JPH06170516A - Production of metal-base composite material by pressurized casting - Google Patents

Abstract

PURPOSE:To produce a metal-base composite material without decect such as crack, penetration even in the case of the large size composite material. CONSTITUTION:A case 18 having plural holes 14b in a punching metal-like is prepared. Successively, a reinforced forming body 12 is densely housed in the case, arranged in the mold together with the case, and subjected to pressure- casting, thereby the molten matrix metal is uniformly pressure-penetrated into the reinforced forming body from the surroundings as much as possible.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a metal matrix composite material, and more particularly to a method for producing a metal matrix composite material by pressure casting.

[0002]

2. Description of the Related Art As one of the methods for producing a metal matrix composite material, a reinforcing material compact is placed in a mold, a molten matrix metal is poured into the mold, and the molten metal is pressurized to a high pressure to mold the reinforcing material. 2. Description of the Related Art A method for producing a metal-based composite material by pressure casting in which a molten metal is infiltrated into a body under pressure has been well known.

As one of the methods for producing a metal matrix composite material by pressure casting, for example, as described in Japanese Patent Publication No. 63-62306 filed by the applicant of the present application, an opening is provided. 2. Description of the Related Art A method for producing a metal-based composite material, in which a reinforcing material molded body is housed in a case, and a molten metal of a matrix metal is pressure-penetrated into the reinforcing material molded body by pressure casting, has been conventionally known. According to this method, it is possible to reliably prevent the reinforcing material molded body from moving or rising, which occurs in a general pressure casting method in which a case is not used.

[0004]

In the method for producing a metal-based composite material by pressure casting, as the composite material to be produced becomes larger and the pressure applied to the molten metal is set higher, the composite material is not cracked or melted. Although defects such as slag are likely to occur, it is also effective to cause defects such as cracks and water bottles in the composite material by the method of manufacturing a metal-based composite material by pressure casting performed using the case as described above. Cannot be prevented.

In view of the above-mentioned problems in the conventional method for producing a metal-based composite material by pressure casting, the present invention produces a large-sized composite material without causing defects such as cracks and a water bath. It is an object of the present invention to provide an improved method for producing a metal matrix composite material.

[0006]

According to the present invention, the above-mentioned object is to store the reinforcing material molded body in a case having a plurality of holes formed in the shape of punching metal, and press-cast the reinforcing material molded body. This is achieved by a method for producing a metal matrix composite material in which a molten metal of a matrix metal is pressure-penetrated into a reinforcing material compact.

[0007]

According to the present invention, since the reinforcing material molded body is housed in the case, the reinforcing material molded body can be effectively prevented from moving, rising, and deforming, and the case can be made of a metal-like metal. Since the molten metal of the matrix metal is pressurized to a high pressure, the molten metal enters the case through the multiple holes, so that the molten metal enters the case only through the opening of the case. The molten metal penetrates into the reinforcing material compact more uniformly than when it intrudes, and therefore defects such as cracks and water bottles in the composite material are caused by the difference in the solidification time of the molten metal in the reinforcing material compact. The risk of occurrence of is effectively reduced.

[0008]

[Supplementary Explanation of Means for Solving the Problems] In the present specification, "punching metal" means that a plurality of holes are regularly or irregularly spaced from each other and dispersed. Is shown. Further, the shape of the hole of the case used in the method of the present invention is not limited to the circular shape, and may be a polygon such as a square. When the shape of the holes is circular, the diameter of each hole and the distance between the centers of adjacent holes are preferably about 1 to 15 mm and about 2 to 10 mm, respectively.

The case used in the method of the present invention may be made of any material that is stable in the molten matrix metal, but the stability in the molten metal, heat transfer, The case is preferably made of steel, particularly stainless steel, from the viewpoint of ease of taking out the composite material after completion of casting.

[0010]

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

FIG. 1 is a perspective view showing a reinforcing material molded body in one embodiment of a method for producing a metal-based composite material according to the present invention, and FIG. 2 is an implementation of a method for producing a metal-based composite material in accordance with the present invention. 4 is a perspective view showing an example of a case used in the example, FIG. 3 is a longitudinal sectional view showing a state where the reinforcing material molded body shown in FIG. 1 is housed in the case shown in FIG. 2, and FIG. FIG. 4 is a cross-sectional view showing a casting step of the method for producing a metal matrix composite material according to the present invention.

First, although not shown in the figure, alumina whiskers having an average whisker diameter of 0.5 μm and an average whisker length of 20 μm are compression-molded by a wet process and dried to obtain the results shown in FIG.
185 × 85 consisting of three-dimensionally randomly oriented alumina whiskers 10 with a volume percentage of 30% as shown in FIG.
Ten reinforcing material compacts 12 having a size of 30 mm were formed.

Further, as shown in FIG. 2, a reinforcing material molded body storage chamber 1 which is opened at the upper end to tightly receive the reinforcing material molded body
Ten cases 18 including a case body 14 having 4a and a weight 16 fixed to the lower end thereof were prepared. It should be noted that the diameter is 5 on the two largest side surfaces of the case body 14 of each case.
mm, a large number of holes with a centering distance of 10 mm
4b are regularly provided, and the reinforcing material molded body storage chamber 1 is provided.
The bottom wall 14c of 4a is provided with a hole 14e for connecting the reinforcing material molded body housing chamber 14a and the space 14d therebelow, and the case body 14 and the bottom wall 14c are made of stainless steel (JIS standard SUS304). Had been formed.

Next, as shown in FIG. 3, each of the reinforcing material molded bodies 12 is housed in the reinforcing material molded body housing chamber 14a of the case 18, and in that state, the reinforcing material molded body is heated to 800 ° C. for each case. Preheated for 1 hour. Next, as shown in FIG. 4, the reinforcing material molded body 12 and the case 18 are heated to 300 ° C.
Placed in the mold 24 of the high pressure casting apparatus 22 preheated to
A molten aluminum 26 of 750 ° C. is poured into the mold, and a plunger 28 that fits the molten metal into the mold is used for about 1000 kgf.
Pressurization was performed at a pressure of / cm ² , and the pressurized state was maintained until the molten metal was completely solidified.

After the molten metal was completely solidified, the solidified body was taken out from the mold 24 by the knockout pin 30 and the solidified body was machined to cut out the composite material formed in the case. Then, the inside of the 10 composite materials thus produced was examined by a nondestructive test machine,
It was confirmed that neither of the composite materials had defects such as cracks and water bottles.

Comparative Example 1 Example 1 except that the reinforcing material compact was placed in the mold in a state of contacting the inner wall surface of the mold of the high-pressure casting apparatus without using the case 18 in the above-mentioned embodiment. Ten composite materials were manufactured under the same procedure and conditions as in the above.

As a result, as shown in FIG. 5, in all 10 composite materials 32, a crack 34 is formed in the central portion thereof along the pressing direction of the molten metal (longitudinal direction of the composite material). It was confirmed.

Comparative Example 2 Instead of the case 18 in the above-mentioned embodiment, as shown in FIG. 6, a case 18 in which an opening 36 of 165 × 65 mm is provided on one of the largest side surfaces of the case body 14. ′
Ten composite materials were manufactured under the same procedure and conditions as in the example, except that was used.

As a result, as shown in FIG. 7, in three of the ten composite materials 32, a region 38 having a volume fraction of alumina whiskers lower than that of the other regions is formed in a portion corresponding to the opening 36. It was confirmed to have occurred.

COMPARATIVE EXAMPLE 3 Instead of the case 18 in the above-mentioned embodiment, a case (not shown) in which the largest side surface of the case main body 14 is not provided with the hole 14b having a metal pattern is used. Except for the above, 10 composite materials were manufactured under the same procedure and conditions as in the example.

As a result, as shown in FIG. 8, it was confirmed that all the ten composite materials 32 had a water bottle 40 extending upward from the lower end thereof.

Although the present invention has been described above in detail with reference to specific embodiments, the present invention is not limited to the above-described embodiments, and various other embodiments are also possible within the scope of the present invention. It will be apparent to those skilled in the art that

[0023]

As is apparent from the above description, according to the present invention, the case in which the reinforcing material molded body is housed is provided with a plurality of holes in the shape of a patching metal, and the molten metal of the matrix metal has a high pressure. When pressurized, the molten metal penetrates into the case through multiple holes.Therefore, the molten metal is more evenly distributed in the reinforced compact than when it enters the case only through the opening of the case. It is possible to reduce the difference in the solidification time of the molten metal in the reinforcing material molded body, which reliably prevents the occurrence of defects such as cracks and water bottles even when the composite material is large. can do.

[Brief description of drawings]

FIG. 1 is a perspective view showing a reinforcing material molded body in one embodiment of the method for producing a metal-based composite material according to the present invention.

FIG. 2 is a perspective view showing an example of a case used in one embodiment of the method for producing a metal-based composite material according to the present invention.

FIG. 3 is a vertical cross-sectional view showing a state where the reinforcing material molded body shown in FIG. 1 is housed in the case shown in FIG.

FIG. 4 is a cross-sectional view showing a casting step of the method for producing a metal-based composite material according to the present invention.

FIG. 5 is a perspective view showing a composite material produced in Comparative Example 1 and having cracks.

6 is a perspective view showing a case used in Comparative Example 2. FIG.

FIG. 7 is a perspective view showing a composite material produced in Comparative Example 2 in which a portion having a low volume ratio of alumina whiskers is produced.

FIG. 8 is a perspective view showing a composite material produced in Comparative Example 3 in which a molten metal is generated.

[Explanation of symbols]

 10 ... Alumina whisker 12 ... Reinforcement molded body 14 ... Case body 14b ... Hole 16 ... Weight 18 ... Case 22 ... High pressure casting device 24 ... Mold 26 ... Pure Al melt 32 ... Composite material 34 ... Crack 38 ... Alumina whisker volume Area with low rate 40 ...

Claims (1)

[Claims] 1. A metal in which a reinforcing material compact is housed in a case having a plurality of holes formed in a punching metal shape, and a molten metal of a matrix metal is pressure-penetrated into the reinforcing material compact by pressure casting. Method of manufacturing base composite material.