JP2005324989A - Fitted body and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fitted body wherein a ceramic plate is fitted into a metal-ceramic composite material without using any brazing material, wherein the ceramic plate is fitted into a concave part of the metal-ceramic composite material substantially without any gap. <P>SOLUTION: The manufacturing method of the fitted body wherein the ceramic plate is fitted into the metal-ceramic composite material comprises a concave part-forming step wherein the concave part is formed on a preform made of a ceramic reinforcement, a fitting step wherein the ceramic plate is fitted into the concave part, a lid-placing step wherein a lid made of a preform plate is placed over the concave part on the preform into which the ceramic plate is fitted, an infiltration step wherein the preform and the lid made of the preform plate are infiltrated with a molten metal without pressurization and a scraping step wherein the lid of the obtained metal-ceramic composite material is scraped off. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a fitting body of a metal-ceramic composite material obtained by combining a ceramic reinforcing material in a metal matrix and a ceramic plate, and more specifically, an Al alloy combined with SiC powder and / or SiC fiber as a reinforcing material. The present invention relates to a fitting body of an Al alloy-ceramic composite material and a ceramic plate and a manufacturing method thereof.

In recent years, metal matrix composite materials that combine high toughness of metal materials, high thermal conductivity, low thermal expansion of ceramics, wear resistance, and the like, have attracted attention as a new material for the next generation.
Conventionally, powder metallurgy, high-pressure forging, vacuum casting, and the like are known as methods for producing the metal matrix composite material. However, these methods do not allow the content of the ceramic reinforcement to be controlled and are large-scale processing. Neither was fully satisfactory due to the necessity of a pressure device or difficulty in near-net molding.

Here, there is a non-pressurized metal permeation method developed by the US rank side company as a manufacturing method which has recently attracted particular attention. In this method, a preform formed from ceramics such as SiC or Al ₂ O ₃ is brought into contact with an aluminum alloy, and this is heated to 700 to 900 ° C. in an N ₂ atmosphere furnace to infiltrate the molten aluminum alloy. Is the method. Therefore, there is a feature that the wettability between the ceramic grains and the molten alloy can be improved by utilizing a chemical reaction as in the conventional case, and the molten metal can be permeated without mechanical pressurization.

According to this method, by controlling the filling rate of the preform, the ceramic reinforcement content can be freely varied between 30 and 85%.
In addition, since the degree of freedom of the shape of the preform is high, it is possible to make a fairly complicated shape with a near net.

On the other hand, a joined body imparted with a special function by integrating and bonding such a metal-ceramic composite material and ceramic with high strength is being studied in the field of mechanical ceramics and electroceramics.

As a response to such a requirement, a joined body in which a metal-ceramic composite material and ceramics are joined via a brazing material and a joining method thereof have been proposed (for example, see Patent Document 1).
JP 2001-48669 A

However, in the above-described metal-ceramic composite material and ceramic bonding method, the brazing material is interposed in the bonding layer, so that the operating temperature is limited, or in the special application in the electroceramics field, the brazing material component is an impurity in the system. It may become a problem because of diffusion.
Furthermore, depending on the joining conditions, there is a problem that cracks occur in the joined ceramics.

The present invention has been made in view of the problems of the above-described method for joining a metal-ceramic composite material and a ceramic, and the object thereof is a fitting body that does not use a brazing material between the metal-ceramic composite material and the ceramic plate. The ceramic plate is provided with a fitting body in which the ceramic plate is fitted into the concave portion of the metal-ceramic composite material with substantially no gap and a manufacturing method thereof.

The object of the present invention can be achieved by the following means.
(1) A fitting body of a metal-ceramic composite material and a ceramic plate, wherein the ceramic plate is fitted in a concave portion of the metal-ceramic composite material with substantially no gap, and the ceramics A fitting body characterized in that no visible cracks are observed on the plate.
(2) A recess forming step of forming a recess in a preform made of a ceramic reinforcing material, a fitting step of fitting a ceramic plate into the recess, and a recess of the preform fitted with the ceramic plate are covered. A lid placing step for placing a lid made of a preform plate, an infiltration step for infiltrating molten metal into the lid made of the preform and the preform plate without pressure, and the metal thus obtained A method for producing a fitting body of a metal-ceramic composite material and a ceramic plate according to (1), comprising: a grinding step of scraping off the lid portion of the ceramic composite material.

According to the fitting body and the manufacturing method thereof of the present invention, the metal-ceramic composite material and the ceramic plate can be fitted and joined without using a brazing material.
Therefore, there is no problem that the use temperature of the fitting body is limited or the problem that the brazing material component diffuses as impurities in the system in a special application in the field of electroceramics, and the application can be expanded.

The present invention is described in further detail below.
In the present invention, the metal-ceramic composite material and the ceramic plate are fitted to each other, and the ceramic plate is fitted in a recess of the metal-ceramic composite material with substantially no gap, and A fitting body characterized in that no visible cracks are observed in the ceramic plate is proposed.

Here, as the ceramic used as the reinforcing material in the present invention, it is preferable to use SiC powder and / or SiC fiber.
Moreover, as a metal which penetrates the preform, an Al alloy containing Mg is preferable.

In the present invention, a SiC powder and / or SiC fiber whose particle size has been adjusted so as to obtain a predetermined filling state is mixed with a dispersant, a binder, and the like, and the mixture is obtained by various methods such as casting and pressure molding. A preform having a SiC content is used.
By heat-treating this preform and the Al alloy, the molten Al alloy penetrates into the pores in the preform, and the metal-ceramic composite material according to the present invention is obtained.

In the fitting body of the metal-ceramic composite material of the present invention and the ceramic plate (hereinafter sometimes referred to as both members), the ceramic plate is substantially free from a gap in the recess of the metal-ceramic composite material. It is characterized by being fitted with.
Here, the two members are directly in contact and joined to each other between the ceramic plate of the present invention and the metal-ceramic composite material without interposing a brazing material.
In addition, being fitted with substantially no gap means that there is no gap such as a void or void in the joint between the ceramic plate and the metal-ceramic composite material (that is, the gap between the two members). Means that the molten Al alloy is infiltrated, and that both members are fitted.

Next, the fact that no visible cracks are observed in the ceramic plate of the present invention means that the fitting body of the present invention is obtained by the manufacturing method described below, so that distortion due to the difference in thermal shrinkage between the two members during manufacturing is obtained. This means that no cracks are generated in the ceramic plate as in the prior art, and no cracks can be found by visual inspection.

Next, in the present invention, a recess forming step of forming a recess in a preform made of a ceramic reinforcing material, a fitting step of fitting a ceramic plate into the recess, and a recess of the preform fitted with the ceramic plate are provided. A lid placing step for placing a lid made of a preform plate so as to cover, a permeation step for infiltrating the molten metal into the lid made of the preform and the preform plate without pressure, and thus obtained. And a grinding step of scraping off the lid portion of the metal-ceramic composite material. A method for producing a fitting body of the metal-ceramic composite material and the ceramic plate is proposed.

Here, the method for producing the preform of the present invention is as described above. However, as a method for forming the concave portion, the concave portion is formed by various methods such as casting molding and pressure molding using a mold having a concave portion in advance. Alternatively, the recess may be formed by grinding an existing preform by a known method.
At this time, the inner dimension of the recess formed in the preform is preferably larger than the outer dimension of the ceramic plate in order to facilitate the fitting of the ceramic plate.
Moreover, it is preferable that the depth of the concave portion formed in the preform is deeper than the thickness of the ceramic plate so that the lid portion made of the preform plate in the next process can be placed.

The present invention includes a lid placing step of placing a lid made of a preform plate so as to cover the concave portion of the preform fitted with the ceramic plate.
The reason for this is that, in this way, it is possible to reduce distortion due to the difference in thermal shrinkage between the two members during cooling of the permeated molten metal.

In the permeation step of infiltrating the molten metal without pressure, the molten metal (preferably an Al alloy) is preferably used in a vacuum or an inert gas having a nitrogen partial pressure of 1 × 10 ⁻³ Torr (0.133 Pa) or less. Infiltrate into the preform. Next, by cooling the resultant product, a metal-ceramic composite material including a ceramic plate is obtained.

  Next, the metal-ceramic composite material of the present invention and the ceramic plate are obtained by scraping off the metal on the surface of the lid and the ceramic plate from the metal-ceramic composite material containing the ceramic plate.

EXAMPLES Hereinafter, although the Example of this invention is specifically mentioned with a comparative example and this invention is demonstrated in detail, this invention is not limited to an Example.
In addition, in order to demonstrate the manufacturing method of this invention in FIG. 1, arrangement | positioning of each member before infiltrating molten metal was shown typically as a plane block diagram.
FIG. 2 is a cross-sectional view taken along the line AA of the plan configuration diagram shown in FIG.
FIG. 3 is a plan configuration diagram schematically showing the fitting body of the present invention.
4 is a cross-sectional view taken along the line B-B in the plan view of FIG. 3.
(However, each drawing is a schematic diagram, and the ratio of each dimension is arbitrary. Therefore, the drawing dimensions are not compatible.)

(Example 1)
A preform having a SiC reinforcing material filling rate of 70% was prepared by a sedimentation molding method as shown below.
That is, 10 parts by weight of colloidal silica as a binder and 70 parts by weight of a commercial SiC powder of # 180 (average particle diameter of 66 μm) and 30 parts by weight of commercially available SiC powder of # 800 (average particle diameter of 14 μm) as an antifoaming material Formass VL (manufactured by San Nopco) (0.2 parts by mass) was added, and 24 parts by mass of ion-exchanged water was further added and mixed in a pot mill for 12 hours to obtain a slurry. The slurry is poured into a rubber mold and left to stand for 24 hours to allow the SiC powder to settle, and after the upper liquid is removed with a cloth or the like, the molded body is frozen in a freezer and demolded. And a preform body 1 having a square of 700 × 30 mm in thickness was obtained.

Next, the preform body 1 was dug into the center of the preform body 1 by an end mill to form a □ 301 × depth 10 mm recess 2. Next, as the ceramic, alumina (purity 99.5%, porosity 0.1%) was used, and a ceramic body 3 of □ 300 × 10 mm in thickness was fitted. The gap between the preform and the alumina body was about 0.5 mm.
Next, a lid portion 4 made of a □ 400 × 10 mm-thick preform plate produced in the same manner as described above was placed so as to cover the concave portion 2 of the preform body 1 fitted with the ceramic body 2. Bonded using sodium silicate glass.

Next, a preform containing the ceramic body 3 was placed in a furnace together with an Al alloy, and heat-treated in an electric furnace at an infiltration temperature of 800 ° C. for 50 hours in an N 2 airflow. During the heating, the molten alloy penetrated into the preform without pressure. After cooling, when taken out from the electric furnace, the permeation was completed and a metal-ceramic composite material including the ceramic body 3 was obtained.
Next, if the metal of the metal-ceramic composite material lid (not shown) and the metal on the surface of the ceramic plate are scraped off, the metal-ceramic composite material and ceramic of the present invention schematically shown in FIGS. A fitting body with the plate is obtained.
When the obtained fitting body was visually observed, no displacement or cracking was observed in the ceramic body 3 exposed on the surface.
Further, the ceramic plate 3 was fitted in the recess of the metal-ceramic composite material 5 with substantially no gap.

(Comparative Example 1)
□ The molten alloy was non-pressurized and infiltrated into the preform in the same manner as in Example 1 except that the lid portion composed of a 400 × 10 mm thick preform plate was not placed, that is, the alumina body was not covered with the preform. . After cooling, when taken out from the electric furnace, the infiltration was complete. When the surface layer was checked for cracks, cracks were found in the alumina ceramic body. This was presumed that since the lid was not placed, the ceramic body was cooled faster than the surrounding composite material compared to Example 1, and cracks were generated due to the difference in thermal expansion.
Therefore, the superiority with the comparative example of this invention was able to be confirmed.

(Reference example)
The molten alloy was impregnated into the preform in a non-pressure manner in the same manner as in Example 1 except that alumina was changed to a purity of 88% and a porosity of 15% as the ceramic body used. After cooling, when taken out from the electric furnace, the infiltration was complete. When the penetrating material was ground and the Al alloy-based composite material of □ 400 × 10 mm thick was scraped off, the exposed ceramic body was infiltrated with the molten alloy and became a conductor.
From this result, it was found that the ceramic plate to be fitted is preferably a high purity and dense one.

It is the plane lineblock diagram showing typically arrangement of each member before penetrating a molten metal. FIG. 2 is a cross-sectional view taken along the line AA in FIG. It is a plane block diagram of the fitting body of this invention. FIG. 5 is a cross-sectional view taken along the line BB in FIG. 3.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1; Preform body 2; Concave part 3; Ceramic body 4; Cover part 5 which consists of preform plates; Metal-ceramic composite material

Claims (2)

A fitting body of a metal-ceramic composite material and a ceramic plate, wherein the ceramic plate is fitted in a recess of the metal-ceramic composite material with substantially no gap, and the ceramic plate A fitting body characterized in that no visible cracks are observed. A recess forming step for forming a recess in a preform made of a ceramic reinforcing material, a fitting step for fitting a ceramic plate into the recess, and a preform plate so as to cover the recess of the preform fitted with the ceramic plate A lid portion placing step for placing the lid portion made of, a permeation step for infiltrating the molten metal into the lid portion made of the preform and the preform plate without pressure, and the metal-ceramic composite thus obtained A method for producing a fitting body of a metal-ceramic composite material and a ceramic plate according to claim 1, further comprising a grinding step of scraping off the lid portion of the material.

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