JPS61117172A - Ceramic bonding structure - 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 (Industrial Application Field) The present invention relates to two strong connection structures C in which one is made of ceramic and the other is made of ceramic or metal.

(Conventional technology) Seven? Mixes generally have excellent heat resistance, thermal shock strength, mechanical strength at high temperatures, abrasion resistance, or high insulation properties, so
By joining metals, we can manufacture peripheral parts of automobile engines and gas turbine parts.

It is expected to be used in a wide range of applications, including assemblies of substrates and metal leads for engineering C, vacuum switches, and magnetrons for microwave ovens.

In this case, it is necessary to bond ceramics to metals (ceramics are bonded together) or to bond ceramics and metals to fully demonstrate their functions.

Conventionally, it has been known that this type of joining is usually performed using a metal brazing material such as silver solder, and an example of its structure will be explained with reference to FIG. 2. A metal shaft 2 is formed by applying the paste to form a metal 2ize layer 3.
The end face of the metal plate is brazed with a brazing material such as silver solder.

Such a bonding structure can achieve strong bonding by appropriately selecting the type of brazing material and by properly treating the surfaces of the ceramic and metal.

(Issues that should be improved) However, although this type of bonding structure is good at room temperature and low temperature,
For example, in the case of a brazing material mainly composed of mug, when the temperature reaches a high temperature range of 400 to 500 DEG C. or higher, depending on the material of the brazing material, the heat resistance and oxidation resistance are poor, and the strength often deteriorates.

Therefore, there is a demand for a joining structure that does not have these drawbacks.

(Means for Solving the Problems) The present invention has been made as a result of intensive research in view of the above-mentioned circumstances (2), and is a method for connecting ceramics and ceramics or metals with a brazing filler metal containing at least one type of Ti and Ni. M
Covered with a metal spray coating layer containing l.

This provides a connection structure with strong bonding strength without causing oxidation or deterioration of the bonded portion.

Here, it is stipulated that at least one type of Ti and Ni is included.
The addition of Ti (2) increases the bonding strength due to its reactivity, so it is possible to bond directly to ceramics under the conditions (2). Ni is added to provide heat resistance. In this case, since Ti in particular is easily reactive, it deteriorates significantly under oxidizing conditions, so Ni, which has good reactivity,
A coating containing

(Function) According to the present invention, in brazing between ceramics and 72 mix or metal, an oxidation-resistant film is created by thermally spraying the joint with a metal such as chromium or nickel-chromium metal, which has strong oxidation resistance. It can cover weaknesses in the heat resistance and oxidation resistance of joints. It is convenient to form a Ti-Ni reaction layer and a Ni-Ni reaction layer when the thermal spray material contains Ni.

In addition, by making this thermal spray coating thick, it is possible to apply pressure from the surroundings near the joint (also known as a metal ring burnout effect).

It is preferable to perform metal spraying under reduced pressure in order to protect the dense internal parts, and the surface of the sprayed metal can be polished to a predetermined dimension C2 if necessary. .

(Example) An example of the present invention is illustrated in the drawings (for a second explanation, FIG.
The ends of the ceramic shaft 1 and the metal shaft 2 are directly brazed 4 with silver solder containing Ti, and this brazing is performed by providing a metal sprayed layer 5 on the exposed surface of the layer to form a joint structure. Thermal spray layer 5 (shielding the internal brazing 4 of the second twist, oxidizing,
It is designed to prevent deterioration.

In addition, when joining the ceramic shaft 1 and the metal shaft 2, as shown in FIG. 3 and the end face of the metal shaft 2 are brazed together (4), and then the exposed surface of this brazing 4 and the surface of the end of the ceramic shaft C are connected to the bifurcated metal 2ize layer 3 This is a case where the metal sprayed layer 5 is provided thicker over a certain length from the connection end of the shaft 2, and the metal sprayed layer 5
Since this is large, it can sufficiently prevent oxidative deterioration of the internal brazing filler metal and also contribute to increasing the mechanical strength of the connection part.

In addition to the above, connection of ceramic shafts (even if there are two, they are not shown but can be easily understood).Example 1 Next, as a sample based on the present invention, alumina was used for the ceramic and Kovar was used for the metal. The shaft diameter was 10H1 and the length was 40m for both alumina and Kovar.
It was set as x.

Connection is alumina 1. 110 parts by weight, 60 parts by weight, 50 parts by weight between the end face of Kovar (Ti is Tin)
, using the mixed paste at 1O-6torr.
Brazing was carried out at approximately 900°C in a vacuum of 300°C. This paste was used because it contains Ti and allows brazing to alumina without metalizing. Thereafter, a plasma-sprayed MO-Ni-Cr-Mul composite (for example, Methi: 11442) was made into a bonded body as shown in FIG. 1(a).

Comparative Example 1 Gunozuma thermal spraying of Mo-ML-Or-A/composite (The same material as in Example was used to prepare the connection body shown in FIG. 2.

For Example 1 and Comparative Example 1, 5 samples were each prepared, and they were placed in an electric furnace at about 500°C in the atmosphere, left for 100 hours, then taken out, and the joint strength was determined from the screw surface.
When used in an oxidizing environment, structures that cannot withstand conventional brazing alone can be easily obtained according to the invention.

Example 2 The same material as in Example 1 was used to make a bonded body as shown in FIG.

Next, a metal sprayed layer 5 was formed by coating the MO-11L-Cr-Mul composite to a thickness of about 1 aC by Guzuma spraying.

Example 1. Five samples were prepared. In the same manner as Comparative Example 1, it was oxidized in an electric furnace and its strength was measured.

As a result, the torsion strength was low, and the metal sprayed layer was slightly oxidized (dioxidized), but the inside was completely protected.

This is thought to be due to the large size of the metal sprayed layer, which also added a kind of shrink-fitting effect.

In the above example, an example was shown in which alumina was used as the upper 2 mix, but it is also possible to use alumina by appropriately selecting the metal spraying conditions and the metal spraying conditions.N4.810. Engineering ceramics such as ZnO can also be applied.

In addition, for joining where there is a large difference in coefficient of thermal expansion, such as a ceramic shaft and a metal shaft, Japanese Patent Application No. 59-806581:

As explained above, by brazing a thin plate made of sintered ceramic material with a composite structure (buffer plate) interposed with a single C2 or gold G4 plate, the joint strength can be increased even under high temperature vibration. It is strong and can prevent ceramic cracking near the joint due to residual stress after joining.

Since thermal spraying is used, internal brazing prevents oxidation deterioration of the layer and provides a joint structure with high joint strength.Also, it is possible to make the metal sprayed layer to a certain thickness (therefore, it is similar to shrink fitting). It can be effective.

[Brief explanation of the drawing]

Figure 1 (a) S (Sakaki is a partial vertical cross-sectional view of each embodiment of the present invention, and Figure 2 is a partial vertical cross-sectional view of a conventional example. 1: Ceramic shaft 2: Metal shaft 3 Nimetal 2 size layer 4 : Brazing layer 5: Gold Tj4 Reaction layer Agent Patent attorney Mamoru Takeuchi Figure 1 (A) Figure 1 (B) Figure 2 I J4

Claims (1)

[Claims] Ti and Ni between ceramics and ceramics or metals
N
A ceramic bonding structure characterized by being covered with a metal sprayed coating layer containing i.