JPH11152530A - Production of metal-ceramics composite - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a metal-ceramics composite in which the time required for penetration of a metal is shortened and an Al2 O3 powder minimal in the occurrence of metal-vein is used as a reinforcement. SOLUTION: A preform is prepared by using ceramic fibers or grains as a reinforcement and a metal as a base material is allowed to penetrate into the preform, by which the metal-ceramics composite is produced. In this method, the preform is prepared by adding, as a binder, 1-10 pts.wt. of inorganic powder composed essentially of alumina-silica and having 0.1-100 μm average grain size to 100 pts.wt. of Al2 O3 powder having 1-150 μm average grain size, molding the resultant powder mixture, and then burning the resultant molded part at 1100-1500 deg.C for 1-5 hr. Subsequently, an alloy composed essentially of aluminum is allowed to penetrate into the resultant preform at 700-1000 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite material comprising a metal and a reinforcing material, and more particularly to a method for producing a metal-ceramic composite material using ceramics as the reinforcing material.

[0002]

2. Description of the Related Art A metal-ceramic composite material reinforced with ceramic fibers or particles has both characteristics of a metal and a ceramic. For example, this composite material has high rigidity, low thermal expansion, abrasion resistance and the like. It has the excellent properties of ceramics and the excellent properties of metals 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, all of these methods are not capable of increasing the content of ceramics as a reinforcing material, require a large-sized pressurizing device, are difficult to form near nets, and are extremely expensive. It was not satisfactory.

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
l to ₂ O ₃ preform formed of ceramic powder, such as, by contacting the aluminum ingots, which N ₂
This is a method of impregnating a preform with an aluminum alloy that has been heated to 700 to 900 ° C. and melted in an atmosphere. This is an excellent method in which the preform can be impregnated with the metal without applying pressure by improving the wettability of the molten metal to the ceramic powder using a chemical reaction.

[0005] More particularly the mechanism of this reaction, firstly volatilize Mg in the aluminum alloy, generate magnesium nitride in the volatilized Mg is N ₂ and the reaction to the surface of the ceramic powder (N ₂ + 3Mg → Mg
₃ N ₂ ), and this Mg ₃ N ₂ is extremely easy to react with Al (M
g ₃ N ₂ + 2Al → 2AlN + 3Mg), so that the molten aluminum alloy permeates the preform without pressing. The aluminum nitride (AlN) produced by this reaction is deposited as a thin layer on the ceramic surface, and Mg dissolves in the aluminum alloy,
The higher the concentration, the higher the penetration rate of the aluminum alloy into the preform, and the shorter the penetration time.

In this method, the content of ceramics can be varied as wide as 30 to 85 vol% and can be changed to a high range. In addition, the preform formed by this method has a high degree of freedom in its shape. It is also possible to make quite complex shapes with near nets. As described above, this method does not require a pressurizing device, can increase the content of ceramics, and enables near-net molding. Therefore, this method is an excellent method that solves the above-described problem. .

[0007]

However, when Al ₂ O ₃ powder is used as a ceramic powder as a reinforcing material,
Although it is superior in mechanical properties such as strength and toughness as compared with SiC or AlN powder, there are some manufacturing problems as follows. For this reason, its spread has been hindered despite its excellent mechanical properties.

[0008] (1) The wettability of metal is inferior to other ceramic powders, and it takes a long time for aluminum alloy to penetrate. (2) Since the distribution of the N ₂ gas is unstable, the metal permeates the surface of the preform quickly, but the permeation into the inside of the preform becomes slow, and it takes a long time for the metal to permeate. . (3) The preform is easily cracked, and the cracked portion becomes a metal vane consisting only of metal, and the strength is reduced. And so on.

The present invention has been made in view of the problems of the above-described method for manufacturing a metal-ceramic composite material, and has as its object to reduce the metal permeation time and suppress the generation of metal vanes. It is an object of the present invention to provide a method for producing a metal-ceramic composite material that can be used.

[0010]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, have found that Al _{2 as a} reinforcing material is used.
It has been found that if alumina-silica-based inorganic powder is used as a binder for binding O ₃ powders, a composite material that can reduce the permeation time of metal and suppress the generation of metal bain can be obtained. Thus, the present invention has been completed.

That is, the present invention relates to a method for producing a metal-ceramic composite material in which a preform is formed by using ceramic fibers or particles as a reinforcing material, and a metal as a base material is penetrated into the preform. Is 0.1 to 100 as a binder with respect to 100 parts by weight of Al ₂ O ₃ powder having an average particle size of 1 to 150 μm.
An alumina powder having an average particle diameter of 1 μm is formed by adding 1 to 10 parts by weight of an inorganic powder containing silica as a main component, and then firing the formed body at a temperature of 1100 to 1500 ° C. for 1 to 5 hours, The gist is to provide a method for producing a metal-ceramic composite material, characterized by infiltrating an alloy containing aluminum as a main component into the formed preform at a temperature of 700 to 1000 ° C. This will be described in more detail below.

As described above, as a method for producing a composite material, a method for forming a preform is such that a binder of 0.1 to 100 μm is used as a binder for 100 parts by weight of Al ₂ O ₃ powder having an average particle size of 1 to 150 μm. After adding 1 to 10 parts by weight of an inorganic powder mainly composed of alumina-silica having an average particle size and molding, the molded body is heated to 1100 to 1500 ° C.
Baking at a temperature of 1 to 5 hours, and forming an alloy containing aluminum as a main component on the formed preform.
A method for producing a metal-ceramic composite material that is permeated at a temperature of 00 to 1000 ° C was adopted.

The fineness of the Al ₂ O ₃ powder is 1 to 1 in average particle size.
When the average particle diameter is smaller than 1 μm, the distance between the particles becomes narrower, which hinders the penetration of the metal. When the average particle diameter is coarser than 150 μm, the packing ratio of the ceramic particles becomes lower than 55 vol%. This is because the strength of the reform is unfavorably reduced.

The kind of the binder to be added is an inorganic powder containing alumina-silica as a main component.
It is selected as one that intervenes in the ₂ O ₃ powder, vitrifies when fired, and strongly bonds the Al ₂ O ₃ particles together. And the fineness is 0.1 to 100 μm in average particle size.
The reason for this is that in the conventional colloidal silica solution of a binder and the colloidal solution of alumina hydrate, the generated inorganic binder is too fine, the gap between the particles of the Al ₂ O ₃ powder is narrowed, and the molten metal during permeation is reduced. Since it is difficult to pass through and the permeation time of the metal is extended, this is roughened to facilitate the permeation of the metal. If the fineness is smaller than 0.1 μm in average particle diameter, the permeation time becomes longer, which is not preferable. Conversely, if the average particle size is coarser than 100 μm, the voids between the ceramic particles become too large and the packing ratio is greatly reduced. This is also not preferred.

The amount of the binder to be added is set to Al ₂ O ₃ powder 1
The reason for setting the amount to 1 to 10 parts by weight with respect to 00 parts by weight is that if the amount is less than 1 part by weight, the strength of the preform decreases, and if it is more than 10 parts by weight, closed pores are formed and penetration becomes difficult. This is because it is not preferable. After the Al ₂ O ₃ powder is molded using the binder, the molded body is fired at a temperature of 1100 to 1500 ° C. for sintering the binder for 1 to 5 hours. By infiltrating the preform with an alloy containing aluminum as a main component at a temperature of 700 to 1000 ° C., a metal-ceramic composite material having a short metal penetration time and little generation of metal vanes can be obtained.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The method for producing a metal-ceramic composite material of the present invention will be described.
An Al ₂ O ₃ powder having an average particle diameter of 0 μm is prepared, and about 10 to 50 parts by weight of ion-exchanged water is used for 100 parts by weight of the powder, and the above-mentioned inorganic powder such as kaolin, high silica, or mullite as a binder is used. 1-10 parts by weight of an inorganic powder mainly composed of alumina-silica is added, and if necessary, an antifoaming agent, urea, etc. are added.

The resulting composition is mixed with a pot mill or the like. The mixed slurry is subjected to sedimentation molding by applying vibration. The viscosity of the slurry is preferably 100 poise or less because the powder does not settle if the viscosity is high. Normally, a silicone rubber mold is used, but a mold of plastic, aluminum or the like may be used, and there is no particular limitation. During the sedimentation of the particles, vibration is applied as much as possible to improve the filling. The obtained compact is frozen and demolded. Freezing is not limited as long as the water is frozen. The demolded molded body is fired in the air at a firing temperature of 1100 to 1500 ° C for 1 to 5 hours to produce a preform.

The obtained preform is not pressurized or pressurized in a nitrogen stream at a temperature of 700 to 1000 ° C.
After infiltrating an aluminum alloy such as -Si-Mg or Al-Mg, the metal-ceramic composite material is produced by cooling.

When a metal-ceramic composite material is prepared by the above-described method, a metal-ceramic composite material having a reduced metal permeation time and less generation of metal vanes can be obtained.

[0020]

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

(Examples 1 to 4) (1) Formation of preform Commercially available Al having # 320 (average particle size: 40 μm) as a reinforcing material
₂ O ₃ powder of 70 parts by weight, # 600 30 parts by weight of commercially available Al ₂ O ₃ powder (average particle size 20 [mu]), it 40 parts by weight of ion-exchanged water, binder 2.5 parts by weight of shown in Table 1 And mixed in a pot mill for 16 hours. The obtained slurry was poured into a silicone rubber mold from which a molded body of 200 × 200 × 20 mm in thickness was obtained, and subjected to sedimentation molding by applying vibration. After the molding, the whole rubber mold was frozen at -30 ° C and demolded.
After releasing from the mold, it was baked at 1200 ° C. for 3 hours to form a preform.

(2) Preparation of Metal-Ceramic Composite Material An Al-7Mg alloy was placed on the obtained preform in an amount 1.0% by weight of the preform, and the preform was formed in a nitrogen stream at 825 ° C. for 45 hours. A metal-ceramic composite material was produced by infiltrating the alloy.

(3) Evaluation The bulk density of the obtained preform was measured by the Archimedes method, and the powder filling rate of the preform was determined. Further, the appearance of the preform was visually observed, and those having cracks were evaluated as ×, those without cracks but with cracks were marked with △, and those without cracks and cracks were marked with ○. Further, a 4 × 3 × 40 mm test piece cut out from the preform was subjected to JIS R 16
The three-point bending strength was determined by 01 (test method for bending strength of fine ceramics). Furthermore, the appearance of the obtained composite material was visually observed, and those having metal vanes were evaluated as ×,
A sample without metal vanes was marked with a circle. In addition, a test piece was cut out in the same manner as the preform, and the three-point bending strength was measured according to JIS R
1601. In addition, JIS R 1602
The Young's modulus was determined by an ultrasonic pulse method based on (Fine ceramics elastic modulus test method). Further, a test piece into which a chevron notch was introduced was prepared, and JIS R 16
The fracture toughness value was determined according to 07 (the method for testing the fracture toughness of fine ceramics). Table 1 shows the results.

(Comparative Examples 1 and 2) A preform was formed in the same manner as in Example 1 except that the binder was used as the binder shown in Table 1 and the added amount was changed to 10 parts by weight to produce a composite material. The powder filling ratio, appearance, bending strength, and appearance, bending strength, Young's modulus, and fracture toughness of the preform were determined in the same manner as in Example 1. Table 1 shows the results.

[0025]

[Table 1]

As is clear from Table 1, in the examples, no cracks were observed in the appearance, the powder filling ratio was around 60% or more, the bending strength was more than 1.5 MPa, and the solid preform was hard. Had become. The metal-ceramic composite material produced from the preform had no metal vanes and had good mechanical properties.

On the other hand, in the comparative examples, the bending strengths of the preforms were all the same as those of the examples, but cracks were observed. Metal vanes were generated in the composite material in which the preform was impregnated with metal, and the strength of the portions (lower value) was lower than the strength of the portions where no metal vanes were observed (upper value). In addition, the metal permeation time was 48 hours in the example, but the metal did not completely penetrate in the comparative examples unless both the comparative examples 1 and 2 had 72 hours or more.

[0028]

According to the present invention, a metal-ceramic composite material is prepared by the above-described method, and the metal permeation time is reduced, and a metal-ceramic composite material using Al ₂ O ₃ powder, which generates less metal bain, as a reinforcing material. Can be obtained.
As a result, since the material properties such as strength and toughness are superior to composite materials using other ceramic powders, the use thereof can be expected to be further expanded.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kazunari Naito 3204-7 Fukami, Yamato-shi, Kanagawa (72) Inventor Mutsumi Hayashi 560 Omaki, Urawa-shi, Saitama (72) Inventor Takeshi Higuchi Hikawadai, Higashi-Kurume-shi, Tokyo 1-3-9 (72) Inventor Tomiwa Koyama 1-3-1-805, Ukima, Kita-ku, Tokyo

Claims (1)

[Claims] 1. A method for producing a metal-ceramic composite material in which a preform is formed by using ceramic fibers or particles as a reinforcing material, and a metal as a base material is permeated into the preform. ~ 1
To 100 parts by weight of Al ₂ O ₃ powder having an average particle diameter of 50 μm, 1 to 10 parts by weight of an inorganic powder mainly composed of alumina-silica having an average particle diameter of 0.1 to 100 μm is added as a binder and molded. After that, the molded body is
A method of firing at a temperature of 0 to 1500 ° C for 1 to 5 hours, wherein an alloy containing aluminum as a main component is infiltrated into the formed preform at a temperature of 700 to 1000 ° C. Material manufacturing method.