JPS5891088A - Method of bonding ceramic and metal - 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 of joining ceramics and metal.

Conventionally, various methods have been used in this field of technology, ie, for joining metal to ceramics, depending on the purpose and the material used.

Examples of methods include joining using organic adhesives such as epoxy resin and polyvinyl acetate, or inorganic adhesives such as glass and cement, joining methods using laser welding, electron beam welding, and soldering. be.

However, all of these methods resulted in the following problems and resulted in unsatisfactory results. That is, (1) When an organic adhesive is used, the adhesive decomposes and burns at high temperatures.

(2) When an inorganic adhesive is used, the adhesive layer peels off and comes off at high temperatures.

(3) When laser welding or electron beam welding is used, the ceramic base material decomposes and detaches during welding.

(4) When soldering is used, solder has poor wettability with ceramics and detachment occurs.

As a result of extensive research into the bonding method between ceramics and metals, the present inventors found that if ceramics and wire mesh are bonded using a mixed powder containing copper and titanium as essential components, the adhesive strength will be stable even at high temperatures. It was discovered that a highly conjugated product could be obtained, and the present invention was completed based on this finding.

The purpose of the present invention is to obtain a ceramic-metal bonded body that is stable even at high temperatures and has high adhesive strength. This is a method for joining ceramics and metal, which is characterized by pressure-welding the metal to the metal and heat-treating it.

As the ceramics used in the present invention, non-oxide or oxide ceramics whose coefficient of thermal expansion is not significantly different from that of the mating metal to be joined can be used, and non-oxide ceramics are particularly desirable. Examples of such ceramics include silicon nitride (Si, N), silicon carbide (SiC), tungsten carbide (WC), and aluminum nitride (AIN). A sintered body sintered by a normal method can be used as the ceramic, and is not limited by its shape or the like.

As the mixed powder to be applied to the ceramics, it is possible to use a powder preferably in the form of a fine powder, which shows high wettability to the ceramics and contains steel (Cu) and titanium ('ri) as essential components. The mixing ratio is not specified, but from the viewpoint of improving bonding strength, it is preferable to use copper 6
A ratio of 0 to 90% by weight and 40 to 5% by weight of titanium is reasonable. To apply this mixed powder to ceramics,
Make it into a paste and apply it to a thickness of about 1 fm at most.

Various mating metals can be used depending on the ceramics used, including titanium (Ti), cobalt (co), chromium (Cr), nickel (Ni) alone, alloys containing these, and iron. etc. can be used.

In order to bond metal to ceramics whose surface is coated with the above mixed powder, two metals are applied to the surface coated with the mixed powder of the ceramic.
The pressure is applied at a pressure of kg/cr/I or more, preferably 5 kq/cd, and heat treatment is performed at at least 900° C. for 15 minutes or more. The atmosphere for this heat treatment may be air, but it is preferably carried out under a hydrogen-steam atmosphere. By processing in this way, it is possible to obtain a bonded body that is stable and has high adhesive strength even at high temperatures.

The present invention will be further explained below with reference to Examples.

Example 1 In the figure, on the surface to be joined of the shaft portion 2 of a gas turbine rotor 1 made of a sintered body of silicon nitride (813N4),
80 parts by weight of copper powder with a particle size of 6μ and 2 parts of titanium powder with a particle size of 5μ
0 parts by weight of the mixed powder is applied to a thickness of approximately 50μ. A main shaft 3 made of a Ni-Cr alloy, which is a shaft metal, is pressed against the surface of the shaft portion 2 to be joined, and heated at 1100° C. for 60 minutes. The heating atmosphere at this time may be air, but preferably hydrogen-
Perform in a water vapor atmosphere.

The resulting gas turbine rotor was subjected to a high-temperature rotation testing machine at a temperature of 1050°C and a rotation speed of 62,000 times/min.
After 50 hours, it was taken out and visually inspected, but no defects were found at the joint between the gas turbine rotor and the main shaft, that is, at the joint between the ceramic and the metal.

Example 2 A gas turbine rotor 1 made of silicon carbide instead of silicon nitride in Example 1 was used, and copper powder 90 with a particle size of 1 μm was used.
A mixed powder of 1.0 parts and 10 parts of titanium powder with a particle size of 2 μm was applied to the welded surface of the shaft portion 2 of the gas turbine rotor 1 to a thickness of 30 μm.
Ni −
15 at 1300°C while pressing the main shaft 3 made of Cr alloy.
The shaft portion 2 and the main shaft 3 were crimped together by heat treatment for a minute.

The resulting gas turbine rotor assembly was run at 0 to 60,000 revolutions per minute in a low-temperature rotation testing machine, and after 5,000 cycles, it was taken out and visually inspected, but no defects were found in the ceramic and metal joints. I couldn't.

Therefore, according to the method of the present invention, ceramics, especially non-oxide ceramics, and metals are bonded by pressure using a mixed powder that has copper and titanium as essential components and exhibits high wettability to ceramics, so that it can be bonded at high temperatures. It is possible to obtain a stable bonded body that is stable and has high adhesive strength, and does not decompose or oxidize at high temperatures. Furthermore, the method of the present invention does not require expensive equipment such as laser welding equipment or electron beam welding equipment as in the past, and is therefore suitable as an industrial method for joining ceramics and metals.

Furthermore, the method of the present invention can be used not only for rotating parts such as gas turbine rotors, but also for stationary parts such as gas turbine sea louds, nose cones, guide vanes, etc.
It can also be used to join camshafts, valve lifters, swirl chambers, and cam pieces.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an example of members to be joined in the method of the present invention. In the diagram, 1... Gas turbine rotor 2
......Shaft portion 3...Main shaft Patent applicant Toyota Motor Corporation (and one other person)

Claims (1)

[Claims] (1) A method for joining ceramics and metal, which comprises applying a powder containing copper and titanium as essential components to the surface of the ceramic to be joined, and applying pressure to the applied surface with metal and heat-treating the surface.