JPH0369863B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to non-oxide ceramics mainly composed of nitrides and carbides, or oxide ceramics mainly composed of oxides such as zirconia, alumina, silica, and magnesia, and iron and copper. , nickel, stainless steel, and other metals and alloys (alloys are also referred to as metals in this specification). [Conventional technology] Ceramics have excellent heat resistance, corrosion resistance, and wear resistance, but when trying to make effective use of them, the difficulty is that ceramics are brittle, that is, weak against impact, so they cannot be used as structural materials. In many cases, it is more convenient to use it in conjunction with a metal that has superior toughness. On the contrary, this also expands its uses. Various studies are being conducted regarding the bonding of ceramics and metals. That is, there are organic and inorganic adhesives, as well as mechanical bonding such as shrink fitting, and excellent adhesives have been developed and are being evaluated to a certain extent. However,
Bonding through chemical reactions, diffusion and penetration effects, and the so-called metallization method, in which metal is formed on the surface of ceramics, are attracting attention in terms of heat resistance and other properties. This metallization method is broadly classified as follows. This is also known as the high melting point metal method.
Mo-Mn, W, W-Mo or kaolin etc. are added to these, mixed with a binder, heated to around 1600℃ in humidified hydrogen to infiltrate Mo and W,
A method of applying Ni plating etc. to this and then brazing it with the joining metal. The bonding mechanism is that Mn becomes MnO and dissolves into the ceramic, and Mo is slightly oxidized and penetrates into the glass phase of the ceramic phase and the Ni plating layer to bond. A method of joining ceramics and metal by interposing an intermediate insert material that easily reacts with the material. As the insert material, a mixture of a copper compound such as copper sulfide and kaolin is generally known. During bonding, the insert material is inserted between the ceramic and the metal to be bonded, and heated to a temperature equal to or higher than the melting point of the insert material. Mechanically, method (2) requires a lot of man-hours, so method (2) is attracting attention. [Problems to be Solved by the Invention] Various examples have been reported in which oxide-based ceramics such as alumina-based, magnesia-based, and silica-based ceramics have been successfully joined by methods using insert materials. However, zirconia-based ceramics containing 90% or more of ZrO ₂ are either impossible to bond or are extremely fragile, and have not been put to practical use. Furthermore, sufficient bonding strength has not been obtained with non-oxide ceramics. The present invention applies not only to oxide-based ceramics such as alumina-based, magnesia-based, and silica-based ceramics, but also to
The present invention attempts to propose a bonding method that can firmly bond zirconia ceramics containing 90% or more of ZrO ₂ and non-oxide ceramics to metals. [Means for Solving the Problems] The present invention focuses on the stability of zirconia ceramics and non-oxide ceramics, and takes into consideration the phase formed by forced reduction. ~80%, balance Si, Al 1
Insert material consisting of a species or two species and unavoidable impurities, or by weight% Ca15-80%, Ti15
% or less, the balance being one or two of Si and Al and unavoidable impurities is placed, heat-treated at 1150°C or higher in a non-oxidizing atmosphere, and then the metal to be bonded to the surface to be bonded. By bringing them into contact with each other and heat-treating them in a non-oxidizing atmosphere at temperatures above 900°C and below the melting point of the metals to be joined, it is possible to bond zirconia-based ceramics and non-oxide-based ceramics, which have traditionally been difficult to bond firmly, to metals. We succeeded in making a strong bond. [Function] In the present invention, the surface of ceramics is reduced with calcium, which is a strong reducing agent, and a structure of metal, which is a component element of ceramics, or a structure similar to this is produced on the surface of the ceramic, and this and the insert material are combined. It is expected that the compound will bond to the metal. Possible substances that can effectively reduce the ceramic surface include Ca, Be, Sr, Y, and rare earth elements, but they are difficult to handle except for Ca. Next, heat treatment conditions will be explained. In order to reduce the ceramic surface and make it into a metallic or similar structure, which is a constituent element of ceramics, and at the same time to sufficiently react and bond this phase with the insert material, the temperature should be 1150°C or higher, preferably the insert material. The temperature is preferably 200°C or more higher than the melting point. In addition, in the second heating, 900
C. or higher is required, and the upper limit at this time is set to be below the melting point of the metals to be joined. It is important that the heating atmosphere be an atmosphere that does not oxidize Ca in the insert material, such as a dry hydrogen atmosphere, an inert gas atmosphere, or a vacuum, that is, a non-oxidizing atmosphere. Next, the insert material used in the present invention will be explained. Due to the heat treatment temperature mentioned above, the melting point of the insert material needs to be 900°C or higher. The melting point of Ca is approximately 800°C, but it is necessary to alloy it to have a melting point of 900°C or higher, and as a suitable alloying component, Si or Al is appropriately added to Ca in consideration of reducing performance. is possible. Ca content is 15
If the reduction reaction is less than 80%, sufficient reduction reaction will not be obtained.
If the temperature exceeds 900° C., the melting point becomes less than 900° C., making it impossible to form a good bond. Therefore, the Ca content was set at 15 to 80%. In addition, the wettability of the insert material is taken into consideration, and the weight percentage is set so that the melting point of the insert material does not become extremely high.
It is also possible to add Ti in a range of 15% or less. In addition, in the present invention, even if elements other than the above-mentioned Ca, Si, and Ti are contained, the presence of other elements does not pose a particular problem as long as Ca has a strong reducing power and a melting point of 900°C or higher. Conceivable. Furthermore, in the present invention, applying pressure to the bonded body during heat treatment contributes to improving the bonding strength. [Examples] The present invention will be described below based on Examples. Example 1 Ca-Si alloys having the compositions shown in Samples No. 1 and 2 in Table 1 were ground to 150 meshes or less, made into a paste with isopropyl alcohol, and applied to a SiAlON plate at a rate of 50 mg/cm ² . . This was heated at 1300°C for 10 minutes in a hydrogen atmosphere to metallize Sialon. Next, a Cu plate (0.5 mm thick) was placed on the metallized surface and heated at 1050℃ in a dry hydrogen atmosphere.
It was held for 15 minutes to bond. A steel bar of φ10 was silver-brazed on the surface of the Cu plate of this joined body, and a tensile test was conducted. As shown in Table 1, sample No. 1,
Both are strongly connected, 9.4Kg/mm ² , 9.5
A joint strength of Kg/mm ² was obtained. In addition, sample No. 3 (50Ca−30Si−
When SiAlON and Cu were bonded using 15Ti) in the same manner as above, a bond strength of 11 Kg/mm ² was obtained. As a comparative example, 10% shown in sample No. 4 in Table 1
We attempted to bond the two under the same conditions as above using a Ca-Si alloy containing Ca, but no bonded body could be obtained.
It has also been known as an insert material.
Mix CuO (Sample No. 5) and CuS (Sample No. 6) powder of 150 mesh or less, apply it to the surface of a Sialon plate, hold it in the atmosphere at 1250℃ for 30 minutes, and then A Cu plate (thickness 5 mm) was layered on top of the plate in a hydrogen atmosphere.
Although the mixture was held at 1000°C for 20 minutes, no zygote was obtained.

[Table] Sample No. 7 in Table 1, a Ca-Si alloy containing 50% Ca, was crushed into 150 meshes or less, made into a paste with isopropyl alcohol, and then placed on a SiAlON plate with 30% Ca-Si alloy.
13 mg/ ^mm2 at 1180°C in a hydrogen atmosphere.
Heat treated for 1 minute. Next, a Ni plate (thickness: 1 mm) was placed on the coated surface and held at 1200° C. for 15 minutes in a hydrogen atmosphere to obtain a bonded body. This bonded body was strongly bonded, and as a result of the tensile test conducted in the same manner as described above, the bond strength was 10.5 Kg/mm ² . In addition, as shown in sample No. 9 in Table 1, Ca was added to 50
% Ca-Si alloy powder (150 mesh or less) is made into a paste with isopropyl alcohol,
This was applied to a sialon plate at a rate of 50 mg/mm ² and dried, followed by heating at 1300° C. for 10 minutes in a hydrogen atmosphere. Then, when a SUS304 round bar (8φ) was placed on top of this and heated at 1300℃ for 10 minutes in a hydrogen atmosphere, the bond strength was 12Kg/
mm ² was obtained. In the present invention, it may be possible to obtain a good bonded body by applying a slight pressure during bonding. An example is shown below. Sample No. 8 in Table 1, a Ca-Si alloy containing 40% Ca, was crushed into 150 meshes or less, made into a paste with isopropyl alcohol, and then placed on a SiAlON plate with 30% Ca-Si alloy.
13 mg/ ^mm2 at 1180°C in a hydrogen atmosphere.
Heat treated for 1 minute. Next, a Ni plate (thickness: 1 mm) was placed on the coated surface, a pressure of 20 g/cm ² was applied, and the temperature was maintained at 1050° C. for 10 minutes in an argon atmosphere. The resulting bonded body was subjected to a tensile test in the same manner as in Example 1, and as a result, a bonding strength of 10.5 Kg/mm ² was obtained as shown in Table 1. Example 2 Ca-Si alloys having the composition shown in sample Nos. 10 and 11 in Table 2 were ground to 150 meshes or less, made into a paste with isopropyl alcohol, and applied to the surface of zirconia ceramics containing 90% or more of ZrO ₂ . 50mg/ ^cm2
It was applied at the rate of This was done at 1150℃ in a hydrogen atmosphere.
The sialon was heated for 10 minutes to metalize it. Next, a Cu plate (thickness: 0.4 mm) was placed on the metallized surface and held at 1050°C in a hydrogen atmosphere for 10 minutes to bond. A steel bar of φ10 was silver-brazed to the surface of the Cu plate of this bonded body, and a tensile test was conducted. As shown in Table 2, both samples No. 10 and 11 were firmly bonded. Bond strengths of 9.5Kg/mm ² and 10.0Kg/mm ² were obtained. As a comparative example, 10% shown in sample No. 12 in Table 2
We attempted to bond the two under the same conditions as above using a Ca-Si alloy containing Ca, but no bonded body could be obtained.
It has also been known as an insert material.
CuO (Sample No. 13), CuS (Sample No. 14) powder of 150 mesh or less and alumina powder are mixed, and ZrO ₂
50 on the surface of over 90% zirconia ceramics
After coating at a rate of mg/ ^cm2 , it was held at 1250°C in the air for 30 minutes, and then a Cu plate (4 mm thick) was placed on the coated surface and held at 1000°C for 20 minutes in a hydrogen atmosphere. I couldn't get it. After grinding the insert material of sample No. 15 in Table 2 to 150 mesh or less into a paste with isopropyl alcohol, paste it on an alumina ceramic plate with 70 mesh.
mg/mm ² at 1200°C in a hydrogen atmosphere.
Heat treated for 1 minute. Next, a Ni plate (thickness: 4 mm) was placed on the coated surface and held at 1200° C. for 10 minutes in a hydrogen atmosphere to obtain a bonded body. This bonded body was firmly bonded, and as a result of a tensile test conducted in the same manner as in Example 1, the bond strength was 10.5 Kg/mm ² .

〔Effect of the invention〕

As described above, according to the present invention, it is possible to firmly bond ceramics and metals, which has been difficult to bond using conventional insert materials, thereby expanding the applications of ceramics.

Claims (1)

[Claims] 1. On the surface to be joined of ceramics, in weight%,
Place an insert material consisting of 15 to 80% Ca, the balance being one or two of Si and Al, and unavoidable impurities,
Heat treatment at 1150°C or higher in a non-oxidizing atmosphere, then bring the metal to be joined to the surface to be joined, and heat treatment at a temperature of 900°C or higher and below the melting point of the metal to be joined in a non-oxidizing atmosphere. A method for joining ceramics and metal, characterized by: 2. On the surface to be joined of the ceramics, in weight%,
An insert material consisting of 15 to 80% Ca, 15% Ti or less, the remainder Si and Al, and unavoidable impurities is placed, heat-treated at 1150°C or higher in a non-oxidizing atmosphere, and then the surface to be joined is 1. A method for joining ceramics and metals, which comprises bringing the metals to be joined into contact with each other and heat-treating the metals in a non-oxidizing atmosphere at a temperature of 900° C. or more and below the melting point of the metals to be joined.