JP6679101B2 - Method of joining ceramics and metal and joined body of ceramics and metal - Google Patents

Description

  The present invention relates to a technique for joining ceramics and a metal by applying a technique of a functionally gradient material.

  Semiconductor devices are used in all electronic devices, from home appliances to industrial equipment. The demand for miniaturization and improvement of functions of electronic equipment is extremely large, and accordingly, semiconductor devices make rapid progress in the direction of higher integration density, higher functionality, higher speed, higher output and higher reliability, and are consumed within the device. Electric power tends to increase. Therefore, many strict requirements are imposed on the substrate on which the semiconductor device is mounted, in addition to the function of simply supporting the semiconductor to form a circuit. Among the requirements for the substrate, the increasing heat generation of the semiconductor causes a failure, so how to dissipate heat is a particularly important issue. Therefore, the material used for the substrate is required to have high thermal conductivity.

  The substrate is generally a ceramic plate to which a metal circuit plate, a metal heat dissipation plate, etc. are joined. However, these substrates in which ceramics and metals are bonded have a problem that peeling occurs at the bonding interface between the ceramics and the metal due to temperature change from room temperature to high temperature or room temperature change from high temperature to room temperature. This is because the difference in the coefficient of thermal expansion between the ceramics and the metal is large, and the stress generated by the temperature change exceeds the bonding strength between the ceramics and the metal.

  In order to prevent such peeling, it is necessary to disperse the generated thermal stress in a certain region without concentrating it on a specific bonding interface. As a method for realizing this, there is a functionally gradient material technology described in Non-Patent Document 1. Here, the functionally gradient material means that the thermal expansion coefficient at each position is continuously changed from the metal value to the ceramic value by continuously changing the composition at each position from the metal composition to the ceramic composition. It is a material concept aimed at changing. Examples of the method of manufacturing the functionally graded material include a thermal spraying method described in Patent Document 1, a powder metallurgy method described in Patent Document 2, and a centrifugal casting method described in Patent Documents 3 and 4.

  In Patent Document 5, a mixed powder in which a metal powder serving as a mother phase and a ceramic particle powder to be composited are mixed is prepared, and the mixed powder is put into a mold of a centrifugal force casting device and the mold is rotated. By applying centrifugal force and preheating the mold, and by pouring the molten metal base material melted in the melting furnace into the rotating mold, the ceramic particles are firmly fixed to the mother phase and uniformly or inclined in the mother phase. A method of making a dispersed metal / ceramic particle composite is disclosed. With this technique, it was possible to manufacture a functionally graded material whose composition changed from position to position, and it was also possible to make the composition at one end 100% metal, but the composition at the other end 100% ceramic. It was impossible in principle to make a composition.

  Further, in Patent Document 6, a high-speed sedimentation particle having a large density and / or a particle diameter and a low-speed sedimentation particle having a small density and / or a particle diameter are mixed to prepare a mixed powder, which is crushed and meltable. The mixed powder was put into a container having a solid placed at the bottom, and the mixed powder was allowed to settle by heating, and then the liquid was sufficiently removed to produce a continuously-graded grin body. There is disclosed a method for producing a functionally graded material in which one end is a metal and the other end is a ceramic by sintering a green body having the composition gradient. However, in this technique, composition gradient formation and sintering are performed in separate steps, and the manufacturing process is complicated and there is a drawback that the cost is increased.

JP-A-5-323067 JP-A-7-310103 JP, 2002-69546, A JP, 2003-166028, A Japanese Patent No. 5077933 JP, 2013-181218, A JP 2012-192416 A

Edited by Seiichi Uemura and Yoshimi Watanabe, “Illustrated Basics and Applications of Functionally Graded Materials,” Corona Publishing Co., Ltd. (2014). Yoshimi Watanabe, Yuko Hattori and Hisashi Sato, Distribution of Microstructure and Cooling Rate in Al-Al2Cu Functionally Fabricated Fabricated Material. Mater. Proc. Tech. , 221, 197-204 (2015).

  Ceramics and metals have their own characteristic advantages, and if a joined body of them is manufactured, it is possible to provide a good material having both advantages. Since there is a large difference in the physical property values between ceramics and metal, it is difficult to manufacture by a normal direct bonding method, but the problem can be overcome by using a functionally graded material. However, with the existing manufacturing method, it was difficult to manufacture a functionally graded material having a continuous gradient and a composition gradient from 100% ceramics to 100% metal. Therefore, it is desired to provide a simple technique for producing a functionally gradient material having a composition gradient from 100% ceramics to 100% metal and contributing to a joining medium of ceramics and metals. The present invention provides this technique. .

  The functionally graded material disclosed in this specification has a composition of ceramics at one end and a metal at the other end. Therefore, not only can it be used as a bonding medium between ceramics and metal, but it can also be itself used as a functionally gradient material.

  Since the functionally graded material includes a material in which the ceramic is AlN and the metal is Al, it is possible to improve the strength of the material surface while maintaining high heat dissipation. Also, the bonding strength can exceed the strength on the metal side.

  The present specification also provides a method for joining ceramics and metal. In this method, the composition gradient forming process and the joining process of ceramics and metal are performed simultaneously. The composition gradient formation process utilizes the movement phenomenon of ceramic particles in the molten metal due to centrifugal force, and the joining process utilizes the pressure permeation phenomenon of the molten metal by centrifugal casting. This makes it possible to manufacture a material in which ceramics and metal are firmly bonded via the functionally graded material region.

  A ceramic produced by injecting molten metal into a bulk ceramic and a mixed powder composed of metal particles and ceramic particles by a centrifugal force field, and joining the ceramic and the metal through an inclined layer obtained thereby to produce the ceramic. Material for metal and metal.

  Molten metal is injected into a powder mixture of bulk ceramics and metal particles and ceramics particles by a centrifugal force field, and the ceramics and the metal are joined together via an inclined layer obtained thereby, and the ceramics and the metal. Method for manufacturing joint materials.

  Molten Al is injected into a mixed powder composed of AlN as the ceramic, AlN as the metal, and AlN particles having the same particle size and bulk AlN by a centrifugal force field, and through the gradient layer obtained by the injection. An AlN / Al bonding material, in which AlN and Al are bonded.

  Molten Al is injected into a mixed powder composed of AlN as the ceramic, AlN as the metal, and AlN particles having the same particle size and bulk AlN by a centrifugal force field, and through the gradient layer obtained by the injection. A method for manufacturing a bonding material of AlN and Al, which comprises bonding AlN and Al.

  Molten Al is injected into a mixed powder composed of bulk AlN, Al particles, and AlN particles having a particle size similar to that of Al particles, in which the ceramic is AlN and the metal is Al. A method for producing a bonding material of ceramics and metal, wherein AlN and Al are bonded via an inclined layer in which the volume fraction of AlN varies from 20% to 40%.

FIG. 1 is a diagram showing a procedure for manufacturing a bonded body of ceramics and metal according to the present invention. (A) A bulk ceramic is placed in a mold to which centrifugal force can be applied, and a mixed powder composed of ceramic particles and metal particles is put therein. (B) The molten metal is poured while applying a centrifugal force to the mold. (C) The metal particles in the mixed powder are melted by the heat of the molten metal, and the ceramic particles move in the molten metal to form a composition gradient. (D) The ceramic and the metal are firmly bonded via the inclined layer. FIG. 2 is a schematic view showing an example of the composition gradient of the joined body of ceramics and metal obtained by the present invention. FIG. 3 is a diagram showing a procedure for manufacturing a joined body of ceramics and a metal according to the present invention. FIG. 4 is a diagram showing a microstructure observation photograph of a scanning electron microscope (SEM) of an AlN sintered body produced by SPS sintering under the conditions of a sintering temperature of 1550 ° C., a molding pressure of 40 MPa, and a holding time of 10 min. is there. FIG. 5 is a diagram showing the outline of a small vacuum centrifugal casting apparatus used in the present invention. FIG. 6 is a view showing an appearance photograph of the manufactured AlN / Al joined body. FIG. 7 is a diagram showing a backscattered electron image by SEM. (A) Mixed powder thickness is 2 mm, AlN particle volume fraction is 30 vol%, AlN particle size is 3 μm, and there is no retention time. (B) Mixed powder The thickness is 2 mm, the volume fraction of AlN particles is 30 vol%, the particle size of AlN particles is 75-150 μm, and there is no retention time. (C) Mixed powder thickness is 2 mm, the volume fraction of AlN particles is 30 vol%, Hold particle size 75-150 μm for 1 hour, (d) Mixed powder thickness 2 mm, AlN particle volume fraction is 20 vol%, AlN particle size 75-150 μm, no holding time, (e) Mixed powder thickness 4 mm , The volume fraction of AlN particles is 30 vol%, the particle size of AlN particles is 75-150 μm and there is no holding time, (f) the mixed powder thickness is 4 mm, the volume fraction of AlN particles is 30 vol%, and the particle size of AlN particles is 150. 6 shows a backscattered electron image by SEM of the vicinity of the interface of an AlN / Al joined sample that was cast at −212 μm without holding time and cooled by furnace cooling. FIG. 8 shows the vicinity of the interface of an AlN / Al joined body produced by casting in a furnace with a mixed powder thickness of 2 mm, a volume fraction of AlN particles of 30 vol%, a particle size of AlN particles of 3 μm and no holding time. FIG. 6 is a view showing a secondary electron image by SEM of an aggregated portion of AlN particles of FIG. FIG. 9A is a schematic diagram showing the appearance of the mixed powder when the particle size difference between the ceramic particles and the metal particles is large, and FIG. 9B is the case where the particle size difference between the ceramic particles and the metal particles is small. FIG. 10A shows a mixed powder thickness of 2 mm, an AlN particle volume fraction of 30 vol%, an AlN particle size of 75 to 150 μm and no holding time, and FIG. 10B shows a mixed powder thickness of 2 mm and AlN particle volume. Hold for 1 hour with a fraction of 30 vol% and AlN particle size of 75-150 μm, (c) is a mixed powder thickness of 2 mm, AlN particle volume fraction of 20 vol%, AlN particle size of 75-150 μm and holding time None, (d) mixed powder thickness 4 mm, AlN particle volume fraction 30 vol%, AlN particle size 75-150 μm and no holding time, (e) mixed powder thickness 4 mm, AlN particle volume FIG. 3 is a diagram showing dispersion of AlN particles in a graded layer region of an AlN / Al joined body produced by casting at a rate of 30 vol% and a particle size of AlN particles of 150 to 212 μm without holding time, and manufactured by furnace cooling. FIG. 11A shows a mixed powder thickness of 2 mm, an AlN particle volume fraction of 30 vol%, an AlN particle size of 75 to 150 μm and no holding time, and FIG. 11B shows a mixed powder thickness of 2 mm and an AlN particle volume. Hold for 1 hour with a fraction of 30 vol% and AlN particle size of 75-150 μm, (c) is a mixed powder thickness of 2 mm, AlN particle volume fraction of 20 vol%, AlN particle size of 75-150 μm and holding time None, (d) mixed powder thickness 4 mm, AlN particle volume fraction 30 vol%, AlN particle size 75-150 μm and no holding time, (e) mixed powder thickness 4 mm, AlN particle volume FIG. 3 is a diagram showing a volume fraction of AlN particles in a graded layer region of an AlN / Al joined body produced by casting in a furnace cooling with a rate of 30 vol% and a particle size of AlN particles of 150-212 μm without holding time. . The horizontal axis indicates the standardized position. FIG. 12 is a diagram showing the moving speed of AlN particles in molten Al at 660 ° C. and 700 ° C. when a centrifugal force of 84 G or 42 G is applied.

  First, some of the technical features of the functionally graded material disclosed in this specification will be described. In addition, each of the matters described below has technical utility independently.

  The functionally graded material disclosed in this specification is used for joining ceramics and metal. By grading the composition, the physical properties such as the coefficient of thermal expansion continuously change at each position, so that the thermal stress due to the difference in the physical properties between ceramics and metal can be relaxed. Preferably, the functionally gradient material disclosed in the present specification has a composition of ceramics at one end and a composition of metal at the other end, in which both are mixed and the composition is continuously graded. However, if the thermal stress can be relaxed, the composition gradient may be stepwise, and 100% of the composition at one end may not be ceramics, and 100% at the other end may be metal. You don't have to.

  It is desirable that the ceramic side of the functionally gradient material has the same composition as the ceramic to be bonded and the metal end side has the same composition as the metal to be bonded, but if the thermal stress can be relaxed, its component or composition is It is not limited. Further, in the inclined region, it is preferable that the ceramic and the metal are mixed in a state where they do not react with each other, but even if the reaction occurs, there is no problem as long as it does not affect thermal stress relaxation.

  The functionally graded material disclosed in the present specification forms a composition gradient for the purpose of joining ceramics and metal, but also as a bonded body in which ceramics and metal themselves are joined via a compositionally graded region, It is also used as an intermediate for joining ceramics and metals.

AlN is given as an example of ceramics and Al is given as an example of metals. It is a functionally graded material having a composition of AlN only at one end and Al at the other end. This material is characterized by having an AlN-only region having no composition gradient at one end and an Al-only region having no composition gradient at the other end. Further, in the compositionally graded region, AlN and AlN are strongly mixed together.

Next, some of the technical features of the functionally graded material production disclosed in this specification will be described. In addition, each of the matters described below has technical utility independently.

  In the centrifugal force mixing powder method used in the present invention, the ceramic and the metal placed in the mold are joined together. Fig. 1 shows an outline of the joining method. First, as shown in FIG. 1A, bulk ceramics are placed in a mold to which centrifugal force can be applied, and a mixed powder composed of ceramic particles and metal particles is put therein. Next, as shown in FIG. 1B, a molten metal is poured while applying a centrifugal force to the mold. At this time, inside the mold, due to the pressurizing effect of the centrifugal force, the molten metal spreads in the particle gaps of the mixed powder, and at the same time, as shown in FIG. 1C, the heat of the molten metal melts the metallic particles in the mixed powder. To do. Further, at this time, when there is a density difference between the ceramic and the metal melt, the ceramic particles in the mixed powder move in the metal melt to form a gradient layer having a continuous composition gradient. After that, by solidifying the molten metal, as shown in FIG. 1 (d), a joined body of ceramics and metal is obtained through an inclined layer in which ceramic particles are dispersed in a metal matrix.

  The characteristic of the composition gradient in the obtained joined body is shown in FIG. 2 as a schematic diagram. Ceramics and metal are bonded via a graded layer, and the thickness and composition gradient of the graded layer are the particle size of the ceramic particles in the mixed powder, the volume fraction of the ceramic particles in the mixed powder, and the charging of the mixed powder. It can be controlled by the amount, the preheating temperature of the mold, the temperature of the molten metal, the magnitude of the centrifugal force to be applied, the centrifugal force application time, and the like.

The production of an AlN / Al joined body using AlN as the ceramic and Al as the metal is mentioned as an example, but this does not specify the material system of the present invention. Table 1 shows the physical properties of AlN and Al, and FIG. 3 shows the manufacturing procedure. First, a bulk AlN sintered body is placed in a mold, and a mixed powder composed of AlN particles and Al particles produced by a powder mixing device is put therein (see FIG. 3A). Next, the mold is rotated, and molten aluminum is poured into the mold while applying a centrifugal force (see FIG. 3 (b)). At this time, inside the mold, due to the pressurizing effect of the centrifugal force, the Al molten metal spreads in the particle gaps of the mixed powder, and at the same time, the Al particles in the mixed powder are melted by the heat of the Al molten metal (see FIG. 3C). Further, since the density of the AlN is the density of the molten Al at 3.26Mg ^/ m 3, 700 ℃ as shown in Table 1 is a 2.369Mg / ^{m 3,} AlN particles occurs precipitation with centrifugal field, continuous Forming a graded layer having a typical composition gradient. Then, the Al melt is solidified to obtain a joined body of Al and AlN via the graded layer in which the AlN particles are dispersed in the Al matrix (see FIG. 3D).

  An AlN sintered body was prepared for use in manufacturing an AlN / Al joined body. As a starting material, AlN powder having a purity of 99% and a particle size of 3 μm manufactured by Kojundo Chemical Laboratory Co., Ltd. was used. In addition, sintering was performed using an SPS-515S discharge plasma sintering apparatus manufactured by Sumitomo Coal Mining Co., Ltd. Here, the discharge plasma method (SPS method) is a method in which a powder is filled between a carbon die and a punch, and a large pulsed current is applied at a low voltage while applying pressure to the powder to sinter the powder. It is a method to do. It has the feature that it can be sintered at low temperature for a short time. However, these do not limit the raw materials, the manufacturing method, and the manufacturing apparatus. In addition, this step was performed to obtain bulk AlN for use in manufacturing the AlN / Al joined body, and can be omitted if bulk AlN having the required physical properties is available.

A sintering die composed of a cylindrical carbon die having an outer diameter of 40 mm and an inner diameter of 20.4 mm and upper and lower punches having a diameter of 20 mm was used. This carbon die has a hole for temperature measurement on the side surface, the temperature of the sample during sintering is measured with a radiation thermometer, and the output is controlled based on that temperature to control the temperature during sintering. The temperature was controlled. Sintering was performed under conditions of a sintering temperature of 1550 ° C., a molding pressure of 40 MPa, and a holding time of 10 min.

A structural photograph of the AlN sintered body produced under these conditions by SEM is shown in FIG. As shown in the figure, it can be confirmed that the sintered body is a dense sintered body with almost no pores. As a result of calculating the density of the produced AlN sintered body by the Archimedes method, the relative density was 97.8%, and a dense AlN sintered body with few pores could be produced by the SPS method. Therefore, the AlN sintered body produced by the SPS method was used for manufacturing the joined body.

Next, AlN particles for a mixed powder for use in manufacturing an AlN / Al joined body were produced. As a starting material, AlN powder having a purity of 99% and a particle size of 3 μm manufactured by Kojundo Chemical Laboratory Co., Ltd. was used. This was sintered by the SPS method under the conditions of a sintering temperature of 1550 ° C., a molding pressure of 40 MPa, and a holding time of 10 min. The AlN sintered body was crushed with a hammer, and the particles classified to 75 μm-150 μm or 150 μm-212 μm were also used as AlN particles for mixed powder. This step was performed to match the particle size with the Al particles to be supplied to the mixed powder, and can be omitted if AlN particles having a particle size similar to that of the Al particles for the mixed powder are available.

  A mixed powder was prepared for use in manufacturing an AlN / Al joined body. First, it was put in a container with an internal volume of 35 mL together with Al particles having a particle size of 106 μm-108 μm and AlN particles having a particle size of 3 μm, 75 μm-150 μm or 150 μm-212 μm, manufactured by Kojundo Chemical Laboratory Co., Ltd. This was mixed for 15 minutes using a Turbula mixer (T2F) powder mixing device manufactured by Shinmaru Enterprises Co., Ltd. to prepare a mixed powder. Here, in the examples, the proportion of AlN particles in the mixed powder was set to 20 vol% or 30 vol%, but this does not limit the scope of the claims of the present invention.

  Next, 1.8 g and 3.6 g of the mixed powder were put into the mold in which the AlN sintered body was installed. This corresponds to the amount formed by the 2 mm or 4 mm inclined layer. Then, the mold was preheated at 600 ° C. by an electric furnace placed outside the casting apparatus, and the mold was moved from the electric furnace to the small vacuum centrifugal casting apparatus shown in FIG. In the embodiment, this preheating is performed outside the casting apparatus, but even if it is performed inside the casting apparatus, there is essentially no difference. Further, the preheating temperature was set to 600 ° C., but it is optional as long as it has a heat amount necessary for melting the Al particles in the mixed powder during centrifugal casting. The heating method in the mixed powder is not limited to the electric furnace.

After that, the inside of the apparatus was evacuated, and an Al ingot manufactured by Kojundo Chemical Laboratory Co., Ltd. and having a purity of 99% and a size of 2 to 5 mm was melted at 1200 ° C. in a high frequency induction furnace. The inside of the apparatus is evacuated in order to prevent the Al particles in the mixed powder from being oxidized. If this preventive measure is taken, the replacement with an inert gas may be performed. Further, the ingot is divided only for the sake of convenience, and this does not narrow the scope of the claims of the present invention. The melting temperature of the Al ingot is arbitrary as long as it can have the amount of heat necessary for melting the Al particles in the mixed powder.

Then, the mold was rotated to apply a centrifugal force, and at the same time, the molten aluminum was poured into the mold, and the rotation of the mold was stopped 5 minutes after the molten metal was poured. The gravity multiple applied at this time was 84 G, but it can be changed as long as the molten aluminum can be impregnated in the mixed powder. Further, the application time of the centrifugal force was set to 5 minutes, but this time can be arbitrarily set as long as it is possible to secure the time for impregnating the mixed powder with the molten aluminum and forming the composition gradient by the sedimentation phenomenon of the AlN particles in the centrifugal force field. is there. The subsequent cooling was performed in a furnace heated to 600 ° C, but this temperature can be changed. When the mold preheating equipment is not provided in the casting apparatus, the mold may be moved to an electric furnace to cool the furnace. At this time, holding may be performed for an arbitrary time, and in the examples, both no holding time and 1 hour holding were observed.

  The appearance photograph of the obtained joined body is shown in FIG. About 15 mm of the tip of the manufactured joined body was cut out and cut into three equal parts in the direction of centrifugal force, and it was observed whether the joined state was maintained or peeled after cutting.

  The bonded body in which the bonded state was maintained was divided into three equal parts, and the cross section of the central part was used as the observation surface, and the structure was observed. The observation surface was wet-polished with No. 400 to No. 2400 emery paper, and then buffed with a diamond suspension having a particle size of 1 μm. Then, the structure near the interface of the AlN / Al joined body was observed by SEM. FIG. 7A shows a mixed powder thickness of 2 mm, an AlN particle volume fraction of 30 vol%, an AlN particle size of 3 μm and no holding time. FIG. 7B shows a mixed powder thickness of 2 mm and AlN particle The volume fraction is 30 vol%, the particle size of AlN particles is 75-150 μm, and there is no retention time. FIG. 7C shows the mixed powder thickness 2 mm, the volume fraction of AlN particles is 30 vol%, the particle size of AlN particles is 75-150 μm. 7h, the mixed powder thickness is 2mm, the volume fraction of AlN particles is 20vol%, the particle size of AlN particles is 75-150μm, there is no holding time, and FIG. 7 (e) is the mixed powder thickness. 4 mm, the volume fraction of AlN particles is 30 vol%, the particle size of AlN particles is 75-150 μm, and there is no holding time. FIG. 7 (f) shows the mixed powder thickness 4 mm, the volume fraction of AlN particles is 30 vol%, and the volume ratio of AlN particles is 30%. Particle size 150-212 It is a microstructure photograph of the interface vicinity of the AlN / Al joined sample which was cast in a condition of μm without holding time and cooled by furnace cooling. The left is the AlN side and the right is the Al side. From the figure, it is understood that, except for the sample produced under the condition that the particle size of AlN particles is 3 μm, the AlN particles form a graded layer in which the AlN particles are dispersed in the Al matrix. In this graded layer, there was a clear interface between the Al matrix and the AlN particles, and no gap was formed. It is also found that the AlN sintered body and the graded layer can be joined together without a gap.

  FIG. 8 shows the vicinity of the interface of an AlN / Al joined body produced by casting in a furnace with a mixed powder thickness of 2 mm, a volume fraction of AlN particles of 30 vol%, a particle size of AlN particles of 3 μm and no holding time. 3 is a microstructure photograph of an aggregated portion of AlN particles of FIG. In the sample prepared under the condition that the particle size of the AlN particles is 3 μm, partial joining is observed, but from the figure, the AlN particles are aggregated near the interface, and impregnation of the molten Al is prevented in this part. , A gap is seen between the AlN sintered body and the Al mother phase. It is considered that this is because the difference in particle size between the Al particles and the AlN particles in the mixed powder is large.

FIG. 9A schematically shows an aspect of the mixed powder when the difference in particle size between the ceramic particles and the metal particles is large and FIG. 9B shows when the difference in particle size between the ceramic particles and the metal particles is small. As shown in FIG. 9A, when the particle size of the ceramic particles is extremely smaller than that of the metal particles, the ceramic particles surround the metal particles to hinder the joining of the metal particles. Moreover, in the centrifugal force mixing powder method, the ceramic particles filling the voids between the metal particles impede the impregnation of the molten metal. Therefore, it is considered that when the particle size of the AlN particles was 3 μm, the entire surface could not be joined.
On the other hand, as shown in FIG. 9B, when the difference in particle size between the ceramic particles and the metal particles is small, the contact area between the metal particles becomes large, so that when the difference in particle size between the ceramic particles and the metal particles is large. As compared with the above, a good bonding state of metal particles can be obtained. In addition, since the voids between the metal particles are not filled with the ceramic particles, the impregnation of the molten metal is easy. Therefore, in order to bond them on the entire surface, it is desirable that the difference in particle diameter between the ceramic particles and the metal particles is small, and as the AlN particles used for the mixed powder, AlN particles having the same particle diameter as the Al particles are suitable.

  FIG. 10 shows an enlarged view of an Al mother phase in which AlN particles are dispersed. Here, FIG. 10A shows a mixed powder thickness of 2 mm, an AlN particle volume fraction of 30 vol%, an AlN particle diameter of 75-150 μm and no holding time, and FIG. 10B shows a mixed powder thickness of 2 mm. , The volume fraction of AlN particles is 30 vol%, the particle diameter of AlN particles is kept at 75-150 μm for 1 hour, FIG. 10 (c) shows the mixed powder thickness 2 mm, the volume fraction of AlN particles is 20 vol%, the particles of AlN particles The diameter is 75-150 μm and there is no holding time. FIG. 10D shows the mixed powder thickness 4 mm, the volume fraction of AlN particles is 30 vol%, the particle size of AlN particles is 75-150 μm, and there is no holding time. A mixed powder having a thickness of 4 mm, a volume fraction of AlN particles of 30 vol%, a particle size of AlN particles of 150 to 212 μm, was cast without holding time, and was then cooled in a furnace. As shown in the figure, in any of the samples, Al was present around the AlN particles, and there was no reaction or gap at the interface. In addition, no cavities were observed in the Al matrix phase, and it was found that a joined body having a dense structure can be manufactured by performing centrifugal casting.

  FIG. 11 shows the volume fraction of AlN particles in this gradient layer as a distance from the interface. FIG. 11A shows a mixed powder thickness of 2 mm, an AlN particle volume fraction of 30 vol%, an AlN particle size of 75 to 150 μm and no holding time. FIG. 11B shows a mixed powder thickness of 2 mm and AlN. The volume fraction of particles is 30 vol%, the particle size of AlN particles is kept at 75-150 μm for 1 hour, FIG. 11C shows the mixed powder thickness 2 mm, the volume fraction of AlN particles is 20 vol%, and the particle size of AlN particles is 75. Fig. 11 (d) shows a mixed powder thickness of 4 mm, a volume fraction of AlN particles was 30 vol%, and a particle size of AlN particles was 75-150 µm with no holding time. Fig. 11 (e) shows a mixed powder. The results are obtained under the conditions that the thickness is 4 mm, the volume fraction of AlN particles is 30 vol%, the particle size of AlN particles is 150 to 212 μm, and there is no holding time, and the horizontal axis shows the normalized position. In the sample having a mixed powder thickness of 2 mm, the thickness of the graded layer in which AlN particles were dispersed in the Al matrix phase was about 3 mm, and in the sample having a mixed powder thickness of 4 mm and the AlN particle size of 75-150 μm, the Al matrix was formed. The thickness of the graded layer in which AlN particles are dispersed in the phase is about 10 mm, the mixed powder thickness is 4 mm, and the thickness of the graded layer in which AlN particles are dispersed in the Al matrix phase in the sample having a particle size of AlN particles of 150 to 212 μm. The height was about 6 mm. Further, the volume fraction of AlN particles in the gradient layer is 20% to 40%, and the thickness of these gradient layers and the volume fraction of AlN particles are the amount of mixed powder, the volume fraction of AlN particles in the mixed powder. , AlN particles can be controlled by adjusting the particle size.

Furthermore, the density of the AlN because the density of the molten Al is in 3.39Mg ^/ m 3, 700 ℃ as shown in Table 1 is 2.35 mg / ^{m 3,} in centrifugal casting, AlN particles in a centrifugal force field Sedimentation occurs and it is possible to form a continuous compositional gradient in the graded layer. The Stokes' theorem was converted into a form applicable to the centrifugal force field, and the moving speed dx / dt of AlN particles in the molten aluminum at 660 ° C. and 700 ° C. was calculated by the formula 1.

Here, ρ _c , ρ _m , g, D _p and η are the density of the AlN particles, the density of the molten Al, the gravity, the particle size of the AlN particles and the apparent viscosity, respectively. The gravity factor is 84G or 42G, and the viscosity of the molten metal is 1.38 × 10 ⁻³ Pa · s at 660 ° C and 1.29 × 10 ⁻³ Pa · s at 700 ° C. 13 shows. As shown in the figure, the AlN particles move in the direction of the centrifugal force in the molten aluminum in the centrifugal force application field, and the speed is higher for the larger particles. Further, the higher the temperature of the molten metal, the lower the viscosity, so that the moving speed becomes faster, and when the gravity multiple is increased, the moving speed becomes faster.

Further, the apparent viscosity η of the suspended Al molten metal is η ₀ which is the viscosity inherent to the Al molten metal, V is the volume fraction of AlN particles in the suspension, and V _max is the volume fraction when the AlN particles are filled to the _maximum . When you do, as in Equation 2,

Since it is also affected by the volume fraction of the suspension particles, the sedimentation moving speed of the AlN particles can be predicted and the degree of composition gradient in the gradient layer can be controlled by considering these equations.

In the above example, AlN was used as the ceramic and Al was used as the metal. However, AlN may be replaced with other ceramics such as Al ₂ O ₃ , TiO ₂ , SiO ₂ , ZrO ₂ , MgO, TiC, SiC, TiN, or Si ₃ N ₄ , semiconductors such as Si, GaAs, GaN, GaN, or Ni _3. Even if the intermetallic compound such as Al, NiAl, NiAl ₃ , Ti ₃ Al, TiAl or TiAl ₃ is used, the same effect can be obtained. Further, even if Al is changed to Mg, Ti, Cr, Fe, Co, Ni, Cu, Zn or alloys thereof, the same effect can be obtained. What is important is that molten metal is injected into a mixed powder composed of ceramic particles and metal particles by a centrifugal force field, and the ceramic and the metal are bonded to each other via a gradient layer obtained thereby.

  The present invention relates to a joined body of ceramics and metal used in electronic parts, automobile parts, aircraft parts, space parts, marine parts, industrial machine parts, electric equipment parts, building parts and various molds. Available for manufacturing.

Specific examples of the present invention have been described above in detail, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. Further, the technical elements described in the present specification or the drawings exert technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technique illustrated in the present specification or the drawings can achieve a plurality of purposes at the same time, and achieving the one purpose among them has technical utility.

Claims (4)

Established the bulk ceramic to the centrifugal force which can be applied in a mold, the mixed powder consisting of ceramic particles and metal particles are introduced therein, the molten metal was pouring while applying a centrifugal force to the mold, thereby through the gradient layer obtained by a bonding material preparation of bulk ceramics and metals Ru is bonded to the said bulk ceramic and metal, the bonding material is only ceramics of the bulk ceramic no composition gradient at one end Region, the other end has a region only of the metal having no composition gradient, the thickness of the gradient layer and the volume fraction of the ceramic particles, the amount of the mixed powder, the ceramic in the mixed powder It can be controlled by adjusting the volume fraction of particles and the particle size of the ceramic particles. The ceramics are AlN and the ceramic particles are AlN. Child, said metals Al, bonding material production method of a ceramic and a metal wherein the metal particles are characterized by Oh Rukoto of Al particles. The Al particles and the bonding material preparation of a ceramic and a metal according to claim 1, wherein the AlN particles, characterized in that the chromatic equivalent particle size. Bulk ceramics is placed in a mold to which centrifugal force can be applied, mixed powder consisting of ceramic particles and metal particles is placed therein, and molten metal is poured while applying centrifugal force to the vacuumed mold. , The bulk ceramics and the metal, which are joined to each other through the graded layer, in which the volume fraction of the ceramics obtained by cooling by the furnace cooling changes between 20% and 40% A bonding material manufacturing method, wherein the bonding material has a ceramic-only region of the bulk ceramics having no composition gradient at one end, and a metal-only region having no composition gradient at the other end, wherein the gradient layer And the volume fraction of the ceramic particles are the amount of the mixed powder, the volume fraction of the ceramic particles in the mixed powder, the ceramic particles. Can be controlled by adjusting the particle diameter, the ceramic AlN, the ceramic particles AlN particles, the metal is Al, said metal particles bonded with features and be Rousset La mix and metal Oh Rukoto of Al particles Wood manufacturing method . The method for producing a bonding material for ceramics and metal according to any one of claims 1 to 3, wherein the AlN particles have a particle diameter of 75-150 µm or 150-212 µm .