JP2000119767A - Metal-ceramic composite material for casting, and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metal-ceramic composite material for casting, capable of reducing the wear amount of a tool at screw hole working and excellent in workability, and its manufacturing, method. SOLUTION: In the metal-ceramic composite material for casting, formed by composing an aluminum alloy as a matrix material with a ceramic powder as a reinforcement, the ceramic powder has 15-25 vol.% powder filling rate and is uniformly dispersed in the composite material. Further, JIS 2 class M4 screw holes not smaller than 60 holes in number can be made by the use of a single cemented carbide rolled tap tool (OT-NRTM4×0.7) alone in a product made of this composite material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal-ceramic composite material obtained by compounding a metal with a reinforcing material and a method for producing the same, and more particularly to a metal-ceramic composite material for casting and a method for producing the same.

[0002]

2. Description of the Related Art A ceramic-metal composite material reinforced with ceramic fibers or particles has both characteristics of ceramic and metal. For example, this composite material has high rigidity, low thermal expansion property, abrasion resistance, etc. It has the excellent properties of metal such as ductility, high toughness, and high thermal conductivity. As described above, since it has both the characteristics of ceramics and metal, which have been considered difficult, it has been drawing attention as a next-generation material from industries such as mechanical device manufacturers.

As a method for producing this composite material, particularly a composite material using aluminum as a matrix as a metal, methods such as powder metallurgy, high pressure casting, and vacuum casting have been conventionally known. However, none of these methods is satisfactory because the content of the ceramics as a reinforcing material cannot be increased, or near-net molding is difficult, or the cost is extremely high.

Accordingly, recently, a non-pressurized metal infiltration method developed by Rankside Company of the United States has attracted particular attention as a manufacturing method for solving the above problem. This method uses SiC or A
An aluminum ingot containing Mg is brought into contact with a preform formed of a ceramic powder such as l ₂ O ₃ ,
This is a method in which the preform is impregnated with a molten aluminum alloy by heating the same to 700 to 900 ° C. in an N ₂ atmosphere. This is an excellent method in which the preform can be impregnated with metal without applying pressure by improving the wettability of the molten metal to the ceramic powder by utilizing the chemical reaction between Mg and N _2. .

[0005] There has also been proposed a method for producing a metal-ceramic composite material for casting, in which the composite material produced by this production method is further melted and diluted so that it can be cast with a molten aluminum alloy. In this method, since the wettability of the ceramic powder in the composite material as the intermediate material has already been improved by the addition of Mg, it can be diluted with another molten aluminum alloy, or the diluted ceramic powder can be used. 30-35vol is considered difficult to fill
%, The fluidity is secured, and it is an excellent method that can be used to produce a composite material of a larger product or a more complicated shape by casting into a mold. The casting includes a sand mold /
If it is a casting method generally used for aluminum casting, such as gravity casting using a mold, precision casting typified by lost wax, die casting, etc., the casting can be performed as it is.

[0006]

However, since these composite materials are composites of ceramic powder as a reinforcing material, it is extremely difficult to drill a screw hole, and the non-pressurized metal infiltration with a high filling rate of ceramic powder is high. Needless to say, even in the case of the composite material for casting, which has a low filling rate of ceramic powder, not only the composite material produced by the method but also the screw hole processing is possible, but the tool wear amount during the processing is large and the processing cost is extremely high There was a problem.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the metal-ceramic composite material for casting, and has as its object to reduce the amount of tool wear during drilling a screw hole.
An object of the present invention is to provide a metal-ceramic composite material for casting with low processing cost and a method for producing the same.

[0008]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, if the filling rate of ceramic powder is limited and the dispersion of the ceramic powder is improved, the screw hole drilling time is reduced. The present inventors have found that a metal-ceramic composite material for casting with low tool wear and low processing cost can be obtained, and have completed the present invention.

That is, the present invention provides (1) a metal-ceramic composite material for casting in which a ceramic powder as a reinforcing material is combined with an aluminum alloy as a base material, wherein the ceramic powder is filled with 15 to 25% by volume of a powder. Have a rate,
And it is a ceramic powder uniformly dispersed in a composite material, said composite material being used in a product made therefrom.
IS2 class M4 screw hole with carbide rolled tapping tool (OT-NR
(TM4 × 0.7) a metal-ceramic composite material for casting (Claim 1), characterized in that it is a composite material capable of forming 60 holes or more with one piece, and (2) an aluminum alloy as a base material A method for producing a metal-ceramic composite material for casting in which a ceramic powder as a reinforcing material is compounded, wherein the method of compounding the ceramic powder is
First, a mixed powder of ceramic powder and Mg powder or Mg alloy powder is filled in a container, and an aluminum alloy is infiltrated into the mixed powder to produce a composite material as an intermediate material. A method in which a predetermined amount of an aluminum alloy and a ceramic powder is put into a crucible so that the filling rate of the ceramic powder is 15 to 25% by volume, the mixture is melted at a temperature higher than the melting point of the aluminum alloy by 50 to 150 ° C., stirred, cooled, and combined. It is a gist of the present invention to provide a method for producing a metal-ceramics composite material for casting (claim 2). This will be described in more detail below.

[0010] As described above, as the composite material for casting of the present invention, the ceramic powder in the composite material is used for 15 to 15 times.
Ceramic powder having a powder filling rate of 25% by volume and uniformly dispersed in a composite material, and the composite material formed is made of a JIS class M4 screw hole with a carbide rolling tapping tool in a product made therefrom. (OT-NRTM4 × 0.7) 1
A metal-ceramic composite material for casting is used as a composite material capable of forming 60 or more holes in a book (claim 1).

The ceramic powder used as the reinforcing material includes SiC powder, Al ₂ O ₃ powder, AlN powder or S
i ₃ N ₄ powder and the like, and their powder filling rate is 15 to
The reason for setting the volume at 25% by volume is that if the volume is lower than 15% by volume, the required rigidity (100 GPa or more in Young's modulus) cannot be obtained. This is due to the fact that the JIS Class 2 M4 screw hole cannot be formed in a product made from this composite material for casting with a single carbide-rolled tapping tool in an amount of 60 or more, resulting in poor workability. The uniform dispersibility of these ceramic powders also has a significant effect, and if it is not good, screw hole drilling becomes difficult.For example, if the ceramic powder sediments as described below and cannot be uniformly dispersed, the sedimented portion will become powdery. When the screw hole is formed by penetrating the screw hole from the top to the bottom with a high filling rate, the lower part having a high powder filling rate becomes an obstacle and it is difficult to form a screw hole that penetrates. Also, when a screw hole is formed by opening the side portions in parallel from the top, it becomes difficult to machine the screw hole in the lower portion of the side having the same high powder filling rate.

As a method of producing the composite material, a method of combining ceramic powder is described. First, a mixed powder of ceramic powder and Mg powder or Mg alloy powder is filled in a container, and an aluminum alloy is infiltrated into the mixed powder. After preparing a composite material as an intermediate material by heating, the obtained composite material and the aluminum alloy are put into a crucible in a predetermined amount so that the filling rate of the ceramic powder is 15 to 25% by volume, and the melting point of the aluminum alloy is lowered. A method for producing a metal-ceramic composite material for casting is a method of melting and stirring at a temperature higher by 50 to 150 ° C., cooling, and compounding (claim 2).

In this manufacturing method, first, an aluminum alloy is infiltrated into a ceramic powder to produce a composite material as an intermediate material, and the composite material is made of the same aluminum alloy so that the filling rate of the ceramic powder is 15 to 25% by volume. ,
In addition, the ceramic powder is diluted so that the ceramic powder is uniformly dispersed to produce a casting composite material. For this purpose, the melting temperature of the aluminum alloy at the time of dilution is melted at a temperature 50 to 150 ° C. higher than its melting point. Need
If the temperature is lower than this temperature, the flowability of the molten metal decreases, and poor run-off tends to occur.On the other hand, if the temperature is higher than that temperature, the time until solidification is long, and the sedimentation of the ceramic powder due to the difference in specific gravity between the aluminum alloy and the reinforcing material. And uniform dispersion cannot be achieved.

[0014]

DETAILED DESCRIPTION OF THE INVENTION The manufacturing method of the present invention will be described in more detail. First, reinforcing materials such as SiC, Al ₂ O ₃ , Al
A ceramic powder such as N, Si ₃ N ₄ is prepared. An appropriate amount of Mg or Mg alloy powder is added thereto and mixed. The obtained mixed powder was filled into the container, place the aluminum alloy ingot thereon, 70 in a non-pressurized with N ₂ atmosphere
An aluminum alloy is infiltrated at a temperature of 0 to 900 ° C. and cooled to produce a composite material as an intermediate material.

In the above-mentioned Rankside method, the aluminum alloy is infiltrated under no pressure. However, even if the aluminum alloy is infiltrated at high pressure, the aluminum alloy can be sufficiently infiltrated and there is no problem. The powder is preheated at a temperature of 700 to 900 ° C., and an aluminum alloy that is heated and melted at a temperature of 700 to 900 ° C. is poured into the container, and 50 to 1
The aluminum alloy may be permeated by applying a pressure of 00 MPa.

The obtained composite material is re-melted in a crucible at a predetermined temperature, a separately melted aluminum alloy is added thereto, and the mixture is melted at a temperature 50 to 150 ° C. higher than the melting point of the aluminum alloy. Is diluted to 15-25% by volume. This is further sufficiently stirred by a stirrer to sufficiently disperse the ceramic powder, and then cooled to produce a metal-ceramic composite material for casting. There is no problem if a predetermined amount of the composite material and the above-mentioned aluminum alloy ingot are put into a crucible, melted at a predetermined temperature, and stirred by a stirrer. The obtained composite material for casting may be cast as it is without cooling to produce a composite material as a target product, or may be cooled and formed once into an ingot shape, and then melted and cast again. A composite material that is a target product may be manufactured.

When a metal-ceramic composite material for casting is produced by the above-described method, a metal-ceramic composite material for casting having excellent workability with a small amount of tool wear during drilling of a screw hole is obtained.

[0018]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples of the present invention and Comparative Examples.

(Examples 1 and 2) (1) Preparation of composite material as intermediate material In Example 1, ESK (ELEKTRO) was used as a reinforcing material.
SCHMELZWERK KEMPTEM GMBH)
A commercially available SiC powder (C # 700D Dark, average particle size 17 μm) was prepared. In Example 2, a commercial SiC powder (F600, average particle size 9 μm) from NORTON was prepared, and Mg powder was added to them by 2 weight%. % And mixed by a V-type mixer for 15 minutes. Each of the obtained mixed powders was 200 ×
After filling into a 400 x 200 mm container made of graphoil, an ingot of an aluminum alloy (containing 10 wt% Si) in an amount 1.2 times the mixed powder was placed thereon, and set in an electric furnace. This is placed in a stream of N ₂ at 800 ° C. for 1 hour.
After holding for 2 hours and allowing the aluminum alloy to permeate without pressure, the mixture was cooled to produce a composite material.

(2) Preparation of Composite Material for Casting The ingot of the obtained composite material and the aluminum alloy was filled with a filling rate of 20 vol. Of SiC powder in the composite material for casting.
% Were put into a crucible, melted at a temperature of 800 ° C., and further stirred at 700 ° C. for 2 hours to prepare a molten metal of a composite material for casting. 50 as it is
It was poured into a sand mold of × 50 × H500 mm, cast, and the cast was subjected to evaluation.

(3) Evaluation A 50 × 50 × t5 mm plate was cut out from the upper and lower parts of the obtained casting having a shape of 50 × 50 × H500 mm, and a test piece of 3 × 4 × 40 mm was further cut out from the plate. According to 1602, the Young's modulus is measured, and the uniform dispersibility of the powder is examined. If the Young's modulus is not different or the difference is small, it is regarded as having good uniform dispersibility. did. After the casting was surfaced, the 50 × 500 mm surface was subjected to a carbide roll tapping tool (OT-NRTM4 × 0.7).
Tapping at two places, upper and lower, according to JIS2
The average of the number of tappings that passed the class was determined. Table 1 shows the results.

(Comparative Examples 1 to 4) For comparison, Comparative Example 1
Then, except that the filling rate of the SiC powder was set to 10 vol%,
In Comparative Example 2, except that the filling rate was 30 vol%,
In Comparative Example 3, a casting composite material was produced and evaluated in the same manner as in Example 1 except that the temperature of the molten metal was set to 800 ° C., and in Comparative Example 4, except that the temperature was set to 600 ° C. The results are also shown in Table 1.

[0023]

[Table 1]

As is apparent from Table 1, in Examples 1 and 2, the filling rate of the SiC powder was within the range of the present invention.
Since the dispersibility of the SiC powder was good, the workability was so good that it was possible to form 60 or more JIS class M4 screw holes, which were almost the same at the upper and lower parts, with one carbide-tapped tapping tool. This means that if the filling rate of the SiC powder is limited and the dispersion of the SiC powder is improved, a metal-ceramic composite material for casting having excellent workability with a small amount of tool wear during screw hole processing can be obtained. It is shown that.

On the other hand, in Comparative Example 1, since the filling rate of the SiC powder was too low, the Young's modulus was low and the required rigidity could not be satisfied. In Comparative Example 2, S
Since the filling rate of the iC powder was too high, the amount of tap abrasion was large, and the number of tappings was significantly reduced as compared with the example. Further, in Comparative Example 3, since the temperature of the molten metal was too high, the SiC powder settled out and dispersion was poor, and the powder filling rate was low at the upper part, so that 60 or more screw holes could be formed, but the Young's modulus was 100 GPa. In the lower part, the powder filling rate in the lower part was increased, and the number of tappings was greatly reduced. Furthermore, in Comparative Example 4, since the temperature of the molten metal was too low, the flowability of the molten metal was poor, and poor running of the molten metal occurred.

[0026]

As described above, the metal-ceramic composite material for casting of the present invention can be obtained as a metal-ceramic composite material for casting having excellent workability. As a result, if this is re-melted and cast, the workability is so good that 60 or more JIS Class 2 M4 screw holes can be drilled with one carbide-rolled tapping tool (OT-NRTM4 × 0.7). As a result, it has become possible to provide a composite material, which is a final product with significantly reduced processing costs. │ Reference number TKS252 Document describing chemical formula etc.

[Table 1] [Note] The number of processed screw holes in Comparative Example 3 is the number of processed holes in the lower part of the casting.

Claims (2)

[Claims] 1. A casting metal-ceramic composite material in which a ceramic powder as a reinforcing material is composited with an aluminum alloy as a base material, wherein the ceramic powder is 15% or less.
A ceramic powder having a powder filling rate of ２５25% by volume and uniformly dispersed in a composite material, and the composite material is provided with a JIS class M4 screw hole in a product made therefrom with a carbide-rolled tap. Tool (OT-NRTM4 x 0.7) 1
A metal-ceramic composite material for casting, which is a composite material capable of forming 60 or more holes in a book. 2. A method for producing a metal-ceramic composite material for casting in which a ceramic powder as a reinforcing material is compounded with an aluminum alloy as a base material, the method of compounding the ceramic powder is as follows. Filled with powder or mixed powder with Mg alloy powder,
After the aluminum alloy is infiltrated into the mixed powder to prepare a composite material as an intermediate material, the obtained composite material and the aluminum alloy are filled with a ceramic powder at a filling rate of 15%.
A predetermined amount of 金属 25% by volume in a crucible, which is melted at a temperature 50-150 ° C. higher than the melting point of the aluminum alloy, stirred, cooled and combined to form a composite metal; Manufacturing method of ceramic composite material.