JP6796839B2 - Linear friction stir welding method and linear friction stir welding equipment - Google Patents

Description

The present invention relates to a linear friction stir welding method and a linear friction stir welding apparatus for solid-phase bonding of metal materials.

As the strength of metal materials such as steel and aluminum alloys increases, the decrease in strength at joints, which determines the mechanical properties of joint structures, has become a serious problem. On the other hand, in recent years, a solid-state joining method in which the maximum temperature reached during joining does not reach the melting point of the material to be joined and the decrease in strength at the joint is smaller than that of conventional melt welding has attracted attention and is rapidly put into practical use. It is progressing.

In particular, linear friction welding (LFW: Linear Friction Welding) in which metal members slide on a linear trajectory does not require the use of a tool like friction stir welding (FSW), so it is suitable for refractory metal. Can be easily applied, and is expected to be put into practical use in various industries.

However, the joining mechanism of linear friction stir welding and the appropriate process control method have not always been clarified, and the joining conditions for each material to be joined have been optimized based on numerous preliminary tests and experience. Is the reality.

On the other hand, for example, in Patent Document 1 (Japanese Unexamined Patent Publication No. 2015-164738), one member is repeatedly moved relative to each other on the same locus in a state where one member is in contact with the other member. Is a friction joining device for friction-bonding to the other member, and the one member becomes the other member from the generation of the stop command in accordance with a stop command for relative movement of the one member to the other member. On the other hand, a friction joining device is disclosed, which comprises a stopping means for stopping the relative movement of the one member with respect to the other member during the period until the locus is relatively moved once.

In the friction stir welding apparatus described in Patent Document 1, when one member is brought into contact with the other member and they are repeatedly moved relative to each other on the same locus for friction joining, a stop command for relative movement is issued. It is said that it is possible to easily identify when the relative movement of the two members is just stopped at the timing when the two members are in an appropriate joining state.

Japanese Unexamined Patent Publication No. 2015-164738

However, the friction stir welding method disclosed in Patent Document 1 shortens the period from the generation of the stop command to the stop of the actuator and controls the friction stir welding amount, and the minimum friction stir welding amount is sufficient. It does not form a joint having various joint characteristics.

In linear friction joining, the material to be joined is shortened by the amount discharged as burrs, so the joining should be stopped at the timing when a good joint is formed while minimizing the amount of burrs discharged. Is desired. However, there is no suitable way to determine the timing of the stop.

In view of the above problems in the prior art, an object of the present invention is a simple linear friction stir welding method and linear friction stir welding capable of forming a good joint portion while minimizing the amount of burr emission. To provide the equipment.

In order to achieve the above object, the present inventor pays attention to the situation where burrs are discharged as a result of intensive research on the observation method for confirming the progress of the joining process and the appropriate stop timing of sliding. Has been found to be extremely effective, and the present invention has been reached.

That is, the present invention
The first step of bringing one member into contact with the other member to form an interface to be joined,
With the pressure applied substantially perpendicular to the interface to be joined, the one member and the other member are repeatedly slid on the same locus, and the sliding direction is substantially parallel and substantially perpendicular to the sliding direction. The second step of discharging burrs from the interface to be joined,
It has a third step of stopping the sliding and forming a joint surface.
In the second step, the interface to be joined is observed from a direction substantially perpendicular to the sliding direction, and at the moment when the burr is discharged substantially parallel to the sliding direction, the third step is performed. Performing the stop in the process,
The present invention provides a linear friction stir welding method.

FIG. 1 shows a schematic diagram showing a situation during linear friction stir welding. Linear friction stir welding is a solid phase welding in which the frictional heat generated when the materials to be welded are rubbed against each other by linear motion is the main heat source. In the conventional linear friction stir welding, the material softened by the temperature rise is discharged as burrs from the interface to be welded to remove the oxide film formed at the interface to be welded, and the new surfaces are brought into contact with each other to bring the joints into contact with each other. Is said to be obtained.

The present inventor observed in detail the amount, direction and order of burrs discharged during the joining process of linear friction stir welding, and found that burrs were first discharged from the interface to be welded in a direction substantially perpendicular to the sliding direction. After that, it became clear that it was subsequently discharged from a substantially parallel direction. The burr discharge direction at the initial stage of joining, which is generally recalled, is substantially parallel to the sliding direction, but in reality, a different phenomenon occurs. In the present specification, both the "sliding direction and substantially vertical direction" and the "sliding direction and substantially parallel direction" are directions substantially perpendicular to the applied pressure.

It is considered that the temperature distribution of the interface to be bonded has a great influence on the direction and order in which burrs are discharged from the interface to be bonded. Specifically, the materials to be bonded are in constant contact with each other at the center of the interface to be bonded, and frictional heat is likely to be stored. As a result, the softening of the material to be joined first progresses in the region, and burrs are discharged from the shortest distance from the region, "a direction substantially perpendicular to the sliding direction".

Here, in linear friction stir welding, it generally takes 0.2 to 0.5 seconds for the member to completely stop moving after the sliding is stopped. By discharging the softened material (burrs) from all directions of the interface to be joined, it is possible to grasp that the entire surface of the interface to be joined has been joined, but when the movement of the member is stopped at the timing, Unnecessary burrs will be discharged. On the other hand, the present inventor evaluated the joints and mechanical properties of the joint obtained by stopping the sliding at various timings, and as a result, the moment when the burrs were discharged substantially parallel to the sliding direction. It was clarified that a good joint was formed while minimizing the amount of burrs discharged by executing the stop.

In order to accurately observe the moment when the burr is discharged substantially parallel to the sliding direction, it is necessary to observe the interface to be joined from a direction substantially perpendicular to the sliding direction. Therefore, in the linear friction stir welding method of the present invention, it is a constituent requirement to observe the interface to be welded from a direction substantially perpendicular to the sliding direction.

In addition, the present invention
The first step of bringing one member into contact with the other member to form an interface to be joined,
With the pressure applied substantially perpendicular to the interface to be joined, the one member and the other member are repeatedly slid on the same locus, and the sliding direction is substantially parallel and substantially perpendicular to the sliding direction. The second step of discharging burrs from the interface to be joined,
It has a third step of stopping the sliding and forming a joint surface.
In the second step, the interface to be joined is observed from a direction substantially perpendicular to the direction of sliding, and the burrs discharged substantially perpendicular to the direction of sliding are both ends of the interface to be joined. At the moment when the above is reached, the stop in the third step is executed.
Also provided is a linear friction stir welding method.

The burr discharge behavior during the joining process of linear friction stir welding is as described above, but if the stop is executed at the moment when the burr is discharged substantially parallel to the sliding direction, the oxide from the joining interface is oxidized. There are cases where the removal of the material is insufficient, and there are cases where the joint characteristics are slightly deteriorated depending on the type, shape and size of the material to be joined.

On the other hand, the interface to be joined is observed from a direction substantially perpendicular to the sliding direction, and the burr discharged substantially perpendicular to the direction of sliding reaches both ends of the interface to be joined. By stopping the movement, compared to the case where the sliding is stopped at the moment when the burrs are discharged substantially parallel to the sliding direction, the amount of burrs discharged is slightly larger, but the oxide is more reliably discharged. Can be achieved.

Here, by observing the interface to be joined from a direction substantially perpendicular to the sliding direction, the moment when the burr discharged substantially perpendicular to the sliding direction reaches both ends of the interface to be joined can be obtained. It can be easily grasped. Specifically, since the interface to be bonded emits light as the burr is discharged, the moment when the light emission reaches both ends of the interface to be bonded may be observed.

In the linear friction stir welding method of the present invention, it is preferable that the interface to be welded is square or rectangular. The method of determining the timing to stop sliding by observing the discharge of burrs can be applied to the material to be joined having various shapes, but when the interface to be joined is square or rectangular, the discharge direction of burrs. And the timing of discharge can be observed more easily.

Further, in the linear friction stir welding of the present invention, it is preferable that the sliding direction is a substantially short direction of the one member and / or the other member in the second step. By setting the sliding direction to the substantially short direction of one member and / or the other member, the area of the interface to be joined that is in constant contact during the sliding process as compared to the case of the substantially longitudinal direction. Becomes smaller. That is, the temperature gradient caused by the generation of frictional heat and the heat removal is larger when sliding in the substantially short direction, and as a result, the direction dependence on which burrs are discharged becomes more remarkable, and sliding is performed. It is possible to more easily observe the discharge of burrs, which is an index for stopping.

Further, in the linear friction stir welding of the present invention, it is preferable that the one member and / or the other member is an iron-based metal, titanium or a titanium alloy. By using an iron-based metal, titanium, or a titanium alloy for one member and / or the other member, it is possible to easily confirm the generation of burrs or the light emission accompanying the generation of burrs. In addition, it is possible to deal with thick plates that are difficult to join by the conventional solid phase joining method and melt welding method, and it is possible to effectively suppress a decrease in strength of the joined portion due to excessive heat input.

In addition, the present invention
After one member is brought into contact with the other member to form an interface to be welded, the one member and the other member have the same locus in a state where a pressure is applied substantially perpendicular to the interface to be welded. A linear friction stir welding device that repeatedly slides on the surface to stop the sliding after discharging burrs from the interface to be joined.
An observation device for observing the interface to be joined from a direction substantially perpendicular to the sliding direction, and the sliding stop at the moment when the burr is discharged substantially parallel to the sliding direction. A program for executing the sliding, or a program for stopping the sliding at the moment when the burr discharged substantially perpendicular to the sliding direction reaches both ends of the interface to be joined .
Also provided is a linear friction stir welding apparatus.

By using an observation device for observing the interface to be joined from a direction substantially perpendicular to the sliding direction, the above-mentioned linear friction joining method of the present invention can be easily used.

In the linear friction stir welding apparatus of the present invention, it is preferable to further include an observing apparatus for observing the interface to be welded from a direction substantially parallel to the sliding direction.

By using an observation device for observing the interface to be joined from a direction substantially parallel to the sliding direction, it is possible to more reliably observe the discharge behavior of burrs.

Further, in the linear friction stir welding apparatus of the present invention, it is preferable that the observation apparatus is a high-speed video camera. By using a high-speed video camera, it is possible to accurately grasp the timing of burr discharge, which is difficult to measure with the naked eye.

According to the present invention, it is possible to provide a simple linear friction stir welding method and a linear friction stir welding apparatus capable of forming a good joint portion while minimizing the amount of burrs discharged.

It is a schematic diagram which shows one aspect of the linear friction stir welding of this invention. It is a schematic diagram which shows the joining process of the linear friction joining of this invention. It is a high-speed video camera image observed from a direction substantially perpendicular to the sliding direction. It is a high-speed video camera image observed from a direction substantially parallel to the sliding direction. It is a cross-sectional photograph of the joint portion obtained in Examples 2 and 3 and Comparative Examples 1 to 4. It is the tensile strength of the joint obtained in Examples 2 and 3 and Comparative Examples 1, 2 and 4.

Hereinafter, a typical embodiment of the linear friction stir welding method and the linear friction stir welding apparatus of the present invention will be described in detail with reference to the drawings, but the present invention is not limited to these. In the following description, the same or corresponding parts may be designated by the same reference numerals, and duplicate description may be omitted. Moreover, since the drawings are for conceptually explaining the present invention, the dimensions of each component represented and their ratios may differ from the actual ones.

(1) Linear Friction Stir Welding Method FIG. 2 is a schematic view showing a joining process of the linear friction stir welding of the present invention. The linear friction joining method of the present invention includes a first step of bringing one member 2 into contact with the other member 4 to form an interface 6 to be joined, and a state in which pressure is applied substantially perpendicular to the interface 6 to be joined. Then, the second step of repeatedly sliding one member 2 and the other member 4 on the same locus and discharging the burr 8 from the interface to be joined substantially parallel to and substantially perpendicular to the sliding direction, and sliding are performed. It has a third step of stopping and forming a joint surface. Hereinafter, each step will be described in detail.

(1-1) First Step The first step is a step of bringing one member 2 into contact with the other member 4 to form an interface 6 to be joined. One member 2 and / or the other member 4 is moved to a position where the formation of the joint portion is desired, and the surfaces to be joined are brought into contact with each other to form the interface 6 to be joined.

The materials of one member 2 and the other member 4 are not particularly limited as long as the effects of the present invention are not impaired, and may have a metal phase that can be joined by linear friction joining, but iron-based metals and titanium. Alternatively, it is preferably a titanium alloy. By using an iron-based metal, titanium, or a titanium alloy for one member 2 and / or the other member 4, it is possible to easily confirm the generation of burrs 8 or the light emission accompanying the generation of burrs 8. In addition, it is possible to deal with thick plates that are difficult to join by the conventional joining method, and it is possible to effectively suppress a decrease in strength of the joined portion due to excessive heat input. In the present invention, the iron-based metal means a metal mainly composed of iron in its composition, and includes, for example, various steels and cast iron.

Further, since frictional heat is easily removed from metals having a higher thermal conductivity than iron and titanium, such as aluminum, magnesium and copper, linear frictional bonding may be difficult in some cases. However, since the order (direction) in which burrs are discharged due to high thermal conductivity becomes clearer, the present invention can be made by using one member 2 and / or the other member 4 as these metal materials. Linear friction stir welding can be used more accurately.

Further, the shape and size of one member 2 and the other member 4 are not particularly limited as long as the effects of the present invention are not impaired, and any one capable of achieving desired pressurization and vibration by a linear friction stir welding device. However, it is preferable that the interface 6 to be welded is square or rectangular. The method of determining the timing at which sliding is stopped by observing the discharge of the burr 8 can be applied to the material to be joined having various shapes, but when the interface 6 to be joined is square or rectangular, the second In the process, the discharge direction and discharge timing of the burr 8 can be observed more easily.

(1-2) Second step In the second step, one member 2 and the other member 4 are repeatedly slid on the same locus while a pressure is applied substantially perpendicular to the interface to be joined. This is a step of discharging the burr 8 from the interface 6 to be joined substantially parallel to and substantially perpendicular to the sliding direction.

The method of repeatedly sliding one member 2 and the other member 4 on the same locus is not particularly limited as long as the effect of the present invention is not impaired, and even if both members are vibrated together, one is fixed. And the other may be vibrated. Further, the process conditions for linear friction stir welding (applied pressure, frequency and amplitude of excitation, etc.) are not particularly limited, and may be appropriately set according to the material, shape, size, etc. of the material to be welded.

Here, from the viewpoint of separately observing the burrs 8 discharged from the interface to be joined 6 substantially parallel to or substantially perpendicular to the sliding direction, the sliding direction is one member 2 and / or the other member 4. It is preferable that the direction is substantially short. By setting the sliding direction to the substantially short direction of one member 2 and / or the other member 4, the interface to be joined that is in constant contact during the sliding process as compared with the case of the substantially longitudinal direction. The area of 6 becomes smaller. That is, the temperature gradient caused by the generation of frictional heat and the heat removal is larger when sliding in the substantially short direction, and as a result, the direction dependence on which the burr 8 is discharged becomes more remarkable, and sliding. It is possible to more easily observe the discharge of the burr 8 which is an index for stopping the operation.

The discharge behavior of the burr 8 in the second step is grasped by observing the interface 6 to be joined from a direction substantially perpendicular to the sliding direction. The observation method is not particularly limited, but for example, by using a high-speed video camera and using a frame rate of about 2500 fps, it is possible to accurately know the behavior of the burr 8 being discharged.

(1-3) Third step The third step is a step of stopping sliding in the second step to form a joint surface. In the linear friction stir welding method of the present invention, at the moment when the burr 8 is discharged substantially parallel to the sliding direction, the sliding of one member 2 and the other member 4 is stopped to join. Can be completed.

In the second step, the interface 6 to be joined is observed from a direction substantially perpendicular to the sliding direction, and the sliding is stopped at the moment when the burr 8 is discharged substantially parallel to the sliding direction. As a result, it is possible to form a good joint portion while minimizing the discharge amount of the burr 8 (while minimizing the consumption of the material to be joined).

In addition to the high-speed process of linear friction stir welding, it generally takes 0.2 to 0.5 seconds after the sliding stop is performed before the operation is completely stopped. Therefore, it is extremely difficult to form a good joining region on the entire surface of the interface to be joined while minimizing the discharge of the burr 8, but the burr 8 is discharged substantially parallel to the sliding direction. This can be achieved by executing the stop of sliding at the moment (from the moment when the burr 8 is discharged substantially parallel to the direction of sliding, while the sliding is completely stopped, it is joined. A junction region is formed on the entire surface of the interface).

Further, the interface 6 to be joined is observed from a direction substantially perpendicular to the sliding direction, and the burr 8 discharged substantially perpendicular to the direction of sliding reaches both ends of the interface 6 to be slid. By stopping the movement, the discharge amount of the burr 8 is slightly larger than that of the case where the burr 8 is discharged at the moment when the burr 8 is discharged substantially parallel to the sliding direction, but the discharge amount of the burr 8 is more reliable. Removal of oxides and the like can be achieved.

Here, by observing the interface 6 to be joined from a direction substantially perpendicular to the sliding direction, burrs 8 discharged substantially perpendicular to the direction of sliding reached both ends of the interface 6 to be joined. You can easily grasp the moment. Specifically, since the interface 6 to be bonded emits light as the burr 8 is discharged, the moment when the light emission reaches both ends of the interface 6 to be bonded may be observed.

(2) Linear Friction Stir Welding Device The linear friction stir welding device of the present invention is composed of a main body and an observation unit, and the main body is the same as a conventionally known general linear friction stir welding device.

The observation unit includes an observation device for observing the interface 6 to be joined from a direction substantially perpendicular to the sliding direction of one member 2 and the other member 4, and the burrs 8 during the joining process. Emissions can be observed. Here, the linear friction joining method of the present invention can be sufficiently executed only by the observation device arranged in the direction substantially perpendicular to the sliding direction, but the direction substantially parallel to the sliding direction. By arranging an observation device, more accurate observation can be realized.

In the linear friction stir welding device of the present invention, the discharge state of the burr 8 is observed by an observation device, and the moment when the burr 8 is discharged substantially parallel to the sliding direction or substantially perpendicular to the sliding direction. It is preferable to have a program that automatically stops sliding at the moment when the burrs 8 discharged to the surface reach both ends of the interface 6 to be joined, but these moments from the start of joining (start of sliding). By measuring the time until, it is possible to obtain the joining time of joining under the same conditions from the next time onward.

Further, in the linear friction stir welding apparatus of the present invention, it is preferable to use a high-speed video camera as an observation apparatus. By using a high-speed video camera, it is possible to accurately observe the discharge timing and discharge status of the burr 8. Here, the specifications of the high-speed video camera are not particularly limited as long as the effects of the present invention are not impaired, but for example, the frame rate for observation is preferably 100 to 10000 fps, more preferably 125 to 5000 fps. .. By setting the frame rate to these values, the discharge timing of the burr 8 can be accurately observed. As the observation device, for example, a photo sensor or a line sensor can be used in addition to the high-speed video camera.

Further, the linear friction stir welding apparatus of the present invention preferably includes a mirror for observing the discharge state of the burr 8. By arranging the mirror at an appropriate position, the discharge timing and discharge status of the burr 8 can be accurately observed.

Although the typical embodiments of the present invention have been described above, the present invention is not limited to these, and various design changes are possible, and all of these design changes are included in the technical scope of the present invention. Is done.

<< Example 1 >>
A 20 mm × 20 mm × 65 mm titanium alloy (Ti-6Al-4V) was used as the material to be welded, and linear friction welding was performed with the 20 mm × 20 mm surface as the joint surface. Here, the linear friction stir welding was performed by a method in which one material to be welded was fixed and the other material to be welded was vibrated, and the frequency was 50 Hz, the amplitude was ± 2 mm, and the applied pressure was 50 MPa.

FIG. 3 shows an image of the interface to be joined observed from a direction substantially perpendicular to the sliding direction using a high-speed video camera at a frame rate of 2500 fps. In the image 0.2 seconds after the start of joining, it can be confirmed that the burr discharge is started from a direction substantially perpendicular to the sliding direction. At this stage, no burrs are discharged from a direction substantially parallel to the sliding direction. On the other hand, when 1.2 seconds have passed from the start of joining, a large amount of burrs are discharged from both directions substantially perpendicular to and substantially parallel to the sliding direction. By observing the burr discharge state in FIG. 3, it was easy to grasp the moment when the burr discharge reached both ends of the interface to be joined.

FIG. 4 shows an image of the interface to be joined observed from a direction substantially parallel to the sliding direction using a high-speed video camera at a frame rate of 2500 fps. When observed from a substantially parallel direction, it is difficult to confirm the clearly observed discharge of burrs from the substantially vertical direction in the image 0.2 seconds after the start of joining when observed from a substantially vertical direction. is there. The discharge of burrs in the vertical direction can be confirmed 0.5 seconds after the start of joining, but at this stage, the discharge of burrs is also started in the substantially parallel direction. After 1.1 seconds, the length of the burrs discharged from the substantially vertical direction and the substantially parallel direction only increases, and no other particular change is observed. From FIG. 4, it was difficult to grasp the moment when the burr discharge reached both ends of the interface to be joined.

From FIGS. 3 and 4, in order to grasp the moment when the burr is discharged from a direction substantially parallel to the sliding direction and the moment when the burr discharge reaches both ends of the interface to be joined, the interface to be joined is slid. It can be seen that it is necessary to observe from a direction substantially perpendicular to the direction of motion.

<< Example 2 >>
Linear friction stir welding was performed in the same manner as in Example 1 except that the frequency was 15 Hz and the applied pressure was 200 MPa.

As a result of observing the interface to be joined from a direction substantially perpendicular to the sliding direction using a high-speed video camera in the same manner as in Example 1, the sliding was performed in 3 seconds from the start of vibration (sliding). Since the discharge of burrs was observed from a direction substantially parallel to the direction, the vibration (sliding) was stopped in 3 seconds.

<< Example 3 >>
Linear friction stir welding was performed in the same manner as in Example 2 except that the vibration (sliding) was stopped in 3.5 seconds. Note that 3.5 seconds is the time at which the burr discharge reaches both ends of the interface to be joined.

<< Comparative Example 1 >>
Linear friction stir welding was performed in the same manner as in Example 2 except that the vibration (sliding) was stopped in 1 second. No burr discharge was observed in 1 second.

≪Comparative example 2≫
Linear friction stir welding was performed in the same manner as in Example 2 except that the vibration (sliding) was stopped in 2 seconds. In 2 seconds, burrs were discharged from a direction substantially perpendicular to the sliding direction, but burrs were not discharged from a direction substantially parallel to the sliding direction.

≪Comparative example 3≫
Linear friction stir welding was performed in the same manner as in Example 2 except that the vibration (sliding) was stopped in 3.75 seconds. In 3.75 seconds, a large amount of burrs were discharged from both directions substantially perpendicular and substantially parallel to the sliding direction, and the length of the object to be joined was significantly reduced.

<< Comparative Example 4 >>
Linear friction stir welding was performed in the same manner as in Example 2 except that the vibration (sliding) was stopped in 4 seconds. In 4 seconds, a large amount of burrs were discharged from both directions substantially perpendicular and substantially parallel to the sliding direction, and the length of the object to be joined was significantly reduced.

[Cross-section observation of joints]
The cross section of the joint was observed with an optical microscope in order to confirm the presence or absence of defect formation at the joint and the condition of the joint interface.

FIG. 5 shows cross-sectional photographs of the joints obtained in Examples 2 and 3 and Comparative Examples 1 to 4. In Comparative Examples 1 (1s in FIG. 5) and 2 (2s in FIG. 5) in which the joining time is short, unjoined portions are confirmed, but in Example 2 (3s in FIG. 5) and 3 (in FIG. 5). In 3.5s) and Comparative Example 3 (3.75s in FIG. 5) and 4 (4s in FIG. 5), good joints without defects are formed. It can be seen that the thicknesses of the joints are almost the same in Examples 2 and 3 and Comparative Examples 3 and 4, but the joints are shorter in Comparative Examples 3 and 4.

[Tensile test]
Tensile tests were performed on the joints obtained in Examples 2 and 3 and Comparative Examples 1, 2 and 4. A tensile tester (SHIMADZU Autograph AG-10TB) was used for the measurement, and the crosshead speed was 1 mm / min.

The tensile strength of the joints obtained in Examples 2 and 3 and Comparative Examples 1, 2 and 4 is shown in FIG. The joints obtained in Comparative Examples 1 and 2 having a short joining time had lower strength than the other conditions, but in Examples 2, 3 and Comparative Example 4, the base metal was broken and the strength was almost the same.

From the above results, by observing the interface to be joined from a direction substantially perpendicular to the sliding direction and completing the joining process by paying attention to the burr discharge status, it is good while minimizing the burr discharge. It can be seen that a good joint can be obtained.

2 ... One member,
4 ... The other member,
6 ... Interface to be joined,
8 ... Bali.

Claims (8)

The first step of bringing one member into contact with the other member to form an interface to be joined,
With the pressure applied substantially perpendicular to the interface to be joined, the one member and the other member are repeatedly slid on the same locus, and the sliding direction is substantially parallel and substantially perpendicular to the sliding direction. The second step of discharging burrs from the interface to be joined,
It has a third step of stopping the sliding and forming a joint surface.
In the second step, the interface to be joined is observed from a direction substantially perpendicular to the sliding direction, and at the moment when the burr is discharged substantially parallel to the sliding direction, the third step is performed. Performing the stop in the process,
A linear friction stir welding method characterized by. The first step of bringing one member into contact with the other member to form an interface to be joined,
With the pressure applied substantially perpendicular to the interface to be joined, the one member and the other member are repeatedly slid on the same locus, and the sliding direction is substantially parallel and substantially perpendicular to the sliding direction. The second step of discharging burrs from the interface to be joined,
It has a third step of stopping the sliding and forming a joint surface.
In the second step, the interface to be joined is observed from a direction substantially perpendicular to the sliding direction, and the burrs discharged substantially perpendicular to the sliding direction are both ends of the interface to be joined. At the moment when the above is reached, the stop in the third step is executed.
A linear friction stir welding method characterized by. The interface to be joined is square or rectangular,
The linear friction stir welding method according to claim 1 or 2. In the second step, the sliding direction is set to a substantially short direction of the one member and / or the other member.
The linear friction stir welding method according to any one of claims 1 to 3. That one member and / or the other member is an iron-based metal, titanium, or a titanium alloy.
The linear friction stir welding method according to any one of claims 1 to 4. After one member is brought into contact with the other member to form an interface to be welded, the one member and the other member have the same locus in a state where a pressure is applied substantially perpendicular to the interface to be welded. A linear friction stir welding device that repeatedly slides on the surface to stop the sliding after discharging burrs from the interface to be joined.
An observation device for observing the interface to be joined from a direction substantially perpendicular to the sliding direction, and the sliding stop at the moment when the burr is discharged substantially parallel to the sliding direction. A program for executing the sliding, or a program for stopping the sliding at the moment when the burr discharged substantially perpendicular to the sliding direction reaches both ends of the interface to be joined .
A linear friction stir welding device characterized by. Further, an observation device for observing the interface to be joined from a direction substantially parallel to the sliding direction is provided.
The linear friction stir welding apparatus according to claim 6. The observation device is a high-speed video camera.
The linear friction stir welding apparatus according to claim 6 or 7.