JPS63112475A - Method of joining ceramic to metal - Google Patents

Abstract

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

Description

[Detailed Description of the Invention] Industrial Application Field This invention relates to a method for joining ceramics and metals that have properties such as heat resistance, wear resistance, and corrosion resistance. It relates to a method of joining.

Prior art and its problems There are various methods for joining ceramics and metals, ranging from solid-phase bonding performed under high temperature and pressure to coating methods such as thermal spraying, and each method has its own characteristics. For example, one of the most widely used methods is brazing using an insert material that has a lower melting point than ceramics or metals. This method uses a liquid metal or an oxide such as glass as a wax which is inserted between the ceramic and the metal, and the contact between the materials is maintained by wetting with the liquid (wax), so it is very effective. Achieves an airtight joint. However, ceramics inherently have poor wettability with the solder used in general metal brazing. To this end, methods such as metallizing the ceramic surface or adding active metals such as T1 to the solder to facilitate wetting of the solder have been taken.

As a method for metallizing the surface of ceramics, the applicant previously proposed a method in which a mixed powder of Ni and Tic is applied to the surface of ceramics to form a sintered layer (
Patent application Sho 8O-285827). However, in this method, it was rarely necessary to raise the heating temperature to 1200° C. or higher. This is because the eutectic temperature of Ni+TjC is 1285°C, so no reaction occurs on the ceramic surface below 1200°C. The higher the heating temperature, the higher the energy cost, which increases the manufacturing cost, which is not preferable.

Purpose of the Invention The present invention was made in order to lower the heating temperature in the conventional metallizing treatment.
The purpose is to propose a method that can perform metallizing treatment at a lower heating temperature than that of LC mixed powder.

Composition of the Invention The method for joining ceramics and metal according to the present invention includes coating the surface of the ceramic with Ni75 to 99% and TLBz1 to 25%.
It is characterized by metallizing treatment using a mixed powder consisting of %.

Since the Ni TLE12 system has a eutectic point at 1180° C. with a composition of 2 to 3 mol % of T and 82, the eutectic point is lowered by nearly 100° C. compared to Ni Tic. This invention takes advantage of this fact, and by applying a thin layer of mixed powder of Ni and TL'B2 on the surface of ceramics in advance and heating it in a non-oxidizing atmosphere to prevent oxidation of Ni and TL, N with good adhesion to ceramic surfaces
This is a method of joining metal and ceramic by forming a sintered layer of i + Ti B 2 and then directly press-bonding it to the metal material or brazing it with a suitable insert material.

Here, Ni and TiB are used as metallizing treatment agents.
2 was used for the following reasons.

In the case of a mixed powder of Ni and TL2, TLB is formed by heating.
2 is solid dissolved in Ni, and the solid dissolved TL and B react with ceramics. For example, in the case of Zr 02, Zr 02 decomposes, Zr partially combines with B to generate Zr B 2, and O becomes T.
This is because oxides such as L02 are created and stabilized.

The compositions of Ni and TL B2 are 75-99% and 1, respectively.
~25% are effective. N if TL B 2 is less than 1%
The solid solution in i is small, so the reaction with ceramics is slow and a uniform film cannot be formed even after heating for about 1 to 2 hours. This is because it is thought that the bonding strength with the ceramics decreases due to segregation particularly in the vicinity of the ceramics.

In addition, the heating temperature of the mixed powder of Ni and TL B 2 is 11
00°C or higher is required. This is because if the temperature is lower than 1100° C., the solid solution of TL B 2 in Ni is small, so that the reaction with ceramics cannot be achieved sufficiently.

Example 1 Commercially available 99% M203 (201TIm width x 20mm length x
After heating, apply a mixed powder of Ni + 2% TL B 2 to one side of the 1mm thick) to a thickness of about 20%, and then 10'
``1100℃ x 3 layers m r in a vacuum of 3 Torr
n Heated. After heating, normally 11g1 (201r+m width
20mm length x 10+nm thickness) and commercially available silver solder.
A 2 mm thick plate was inserted and brazed at a temperature of 750°C.

The obtained sample was cut from the center perpendicular to the joint surface, polished to a mirror surface, and observed under a microscope. As a result, no cracks were observed at the joint interface or at the N2O3.

Example 2 Commercially available 7. Ni+5% TL B 2 was applied to rO2 (containing 3% Y2O3) ceramics, heated in the same manner as in Example 1, and 5US30. As a result of directly brazing to i, no peeling or cracking was observed.

Example 3 Ni + 5% TL B on Al2203 similar to Example 1
2 and 1300'C x 10m1n in A7 atmosphere.
After heating, 5U of 0.3mm thick Go plate was used as insert material.
Brazed to S304. In this case as well, no peeling or cracking was observed.

Example 4 Ni + 25% TLB2 was applied to Zr02, and 1200'
CX60m1n was heated in a N2 atmosphere, and then a 0.2 mm thick plate was used as an insert material and brazed with ordinary steel. As a result, Tj 82 particles were dispersed in the metallizing layer, but it was different from "1r02". The interface was well bonded. Also, no cracks were observed in 7.rO2.

Comparative Example 1 Ni+ 0.5%TL B2 was applied to M2O3 and 13
00'CX 30ml heated in vacuum. As a result of observing the cross section of the obtained sample with an optical microscope, it was found that Ni + TL
Layer 82 was porous and almost no bonding was observed at the interface with M2O3.

Comparative example 2 Nshi + 3% TL B 2 was applied to 1ro2 and heated to 1000℃
As a result of heating the sample in X1hrN2 and observing the cross section of the obtained sample with an optical microscope, no reaction occurred between 1"f and TL B 2 during sintering, and no bonding with "1rot was observed.

As described in detail, this invention uses Ni + TL B 2 mixed powder as a metallizing treatment agent for ceramics, which makes it possible to form a metallized layer by heating at about 1100 to 1200'C. It is possible to stably and reliably join metals at low temperatures, and has the effect of providing a metal-ceramic composite material with good bonding strength at a low cost.

Claims (1)

[Claims] A method of metallizing the surface of ceramics and joining metal and ceramics, characterized in that the surface of the ceramics is metallized with a mixed powder consisting of 75-99% Ni and 21-25% TiB. joining method.