously installed as a core in a casting mold. The processed member has the same or similar shape as the desired processed part required for the metal matrix composite casting. On the mark after removing such processed parts,
A processed part having a shape similar to the processed member is formed.

The above-mentioned processed member is required to be made of a material that can be easily processed, has a higher melting point than molten metal at the time of casting, and has shape retention. As a processed member having such properties,
Molding of water-soluble salt, metal, metal powder, metal foam, metal fiber fabric, metal fiber nonwoven fabric, carbon or boron nitride fiber fabric, carbon or boron nitride fiber nonwoven fabric, carbon or boron nitride powder molding It is preferably a body. Thereby, the processing of the processing member can be easily performed.

When forming the processed portion, it is preferable to leave a part of the processed member around the portion. As a result, as described above, a processed portion having a complicated shape such as a thread can be easily formed at the processed portion. As a desirable mode when a part of the processed member is left, for example, the difference in thermal expansion coefficient between the processed member and the metal matrix composite is minimized or the interface strength between the processed member and the metal matrix composite is increased. .

As described above, by leaving a part of the processed member and covering the periphery of the processed portion with the processed member, cracks generated around the processed portion when the processed member is removed by processing such as screw cutting are generated. It does not remain in the base composite. If these cracks remain in the metal matrix composite, when a force is applied to the processed part, the cracks may be the starting point and cracks may occur. Problems can be prevented.

According to a seventh aspect of the present invention, the difference in the coefficient of thermal expansion between the processed member and the metal matrix composite is 10 × 10 ^-6 /
It is preferably at most K. Thereby, the metal which casts the processed member does not peel off from the processed member due to thermal fatigue, and the processed member can be kept at the processed portion. Further, during transportation, handling, and the like, the protection of the processing portion by the processing member can be ensured. on the other hand,
The difference in thermal expansion coefficient between the processed member and the metal matrix composite is 10 × 1
If it exceeds 0 ^-6 / K, thermal fatigue may occur in the processed part, and the metal matrix composite around the processed part may be peeled off.

A high quality metal-based composite casting can be manufactured by increasing the strength of the interface between the processed member and the metal-based composite material. As a method of increasing the interfacial strength, it is desirable to form the processed member itself or the surface of the processed member with a substance that easily wets the metal of the metal matrix composite.
Also, mechanical projections may be formed by forming minute projections on the surface of the processed member.

Further, when forming the processed portion, all of the processed members may be removed. As a desirable mode in the case where the processing member is formed by removing the entire processing member, it is preferable to apply a release agent in advance to the surface of the processing member. Thus, the processing member can be removed from the processing site with a smaller force. As the release agent, carbon, boron nitride, or the like can be used, but is not limited thereto.

Further, the processed portion is a hole. When the processed portion is a hole and all of the processed member is to be removed, it is preferable that the processed member is a disk having the same or similar shape as the hole, and is tapered along its thickness direction. Thus, the working member easily comes out of the processing portion by applying an external force in the taper expanding direction from the surface of the metal-based composite casting in the taper reducing direction. Therefore, the processing of the processing portion can be easily performed.

It is preferable that the processed member is cast iron, the characteristic improving dispersant is SiC, and the metal is Al. As a result, the difference in the thermal expansion coefficient between the processed member and the metal matrix composite is reduced, and the thermal fatigue of the processed portion during casting is reduced. For this reason,
Peeling of the processing member around the processing part can be suppressed.

The above-mentioned metal-based composite material is a composite material obtained by mixing a metal as a base material with a dispersion material for improving properties. It is preferable that the metal is an element that permeates around the processed member by high temperature and high pressure during casting. Thereby, the processed member can be cast with metal. for that reason,
The processing member can be easily removed. Further, thermal fatigue around the processed portion is prevented, and the strength of the processed portion is further improved. The metal is not particularly limited, but for example, aluminum, aluminum alloy, magnesium, magnesium alloy, copper, copper alloy and the like can be used.

The above-mentioned dispersant for improving properties is a material which is combined with a metal in order to improve the properties of the metal. Therefore,
The characteristics, components, form, etc., of the dispersing material for improving characteristics differ depending on the characteristics to be imparted to the metal. The dispersing material for improving properties has a form of particles, fibers, short fibers, whiskers and the like. As the dispersion material for improving the characteristics, for example, SiC
(Silicon carbide), carbon, A1N (aluminum nitride), A
l ₂ O ₃ (alumina), BeO (beryllium oxide),
Copper, silicon nitride, diamond, and the like can be used, but are not limited thereto.

When the metal is injected into the cavity filled with the property improving dispersant, the metal may be mixed with the property improving dispersant and then injected. The pressure casting method includes a high pressure casting method, a die casting method, and the like. The metal-based composite casting of the present invention has a wide variety of uses, such as heat sinks for power modules, packages, electronic components such as heat exchangers, and mechanical components such as engine pistons.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION

First Embodiment A metal matrix composite casting according to an embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, the metal-based composite casting 5 of this example is provided at the metal-based composite material 3, the processed member 1 that is formed by casting the processed portion 30 of the metal-based composite material 3, and the processed portion 30. And a processing part 2 having a predetermined shape.

The metal matrix composite 3 is composed of an aluminum alloy (hereinafter, referred to as Al alloy) 32 and silicon carbide powder 31, and has a coefficient of thermal expansion of 7 × 10 ^-6 / K.
The metal matrix composite 3 has a size of 150 mm x 240 mm x
It is a 2.5 mm flat plate. The processing member 1 is made of cast iron and has a coefficient of thermal expansion of 11 × 10 ⁻⁶ / K. Processed member 1
Is a disk having a diameter of 7 mm and a thickness of 2.5 mm.

As shown in FIG. 2, the processing portion 2 is a 5 mm diameter through hole for a bolt having the same axis as the processing member 1, and the wall surface is threaded. In addition, as a processed member, niresist cast iron (coefficient of thermal expansion: 17 × 10 ⁻⁶ / K), carbon (coefficient of thermal expansion: 3 × 10 ⁻⁶ / K), Fe—Ni (coefficient of thermal expansion: 1 × 10 ⁻⁶⁾ / K) can be used.

The method for producing the metal-based composite casting will be described. First, as shown in FIG. 3A, a steel holder 61 was prepared. Inside the holder 61, 150
A cavity 610 of mm × 240 mm × 2.5 mm was provided. Next, a plurality of processing members 1 were installed inside the holder 61.

Next, as shown in FIG. 3B, silicon carbide powder 31 (SiC) having an average particle diameter of 100 μm is filled in the cavity 610 of the holder 61, and the volume of the silicon carbide powder 31 is about Pressurization was performed so that the volume ratio was 65%. This holder 61 is placed in an electric furnace for 800
Heated to ° C. As shown in FIG. 3C, the heated holder 61 was placed in a mold 62 preheated to 250 ° C., and a molten Al alloy (for example, an Al-12% Si alloy) 32 was poured immediately. Pressurized to about 800kg / cm ² ,
Hold for 15 minutes.

After cooling, as shown in FIG.
From the inside, a metal-based composite casting 5 composed of the Al alloy 32 and the silicon carbide powder 31 was taken out. Then, the machining part 30
The processing member 1 is screwed off, and the processing member 1 is removed leaving a part thereof.

As shown in FIG. 1, in the metal-based composite casting 5 of this embodiment, a processing member 1 which is a disk of cast iron is
Existed at zero. Since the processed member 1 is softer than the metal-based composite material 3, it can be easily removed by threading. Further, an alloy layer 37 was formed around the processing portion 2 from the cast iron of the processing member 1 and the Al alloy 32.

In this embodiment, the processed portion is a through hole for a bolt with a thread, but all the processed members may be removed by drilling to form a cylindrical through hole having the same shape as the processed member. .

Embodiment 2 As shown in FIGS. 4 and 5, the metal matrix composite casting of this embodiment is
The processing member 11 has a taper 110 in the thickness direction, and a release agent 7 is applied to the surface of the processing member 11.

That is, the processing member 11 is a copper plate, and has a thermal expansion coefficient of 17 × 10 ⁻⁶ / K. Processed member 1
1 has a taper 110 of 3 ° in the thickness direction. The processing member 11 has a size of 15 mm × 15 mm and a plate thickness of 5 mm. The surface of the processed member 11 is coated with fine boron nitride powder as the release agent 7. The processing member 11
It is filled with a metal-based composite material 3 composed of an Al alloy 32 and silicon carbide powder 31. The size of the metal-based composite casting 51 is 150 mm × 240 mm × 5 mm. Other configurations are the same as those of the first embodiment.

In this embodiment, the processing member 11 is a square plate, and has a taper 110 along the thickness direction. Further, a release agent 7 is applied to the surface of the processed member 11. Therefore, by applying an external force A from the surface of the metal-based composite casting 51 in the direction of reduction of the taper 110 to the direction of enlargement of the taper 110, the processing member 11 easily comes out of the processing portion 30, and the processing member 11 A processed portion having the same shape is formed. Therefore, machining of the machining portion 30 can be easily performed. Also in this example, the same effect as in the first embodiment can be obtained.

Embodiment 3 In this embodiment, a metal-based composite casting was manufactured by using a substance made of a water-soluble salt as a working member and washing the casting after casting. The processed member is specifically made of rock salt, and has a cylindrical shape with a diameter of 10 mm and a height of 20 mm. Other configurations are the same as those of the first embodiment. The processed member can be easily removed by washing with water, and the composite material plate of silicon carbide and aluminum alloy has a diameter of 1 mm.
A through-hole of 0 mm was easily formed.

Comparative Example In this example, a metal-based composite casting was manufactured by filling a cavity of a mold with silicon carbide powder (SiC) and then injecting an Al alloy. Otherwise, a metal-based composite casting was manufactured in the same manner as in Example 1. An attempt was made to drill a hole having a diameter of 10 mm in the obtained metal-based composite casting, but a normal drill was severely worn and could not be machined.

[0041]

According to the present invention, it is possible to provide a metal-based composite casting having excellent workability of a metal-based composite, and a method for producing the same.

[Brief description of the drawings]

FIG. 1 is a perspective view of a metal-based composite casting according to a first embodiment.

FIG. 2 is a cross-sectional view of a metal-based composite casting showing a processed portion in the first embodiment.

FIG. 3 is an explanatory view showing a method for manufacturing a metal-based composite casting according to the first embodiment.

FIG. 4 is a perspective view of a metal-based composite casting according to a second embodiment.

FIG. 5 is a sectional view of a metal-based composite casting according to a second embodiment.

[Explanation of symbols]

 1,11. . . Processed member, 2. . . Processing part, 3. . . Metal-based composite, 30. . . Processing part, 31. . . Silicon carbide powder, 32. . . Al alloy, 5,51. . . 6. Metal-based composite casting, . . Release agent,

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shinichi Towa 41-1, Chuchu-Yokomichi, Nagakute-cho, Aichi-gun, Aichi Prefecture Inside Toyota Central Research Laboratory Co., Ltd. (72) Inventor Nobuo Kamiya Nagakute-cho, Aichi-gun, Aichi (1) Inside Toyota Toyota Central Research Institute Co., Ltd. (72) Inventor Hiroshi Hojo 41, Nagakute-cho Ochi-gun, Aichi-gun, Aichi Prefecture, Japan Inside Toyota Central Research Laboratory Co., Ltd. (72) Inventor Naohisa Nishino 1 Toyota-Chuo R & D Co., Ltd.

Claims (8)

[Claims] 1. A metal comprising a metal-based composite material, a processing member cast into a processing portion of the metal-based composite material, and a processing portion having a predetermined shape provided on the processing member. Basic composite casting. 2. The method according to claim 1, wherein the difference in the coefficient of thermal expansion between the processed member and the metal matrix composite is 10 × 10 ⁻⁶ / K.
A metal-based composite casting, characterized in that: 3. The metal-based composite casting according to claim 1, wherein the processed member is cast iron, and the metal-based composite is a SiC / Al composite. 4. A step of placing a processing member in a cavity of a mold in advance, a step of filling the cavity with a dispersion material for improving characteristics, and injecting metal into the cavity by a pressure casting method to improve characteristics. A method for manufacturing a metal-based composite casting, comprising: a step of forming a metal-based composite material including a dispersing material and the metal; and a step of forming a processed portion having a predetermined shape on the processed member. 5. The method for manufacturing a metal-based composite casting according to claim 4, wherein, when forming the processed portion, a part of the processed member is left around the processed portion. 6. The method of manufacturing a metal-based composite casting according to claim 4, wherein in forming the processed portion, all of the processed member is removed. 7. The method according to claim 5, wherein a difference in thermal expansion coefficient between the processed member and the metal matrix composite is 10 × 10 ⁻⁶ / K.
A method for producing a metal-based composite casting, comprising: 8. The method according to claim 5, wherein the processed member is cast iron, the property improving dispersant is SiC, and the metal is Al.