JPS62297275A - Joined body of non-oxide ceramic and metal - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention Field of Industrial Application The present invention relates to a joined body of non-oxide ceramics and metal. More specifically, the present invention improves the inherent heat resistance, wear resistance, and corrosion resistance of non-oxide ceramics, as well as
The present invention relates to a bonded body of non-oxide ceramics and metal that is satisfactory in terms of mechanical properties, especially toughness.

Conventional technology ceramics are generally heat resistant, wear resistant and corrosion resistant.
Due to its excellent chemical resistance, it has been considered for various applications and has been widely used. However, it is inferior to metals in terms of mechanical strength, especially toughness, and therefore it was necessary to make further improvements in order to apply it as a structural material that requires high mechanical strength.

In recent years, various types of mainly non-oxide-based ceramics, called new ceramics, have been attracting attention because they further improve the various properties of conventional oxide-based ceramics and enable the development of new application fields. For example, silicon carbide (SiC), silicon nitride (Si3N), aluminum nitride, etc. are known as non-oxide ceramics, and these have high high temperature strength, wear resistance, corrosion resistance, etc. Applications to mechanical parts that require wear resistance and corrosion resistance have been attempted, and some have been put into practical use.

However, even with this non-oxide ceramic,
As mentioned above, there are problems with the mechanical strength inherent in ceramics, and there are also limits in terms of processing accuracy, so it is still difficult to construct the entire desired device using only ceramics, and under severe temperature conditions such as high temperatures. It has only been partially applied as a material for parts that are placed in high temperatures, where a high degree of wear resistance and/or corrosion resistance is required.

In this way, when non-oxide ceramics are partially applied, it is necessary to use them in combination with various other structural materials, especially metals. Therefore, bondability with these becomes an important issue. Therefore, the conventional brazing method (i) involves inserting an oxide such as metal or glass between ceramic and metal (the intervening layer is mainly in the form of a paste);
(ii) A solid-state bonding method in which ceramics and metal are bonded in a solid state by direct pressure or without pressure (the intervening layer is mainly in the form of a foil or plate); (iii) Ceramics and metal are bonded using a laser beam. Fusion welding methods, which join in a molten state, are being considered.

Furthermore, as in the invention disclosed in JP-A-59-18184, ceramics are ion-etched under vacuum, and then a predetermined ceramic or metal is immediately ion-plated to form a metal coating layer on the surface of the ceramic. A method of ion plating metal in a single layer is also known.

Problems to be Solved by the Invention As mentioned above, it is difficult to construct an entire device using non-oxide ceramics due to their mechanical properties, but their inherent mechanical properties are It is extremely attractive and is used for various parts. In this case, it is necessary to bond it with other metals, etc.
Various methods such as those described above have been proposed and put into practical use.

However, in conventional methods, paste-like, foil-like,
Since a plate-shaped film was used, it was extremely thick, and it was difficult to control the film thickness to a predetermined value. Therefore,
Depending on the mode of application, there are problems with bonding strength, heat resistance, etc. Further, since conventional intervening layers are used in bulk form such as paste, it is considered difficult to design the structure. Furthermore, in paste form, substances with different purposes are dispersed, but for example, only a part of the substances added to have activity on ceramics contributes to the effect, and as a result, They must be added in higher amounts than necessary, often at the expense of other effects. -For cylindrical or plate-shaped materials, the contact area with the ceramics to be joined is too small, so a pressure or melting process is required, and considerably high values of pressure and temperature are required.

Therefore, in order to solve such problems, the use of ion plating method was proposed. By using this method, it is possible to form an extremely thin metal film, and the thickness of the film can also be freely controlled, making it possible to improve bonding strength and heat resistance. The layer structure design becomes easy.

However, by using only a single layer, various functions cannot be imparted at once, and further efforts are required to obtain a bonded body that is sufficiently durable for practical use.

Therefore, the present inventors have found that it is advantageous to form the intervening layer with a multilayer structure of at least three layers, and to form each layer by an ion plating method, and have filed a separate patent application. However, even in this case, it was found that stress and strain caused by the difference in coefficient of thermal expansion between the non-oxide ceramics to be joined and the joining metal led to breakage at the intervening layer portion of the joined body or at the interface between this and the ceramic. Solving these problems and developing ceramic-metal joints with improved heat resistance, mechanical strength, etc. will lead to the practical application of non-oxide ceramics and further expand the field of use. It is extremely important to do so.

That is, the purpose of the present invention is to improve the mechanical properties, especially the toughness, of non-oxide ceramics, which are originally attracting attention as heat-resistant, wear-resistant, and corrosion-resistant materials, and to improve the fracture resistance due to residual stress strain. The object is to provide a joined body of oxide ceramics and metal.

Means for Solving the Problems In view of the above-mentioned current state of bonding between non-oxide ceramics and metals, the present inventors have solved the above-mentioned drawbacks of conventional methods, and have achieved the desired non-oxide As a result of various studies and studies aimed at developing an excellent bonded body between ceramics and metals, we found that it is advantageous to form the intervening layer for bonding using a vapor phase deposition method to create a multilayered structure, and to use a stress-relaxing material. They discovered something and completed the present invention.

That is, the bonded body of non-oxide ceramic and metal of the present invention is a bonded body composed of a non-oxide ceramic sintered body, a bonded metal, and an intervening layer disposed between them. , the intervening layer has a multilayer structure, the inner layer in contact with the non-oxide ceramic sintered body is composed of a highly active metal layer, and the intermediate layer is at least one layer that reacts with the inner layer and the outer layer. and the outer layer in contact with the merizing metal is made of a metal layer that has a protective effect to prevent corrosion of the inner layer and the intermediate layer, and the bonding metal layer and the intervening layer. It is characterized by providing a stress relaxation layer between the two.

In the joined body of the present invention, non-oxide ceramics include nitrides, carbides, silicides, borides, sulfides, carbonitrides, etc. of various metals, and specifically, Si3N4, AIN, etc.
, BNS TiN5 Li,N,,SiC.

WC, TiC, B4C, MoSi2.1aBs, TiB
2.2rB2, Cd55ZnS, PbS, Sialon Ceramics, S! g-JlzOzNa-z (z= 1
~4.2), etc. can be exemplified.

In addition, metals to be bonded to this non-oxide ceramic include various metals such as steel and stainless steel, which are commonly used as structural materials and mechanical parts materials, such as A1, W, Mo, Fe, etc. Alloys such as Kovar alloy and Dumet alloy can be used.

The intervening layer, which is characteristic of the bonded body of the present invention, is generally realized in a three-layer structure including an inner layer adjacent to non-oxide ceramic, an outer layer on the metal side, and an intermediate layer between these layers. First, the internal metals are selected from metals that are highly active and form strong bonds with non-oxide ceramics, such as 5iSTi, Fe,
Ni, Cu, Zr, Nb, Mo, Mn, Ta
The layer is at least one metal selected from the group consisting of 5W, Y, and Cr. On the other hand, the intermediate layer is made up of at least one layer, and is not particularly limited as long as it is a metal that reacts with the inner layer and the outer layer to lower their melting points, such as A.
I, Si, TiSCrSMn, Fe.

At least one metal selected from the group consisting of C01Ni, Cu, and ZnSNbSMo can be advantageously used.

Furthermore, the outer layer is advantageously made of a metal that has the effect of preventing internal and intermediate layers from corrosion such as oxidation, such as CulNb.
It is preferable to use at least one metal selected from the group consisting of SMo and PdSAg5WSPLSAu.

These are deposited according to gas phase vapor methods, in particular ion plating methods. For example, activated reactive deposition (AR)
E method), enhanced ARE method, DC excited ion plating method, high frequency excited ion plating method, multi-cathode ion plating method, hollow cathode discharge method (HCD method), and low voltage arc discharge method. can also be used.

In the intervening layer in the present invention, each metal layer (inner layer, intermediate layer,
After the formation (deposition) of the outer layer (outer layer) or after the formation of the entire intervening layer, a heat treatment can be carried out, that is, a heat treatment can be performed, for example, at a temperature of 500 to 1.600° C. for several seconds to several hours.

The thickness of this intervening layer or its constituent layers, the inner layer, the daytime layer, and the outer layer, can be changed arbitrarily depending on the purpose, use, etc., but generally it is sufficient within the range of 0.01 to 100 μm. .

In the bonded body of the present invention, a stress relaxation material layer is inserted into ceramics to which an intervening layer is applied as described above, and a silver solder, N1
Using a known brazing material such as wax, under slight pressure,
Or at low temperature without applying pressure, e.g.
It can be easily obtained by heating at a temperature within the range of 1,000°C.

This temperature varies depending on materials, properties, combinations, etc., but generally the above range is sufficient.

The characteristic stress relaxation material in the joined body of the present invention is S
i, Ti, V, Cr, Mn, Fe, Co,
Ni, Cu, Zn.

Zr5Nb, Mo, Ta, 'W and alloys containing these elements as main components, Kovar alloy, Dumet alloy, etc. can be used, and these can be formed in a single layer in the form of a plate or foil with a thickness of 0.1 to 30 mm. Used above.

This thickness is also not particularly critical and varies over a wide range depending on the type and properties of the ceramic, metal, or intervening layer metal used. Generally, sufficient effects can be achieved within the above range.

Function Non-oxidizing ceramics have excellent heat resistance, corrosion resistance, etc., so they are used to overcome the impasses due to the limitations of metal properties in various devices conventionally made of metals, alloys, etc., such as in high-temperature heat engines. , its use has been considered in order to reduce weight and cost. however,
Ceramics, including non-oxide ceramics, generally have poor toughness. Therefore, when used as a mechanical material, it will be placed in a complex stress environment in which thermal and mechanical stresses are involved in a complex manner, so it is currently impossible to construct an entire device using only ceramics. Generally used as a bonded body with metal.

By the way, when bonding non-oxide ceramics and metals, there are various problems as mentioned above, and in order to obtain a highly reliable and high-quality bonded product and to put it into practical use, further ingenuity is required. , improvements must be made5).

Therefore, in the present invention, the drawbacks of the conventional bonding methods described above are almost solved by forming the intervening layer by ion plating and making it a multilayer structure.

First, by using the ion plating method for the intervening layer, the structural design of the intervening layer is extremely easy and the control of the film thickness is simplified, resulting in greater bonding strength, heat resistance, etc. compared to conventional products. It has become possible to make significant improvements. This is also due to the fact that the intervening layer has a laminated structure consisting of multiple layers, making it possible to solve the problems associated with dispersing substances with various functions in a single layer, as in the past. do. That is, as already mentioned, for example, only a portion of highly active additives to ceramics performs a given function and is required to be used in large quantities, which may reduce the effectiveness of substances added for other purposes. The problem of being sacrificed can be completely solved. In accordance with the present invention, it has been found that by depositing and stacking separate metal layers with individual roles in a multilayer structure, a good, overall satisfactory assembly can be obtained.

Furthermore, by forming the intervening layer by ion plating, even if there are many irregularities on the surface of the non-oxide ceramic to be metallized, these irregularities can be removed due to the good wraparound properties of the ion plating method. The area of contact with the joining metal increases significantly. In addition, a metal that has the effect of producing a eutectic substance and lowering the melting point is deposited in the intermediate layer of the intervening layer, and since the intervening layer is thin, it melts at a low temperature and therefore does not react with the ceramic. It can greatly improve your sexuality.

That is, the processing temperature can be significantly lowered, there is no need for a high melting temperature as in the conventional method, and since the contact area is small, there is no need for bonding under high pressure. That is,
Pressurization can be done at a low pressure or is unnecessary.

In addition, due to the difference in coefficient of thermal expansion between the two, residual stress may exist in the bonded body of non-oxide ceramics and the bonded metal due to thermal cycles during the bonding process or during use. This may cause cracks or damage during use. Therefore, this problem was solved by providing a stress relaxation layer between the intervening layer and the bonding metal. That is, by inserting such a layer between the two, it will plastically deform under the action of stress, resulting in stress relaxation, and will also have a thermal expansion coefficient close to that of ceramics. It is also possible to create a stress relaxation layer by arranging the material as a stress relaxation layer, and even if it is subjected to a thermal cycle that may cause stress as described above, this will almost completely be eliminated, and defects such as breakage can be avoided. . In addition, it can sufficiently cope with bonding over a large area.

Thus, according to the present invention, a high-grade material having high bonding strength sufficient to withstand practical use, satisfactory corrosion resistance and heat resistance, and sufficient relaxation effect against stress caused by thermal cycles, etc. A composite of a non-oxide and a metal can be advantageously provided.

EXAMPLES The conjugate of the present invention will be described in more detail below based on Examples. However, the following examples do not limit the scope of the invention.

A preferred embodiment of the conjugated body of the present invention is shown in a schematic cross-sectional view in the attached FIG. 1.

As is clear from the figure, it is composed of a silicon nitride sintered body 1, an intervening layer 2, and a bonding metal 3, and the intervening layer 2 is further composed of an inner layer 4, a daytime layer 5, and an outer layer 6.

Each of these layers is made of the above-mentioned materials, and each has a predetermined function. In this example, due to the heat treatment, interdiffusion occurs between adjacent layers of the intervening layers 4, 5, and 6, respectively.
A diffusion layer A (4-5) is formed between layers 5 and 5, and a diffusion layer B (5-6) is formed between layers 5 and 6. This diffusion layer is formed by vapor deposition using ion plating, heat treatment, or heating during bonding, and the formation of this layer further improves various physical properties such as bonding strength.

Further, a metal or alloy relaxation layer 7 is disposed between the outer layer 6 and the joining metal 3 to relieve stress due to the difference in thermal expansion coefficient between the silicon nitride sintered body 1 and the joining metal 3. There is.

Specific materials, dimensions, etc. of each element are as shown in the following production example.

Preparation Example 1 A prismatic silicon nitride sintered body measuring 1l10x10x20 was coated with Nb as the first layer (inner layer) and Fe and Ni as the second and third intermediate layers, respectively, with a thickness of 1.0 μm using an ion plating device. , and W was also vapor-deposited as the fourth layer (outer layer). Next, this was heated to 1,400 ml in a high vacuum heating furnace.
After heating for a short time (20 seconds) at a time, and after cooling, it was joined to a Dumet alloy using Ni brazing. At this time, A1 and W were each added as a thermal stress relaxation layer between the intervening layer and the Dumet alloy.
．． The bending strength was compared between those introduced in the range of 1 to 20 mm and those not introduced at all. The results are shown in Table 1.

The bending strength was measured according to a four-point bending test method at room temperature.

Table 1: Bending strength test results of joined body Fabrication example 2 Using a prismatic silicon carbide sintered body with the same dimensions as fabrication example 1,
According to Production Example 1, a joined body with Dumet alloy was formed. The results of measuring the bending strength in the same manner are shown in the table below.

Table 2: Results of bending strength test of bonded body Preparation Example 3 The ceramics to be joined having the intervening layer obtained in Preparation Example 1 and the Dumet alloy were bonded to an AI with a thickness of 1 and 5 mm, respectively.

A bonded body of silicon nitride and Dumet alloy was obtained by bonding with Ni solder via a Cu$ and/or Nb plate.

The bending strength of the obtained samples is shown in Table 3 below.

Table 3 Production Example 4 A silicon nitride sintered body processed into a shaft shape of 15 mm φ
Fe was deposited as the first layer (inner layer), Si was deposited as the second layer (intermediate layer), and Cu was deposited as the third layer (outer layer) to a thickness of m, and then heated at 1,250°C for 10 minutes. After heat treatment, a 16mmφ shaft-shaped stainless steel (SU
53103), each with a thickness of 2 mm as a thermal stress relaxation layer.
Nb and Mo plates were introduced and joined with silver solder.

The obtained shaft was placed in a reducing cloud atmosphere for 40 minutes as a mechanical part.
I used it as a shaft for 500 hours at 0℃ and 10.00 rpm, but no trouble occurred during use.
After use, it was analyzed using an ultrasonic testing machine, but no abnormalities such as cracks were observed.

Fabrication Example 5 A shaft made of a bonded body of ceramics and metal was fabricated in the same manner as Fabrication Example 4, except that silicon carbide was used instead of silicon nitride, and the shaft was subjected to similar operational tests, but troubles occurred and cracks formed. No other abnormalities were observed.

Production example 6 Sialon ceramic sintered body (dimensions: 20 x 20
x 20 mm) using an ion plating device to a thickness of 1.0 μm each, with Nb as the first layer (inner layer) and Fe and Ni as the second and third intermediate layers, respectively.
Further, W was vapor-deposited as a fourth layer (outer layer), and then heated in a high vacuum heating furnace at 1.400° C. for a short time (30 seconds), cooled, and then joined to the Dumet alloy using N1 solder.

In addition, during this bonding, AI and W were each added 0.03 to 20 m thick as thermal stress relaxation layers between the intervening layer and the Dumet alloy.
The bending strength was measured and compared between those inserted with a thickness in the range of m and those not inserted. The results are shown in Table 2 below.

* Destructive production example 7 on the sialon ceramic side A sialon ceramic sintered body with an intervening layer similar to that in production example 6 was obtained, and various stress relaxation layers shown below were bonded to the Dumet alloy using Ni brazing to reduce the stress. A bonded body of Sialon ceramics and Dumet alloy having a relaxation layer was obtained. The thickness of each stress relaxation layer was 1.5 μm. The bending strength was as follows.

Table 5 *Example 8 of destructive production on the Sialon ceramic side Sialon ceramic sintered body (Dimensions = 15iTIIT)
IφX50++un) was processed into a shaft shape, and an ion plating machine was used to coat it with Fe as the first layer (inner layer), Si as the second layer (intermediate layer), and third layer so that each layer had a thickness of 0.7 μm. Cu was vapor-deposited as an outer layer, then heat treated at 1,250°C for 10 minutes, then 1
A shaft-shaped stainless steel (SUS310S) with a diameter of 6 mm was coated with %b and 1,1 with a thickness of 2 mm each as a thermal stress relaxation layer.
They were joined using silver solder through the plate o. As a mechanical part, in a reducing cloud atmosphere at 400°C, 5.00 Or, p,
It was used as a shaft for 500 hours under the conditions of m, , to, 000r, p, m, but no trouble occurred during use, and it was analyzed with an ultrasonic testing machine after use.
Abnormalities such as cracks were intolerable.

Effects of the Invention As explained in detail above, according to the present invention, the intervening layer has a multilayer structure and is formed by the ion plating method, thereby achieving the desired excellent properties and creating a non-woven material that can withstand practical use. A joined body of oxide ceramics and metal is obtained. This is because, unlike conventional methods, it is possible to give each layer a specific function, and in addition, the thickness and structure of the intervening layer can be freely selected, and it can be made extremely thin, preventing problems caused by being too thick. Various drawbacks such as those mentioned above can be solved. For example, although Ti exhibits high activity against sialon ceramics, silicon nitride, etc., it is easily oxidized, so in order to prevent this, the outer layer can be provided as a corrosion prevention layer, thereby forming Ti01Tie, etc. can be effectively prevented.

Furthermore, by providing the stress relaxation layer, problems such as cracking and breakage can be solved even when subjected to thermal cycles, etc., and a superior bonded body can be provided.

[Brief explanation of the drawing]

The attached FIG. 1 is a schematic cross-sectional view showing the structure of a joined body of non-oxide ceramic and metal according to the present invention. (Main reference numbers) 1. Non-oxide ceramics, 2. Intervening layer, 3. Metal layer,

Claims (9)

[Claims] (1) A bonded body consisting of a non-oxide ceramic sintered body, a bonding metal, and an intervening layer disposed between these, wherein the intervening layer has a multilayer structure and the non-oxidized The inner layer in contact with the ceramic sintered body is composed of a highly active metal layer, and the intermediate layer is composed of at least one metal layer that reacts with the inner layer and the outer layer and has the effect of lowering their melting point, Further, the outer layer in contact with the merizing metal is made of a metal layer having a protective effect of preventing corrosion of the inner layer and the intermediate layer, and a stress relaxation layer is provided between the bonding metal layer and the intervening layer. The above zygote. (2) The joined body according to claim 1, wherein the non-oxide ceramic is silicon nitride. (3) The joined body according to claim 1, wherein the non-oxide ceramic is silicon carbide. (4) The non-oxide ceramic is SiAlON ceramic, Si_6_-_zAl_zO_zN_8_z(z
1 to 4.2). (5) Claim 1, wherein the intervening layer is formed by an ion plating method.
The zygote according to any one of items 1 to 4. (6) The joined body according to any one of claims 1 to 5, wherein the intervening layer is subjected to heat treatment after the deposition treatment. (7) The inner layer metal is Si, Ti, Fe, Ni, Cu,
The conjugate according to any one of claims 1 to 6, characterized in that it is at least one member selected from the group consisting of Zr, Nb, Mo, Mn, Ta, W, Y, and Cr. . (8) The outer layer metal is Cu, Nb, Mo, Pd, Ag,
The conjugate according to any one of claims 1 to 7, characterized in that it is at least one member selected from the group consisting of W, Pt, and Au. (9) The stress relaxation layer is Si, Ti, V, Cr, Mn,
Fe, Co, Ni, Cu, Zn, Zr, Nb, Mo, T
Claim 1, characterized in that it is at least one selected from the group consisting of a, W, alloys containing these elements as main components, Kovar alloys, and Dumet alloys.
The zygote according to any one of items 1 to 8.