JP2762558B2 - Method of joining ceramic member and metal member - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for joining a ceramic member and a metal member.

[Prior Art] Japanese Patent Application Laid-Open No. 58-55382 discloses that a ceramic member and a metal member are shrink-fitted and, before cooling down, to reduce the stress at the time of joining, a metal member is fitted with a fitting portion. A method of plating a soft metal in advance is disclosed.

[Problem to be Solved by the Invention] The present inventor has proposed a case in which a ceramic member and a metal member are used as a ceramic turbo rotor which is required to rotate at high speed in a high-temperature atmosphere. Assuming, a bonding strength test was performed using a plurality of test pieces in which the thickness of the soft metal plated on the fitting portion of the metal member was variously changed. As a result, in order to obtain a bonding strength that can withstand practical use as the ceramic turbo rotor, the thickness of the plated soft metal is 50 to 200 μm.
Those in the range of m were found to be preferred. Further, the thickness of the soft metal needs to be 200 μm or more in consideration of dimensional tolerance, shape tolerance, and the like at the time of machining the mounting portion.

However, the thickness of the metal part is 200μ by plating
In order to form a soft metal having a length of m or more, a long time (15 to 25 hours) is required for the plating process, which is disadvantageous in terms of cost.

The present invention provides a method for joining a ceramic member and a metal member that solves the above problems.

[Means for Solving the Problems] A method for joining a ceramic member and a metal member according to the present invention includes:
Forming a stress relaxation layer made of a soft metal on the inner surface of the concave fitting portion of the metal member; inserting a convex fitting portion of the ceramic member into the concave fitting portion of the metal member; In a method of joining a ceramic member and a metal member, the method comprising: joining a mating portion and a convex fitting portion of the ceramic member. The step of forming the stress relaxation layer includes forming the stress relaxation layer on the inner surface of the concave fitting portion of the metal member. A first step of welding a soft metal to form a hardfacing part, a second step of shaving the exposed surface of the hardfacing part by machining to form an inner circumferential working surface, and applying a soft metal to the inner circumferential working surface. And a third step of forming a plated portion by plating.

The first, second, and third steps are for forming a stress relaxation layer made of a soft metal on the inner surface of the concave fitting portion of the metal member. This stress relaxation layer, when the convex fitting portion of the ceramic member is coupled to the concave fitting portion of the metal member,
This is for reducing the stress of the joint. That is,
Generally, a ceramic member has high rigidity and is brittle, so that localized concentrated stress is generated and is liable to break therefrom. The stress relieving layer relieves the localized concentrated stress.

The first step is a step of forming a built-up part by welding a soft metal into the concave fitting part of the metal member. The build-up portion is made of a soft metal and has a thickness of 200 μm or more. As the soft metal forming the overlay, copper, silver, nickel, and the like are preferable. The soft metal is formed in advance as a ring-shaped material, and after disposing the material along the inner surface of the concave fitting portion of the metal member, the soft metal is melted by a high-frequency heating device, an ultrasonic welding device, etc. It can be welded and built up on the inner surface of the part.

The second step is a step of shaving off the exposed surface of the built-up portion formed in the first step by machining to form an inner peripheral processed surface. It is preferable that the amount removed by the mechanical processing is such that a thickness of 50 to 200 μm of the built-up portion after the removal is left. The mechanical processing can be performed using a processing device such as cutting or grinding.

The third step is a plating step of forming a plated portion by plating a soft metal on the inner peripheral processing surface formed on the overlay portion in the second step. As the soft metal forming the plated portion, it is preferable to use a metal such as copper or gold or silver. A stress relieving layer is formed by the plated portion and the built-up portion having an inner peripheral processed surface formed in the second step. For this reason, the thickness of the plating part is the thickness of the entire stress relaxation layer.
Various settings can be made by changing the thickness occupied by the built-up portion whose exposed surface has been cut off in the second step. Further, the thickness of the plated portion is set to 5 to reduce the time required for the plating process.
It is desirable to set it within the range of μm to 20 μm. The plated portion is effective for increasing the filling efficiency of the brazing material.

[Operation and Effect] The method for joining the ceramic member and the metal member of the present invention is as follows.
Inserting the convex fitting portion of the ceramic member into the concave fitting portion of the metal member, and performing a step of forming a stress relaxation layer made of a soft metal on the inner surface of the concave fitting portion of the metal member prior to coupling, the first step, The second step and the third step are performed in this order.

In the first step, a ring-shaped overlay material made of a soft metal and a metal member having a concave fitting portion to be overlaid in advance are prepared before the overlay process. Then, the overlay material is arranged in the concave fitting portion of the metal member, and is heated and welded to the inner surface of the concave fitting portion to form the overlay portion in a short time.

In the second step, the exposed surface of the overlay is machined away to form an inner peripheral processed surface.

In the third step, the soft metal is plated on the inner peripheral processing surface of the built-up part formed in the second step, and a plated part is formed in a short time.

In this way, a stress relaxation layer made of a soft metal is formed on the inner surface of the concave fitting portion of the metal member. Thereafter, the convex fitting portion of the ceramic member is inserted into the concave fitting portion of the metal member, and the two members are integrally joined by shrink fitting, cold fitting, brazing using a brazing material, or the like. Is done.

The stress relieving layer formed by the bonding method of the present invention includes the build-up portion formed in the first step and the second step,
Since it is composed of two layers including the plated portion formed in the process, the remaining portion obtained by subtracting the thickness occupied by the built-up portion can be used as the thickness of the plated portion in the entire stress relaxation layer.

The thickness of the plated portion can be reduced by the presence of the build-up portion, and the plating time in the third step can be reduced. Therefore, when the present coupling method is used, the process time for forming a stress relaxation layer having a thickness capable of sufficiently relaxing localized concentrated stress can be greatly reduced, which is advantageous in terms of product cost. .

[Embodiment] A method of joining a ceramic member and a metal member according to an embodiment of the present invention will be described with reference to FIGS.

The method of joining the ceramic member and the metal member is as follows.
As shown in the figure, it is used in a process of manufacturing a ceramic turbo rotor 6 including a metal member 1 and a ceramic member 4.

The metal member 1 includes a rotating shaft 12 made of a steel material, and a metal ring 14 integrally fixed to a tip of the rotating shaft 12 by welding.

The metal ring 14 has a concave fitting portion 15 as shown in FIG. 2, and a stress relaxation layer 2 made of copper as a soft metal is formed on an inner surface 16 thereof. The stress relaxation layer 2 is formed by connecting the metal ring 14 to the rotating shaft 12.
The first step, the second step, and the third step are performed in this order before being integrally fixed to the front end of the substrate.

In the first step, as shown in FIG.
The metal ring material 14a on which 15 is formed is mounted on a fixed mounting table (not shown) inside the coil 7 of the high-frequency heating device. The shape of the metal ring material 14a is a bottomed cylindrical body having a through hole at the center bottom surface. A ring-shaped overlay material 20 made of copper as a soft metal is arranged on the inner surface 16 of the concave fitting portion 15.
This cladding material 20 has a circular cross section of 1.3 m in diameter.
m. The high frequency heating device heats and melts the cladding material 20 and welds it to the inner surface 16 of the concave fitting portion 15 of the metal ring 14b, as shown in FIG.
21 is formed. The time required for overlaying in the first step is about 1 minute.

In the second step, the exposed surface 21a of the build-up portion 21 is cut off by machining to the metal ring 14b taken out from the high-frequency heating device as shown by a two-dot chain line in FIG. An inner peripheral processing surface 22 is formed (see FIG. 5). The time required for machining in this second step is about 35 seconds.

In the third step, the inner peripheral processing surface formed in the second step
A metal ring 14c having 22 is disposed in a plating apparatus (not shown), and the inner peripheral processing surface 22 is plated with copper having a thickness of 5 μm to 20 μm to form a plating portion 23 as shown in FIG. The time required for the plating process in the third step is about 5 minutes.

As a result, the inner surface 16 of the concave fitting portion 15 of the metal ring 14 has a built-up portion 21 having an inner peripheral processed surface 22 and a plated portion 23 plated on the inner peripheral processed surface 22. Is formed.

As described above, in the present embodiment, the processing time for forming the plated portion 23 in the third step can be completed in about 5 minutes, and is necessary for forming a copper plating layer having a thickness of 200 μm or more.
The processing can be completed in an extremely short time as compared with the time. The total time of the first to third steps is a very short processing time of about 6 minutes and 35 seconds. This allows the metal ring
The process time for forming the stress relaxation layer 2 in FIG. 14 can be greatly reduced.

After the step of forming the stress relaxation layer 2 made of a soft metal on the inner surface 16 of the concave fitting portion 15 of the metal ring 14 has been completed in this manner, the protrusion of the ceramic member 4 is formed on the concave fitting portion 15 shown in FIG. Inserting the shape fitting portion 40, heating the concave fitting portion 15 of the metal ring 14 and the convex fitting portion 40 of the ceramic member 1 and flowing and filling the molten brazing material 3 into the gap between the two. After that, the step of solidifying the brazing material 3 and the rotating shaft contacting the bottom outer wall surface 17 of the metal ring 14 shown in FIG.
And a step of integrally joining the front end face 12a of the base member 12 by welding to form the ceramic turbo rotor 6. In this embodiment, the exposed surface of the stress relieving layer 2 of the metal ring 14 is formed by plating the inner peripheral processing surface 22 of the built-up portion 21.
23. Therefore, the molten brazing material 3 flows into the gap between the ceramic member 1 and the convex fitting portion 40,
At the time of filling, the brazing material 3 can quickly move to every corner along the surface of the plated portion 23, and the filling efficiency can be improved.

(Comparative Example) For comparison, as shown in FIG. 7, the convex fitting portion 40 of the ceramic member 4 is inserted into the concave fitting portion 15 by using the metal ring 14c which does not perform the third step of the embodiment of the present invention. And a step of heating the concave fitting portion 15 and the convex fitting portion 40, flowing the molten brazing material 3 into a gap between the two, and then bonding the brazing material 3 by solidification. The test was performed, and 100 test pieces each made of a combination of the ceramic member 4 and the metal ring 14 were manufactured. Then, as a result of observing the filling state of the brazing material 3 by longitudinally cutting 100 test pieces, 40 of the test pieces were not completely filled with the brazing material 3 in the gap.
40% of defective products were generated.

On the other hand, the convex fitting portion 40 of the ceramic member 4 is inserted into the concave fitting portion 15 by using the metal ring 14 which has been subjected to the first, second and third steps of the above embodiment. A step of heating the concave fitting portion 15 and the convex fitting portion 40, flowing the molten brazing material 3 into a gap between the two, and then bonding the solidified brazing material 3 by solidification. 200 test pieces each composed of a combination of the member 4 and the metal ring 14 were manufactured. Then, as a result of observing the filling state of the brazing material 3 by vertically traversing 200 test pieces, the brazing material 3 was completely filled in the gaps of all the test pieces,
The joint at the joint was good.

In this embodiment, as shown in FIGS. 1 and 2, after the metal ring 14 in which the stress relaxation layer 2 is formed in the concave fitting portion 15 is bonded to the ceramic member 4 as the metal member 1, Although the one in which the metal rotary shaft 12 is integrally connected to the outer peripheral end by welding is shown, the present invention is not limited to this, and the concave fitting portion 15 is integrally formed in advance at one end. The operation and effect are the same even when a metal rotating shaft is used.

[Brief description of the drawings]

1 to 6 are explanatory views of the present embodiment. FIG. 1 is a side view showing an example of use after a ceramic member and a metal member are joined, and FIG. 2 is a concave fitting of a metal ring. FIG. 3 is a longitudinal sectional view showing a state in which a stress relaxation layer is formed in the joining portion, FIG. 3 is a longitudinal sectional view showing a state in which a cladding material is arranged in a concave fitting portion of the metal ring, and FIG. FIG. 5 is a longitudinal sectional view showing a state in which a built-up portion is formed on the inner surface of the concave fitting portion of the metal ring. FIG. 5 is a diagram showing a metal ring in which the built-up portion in FIG. FIG. 6 is a partially enlarged longitudinal sectional view showing a state in which a convex fitting portion of a ceramic member is inserted and connected to a concave fitting portion of a metal ring, and FIG. 7 is a metal ring of a comparative example. 5 is a partially longitudinal enlarged view showing a state where a convex fitting portion of a ceramic member is inserted and coupled to the concave fitting portion of FIG. DESCRIPTION OF SYMBOLS 1 ... Metal member, 15 ... Concave fitting part 16 ... Inner surface of concave fitting part 2, ... Stress relief layer 20 ... Overlay material, 21 ... Overlay part 22 ... Inner peripheral processing surface, 23 plating part 3 brazing material 4 ceramic member 40 convex fitting part

Continued on the front page (72) Inventor Toru Shimada 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Kazuhisa Sanpe 1 Toyota Town Toyota City, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (56) Reference Document JP-A-58-55382 (JP, A) JP-A-63-97378 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C04B 37/02 F01D 5/04

Claims (1)

(57) [Claims] A step of forming a stress relaxation layer made of a soft metal on an inner surface of the concave fitting portion of the metal member; a step of inserting a convex fitting portion of the ceramic member into the concave fitting portion of the metal member; In a method for joining a ceramic member and a metal member, the method comprising: joining a concave fitting portion of a metal member and a convex fitting portion of the ceramic member. A first step of welding the soft metal to the inner surface of the joining portion to form a built-up portion; a second step of shaving the exposed surface of the built-up portion by machining to form an inner peripheral processed surface; A third step of plating a soft metal on the surface to form a plated portion. A method of joining a ceramic member and a metal member, the method comprising: