JPH02107579A - Joining method for ceramic - Google Patents

Abstract

PURPOSE:To tightly join ceramic without heating ceramic at high temp. by providing a specified layer contg. an electroless plating layer and a soldering material layer to the joint face of both a ceramic member and a metal-based member or the ceramic member and performing high-frequency induction heating therefor. CONSTITUTION:A ceramic member 1 coated with a first electroless plating layer 4 and a second soldering material layer 7 is engaged with an opposite joint member 10 and an inductor 12 is provided along the outer face of the part to be joined. High-frequency induction heating is exerted to melt the soldering material in the part to be joined. The melted soldering material is homogeneously mixed with the electroless plating layer and this mixture is uniformly diffused into the ceramic member and the opposite joint member and a tight joint face is formed. At this time, prescribed heating temp. and heating time can be controlled by setting the frequency and output of high-frequency, size, a shape and number of turns of the inductor.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for joining ceramics and metal or ceramic members together. More specifically, the present invention relates to a method for joining ceramics and metal or ceramic members of the same type, which can further improve the joining force.

[Conventional technology] Mechanical parts or space equipment parts used in internal combustion engines such as gas turbines and diesel engines at high temperatures and high loads, and bearings used under special conditions have high load resistance, heat resistance, corrosion resistance, and Ceramics are often used for the purpose of improving wear resistance and light weight.

In addition, ceramics have begun to be used in cutlery such as kitchen knives and knives due to their high cutting properties due to their ultra-high strength, wear resistance, corrosion resistance, and light weight.

However, since ceramics are difficult to process, it is generally difficult to manufacture highly accurate parts or large parts with complex shapes, and if you try to do it forcibly, it will be too costly.

In addition, since ceramics have low toughness, they are easily damaged by impacts such as drops or blows on knives, etc., and special care must be taken when handling them.

For this reason, attempts have been made to simplify manufacturing and reduce manufacturing costs by separately manufacturing multiple ceramic components or ceramic and metal or alloy components, and then joining and integrating these components to suit usage conditions. It is being done.

[Problems to be Solved by the Invention] Relatively small ceramic parts and cutlery have this structure, but gas turbine blades and engine parts shade are made of ceramics and 5111 metals or alloys such as iron, copper, aluminum, etc. Diffusion bonding, pressure welding, firing, brazing, etc. are performed.

Diffusion bonding requires large equipment, and since the joint of ceramic components and metal or alloy components is heated to near the melting point during bonding, there may be deterioration of function and quality due to structural changes, and accuracy and strength may be affected due to thermal deformation or thermal stress. This may cause low energy levels.

On the other hand, in II-welding, firing, brazing, etc., a large joint is required to ensure the joining force, and a large pressing force or fitting force is also required, which tends to cause distortion, residual stress, etc.

Apply high-temperature brazing to the joint surfaces of the parts and place high / I! A method of brazing by la conduction heating has been implemented. In order to obtain the necessary bonding force, this method involves covering a large area, which tends to cause distortion and residual stress due to high-temperature heating. Furthermore, when using a wax hod as an insert, the shape of the joining member is restricted.

Therefore, one object of the present invention is to provide a method that can firmly join a ceramic member and a metal or alloy member or a ceramic member without subjecting both members to high heat. It is.

[To solve the problem] In order to avoid the above-mentioned point L1, in the present invention, in the method of joining a ceramic member and a metal member or between ceramic members, at least one of the joining parts of the force member is used. An electroless plating layer of at least one of a conductive metal or an alloy and a brazing material layer formed by laminating layers of at least two different materials in an alternating manner are continuously provided, or one of the electroless plating layers is continuously provided. By providing the electroless plating layer on the joining surface of the members, providing the brazing material layer on the joining part of the other member, heating the joining part and its vicinity by high-frequency induction heating, and melting and diffusing the brazing material layer. A method of bonding force for ceramics is provided, which is characterized by bonding both members.

It is preferable to perform an etching treatment on one or both of the base surface of the part that will become the joint surface of the ceramic member and the base surface of the part that will become the joint part of the metal-based member (! (It is preferable to provide an electrolytic plating layer.

Even higher bonding strength can be obtained by creating a structure in which the ceramic member and the metal member or the ceramic members fit into each other.

[Function] As described in +lif, according to the joining method of the present invention, a ceramic member can be bonded by interposing a brazing material layer in which layers of at least two different materials are laminated in an alternating IE together with an electroless plating layer. and metal or ceramic members.

A method for joining ceramic members and metal members by using both an electroless plating layer and a brazing material layer is disclosed in Japanese Patent Application Laid-Open No. 60-2008.
It is disclosed in Publication No. 89. However, with this method, M
An electroless plating layer is formed through the o -M n coating layer, and the brazing material layer is also N1-P amorphous 7.
This is the middle layer of 1, and is manifested as the NoJ method of the present invention.

In fact, by comparing +1 with the row material of the layer, a row material layer formed by laminating two or more types of hole materials in a j! 1 (It has been discovered that the bonding strength can be greatly increased when used in combination with an electrolytic plated layer, and that distortion of both members can be suppressed by selecting an appropriate bonding temperature that is relatively low.

[Example] Hereinafter, specific examples of the present invention will be described in detail with reference to the drawings.

Ceramics are electrical insulators or highly electrically resistive materials, and it is extremely difficult to apply a metal coating directly to them by electroplating or brazing.

Therefore, in the present invention, the surface of the ceramic base is chemically etched to form micropores necessary to obtain a strong coating. When a metal and/or alloy is electrolessly etched onto the surface of a ceramic base material having fine pores, the metal and/or alloy becomes
It penetrates into the holes and forms an extremely strong electroless plating layer due to the so-called "anchoring" effect. However, this etching process is not essential to the present invention. Glass ceramic.

If the surface of the material is inherently rough, such as clay, direct electroless plating can provide the anchoring effect of the plating layer.

To perform chemical corrosion (etching), use caustic alkali,
Hydrofluoric acid, hydrofluoric acid, etc., and nitric acid, hydrofluoric acid, etc. are used.

For example, a solution consisting of sodium hydroxide (NaOH, 200 g) and sodium fluoride (NaF, 100 g/λ) is heated to 140'C, and a ceramic material mainly composed of aluminum and alumina (AJ!203) is added to the solution. By soaking for about 25 minutes, erosion pores are formed in the sintered grain boundaries of Aλ203. Erosion hole is approximately 0.5μ
It has a hole diameter and depth of approximately 10 μm to 10 μm, and can sufficiently provide an anchoring effect for the metal to be plated. The maximum depth of the hole is preferably approximately the same as the thickness of the electroless plating layer covering the hole. The depth of the pores can be controlled by the etching solution concentration, temperature, immersion time, etc.

In order to form a metal and/or alloy coating on ceramics that have undergone etching treatment, it is preferable to use an electroless plating (chemical plating) method that performs chemical substitution and self-reduction.

To perform electroless plating directly on ceramic materials, N+
+ N+ Co+ Ag+ Au+ Cu+ Pd
+Sr1 etc. can be used, but Ni is precipitated in the etched micropores of the ceramic material and is required for anchoring strength.
and its alloys are most preferred.

Electroless plating generally involves (1) susceptibility, (reaction acceleration), (2) catalyst activation, and (3) chemical plating.
It consists of steps.

First, metal Pd, which serves as a catalyst for chemical plating, is precipitated in micropores on the surface of the ceramic, and then chemical plating is performed. The ceramic material treated in this way is treated with 5% tin of tin chloride.
~20g and 50-200mJ of hydrochloric acid (12N)! /J
! It is immersed in an aqueous solution consisting of for about 1 to 5 minutes at a temperature of 20 to 50°C.

Next, this ceramic was washed with water for 1°, and then added to a catalyst activation solution (an aqueous solution of 100,100 O consisting of 0.05 to 0.1 g of palladium chloride and 10 to 50 molar hydrochloric acid at a temperature of 20 to 50'C, about Immerse for 1 to 5 minutes.In this way, ultrafine particles f of metallic palladium reduced by the stannous chloride are deposited on the surface of the ceramic material.

After the ceramics are soaked in water for 1 min to remove residual chloride ions, a nickel coating is deposited in a chemical nickel plating bath. In a chemical nickel plating bath,
Metallic palladium precipitated on the material at a temperature of 60 to 95°C reacts with Ni-nogel ions in the chemical nickel bath as an initial reaction, precipitating metal nickel on the ceramic surface,
Next, further nickel is reduced and precipitated on the nickel surface 1-. By controlling factors such as the temperature, hydrogen ion concentration, and immersion time of the chemical nickel bath, it is possible to form the electroless nickel coated first layer with a film thickness of 70%.

FIG. 1 shows a cross-sectional structure of a ceramic member having an electroless plating layer formed in this way.

As shown in the figure, metal 3 deposited by electroless plating enters into micropores 2 formed by etching on one side of ceramic 1, exerting an anchoring effect. Metal is precipitated on the surface of these fine holes to form an electroless plating layer 4.

The material for forming this first layer (electroless plating layer) is N
In addition to i, Ni-Co, Ag+ Au+ CurPd, 8
However, according to Ni or Ni alloy -
・In terms of strength, the highest precipitation and anchoring strength of 19 materials can be obtained.

This first layer is heated at a predetermined temperature for 1 minute to a metal member (for example, shell metal or alloy) or a ceramic member to be bonded to the ceramic member on which the first layer is formed. A brazing material layer capable of thermal diffusion is formed by electroplating or electroless plating. The shape of the member is t
If it is a pure back surface, a brazing material layer can be formed by electroplating, but in the case of a complex shape such as a hole, it is generally not possible to form a brazing material layer unless electroless plating is used. It is difficult or impossible to form a material layer.
+J Noh.

Note that the second layer of brazing material is not necessarily j! ! (Electrolytic plating 1st
It is not necessary to continuously laminate the layers 1 and 2, but it can also be formed on the metal member or ceramic member that will be the mating member to be joined. Also, in this way, the joining phase T:
When a brazing material layer is formed on a member, the material surface of the material on which the brazing material layer is to be formed is processed to create micropores, and the brazing material is allowed to penetrate into these micropores. It is also possible to obtain a similar anchoring effect.

As the brazing material used, it is preferable to select a metal or alloy with a low melting point, taking into account the melting point of the joining member, especially the metal or alloy member, and prevention of thermal transformation during heating.

The Ag-Cu alloy is a complete solid solution between its two components over the entire region, and in particular, in the vicinity of 70 wt% Ag:30 wt% Cu, it becomes the best brazing material with a eutectic point of 780°C.

Therefore, as an example, using a ceramic member, metal, or alloy member having the first layer plated electrolessly as a cathode, Ag plated, plated, and Cu plated are alternately plated for each layer 2 to 3.
The layers are stacked to a thickness of .mu.m, and multilayer plating is performed so that the Ag:Cu ratio becomes a predetermined ratio (7:3 at a melting point of 780.degree. C.).

The alloy mixing ratio can be controlled not only by changing the number of laminated layers but also by changing the film thickness.

FIG. 2 shows the cross-sectional structure of a ceramic member plated with Ag-Cu brazing material. As shown! !
A second brazing material layer 7 is formed by stacking an Ag brazing material 5 and a Cu brazing material 6 in an alternating manner on the first electroplated layer 4.

The overall thickness of the brazing material plating layer depends on the required bonding force.
It can be appropriately selected within the range of 5 to 100 μm.

Metal diffusion between Ag and Cu occurs gradually over time even at room temperature, but it progresses rapidly from around 250°C, and at the eutectic point, the electroless plated metal of the first layer (for example, Ni) and the bonding partner It also diffuses into metal parts or ceramic parts and completely brazes them.

Typical brazing materials that can be used in the present invention are listed in Table 1 below.

We have described an example in which an electroless plating layer and a brazing material layer are continuously laminated only on one ceramic member, but the electroless plating layer and brazing material layer are also laminated on the other metal or ceramic member to be joined. Of course, it is also possible to laminate layers of materials.
iJ Noh. In this case, it is necessary to adjust so that a desired brazing material layer is formed by the sum of the brazing material layer of one joining member and the brazing material layer of the other joining member.

Next, the joining stages of the members will be explained.

As shown in FIG. 3, the ceramic sock member 1 coated with the first layer 4 of electroless plating and the second layer 7 of brazing material is engaged with the mating member 10, and an induced r
12 are aligned and high-frequency induction heating is applied to melt the brazing material on the joint surface. The molten brazing material is homogeneously bonded to the electroless plating layer and diffused uniformly into the ceramic member and the mating member to form a strong bonding surface.

At this time, the heating temperature and heating time can be controlled to a predetermined value by setting the high frequency, the size, shape, and number of turns of the protruding flange inductor according to the structure, J method, and material of the mountain member. .

Additionally, the frequency added to the high frequency inductor is generally 1
It is within the range of ~1000 kHz, and can be appropriately selected depending on the material and shape of the joining member and the J method.

By appropriately controlling the output of the high-frequency induction Y- according to the melting temperature of the brazing material at 71 degrees and the size of the joining members, heating and joining can be carried out within a short period of several seconds to several minutes.

The method of the present invention and the conventional method were compared with respect to the bonding strength of members having the shape shown in FIG.

AJI203 was used as the ceramic member, and mild steel was used as the metal member. The bonding surface of the ceramic member is etched and made of N1-P, with a film thickness of 2~
An electroless plating layer of 5 tt m was formed, and Ag and Cu were further alternately laminated on this layer (3 layers of Ag + 2 layers of Cu, total of 5 layers), and the small ht ratio of Ag:Cu was 7. Brazing material layers with film thicknesses of 20, 30, 40 and 60 μm were formed. The joint surface of the metal member is brought into contact with this joint surface, and an inductor (frequency: 200 kHz) is applied from the outer periphery of the joint to approximately 5
It was heated for seconds to melt and diffuse the brazing material to join both members together. On the other hand, as a comparative example, an Ag-Cu alloy brazing material whose heavy absorption ratio was adjusted to about 7=3 was coated with the same electroless plating layer as above in the form of one layer with the same film thickness as above. They were laminated and bonded under the same conditions as above. The joining member of the present invention and the joining member of the comparative example were subjected to an Amsura tensile compression tester to measure the joining strength. As a result, the bonding strength of the bonding member of the present invention was 120 MPa on average, whereas the bonding strength of the bonding member of the comparative example was only 80 MPa on average.

From the facts in 1-1 below, extremely excellent bonding strength can be obtained when a brazing material layer formed by laminating two or more types of +fit materials in an intersecting manner according to the method of the present invention is used in combination with an electroless plating layer. It is understood that what is gained.

The joining method shown in FIG. 4 is used for joining alloy steel and ceramics. Inner diameter surface 16 of alloy steel 14
A brazing material layer 18 made of Ag-Cu (7:3) was laminated thereon to a thickness of 20±1 μm by electroless plating. - The outer diameter surface 20 of the collar ceramic boss 1 is made of Ni90% PI.
An electroless plating layer 22 consisting of 0% was formed. The inner diameter surface 16 of the alloy steel 14 is fitted to the outer diameter surface 20 of the ceramic boss 1 by F heating described below, and the inner diameter surface 16 of the alloy steel 14 is fitted along the outer circumference of the joint part of the alloy steel 14. , the induction 7'12 of the frequency induction heating device was placed. The alloy steel 14 is suitably thermally expanded by high-frequency induction heating (child heating), the ceramic boss 1 is inserted as shown in the figure to integrate both members, and induction heating is performed for several seconds to several minutes using induction T12. By melting and diffusing the brazing material to obtain a strong bonding force, and at the same time shrinking the alloy steel by cooling (for example, air cooling, quenching cooling with oil or water), the fitting force between the alloy steel and ceramics is synergized, Furthermore, even higher bonding strength (bonding strength of 180 MPa in the experimental example) can be obtained. In addition, the shrinkage of the alloy steel imparts appropriate compressive stress to the ceramic joint surface, making it possible to increase the fatigue strength of the ceramic.

As a result, bonding can be achieved by simply heating locally for a short time (several seconds to tens of seconds within the film) at a relatively low temperature of about 250 to 1200 degrees Celsius, resulting in poor structural function and quality, and deformation.
It is possible to suppress noise, etc. to a minimum.

In addition, in the joining method as shown in FIG. 4, it is preferable to determine the inner diameter of the alloy steel and the outer diameter of the ceramic boss so that an appropriate tightening force can be obtained by cooling after joining.

The ceramic member in the case of Ijf is S iN4 +
SiC, AJ! 203.2r02. It is constructed from commonly used ceramic materials such as PSZ. Furthermore, alloy steels include heat-resistant steel, high-strength steel, and structural steel.

Naturally, alloys other than these can also be joined to the ceramic member by the method of the present invention.

FIGS. 5(a) and 5(b) show examples of application to cutlery such as knives and kitchen knives.

In FIGS. 5(a) and (b), 22a and 22
For b, it is preferable to use a metal member such as alloy steel, stainless steel, titanium, or titanium alloy, which is rich in rigidity and has a high fatigue strength. Further, it is preferable to use ceramic members with high hardness and high wear resistance such as Zr01PSZ1A, 11203, and Siathrone for 24a and 24b.

In FIG. 5(a), a first layer of electroless plating with a thickness of 5 μm consisting of 90% Ni and % PIO is laminated on the bonding surface side of the ceramic member 24a by electroplating. Then, a second brazing material layer having a ratio of 7:3 and a thickness of 20 μm was continuously formed.

On the other hand, in FIG. 5(b), an electroless plating layer having the same structure as described above is formed on the joint surface side of the ceramic member 24b,
A brazing material layer having the same structure as described above was formed on the joint surface side of the metal member 22b by electroplating.

As shown in FIGS. 5(a) and 5(b), when fitting both members, each M
It is preferable to adjust the outer diameter or inner diameter of the material.

The high frequency inductor 12 is placed along the junction j1≦outer circumference and heated. The inductors are arranged so that each joint surface is evenly heated and heated, and the applied voltage and current are controlled so that an appropriate heating temperature and heating rate are obtained. When each bonding surface reaches approximately the melting temperature, a load Pl or P2 that applies an appropriate surface pressure to the bonding surfaces of the metal members 22a and 22b and the ceramic members 24a and 24b is applied to bring both members together.
? While heating, induction heating is performed to join both parts.

The highest bonding strength can be obtained by cooling the brazing material after melting and spreading. In particular, in FIG. 5(a), a clamping force is applied to the ceramic member due to contraction of the metal member due to cooling after joining, so that a layer-like joining is achieved.

This method uses relatively low/1.1 (500-800°C
), it is possible to join both parts by local heating for several seconds to several tens of seconds, so the distortion of the ceramic or metal parts is small, preventing deterioration of functions such as machinability and strength, and post-addition. ■It is possible to suppress the increase in the number of conjuncts (due to the addition of 2, etc.).

FIGS. 6(a) and 6(b) show a joining method when the joining surfaces are relatively long.

FIG. 6(a) shows a ceramic member 30 and a metal member 32.
In this method, the inductor 12 is moved along the bonding surface while the inductor is maintained in a fixed state. FIG. 6(b) is a method in which the inductor is maintained in a fixed state and the bonding member is moved. In either method, the output of the induction Y-12 is adjusted appropriately, the metal member 32 is heated, and after it expands, the ceramic member 30 is inserted to the deepest part of the hole drilled in the metal member. If both members are then joined together, an extremely high joint strength similar to the case shown in FIG. 4 described above can be obtained.

For joining, the frequency and moving speed of the inductor are appropriately selected, each part of the joint surface is heated to a specified temperature for 5 yen, and the temperature is maintained for the time necessary for melting and diffusion of the brazing material, and the brazing material is oxidized. It is preferable to prevent deterioration caused by the like.

[Effects of the Invention] As explained above, according to the method of the present invention, ceramics can be made by interposing a brazing material layer formed by alternately laminating layers of at least two different materials together with an electroless plating layer. Joining a member and a metal member or a ceramic member.

Compared to the middle layer brazing material, when a brazing material layer formed by alternately laminating two or more different materials is used in combination with an electroless plating layer, the bonding strength is significantly increased.

Further, by setting the bonding temperature to a relatively low temperature, distortion of the bonded member can be suppressed.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a ceramic member with an electroless plated layer formed after etching, and Figure 2 is a cross-sectional view of a brazing material layer laminated on top of the electroless plated layer. 3, 4, 5(a), and 5.
FIG. 6(b), FIG. 6(a), and FIG. 6(b) are schematic diagrams showing a method of joining a ceramic member and a metal-based member or a ceramic member. ■... Ceramic member, 2... Fine pore, 3...
Deposited metal, 4...jjg electrolytic plating layer, 5...Ag
layer. 6... C, u layer, 7... Brazing material layer, 10... Other joining member, 12... Guiding blades 122a, 22b and 32... Metallic material, 24 at 24 b and 30 b...Ceramics member

Claims (3)

[Claims] (1) In a method for joining a ceramic member and a metallic member or ceramic members to each other, at least one of the members is provided with an electroless plating layer of at least one of conductive metals or alloys on the joining surface, and at least two types of electroless plating layers. Alternatively, the electroless plating layer may be provided on the bonding surface of one member and the brazing material layer may be provided on the bonding surface of the other member. A method for joining ceramics, comprising: providing a layer, heating the joint surface and its vicinity by high-frequency induction heating, and melting and diffusing the brazing material layer to join both members. (2) The electroless plating layer or brazing material layer should be provided after etching at least one surface of the base surface of the part that will be the joint surface of the ceramic member or the base surface of the part that will be the joint surface of the metal-based member. Claim 1
The described method for joining ceramics. (3) The method for joining ceramics according to claim 1, characterized in that the ceramic member and the metal member or the ceramic members are prepared in advance in a structure in which they fit into each other.