JPH07124783A - Joining method - Google Patents

Abstract

PURPOSE:To prevent the generation of the joint defect occurring in mispositioning by placing blocks having the coefft. of thermal expansion larger than the coefft. of thermal expansion of respective members on these members and bringing these blocks into contact with each other before melting an insert material. CONSTITUTION:A first block 1A and a second block 1B made of mild steel having the coefft. of thermal expansion larger than the coefft. of thermal expansion of superhard steel are placed on the members (superhard) 2A, 2B which are the first and second materials to be joined in the state of bringing the blocks into contact with each other. These blocks are thereafter joined by heating in a vacuum furnace. As a result, the mispositioning at the time of setting the materials to be joined and the mispositioning by thermal deformation during heating up of the materials to be joined are easily corrected without touching the materials to be joined during the course of joining. The generation of the joint defect occurring in the mispositioning is prevented by correcting such mispositioning.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joining method, and more specifically, joining a base material having two or more joining surfaces adjacent to each other and a member having a corresponding joining surface via a stress relaxation material. Relating to the joining method.

[0002]

2. Description of the Related Art Ceramics and cemented carbides are materials excellent in heat resistance and wear resistance, so that they are used in the body of equipment and the like which require heat resistance and wear resistance. It is used as a member by joining it to a place where heat resistance and wear resistance of the main body are required. Of these, the latter joining uses are often used as tool members for cutting chips, drawing dies, crushers and the like.

When joining such ceramics or cemented carbide (member) and the body-constituting metal (base material), a brazing method is generally adopted as a joining method. At this time, the members and the base material often have large thermal expansion coefficients, and in this case, a joining method of joining via a stress relaxation material is often adopted. That is, the brazing method is generally a brazing material (insert material) such as silver brazing between the joint surfaces of the materials to be joined.
Is arranged and the materials to be joined are directly joined by heating and melting. However, when the above member and the base material are directly joined by such a method, it occurs due to the difference in thermal expansion coefficient between the two. Therefore, in order to relieve this residual stress, brazing is performed by interposing a stress relaxation material such as copper as an intermediate layer between the member and the base material to braze the member and the base material. In many cases, a method of indirectly joining via the is adopted.

[0004]

However, in the joining method of joining through such a stress relaxation material, the joining surface has two sections as in the case where the section shape of the joining surface is V-shaped or L-shaped. When they are adjacent to each other on one side or another, there are the following problems. As the stress relaxation material, usually, an integrated type that matches the shape of the joint surface is manufactured by machining and used, but at this time, it is necessary to machine so that the size and shape accuracy are good. Therefore, the cost becomes very high. When the size and shape accuracy of the stress relaxation material obtained by the above-mentioned machining are not sufficient, there is a gap in the bonding surface at the time of bonding, and the positional relationship between the bonding surface and the stress relaxation material shifts, That is, there is a deviation (hereinafter, referred to as a positional deviation) from an accurate positional relationship between the joint surface and the stress relaxation material, which causes a joint defect. If you use a stress relaxation material (flat plate) that is divided for each surface that constitutes the joint surface instead of an integrated type, the number of parts will increase and the work of setting will be complicated and misalignment will occur easily. Become.

Therefore, studies have been made to solve these problems, and as a result, an integrally formed stress relaxation material that matches the shape of the joint surface is manufactured by molding rather than machining, and this is annealed. After that, a joining method characterized by being used as a stress relaxation material by arranging it between joining surfaces has been developed (Japanese Patent Application No. 4-197459).

According to this joining method, the size and shape of the stress relaxation material are excellent. Therefore, by accurately setting the stress relaxation material between the joining surfaces so that there is no positional deviation,
The problems described above and can be solved. However, it is not always easy to accurately set such a stress relaxation material, and therefore a positional deviation becomes large or small at the time of setting, and due to this positional deviation, there is a gap in the joint surface, and as a result, There is a problem that defects may occur. It should be noted that there is a problem in that, in order to realize the accurate setting of the stress relieving material, skill is required for setting and very time is required.

Even if there is no positional deviation during the above setting, when the materials to be joined (after being set) are heated during joining, the positional deviation occurs due to the thermal deformation that occurs during the temperature rise. As a result, there is a problem that a bonding defect may occur.

By the way, the brazing method includes a method of hand brazing in the atmosphere such as high frequency brazing and a method of brazing in a furnace such as vacuum brazing. Recently, the former is shifting to the latter. Therefore, the frequency of adopting the latter is increasing. In the former case, in the case of hand brazing, the material to be joined can be touched even during joining, so even if there is a positional deviation during setting, this positional deviation is corrected by correcting it during heating and melting of the insert material. You can However, in the latter case of brazing in a furnace, it is not possible to touch the material to be joined during joining, so the positional deviation at the time of setting and the positional deviation due to thermal deformation during temperature increase may occur during heating and melting of the insert material. It cannot be corrected. Therefore, in the latter case, if there is a positional deviation at the time of setting or a positional deviation due to thermal deformation during temperature rise, these cannot be corrected and there is a problem that a bonding defect is likely to occur.

The present invention has been made in view of such circumstances, and an object thereof is to stress a base material having two or more adjacent bonding surfaces and a member having a corresponding bonding surface. When joining through the relaxation material, it is easy to do without touching the material to be joined during the joining, and to avoid misalignment during setting of the material to be joined and displacement due to thermal deformation during heating of the material to be joined. Even if joining is performed by brazing in a furnace for that purpose, it is possible to correct these positional deviations and correct them, and as a result, it is possible to prevent the occurrence of joining defects due to positional deviations. It is intended to provide a method.

[0010]

In order to achieve the above object, the joining method according to the present invention has the following constitution. That is, the joining method according to claim 1 joins each of a base material having two or more joint surfaces adjacent to each other and a member having a joint surface joined to the joint surface of the base material via a stress relaxation material. A pair of first treated materials in which a stress relaxation material is arranged between the surfaces and an insert material is arranged between the relaxation material and each bonding surface, and another one having the same configuration as the processing material A pair of second materials to be joined are arranged side by side with their respective joining surfaces facing each other, and a first block and a second block made of a material having a coefficient of thermal expansion larger than that of each member are arranged on each member. A joining method for placing a base material and a member through a stress relaxation material by placing them and heating them to heat and melt the insert material, wherein the first block and the second block are made of an insert material. The joining method is characterized in that they are brought into contact with each other before melting.

The joining method according to claim 2 is the joining method according to claim 1, wherein the blocks are brought into contact with each other when the first and second blocks are placed. The joining method according to claim 3 is the joining method according to claim 1, wherein the blocks are brought into contact with each other by thermal expansion of the first and second blocks that occur during the heating. The bonding method according to claim 4 is the bonding method according to claim 1, 2 or 3, wherein the cross-sectional shapes of the two adjacent bonding surfaces of the base material are V-shaped. The joining method according to claim 5, wherein an angle between two adjacent joining surfaces of the base material is 150 ° or less, and at least one of the joining surfaces has an inclination of 40 ° or less with respect to the horizontal. Claim 1,
The joining method is described in 2, 3, or 4. The joining method according to claim 6, wherein the inclination of each of the joining surfaces having the shortest distance among the joining surfaces to be opposed to each other with respect to the horizontal is 40 ° or less. Is the way.

[0012]

In the joining method according to the present invention, the first and second members to be joined as described above are arranged side by side, and each member is made of a material having a coefficient of thermal expansion larger than that of the member. The 1st block and the 2nd block are mounted, respectively, and these are heated. Then, these blocks are brought into contact with each other before the insert material is melted. Therefore, the blocks are pressed against each other by the thermal expansion of each block from the time point of contact between the blocks to the time point of melting the insert material, and further during the melting of the insert material. At this time, each block is mounted on each member, and each block has a higher coefficient of thermal expansion than each member. Therefore, in addition to the force in the direction of gravity (acting from the time of mounting each block), Horizontal force acts. The direction of this force is a direction to increase the distance between the members, and the magnitude of the force depends on the difference in the coefficient of thermal expansion between each block and each member, and between each block and each member. The size is in accordance with the friction coefficient of the.

During the melting of the insert material, there is almost no friction between the stress relaxation material and the members and the base material. Therefore, the horizontal force acting on the members causes the members to move horizontally and between the members. It is moved in the direction of increasing the distance. Therefore, this movement corrects and corrects the positional deviation at the time of setting the material to be joined and the positional deviation due to thermal deformation during the temperature rise of the material to be joined.

At this time, the excessive movement is a force in the antigravity direction due to the shape of the joint surfaces (not just a plane, but two or more joint surfaces are adjacent to each other), and the shape of the joint surfaces Some can be stopped mechanically, so you can prevent it. Furthermore, when arranging the first and second materials to be bonded with the bonding surfaces facing each other, by arranging the bonding surfaces having the smallest inclination angle with respect to the horizontal to be located at the shortest distance, The direction of the positional deviation when setting the material and the direction of the force acting on the member can be made opposite. That is, in the case of such an arrangement, the positional deviation at the time of setting occurs (is displaced) in the direction opposite to the direction of the force acting on the member. This is because, even when the insert material is set, the displacement of the direction of the force acting on the member is not stable due to the relationship with gravity as in the case of melting the insert material, and it is naturally corrected. This is because there is no positional deviation at the time of setting in the direction of the force acting on the above member. Therefore, the correction of the positional deviation is properly performed without excess or deficiency.

As described above, when the base material having two or more bonding surfaces adjacent to each other and the member having the corresponding bonding surface are bonded via the stress relaxation material, the position at the time of setting the material to be bonded is set. The displacement and the positional displacement due to the thermal deformation during the temperature rise of the materials to be joined can be properly corrected without excess or deficiency by the force of the block on the members acting on the members during joining. Therefore, such misalignment can be easily corrected without touching the materials to be welded during the welding, and even if the in-furnace brazing method is used, the misalignment is corrected and corrected. As a result, it is possible to prevent the occurrence of a joint defect due to the positional deviation.

The point of time when the blocks contact each other is before the melting of the insert material. If the blocks are not melted or contracted at that time when the insert material is melted or after melting (during cooling), This is because the force acting on the member disappears and the positional deviation cannot be corrected. Here, as a method of bringing the blocks into contact with each other before melting the insert material, in addition to a method of bringing the blocks into contact with each other when the blocks are placed on the member, when the blocks are placed, they are slightly separated from each other and heated. There is a method of bringing the blocks into contact with each other due to the thermal expansion of the blocks which sometimes occurs.

[0017]

【Example】

(Example 1) First bonded material and second processing target according to Example 1
The material to be bonded is shown in FIG. This first material to be joined A
Is a base material 4A having a joint surface having a V-shaped cross section and a member 2A having a joint surface corresponding to the base material 4A, and a stress relaxation material 3A and an insert material (not shown) are sandwiched between the joint surfaces. The second to-be-bonded material B is also the same. The bonding surface of the first material to be bonded and the bonding surface of the second material to be bonded face each other. The first
The base material 4 is shared by the material to be bonded A and the second material to be bonded B (the base material 4 is an integral type composed of the material 4A and the material 4B).

Here, the base material 4 (base materials 4A and 4B) is steel, a member.
2A and 2B were made of super hard material, the stress relaxation material 3A was made of copper, and silver solder was used as the insert material (each material is the same in the following examples). The dimensions of the upper surfaces of the members 2A and 2B are each 50 × 50 mm. The angle between adjacent joint surfaces is 1
40 °. In addition, the inclination of the joint surface that is the shortest distance between the opposing joint surfaces with respect to the horizontal (the inclination of the joint surface) is 14 °.
And the inclination of the other joint surface adjacent to the joint surface is 26 °. That is, the joint surfaces having the smallest inclination angle with respect to the horizontal are arranged so as to be located at the shortest distance. This is because the direction of the positional deviation when setting the materials to be joined is opposite to the direction of the force that the block exerts on the member when the insert material is melted. This is to do it.

A first block 1A and a second block 1B (dimensions: made of mild steel having a thermal expansion coefficient higher than that of cemented carbide) are placed on the members (carbide) 2A, 2B of the first and second materials to be joined. 55 × each
55 × 80 mm) was placed with the blocks in contact with each other as shown in FIG. Then, in a vacuum furnace at 870 ℃
It was heated to and joined (silver brazing). Such joining
After carrying out about 300 pieces of materials to be joined, an ultrasonic flaw detection test of the joined part was carried out on the obtained joined body,
It was confirmed that there were no joint defects and that all were healthy joints. Further, when these joined bodies were used as hammers for a crusher, cracking and peeling did not occur, and good crushing performance was exhibited.

For comparison, the above blocks were placed at a considerable distance without being brought into contact with each other, and were joined under the same heating conditions as above to obtain 100 joined bodies. As a result, defects were found in 7 (7%) bonded bodies. As a result of cutting them and investigating the cause of defect occurrence,
It was found that this defect was a bonding defect caused by a gap between the bonding surfaces caused by the positional deviation.

(Embodiment 2) First and second embodiments
The material to be bonded is shown in FIG. The first material to be bonded A includes a base material 4A having a bonding surface having an L-shaped cross section and a member 2A having a bonding surface corresponding to the base material 4A, and a stress relaxation material 3A between the bonding surfaces.
And the insert material is sandwiched between them, and the second processed material is also the same. And these 1st and 2nd to-be-joined materials are arrange | positioned along with each joining surface facing. Each material is the same as in the first embodiment.

On the members (carbide) 2A, 2B of the first and second materials to be joined, the first and second blocks 1A, 1A made of mild steel are formed.
1B was placed in a state where the blocks were in contact with each other as shown in FIG. 4, and then joined in the same manner as in Example 1 in a vacuum furnace at 870 ° C. to obtain 300 joined bodies. Then, when an ultrasonic flaw detection test similar to that in Example 1 was performed, it was confirmed that all the bonded bodies were sound. Further, when these joined bodies were applied to a cutting blade of a construction machine, cracks and peeling did not occur and they could be used favorably.

For comparison, the above blocks were placed at a considerable distance without being brought into contact with each other, and were joined under the same heating conditions as above to obtain 100 joined bodies, and an ultrasonic flaw detection test similar to the above was carried out. As a result, defects were found in 5 (5%) bonded bodies. As a result of cutting them and investigating the cause of defect occurrence,
It was found that this defect was a bonding defect caused by a gap between the bonding surfaces caused by the positional deviation.

(Example 3) Except for the following points, with respect to the materials to be bonded which were the same as those in Example 1, the blocks were similarly placed (as shown in FIG. 2) and the bonding was carried out under the same heating conditions. . The angle formed by the adjoining joining surfaces of the materials to be joined was changed as shown in Table 1. However, the inclination of the joint surface at the shortest distance was constant at 14 ° as in Example 1. When the materials to be joined were set, the joining surfaces of the base materials 4A and 4B and the joining surfaces of the members 2A and 2A were misaligned. That is, the position shift at the time of setting was consciously caused.

As a result, the angle formed between the joint surfaces is 150 °.
In the above cases, the positional deviation at the time of setting may remain in the same direction as the force acting on the above-mentioned member (the force acting on the member during the melting of the insert material). At that time, the positional deviation is corrected. Was not done. On the other hand, it was confirmed that the positional deviation at the time of setting is always corrected when the angle is 140 ° or less, and that the effect of the block on the member is always corrected by the force acting on the member.

Example 4 Except for the following points, a block was similarly placed (FIG. 6) on a material to be bonded (FIG. 5) similar to that of Example 1 and bonding was performed under similar heating conditions. It was The angle Θ ₁ formed between the adjacent joint surfaces was set to 60 ° as shown in FIG. The inclination of the joint surface at the shortest distance (θ ₂ shown in FIG. 7) was changed as shown in Table 2. However, Θ ₁ is constant (60 °). As in the case of Example 3, the positional deviation was consciously generated at the time of setting.

As a result, when the inclination Θ _{2 of the} joint surface is 45 ° or more, it is basically difficult to cause the positional deviation at the time of setting, so that it is almost unnecessary to mount the block on the member. On the other hand, if the angle is less than 45 °, a positional deviation at the time of setting is likely to occur, but this positional deviation was corrected, and it was confirmed that there is an effect of correction by the force acting on the member upper block.

[0028]

[Table 1]

[0029]

[Table 2]

From the results of Examples 3 and 4 described above, the present invention is particularly applicable when the angle between the joint surfaces is 150 ° or less and the inclination Θ _{2 of the} joint surface at the shortest distance is less than 45 °. It can be seen that the application of such a joining method is effective.

[0031]

EFFECT OF THE INVENTION The joining method according to the present invention has the above-described structure and functions, and a member having a base material having two or more adjacent bonding surfaces and a corresponding bonding surface. When joining and through the stress relaxation material, touch the material to be joined during the joining due to the positional deviation when setting the material to be joined and the positional deviation due to thermal deformation during heating of the material to be joined. It can be corrected easily and without compensation, and even when joining is performed by brazing in the furnace for that purpose, these misalignments can be corrected and corrected, and as a result, the occurrence of joint defects due to misalignment can be prevented. There is an effect that it becomes possible to do.

[Brief description of drawings]

FIG. 1 is a perspective view showing an outline of a material to be bonded according to a first embodiment.

FIG. 2 is a side sectional view showing an outline of a material to be bonded on which the block according to the first embodiment is mounted.

FIG. 3 is a perspective view showing an outline of a material to be joined according to a second embodiment.

FIG. 4 is a side sectional view showing an outline of a material to be joined on which a block according to a second embodiment is placed.

FIG. 5 is a perspective view showing an outline of a material to be joined according to a fourth embodiment.

FIG. 6 is a side sectional view showing an outline of a material to be bonded on which a block according to Example 4 is placed.

FIG. 7 is a diagram illustrating an angle Θ ₁ formed between the joining surfaces and an inclination angle Θ ₂ of the joining surfaces according to the fourth embodiment.

[Explanation of symbols]

1A--first block, 1B--second block, 2A, 2B--member,
3A, 3B--stress relaxation material, 4--base material, 4A, 4B--base material, A--first bonded material, B--second bonded material.

Claims (6)

[Claims] 1. Stress relaxation between each bonding surface of a base material having two or more bonding surfaces adjacent to each other and a member having a bonding surface bonded to the bonding surface of the base material via a stress relaxation material. Material to be treated and a set of first treated materials in which an insert material is disposed between the relaxing material and each joint surface, and another set of second treated materials having the same configuration as the treated material. The treatment material is arranged side by side with the respective bonding surfaces facing each other, and the first block and the second block made of a material having a coefficient of thermal expansion larger than that of the member are placed on the respective members, and these are placed. A joining method for joining a base material and a member through a stress relaxation material by heating and melting the insert material, wherein the first block and the second block are brought into contact with each other before the insert material is melted. Joining method characterized by. 2. The joining method according to claim 1, wherein the blocks are brought into contact with each other when the first and second blocks are placed. 3. The blocks are brought into contact with each other by thermal expansion of the first and second blocks generated during the heating.
The joining method described. 4. The bonding method according to claim 1, 2 or 3, wherein the cross-sectional shape of the two adjacent bonding surfaces of the base material is V-shaped. 5. The angle formed by two adjacent joint surfaces of the base material is 150 ° or less, and at least one of the joint surfaces has an inclination of 40 ° or less with respect to the horizontal. ,
The joining method according to 2, 3, or 4. 6. The joining method according to claim 1, wherein each of the joining surfaces having the shortest distance among the joining surfaces to be opposed has an inclination of 40 ° or less with respect to the horizontal.