JPS6033266A - Bond pretreatment for ceramics containing si3n4 component - 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] [Field of Application of the Invention] The present invention is directed to +31. The present invention relates to a pre-treatment method for bonding ceramics containing an N4 component.

[Prior art]

In recent years, ceramic materials such as silicon carbide, silicon nitride, sialon, aluminum oxide, and zirconium oxide have attracted a lot of attention because of their excellent mechanical strength at high temperatures and their excellent heat resistance and thermal shock resistance. There is. There are many uses for these ceramics, such as gas turbine sweaters, combustors, diesel engine cylinders, and other high-temperature machine parts.However, B deviations also have strict requirements for shape and dimensional accuracy, so they must be molded and manufactured as one piece from the beginning. It is often difficult to do so.

For this purpose, it is necessary to bond partial products together to create complex shapes, and it is desirable to develop a method for firmly bonding ceramics to themselves or ceramics to other materials such as metals. ing.

Conventionally, the so-called hot press bonding method, in which an adhesive is interposed between ceramics and pressure is applied at high temperatures, has been commonly used as a method for bonding ceramics. Therefore, it is not suitable for joining dissimilar members having different coefficients of thermal expansion.

Additionally, multiple types of inorganic adhesives are being developed.
Various products are manufactured and sold in Japan as well. However, many of these inorganic adhesives are usually made of silica, alumina, or zirconia as their main raw materials, and although they have heat resistance, they have the disadvantage of being weak against forces that would cause the bonded surface to peel off.

Furthermore, brazing is a bonding method with higher bonding strength than such inorganic adhesives. By the way, the conditions for brazing ceramics are that the object to be bonded is wetted by the brazing material and that the part to be welded and the brazing material are tightly bonded. Oxide-based ceramics generally have poor affinity for molten materials (so-called wettability) and low reactivity with various substances, so it is not always possible to obtain sufficient brazing strength.

[Object of the Invention] The object of the present invention is to solve the problems of the above-mentioned prior art, and to
An object of the present invention is to provide a bonding pretreatment method that makes it possible to firmly bond ceramics containing an N4 component to other members.

[Structure of the invention]

To achieve this objective, the bonding pretreatment method of the present invention includes:
This process uses the decomposition of Si and N4 by irradiation with a high power density heat source to treat the surface of ceramics containing Si and N4 components. Si3 characterized in that Si and N4 on the surface to be bonded are partially decomposed by irradiating and heating with a high density heat source.
The gist of this article is a pre-treatment method for bonding ceramics containing an N4 component.

The present invention will be explained in detail below.

In the present invention, the ceramics containing Si, N, and other components can be applied to various known ceramics as long as they contain Si and N4 components.

For example, a small amount of oxide (Si3N containing inder as a sintering aid, a sintered body based on Si-Al-0
-N-based sintered body called Sialon, etc. can be mentioned. Further, oxide-nitride or silicate oxide-carbide mononitride ceramics partially containing Si and N4 components can also be used.

In the present invention, a high power density heat source is irradiated to heat the surfaces of ceramics to be bonded containing Si, N, and other components. As the high power density heat source, arc, primer jet, electron beam, laser, etc. A beam or the like is used. Although the power density is not particularly limited, it is easy to use, for example, a power density of about 10' to 1 O'W/cIn2.

Heating by irradiation with a high power density heat source partially decomposes the Si and N4 on the surface of the ceramic to be bonded, causing the metal S
It is more effective if the temperature is such that 1 is generated. That is, the sublimation temperature of Si and N4 is 19
00'c, the heating is preferably 1900°C or higher. Further, since the metal S1 has a melting point of 1410°C and a boiling point of 2360°C, it is preferable that the heating is performed at a temperature of 2360°C or lower.

In the present invention, a more preferable heating temperature is 2000 to 2
The temperature is 200°C.

Irradiation with such a high power density heat source causes phenomena such as sublimation and decomposition of 5isN and precipitation of metal S1 on the surfaces to be bonded, as described above.

Furthermore, in addition to this phenomenon, low melting point substances such as sintering aids such as S10, etc. Prior to (or concurrently with) the sublimation and decomposition of N4, it undergoes changes such as sublimation, decomposition, and evaporation.

Due to such an action, the roughness of the surface to be joined is increased, and the same effect as that of dimetallization treatment is exerted by the precipitation of metal S1, and the wettability with dissimilar materials such as metals is significantly improved. It will be increased.

Note that the atmosphere when irradiating with the high power density heat source may be an air atmosphere, but if it is a non-oxidizing atmosphere, oxidation of the deposited metal 611 is prevented, which is effective.

The ceramics subjected to the four-coat pretreatment according to the present invention are then firmly joined to other parts by conventional pressure welding or brazing using a suitable brazing material or insert.

[Embodiments of the invention]

EXAMPLES The present invention will be explained in more detail with reference to examples below, but the present invention is not limited to the following examples unless it exceeds the gist thereof.

Example I Si, N4 ceramic plate (20mm x 20mm x 5mm)
2. on the surface of the sample; Using a sKW CO laser processing machine, continuous light with a power density of 10' to IO'W/crn' was applied with an irradiation energy density of 1000 to 4000 J/c.
It was irradiated so that it became rrL2. At this time, it was confirmed with an infrared thermometer that the surface temperature of the ceramic sample was 2100°C, and the temperature was 0.05 to 0.1 mi from the sample surface! It was observed that the ceramics at a depth of

When the surface of this sample was observed with a scanning electron microscope at a magnification of 2000 times, the surface layer was decomposed and removed by the heat generated by the laser beam, and complex irregularities down to the particle order (several μm) were observed. Further, elemental analysis using an X-ray microanalyzer revealed that metal silicon was precipitated in various parts of the irradiated surface.

Commercially available Ni-P (
When bonding was performed at 1000° C. using a PH12wt% brazing filler metal, a strong bond was obtained.

On the other hand, when we attempted to bond in the same manner using a test piece of the same shape that was not subjected to this laser treatment as a comparative material, bonding was impossible.

〔Effect of the invention〕

According to the present invention, a surface suitable for bonding can be obtained by treating the surface of ceramics to be bonded containing J2, Si, N, and other components by heating with irradiation with a high power density heat source. be. That is, the surface of the ceramic treated by the method of the present invention has increased surface roughness due to sublimation and evaporation of low melting point substances. Further, by depositing the metal S1, wettability with other members such as metals can be improved, and it is possible to firmly bond the metal member or ceramics.

Agent: Patent attorney Tsuyoshi Shigeno

Claims (1)

[Claims] (11When a high power density heat source is irradiated and heated on the surface of ceramics to be bonded containing Si and N4 components, the Si and N4 on the surface to be bonded are partially decomposed. (2) The pre-bonding method according to claim 1, characterized in that the heating temperature is 1900° C. or higher. Treatment method (3) The bonding pretreatment method according to claim 2, wherein the heating temperature is 1900 to 2 a 60'C.