JPS60200872A - Metal and ceramic bonding method - 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 The present invention relates to a method for solid-phase bonding metals and ceramics using a hot isostatic press device.

<Industrial Application Fields> In recent years, there has been a noticeable trend toward higher efficiency and larger sizes of various high-temperature devices, and in order to develop high-performance high-temperature materials required to cope with these trends, bonding of metal materials and ceramics has become more important. Technology has come to occupy an extremely important position.

<Prior art> Conventionally, methods for joining metals and ceramics include: ■ Joining with adhesives, ■ Joining by brazing such as glue ring or play song, and ■ Mechanical means such as shrink fit or cold fit. Bonding, etc., have been known and put into practical use, but all of these methods have problems such as weak bonding strength and easy peeling when heated to high temperatures. In particular, when mechanical means are used, it is impossible to avoid the disadvantage that the shape of the metal members or ceramics to be joined is inevitably restricted.

For this reason, in recent years, solid-phase bonding methods that use hot isostatic pressure equipment to directly bond ceramics and metals at high temperatures while applying high pressure have been attracting attention (for example, “Ceramics J 18 (1983),
N [see 12, pages 112-121).

However, except for specific cases such as bonding between Nb-based metals and Al2O5-based ceramics, there is no sufficient bonding even if the metal and ceramics are directly pressure welded using solid phase bonding! Numerous research results have shown that there is no such thing. The reason for this is the following points a) and b).

That is, a) Si, C, and B, which are constituent elements of ceramics;
etc. diffuse into the metal material at high temperatures, forming a brittle layer on the joint interface side of the metal material, or causing deterioration of the ceramic due to the loss of the above-mentioned elements9, making it easy to peel in that area. To become a.

For example, a sintered body of iron-based metal and ceramics (TiN).

TiCHTI B2 r A120s r Zr 02
+ AIN, SiC+ St3 N4, etc.),
Even if you try to bond them directly using a hot isostatic press device, you will not be able to get the desired bonded product because the bond will not bond at all, or the reaction will be so intense that a brittle layer will be formed in the middle. .

b) Because the thermal expansion coefficients of metals and ceramics are different, stress concentrates at the bonding interface during cooling after pressure welding, resulting in peeling.

However, as mentioned above, Nb-based metals and AI! ,, Os
In the case of ceramics, there is almost no difference in thermal expansion between the two, and an appropriate reaction layer (N
bOx) is formed, resulting in an exceptionally good bond.

Therefore, in order to avoid such inconvenience, recently M2
When solid-phase bonding O3 ceramics and Fe, a method has been proposed in which an ``intermediate layer made of a mixed powder of Fe and Al2O3'' is sandwiched between the two in order to alleviate the difference in thermal expansion between the two. (The Ceramics Association's ``1981 Performance'' was held from May 16th to 18th, 1988).

In addition, a method has been proposed in which nitride-based ceramics and Mo are bonded together after sandwiching an intermediate layer consisting of a mixed powder of JMo powder and ceramic powder to be bonded. There is ( [Jour-nal
of American Ceramic 5ocie
tyJ Vol. 66, No. 7, Page 0117).

However, although it was possible to obtain good bonded bodies of M2O3 and Fe or Mo and nitride ceramics using this method, the target was "Al2
This method has disadvantageous problems, such as being limited to ``bonding of O-ceramics and Fe'' and ``bonding of I-nitride ceramics and Mo''.

<Purpose of the Invention> The inventors of the present invention have developed a method to alleviate the thermal expansion difference between metal and ceramics and to reduce the reaction between them when solid-phase joining metal and ceramic. The most promising means to appropriately control the bonding properties and realize a strong joint is to interpose an appropriate intermediate layer between the two. As a result of repeated research to find a method of bonding a metal member and a sintered ceramic member with sufficient bonding strength without causing any damage, the following knowledge was obtained.

<Findings> (a) TiN, which is known as a relatively stable compound even at high temperatures, is a compound that is highly stable even when heated to a high temperature range.
Co, Ni, Nb, Mo, Cr, etc.
It does not react with most metals and is extremely stable against various ceramics.
Nevertheless, since ceramics form a solid solution at high temperatures, solid phase bonding is possible between TiN and ceramics.

(b) As mentioned above, <%TIN is a stable substance for metals, but the TiN film vapor-deposited on the surface of metal parts has extremely good bonding properties with metals and is extremely dense. Something.

(C) On the other hand, when a mixed powder of metal powder and ceramic powder is compressed under high-temperature heating, the ceramic particles are bonded together using the metal as a binder due to the diffusion of the powder metal, and the coefficient of thermal expansion is different from that of the metal and ceramic. It is possible to obtain a cermet-like composite material having a value intermediate between

(d) Therefore, an arbitrary metal material and a ceramic sintered body are prepared, a TiN coating layer is formed on the surface of the metal material by vapor phase deposition, and then an arbitrary metal powder and ceramic are mixed in a specific ratio. When the metal material and the ceramic sintered body are pressed together under high pressure and heated at high temperature with a predetermined thickness of powder interposed between them, the cermet exhibits a coefficient of thermal expansion between that of metals and ceramics. In addition to this, the two will be firmly bonded through the intermediate layer, and if Si, C, B, etc. in the ceramic diffuse into the metal material and form a brittle layer, blocked by the stable TiN layer. This phenomenon is also prevented, and deterioration of the ceramic sintered body does not occur.

In this case, even if the combination is such that the reaction between the metal powder and the ceramic sintered body is intense, the amount of metal added in powder form is small compared to the entire ceramic sintered body, and this may partially affect the ceramic sintered body. Even if it reacts with the ceramic sintered body, it will not cause deterioration of the ceramic sintered body, but will instead result in an increase in the bonding strength with the TiN layer.

(e) The bonded body obtained by the method shown in item (d) above is bonded through an intermediate layer having a coefficient of thermal expansion between that of metal and ceramics, so the difference in coefficient of thermal expansion is There should be almost no peeling caused by this.

<Structure of the Invention> The present invention has been made based on the above-mentioned findings, and provides a method for bonding a metal material and a ceramic sintered body under high temperature and high pressure using a hot isostatic pressing device. A TiN coating layer is provided on the bonding surface by vapor phase deposition, and between the TiN coating layer and the ceramic sintered body, metal powder: 50% by weight or less, the remainder: consisting essentially of ceramic powder. By interposing a mixed powder layer of metal and ceramics with a thickness of 30,011 m or less, a composite member with excellent bonding properties that does not peel off even under heat cycle conditions can be stably manufactured. It is characterized by the following points.

The above-mentioned "metal material" is not limited to a specific type, and includes iron-based metals (including pure iron, carbon steel, various stainless steels, high Cr steel, etc.), tCo + Ni,
Any of Nb, Mo, Cr, or alloys thereof may be used. Furthermore, the above-mentioned "ceramic sintered body" is not limited to a specific type, and includes, for example, carbide ceramics such as SiC and TiC, SiN
4, nitride ceramics such as TiN, or TiB2
All of the sintered bodies such as B-based ceramics, etc. are targeted.

Further, the type of metal powder or ceramic powder used for the bonding intermediate layer is not particularly limited, but it is preferable to use one with a particle size of about -300 mesh.

Of course, it is also possible to use microparticles with a diameter of about 2 to 6 μm.

In addition, if the amount of metal powder in the mixed powder that becomes the bonding intermediate layer exceeds 50% by weight, or if the thickness of the mixed powder layer is 300μ
If the thickness becomes thicker, the amount of reaction between the ceramic sintered body and the metal powder will increase, leading to the risk of deterioration of the ceramic sintered body. Therefore, the amount of non-metal powder in the mixed powder should be reduced to 50% by weight. Hereinafter, the thickness of the mixed powder layer was limited to 300 μm or less.

Additionally, the heating temperature during bonding must be a temperature that does not melt the metal materials to be bonded, but is also a temperature that allows the powder metal to sufficiently diffuse and form a cermet-like composite layer with the ceramic powder. In the case of carbon steel or stainless steel, it is best to select a temperature of about 1100-1400°C.

The pressing force during joining may be selected appropriately considering the degree of adhesion, deformation, capacity of equipment, etc. of the joining members, and is 500 to 15
It is possible to select a wide range from 00 to /cnf.

Now, FIG. 1 is a schematic illustration of a method for assembling a joining member when a metal member 1 and a ceramic sintered body 2 are to be joined by the method of the present invention. This shows a state in which a mixed powder layer 4 of metal powder and ceramic powder is interposed between a metal member 1 whose joint surface is provided with a TiN coating layer 3 and a ceramic sintered body 2.

Now, when this assembly is treated at high temperature and high pressure using a hot isostatic pressing device, the metal powder will diffuse and form a cermet-like bonding intermediate layer together with the ceramic powder, and will adhere strongly to the metal member l. This results in strong bonding with both the TiN coating layer 3 and the ceramic sintered body 2. At this time, the stable TiN coating layer 3 separates the ceramic sintered body 2, the ceramic powder, and the metal part.
Si, C is transferred from ceramics etc. to metal parts even by high temperature heating.

There is no diffusion of B, etc., and therefore there is no possibility that a fragile layer will be formed in the metal member l.

Furthermore, the cermet-like intermediate layer formed by the diffusion of metal powder has a thermal expansion intermediate between that of the metal member 1 and the ceramic sintered body 2, so it has the effect of alleviating the difference in thermal expansion between the two. Even if the metal member 1 and the ceramic sintered body 2 are cooled after the high-temperature bonding operation, the metal member 1 and the ceramic sintered body 2 will not separate.

Next, the present invention will be specifically explained using Examples and Comparative Examples.

<Example> Comparative Example 1 S sintered using a hot isostatic press (HIP) under a pressure of 1000 atm and held at 1700°C for 2 hours.
iC sintered body (dimensions near φX 1.5 t, density: 2.8
8) and iron (dimensions near φX2.5t) were prepared, and the surfaces of both were polished with No. 600 emery paper.

Next, these were superimposed to make three sets of samples, and then 15
Under pressure of 00 atm, 900°C, 1ooo°C and 13
00°C for 1 hour each.
The sample was cooled to room temperature at a cooling rate of 0°C/hr and taken out from the apparatus.

When we examined the samples, it appeared that the iron and SiC sintered bodies were completely bonded, but when we polished the cross section of the sample and observed it under a microscope, we found that in more than half of the samples, SiC had not dissolved into the iron. It was confirmed that the remaining sample had a large number of cracks in the SiC sintered body.

Example 1 First, the surface of an iron material (dimensions near φX 2.5t) was polished with No. 600 emery paper, and the polished surface was coated with TiN using a normal chemical vapor deposition method (gas used: T).
ce, +H2+N2 mixed scum). Nao, formed Ti
The N coating layer was 60 μm thick.

On the other hand, a SiC sintered body (
Dimensions = 7φX 1.5t, density: 2.88).
The surface was polished with #600 emery paper.

Furthermore, reduced iron powder (average particle size: 8 μm) and SiC powder (average particle size: 1 μm or less) were mixed at a weight ratio of 1=1, and the mixture was pressure-molded into a disc shape of 7φ x 0.4m. We also prepared

Next, the compressed mixed powder was interposed between the sintered body and the iron material, as shown in FIG. 1'', and the two were overlapped.

This stacked body was heated under a pressure of 1500 atm using a hot isostatic presser (HIP) using the galanucabcel method.
00°C for 1 hour, 300°C/hr
The sample was cooled to room temperature at a cooling rate of .

When the samples subjected to such treatment were examined, it was confirmed that the iron and the ceramic sintered body were well bonded in all cases.

When the cross sections of these samples were observed under a microscope, it was found that the iron material-TiN coating layer, the TiN coating layer-(Fe+5iC
) mixed layer and (Fe+5iC) mixed layer-8iC sintered body, it was confirmed that good bonding was exhibited at both interfaces, and no cranking was observed. Furthermore, the reaction between the iron powder used as the intermediate layer and the SiC sintered body is slight;
It was also confirmed that there was no destruction of the SiC sintered body.

Example 2 SUS304 stainless steel material (dimensions near φ x 2.5t)
The surface of the sample was polished with No. 600 emery paper, and a 10 μm thick TiN coating layer was formed on the polished surface using the same method as in Example 1.

On the other hand, a commercially available SiC sintered body was machined into a disk shape (dimensions near φ×1t).

Furthermore, 5US304 stainless steel powder (average particle size: 8μ
m) and SiC powder (average particle size: 1 μnt or less) at 1=
A product prepared by mixing the mixture at a weight ratio of 2:2 and press-molding it into a disk shape of 7φ×0.1U was also prepared.

Next, the compressed mixed powder was interposed between the sintered body and the stainless steel material, as shown in FIG. 1, and the two were overlapped.

Using a hot isostatic press (HIP), this stacked body was heated to 900 m
The sample was held at ℃ for 30 minutes, cooled to room temperature at a cooling rate of 300 ℃/hr, and the sample was taken out from the apparatus.

As a result of microscopic observation of the cross section of the sample subjected to such treatment,
No cranking was observed in the joint or the SiC sintered body, and it was confirmed that the joint was in good condition as in Example 1.

<Overall Effects> As described above, according to the present invention, solid-phase bonding between metal materials and ceramic sintered bodies, which has been almost impossible until now, can be achieved stably, reliably, and relatively easily. Industrially useful effects can be brought about, such as the ability to provide metal-ceramic composite materials with good bonding strength at low cost.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing an example of a member assembly method when joining metal and ceramics by the method of the present invention, and Fig. 2 is a microscope view of the joint part of the Fe-8iC sintered composite member obtained by the method of the present invention. In drawing O, which is a photographic diagram, 1... Metal member, 2... Ceramic sintered body, 3... TiN coating layer, 4... Mixed powder layer of metal powder and ceramic powder. Applicant: Sumitomo Metal Industries, Ltd. and one other agent: Tomi 1
) Kazuo and 1 other person 100 μ procedural amendment rumor form) 1. Indication of the case Patent application No. 59-59142 2 Name of the invention Method for joining metals and ceramics 3 Person making the amendment 4 Agent Address Chiyo F, Tokyo, 1. I-ku Kanda Nishikicho-cho [123 Soho Daini Building 8th floor June 6, 1980 (shipment date June 26, 1980)
In the Statement of Contents of the Amendment, page 16, line 15, the phrase "microscopic photograph" should be corrected to "microscopic tissue photograph."that's all

Claims (1)

[Claims] When joining a metal material and a ceramic sintered body under high temperature and high pressure using a hot isostatic pressing device, a TiN coating layer is applied to the joining surface of the metal material by vapor phase deposition. In addition to providing
Furthermore, between the TiN coating layer and the ceramic sintered body, a mixed powder layer of metal and ceramics, the metal powder being 50% by weight or less, the remainder being substantially composed of ceramic powder, and having a thickness of 300 μm or less. A method for joining metals and ceramics, characterized by intervening.