JP2010036230A - Friction stir treating method of dissimilar material joining part, and friction stir welding method of dissimilar material - Google Patents

Abstract

Disclosed is a dissimilar material capable of joining dissimilar materials or subjecting dissimilar materials to friction stir processing without limiting the shape and dimensions of the joining member, and the like. It is an object of the present invention to provide a friction stir processing method for joints and a friction stir welding method for different materials.
In a friction stir processing method for a dissimilar material joint, a friction stir tool 40 having a flat end surface is provided on the end surface of the friction stir tool 40 and the friction stir tool 40. Friction stirrer member comprising taper pin 50 having a truncated cone having a predetermined angle determined based on the range of disappearance of stress singularity obtained from singularity analysis and having a sectional area gradually decreasing toward the tip Is used. Then, the friction stirrer is rotated, and the friction stir processing is performed along at least one joining edge of the joining interface 30 of the different materials.
[Selection] Figure 1D

Description

  The present invention relates to a friction stir processing method for dissimilar material joints in which dissimilar material joints are processed by friction stirring, and a friction stir welding method for dissimilar materials in which dissimilar materials are connected by friction stir welding.

  Conventionally, bonding of dissimilar materials has been widely performed by brazing, diffusion bonding, friction welding, and the like. Since joints of different materials have discontinuous material characteristics, the joint strength of the joined body often decreases.

In order to improve this decrease in bonding strength, a technique is disclosed in which the residual stress generated at the bonding interface is reduced by changing the diameter of the member in accordance with the difference in thermal expansion coefficient of the member in the friction welding method ( For example, see Patent Document 1.) Moreover, the technique which improves a tensile strength by hot-pressing a convex copper material to an aluminum material is disclosed (for example, refer patent document 2). Moreover, the technique which improves the impact strength of a junction part by limiting the angle of a dissimilar-material joining edge to an appropriate range is disclosed (for example, refer patent document 3). Furthermore, a technique for relaxing the stress concentration at the joint edge by stress specificity analysis and optimization analysis at the joint edge of the scarf joint is disclosed (for example, see Patent Document 4).
JP-A-6-47570 Japanese Patent Laid-Open No. 4-143085 JP 2003-53557 A JP 2004-255388 A

  In the conventional joining method described above, in order to improve the joining strength of the joining part of different materials, the joining part of the joining member has various bent or curved shapes, but these complicatedly shaped joining members are joined. There were the following problems.

  First, a processing step for processing a complex-shaped joining member is required. Further, in order to combine joining members having complicated shapes without causing gaps or deviations, high processing accuracy is required. Therefore, the material, shape, dimensions, and the like of the joining member are limited, the processing cost is increased, and the manufacturing cost is increased.

  Further, when joining a joining member having a complicated shape, for example, in brazing, defects such as confinement of void defects and defects around the wax that occur due to uneven gaps are likely to occur. In the case of diffusion bonding, there are problems such as poor adhesion of the bonding members and the occurrence of unbonded portions due to insufficient pressure applied due to a large bonding surface angle with respect to the pressure axis direction. Here, by adopting the hot isostatic pressing process (HIP process), it is possible to solve these problems at the time of diffusion bonding, but when this HIP process is employed, for the HIP process Canning and its removal are required, and further, the size of the member to be processed is limited to the capacity of the HIP furnace.

  In the friction welding method, only one joining member is formed into a desired shape, and this is bitten into the other joining member to be joined, whereby a desired joint shape can be obtained. However, this method has a drawback that the shape and size of the joining member are limited in both the rotary friction joining and the linear friction joining.

  Therefore, the present invention has been made to solve the above-described problems, and the shape of the joining portion in the joining member is made simple, and the dissimilar materials can be joined without limiting the shape and dimensions of the joining member. Another object of the present invention is to provide a friction stir processing method for dissimilar material joints and a friction stir welding method for dissimilar materials capable of friction stir processing of joints of different materials.

  In order to achieve the above object, according to one aspect of the present invention, there is provided a friction stir processing method for dissimilar material joints by friction stir processing of joints of dissimilar materials having different softening temperatures. A stirring tool, and a predetermined tool defined on the end surface of the friction stir tool, which is determined based on a stress singularity disappearance range obtained from a stress singularity analysis of the end surface and a joint interface end portion of the dissimilar material. A friction stirrer including a stirrer configured in a truncated cone shape having an angle and gradually decreasing in cross-sectional area toward the tip is rotated along the joint edge of at least one of the joints of the different materials The stirrer is moved relative to the dissimilar material while plastically flowing the dissimilar material, and the angle formed by the joint surface at the joining edge of the joint and the surface of the dissimilar material is Loss of sex Friction stir processing method dissimilar materials joined portion, characterized in that the predetermined angle which is determined based on the circumference is provided.

  According to another aspect of the present invention, there is provided a friction stir welding method for dissimilar materials having different softening temperatures by friction stirrer, the friction stir welding tool having a flat end surface, and the friction stir tool described above. Provided on an end surface, and gradually toward the tip with a predetermined angle determined based on the stress singularity disappearance range obtained from the stress singularity analysis of the end surface and the joint interface end of the dissimilar material A friction stirrer having a frustoconical stirrer having a reduced cross-sectional area is rotated, and the dissimilar material is plasticized along at least one interface edge to join the dissimilar materials in contact with each other. The stirrer is moved relative to the dissimilar material while flowing, the stirrer is moved to join the dissimilar material, and the joining surface at the joined joint edge and the dissimilar material The angle between the charges of the surface, the friction stir welding method of dissimilar materials, characterized in that the predetermined angle which is determined based on the stress singularity loss range is provided.

  According to the friction stir processing method for dissimilar material joints and the friction stir welding method for dissimilar materials according to the present invention, the shape of the joint part in the joining member is made simple, and the shape and dimensions of the joining member are not limited. , Dissimilar materials can be joined, or joints of dissimilar materials can be friction stir processed.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

(First embodiment)
1A to 1G are diagrams schematically showing a cross section of a joint portion of different materials for explaining the friction stir processing method for the joint portion of different materials according to the first embodiment of the present invention.

  Here, an example is shown in which the first bonding material 10 is formed of a titanium alloy and the second bonding material 20 is formed of an aluminum alloy having a softening temperature different from that of the first bonding material 10. Note that the thicknesses of both the bonding materials are the same.

  As shown in FIG. 1A, the bonding surface 11 of the first bonding material 10 is formed so as to intersect perpendicularly with the surfaces 12 and 13 of the first bonding material 10. Further, the bonding surface 21 of the second bonding material 20 is formed so as to intersect perpendicularly with the surfaces 22 and 23 of the second bonding material 20 similarly to the bonding surface 11 of the first bonding material 10.

  First, as shown in FIG. 1B, the bonding surface 11 of the first bonding material 10 and the bonding surface 21 of the second bonding material 20 are abutted, and the bonding surface 11 of the first bonding material 10 and the second bonding material 21 The bonding surface 21 of the bonding material 20 is diffusion bonded. In diffusion bonding, a predetermined pressure is applied in a direction in which the bonding surface 11 of the first bonding material 10 and the bonding surface 21 of the second bonding material 20 are brought into contact with each other, and in this state, in a vacuum atmosphere at a predetermined temperature. This is done by holding for a predetermined time. The predetermined temperature is set to a temperature equal to or lower than the melting point of the materials constituting the first bonding material 10 and the second bonding material 20. Here, an angle θ1 formed by the bonding interface 30 and the surface 12 of the first bonding material 10 is 90 degrees. In addition, the joining method of the 1st joining material 10 and the 2nd joining material 20 is not restricted to diffusion joining, For example, other methods, such as brazing, HIP joining, and friction stir welding, may be used.

  As shown in FIG. 1C, a frustoconical taper pin 50 that functions as an agitating portion and that gradually decreases in cross-sectional area toward the tip is provided at the end of the friction agitating tool 40 that performs the friction agitating process. Is provided. Further, the end surface of the friction stir tool 40 on which the taper pin 50 is formed has a larger area than the end surface of the taper pin 50 that contacts the end surface, and the surface 12 of the first bonding material 10 is used when the friction stir processing is performed. And the shoulder part 41 which contacts the surface 22 of the 2nd joining material 20 is comprised. The shoulder portion 41 is configured to be a plane that is basically parallel to the surface 12 of the first bonding material 10 and the surface 22 of the second bonding material 20, but is not limited thereto. Absent. Even if the shoulder portion 41 has a shape that inclines so as to form a recess from the peripheral edge toward the tool central portion as in the case of a normal friction stir welding tool, the shoulder portion 41 has a spiral shape from the peripheral edge toward the tool central portion. A spiral concavo-convex structure including a plurality of protrusions may be used. Further, the height of the taper pin 50, that is, the height of the truncated cone is appropriately set depending on the application to be used, and is preferably 5% or more of the thickness of the joining member. It is preferable that the height of the taper pin 50 is in the above-described range. The tensile stress generated at the bonding interface 30 of different materials increases in the surface layer, but the strength is improved by the treatment of only the extreme surface layer below this. This is because the contribution of is small.

  Further, as shown in FIG. 1C, the taper pin 50 is arranged so that the central axis of the taper pin 50 is located on the second bonding material 20 side rather than the bonding interface 30. The taper pin 50 may be arranged so that the central axis of the taper pin 50 is located on the first bonding material 10 side. That is, the taper pin 50 may be disposed so that the central axis of the taper pin 50 is located on either one of the first bonding material 10 side and the second bonding material 20 side rather than the bonding interface 30.

  Here, when the taper pin 50 is arranged so that the central axis of the taper pin 50 is located on the second bonding material 20 side rather than the bonding interface 30, the first bonding material 10 side of the root portion of the taper pin 50 is disposed. It is preferable to arrange the taper pin 50 so that one end edge 50a located at a position closer to the first bonding material 10 than the bonding interface 30 is about 0.1 to 1.5 mm. In this case, since the aluminum alloy is mainly frictionally stirred, the mixing of the titanium alloy into the portion where the friction diffusion treatment is performed (the portion corresponding to the friction diffusion treatment portion 60 described later) can be suppressed to a minimum amount. The mechanical properties of the part are improved. Further, since the soft aluminum alloy is mainly frictionally stirred, friction stirring is easy and consumption of the taper pin 50 can be suppressed.

  On the other hand, when the taper pin 50 is arranged so that the central axis of the taper pin 50 is located on the first bonding material 10 side, the other edge 50b on the second bonding material 20 side of the base portion of the taper pin 50 is The taper pin 50 is preferably disposed so as to be positioned about 0.1 to 1.5 mm closer to the second bonding material 20 than the bonding interface 30.

  As described above, the taper pin 50 is disposed so that the central axis of the taper pin 50 is located on either one of the first bonding material 10 side and the second bonding material 20 side rather than the bonding interface 30. This is because, in the portion where the frictional diffusion treatment is performed (the portion corresponding to the frictional diffusion processing unit 60 described later), either one of the first bonding material 10 and the second bonding material 20 is more than 50% by volume. This is to increase the number.

  When the taper pin 50 is disposed so that the central axis of the taper pin 50 is located on either one of the first bonding material 10 side and the second bonding material 20 side rather than the bonding interface 30, friction is caused. The position where the taper pin 50 is disposed is appropriately set based on the mixing ratio of the first bonding material 10 and the second bonding material 20 and the usage environment of the bonded different materials in the portion where the diffusion treatment is performed. . Further, the taper pin 50 may be a threaded pin generally used for friction stir welding, but when a soft aluminum alloy is mainly friction stir, a screwless pin can be used.

  Further, as shown in FIG. 1C and FIG. 1D, when the taper pin 50 is brought into contact with the bonding member in a state where the central axis of the taper pin 50 is located on the second bonding material 20 side made of an aluminum alloy, the friction stirring process is performed. The angle θ2 formed by the side surface 51 of the taper pin 50 and the shoulder portion 41 is preferably 120 to 178 degrees. On the other hand, when the friction stir processing is performed by bringing the taper pin 50 into contact with the bonding member in a state where the central axis of the taper pin 50 is located on the first bonding material 10 made of a titanium alloy, the side surface 51 of the taper pin 50 and the shoulder portion 41 Is preferably 92 to 135 degrees. The reason why the above-described range is preferable for the angle θ2 formed between the side surface 51 of the taper pin 50 and the shoulder portion 41 will be described later.

  Then, the friction stir tool 40 is rotated at a predetermined rotation speed (for example, 1000 to 5000 rpm). Subsequently, the friction stir tool 40 is moved downward from the disposed position, and the taper pin 50 is connected to the surface 12 of the first bonding material 10 including the edge 31 on one end side of the bonding interface 30 and the second bonding. Contact the surface 22 of the material 20. In this state, after holding for several seconds to several tens of seconds until reaching a temperature at which frictional stirring is satisfactorily performed, as shown in FIG. 1D, a predetermined moving speed (for example, along the edge 31 on one end side of the bonding interface 30) The friction stir tool 40 is moved at 300 to 2000 mm / min. The taper pin 50 is pressed against the bonding material side with a predetermined pressure. After the friction stir tool 40, that is, the taper pin 50 is moved to the end of processing, the friction stir tool 40 is raised and the taper pin 50 is pulled out. Further, as shown in FIG. 1D, when the friction stir processing is performed, the shoulder portion 41 of the friction stir tool 40 is subjected to the surface 12 of the first bonding material 10 and the surface of the second bonding material 20 at a predetermined pressure. Therefore, the plastically flowable material does not flow out to the outside.

  As described above, a friction diffusion processing unit 60 is formed in the portion where the taper pin 50 has moved, as shown in FIG. 1E. When the friction stir processing is performed by bringing the taper pin 50 into contact with the bonding member in a state where the central axis of the taper pin 50 is located on the second bonding material 20 side, the friction diffusion processing unit 60 constitutes the second bonding material 20. It is comprised with the alloy containing the titanium alloy which comprises the 1st joining material 10 which mainly made the aluminum alloy. On the other hand, when the friction stir processing is performed by bringing the taper pin 50 into contact with the bonding member in a state where the central axis of the taper pin 50 is located on the first bonding material 10 side, the friction diffusion processing unit 60 causes the first bonding material 10 to move. It is comprised with the alloy containing the aluminum alloy which comprises the 2nd joining material 20 which mainly comprised the titanium alloy to comprise.

  Further, when the friction stir processing is performed by bringing the taper pin 50 into contact with the bonding member in a state where the central axis of the taper pin 50 is located on the second bonding material 20 side, An angle θ3 formed by the side surface 61 and the surface of the bonding material on the first bonding material 10 side is substantially the same as an angle θ2 formed by the side surface 51 of the taper pin 50 and the shoulder portion 41. On the other hand, when the friction stir processing is performed by bringing the taper pin 50 into contact with the bonding member in a state where the central axis of the taper pin 50 is positioned on the first bonding material 10 side, An angle (not shown) formed on the first bonding material 10 side by the side surface 62 and the surface of the bonding material is substantially the same as a value obtained by subtracting an angle θ2 formed by the side surface 51 of the taper pin 50 and the shoulder portion 41 from 180 degrees. It is.

  Here, as described above, the angle θ3 formed on the first bonding material 10 side by the side surface 61 on the first bonding material 10 side in the friction diffusion processing unit 60 and the surface of the bonding material, and the friction diffusion processing unit 60. The angle (not shown) formed on the first bonding material 10 side by the side surface 62 on the second bonding material 20 side and the surface of the bonding material in FIG. 2 depends on the angle θ2 formed between the side surface 51 of the taper pin 50 and the shoulder portion 41. Determined.

  Here, the angle θ2 formed by the side surface 51 of the taper pin 50 and the shoulder portion 41 is preferably set to 120 to 178 degrees as described above, and the side surface 61 on the first bonding material 10 side in the friction diffusion processing unit 60, This is because it is preferable that the angle θ3 formed on the first bonding material 10 side by the surface of the bonding material is 120 to 178 degrees. In addition, it is preferable that the angle θ2 formed by the side surface 51 of the taper pin 50 and the shoulder portion 41 is 92 to 135 degrees as described above, and the side surface 62 on the second bonding material 20 side in the friction diffusion processing unit 60 and the bonding This is because the angle (not shown) formed by the first bonding material 10 side with the surface of the material is preferably 45 to 88 degrees.

  Next, the angle θ3 formed on the first bonding material 10 side by the side surface 61 on the first bonding material 10 side in the friction diffusion processing unit 60 and the surface of the bonding material is set to 92 to 135 degrees, or the friction diffusion processing unit The reason why the angle (not shown) formed on the first bonding material 10 side by the side surface 62 on the second bonding material 20 side in 60 and the surface of the bonding material is preferably 45 to 88 degrees will be described.

  With respect to the plane problem at the joint interface edge of a two-dimensional dissimilar material, characteristic equations that determine stress singularities have already been derived (see, for example, Japanese Patent Application Laid-Open Nos. 2004-255388 and 2003-53557). Using this characteristic equation, the stress singularity at the end of the joint interface 30 of the joint member by the combination of the titanium alloy of the first joint material 10 and the aluminum alloy of the second joint material 20 shown in FIG. 1B was analyzed. However, it has been found that the stress singularities of the free edges at the both end edges 31 and 32 of the joint interface 30 are generated at these two end edges 31 and 32 of the flat plate. That is, the stress singularities at both end edges 31 and 32 of the flat plate when the angle θ1 formed between the bonding interface 30 and the surface 12 of the first bonding material 10 changed from 0 to 180 degrees were analyzed. Here, an index indicating the stress singularity at the ends of the two joint interfaces 30 was calculated by the perturbation method to obtain the stress singularity.

  As a result of the above analysis, the stress of the free edge at the end of the bonding interface 30 when the angle θ1 between the bonding interface 30 and the surface 12 of the first bonding material 10 is in the range of 45 to 88 degrees and 120 to 178 degrees. Loss of specificity was observed. Therefore, the angle θ3 formed on the first bonding material 10 side by the side surface 61 on the first bonding material 10 side in the friction diffusion processing unit 60 and the surface of the bonding material is set to 92 to 135 degrees, or the friction diffusion processing unit 60. The angle (not shown) formed on the first bonding material 10 side by the side surface 62 on the second bonding material 20 side and the surface of the bonding material is preferably 45 to 88 degrees.

  Further, based on the angle θ3 described above, the angle θ2 formed between the side surface 51 of the taper pin 50 and the shoulder portion 41 is preferably set to 120 to 178 degrees or 92 to 135 degrees.

  Subsequently, as shown in FIG. 1F, the friction stir processing described above is performed on the edge of the bonding interface 30 on the back surface side (the surface 13 side of the first bonding material 10 and the surface 23 side of the second bonding material 20). Repeat for the 32 side. Note that when used in an environment where a tensile force is applied only to the front surface side that has already been subjected to the friction stir processing, the rear surface side friction stir processing shown in FIG. 1F may be omitted.

  And as shown to FIG. 1G, the friction-diffusion process part 60 is formed in both surfaces, and a friction stirring process is completed with respect to the junction part of the 1st joining material 10 and the 2nd joining material 20. As shown in FIG.

  As shown in FIG. 1G, there is a portion where the friction stir processing is not performed in the central portion of the bonding interface 30, but since this portion is bonded in advance by diffusion bonding or the like, there is a problem in mechanical strength. Will not cause.

  Here, an example in which a titanium alloy is used as the first bonding material 10 and an aluminum alloy is used as the second bonding material 20 is shown. Examples of the titanium alloy include pure titanium, α-type alloy Ti-2.5Cu alloy, α + β-type alloy Ti-6Al-4V alloy, β-type alloy Ti-15Mo-5Zr alloy, and the like. Examples of the aluminum alloy include pure aluminum, Al-Mg alloy, Al-Si alloy, Al-Cu alloy, Al-Mg-Si alloy, Al-Zn-Mg alloy wrought material, and cast material. It is done. Further, the combination of different materials is not limited to the above-described titanium alloy and aluminum alloy, and any combination of materials that can be friction-stirred may be used. For example, copper-tungsten, copper-molybdenum, copper-aluminum, copper-steel material, titanium-steel material, etc. are mentioned as an example of a combination. Since the stress singularity at the joint interface end portion described above varies depending on the material to be combined, the stress singularity analysis described above is performed for each material to be combined, and the disappearance range of the stress singularity is calculated. Determine the shape and so on.

  As described above, according to the friction stir processing method for the dissimilar material joint according to the first embodiment of the present invention, the edge 31 of the joint interface 30 with respect to the joint of the dissimilar material already joined, By subjecting the free edge in 32 to friction stir processing at an angle at which the stress specificity disappears, the occurrence of defects and the like in the joint can be suppressed, and the joint strength can be improved. As a result, it is possible to obtain a different kind of bonding material having a bonding portion in which a decrease in strength of the bonding edge is suppressed. Further, since the shape of the bonding surface of the bonding material can be a simple shape such as a flat surface, the processing of the bonding material is facilitated, and the processing time can be shortened, so that the manufacturing cost can be suppressed. .

(Second Embodiment)
In the second embodiment, a method in which prior joining is performed by friction stir welding and then the free edge of the joining interface 30 is friction stir welded will be described.

  2A to 2H are diagrams schematically illustrating a cross section of a joint portion of different materials for explaining the friction stir welding method of different materials according to the second embodiment of the present invention. FIG. 3 is a diagram schematically showing a cross-section of another form of the friction stir tool.

  Here, as shown in FIG. 2A, as the bonding material, a first bonding material 80 having inclined portions 81 inclined in the thickness direction of the bonding material on both edges of the convex shape, and a bonding material on both edges of the concave shape, as shown in FIG. A second bonding material 90 having an inclined portion 91 inclined in the thickness direction was used. An angle θ1 formed by the inclined portion 81 in the first bonding material 80 and the surface 83 of the first bonding material 80 is 110 to 125 degrees. Note that the angle θ1 formed with the surface 83 of the first bonding material 80 is such that the stress singularity disappears at the free edge at the end of the bonding interface according to the analysis of the stress singularity described in the first embodiment. It is an angle. Further, the length of the straight portion 84 of the bonding surface 82 of the first bonding material 80 is 0.05 to 0.5 times the thickness of the first bonding material 80. When the thickness of the first bonding material 80 is 0.05 times or more, the height of the taper pin 50 corresponds to 5% or more of the thickness of the bonding member, and when it is 0.5 times, the straight portion There is no 84 and only the upper and lower inclined portions 81 and 91 are provided. Further, the shape of the bonding surface 92 of the second bonding material 90 is configured to correspond to the shape of the bonding surface 82 of the first bonding material 80.

  Here, an example in which the first bonding material 80 is formed of copper and the second bonding material 90 is formed of aluminum having a softening temperature different from that of the first bonding material 10 is shown. Note that the thicknesses of both the bonding materials are the same.

  First, the bonding surface 82 of the first bonding material 80 and the bonding surface 92 of the second bonding material 90 are butted together. Then, using the friction stir tool 110 having the cylindrical straight pin 100 and the shoulder portion 101 that function as a stirring portion, the side surface on the first bonding material 80 side of the straight pin 100 is the first side when the friction stir welding is performed. The friction stir tool 110 is arranged at a position that is about 0.1 to 1.5 mm from the straight portion 84 of the bonding surface 82 of the bonding material 80 and located on the first bonding material 80 side.

  Subsequently, the friction stir tool 40 is rotated at a predetermined rotation speed (for example, 1000 to 5000 rpm), the friction stir tool 110 is moved downward from the above-described position, and the straight pin 100 is connected to the second joint. Contact the surface 93 of the material 90. In this state, after being held for several seconds to several tens of seconds until reaching a temperature at which frictional stirring is satisfactorily performed, as shown in FIG. 2B, at a predetermined moving speed (for example, 300 to 2000 mm / min) along the bonding interface 120. The friction stir tool 110 is moved. The straight pin 100 is pressed against the bonding material side with a predetermined pressure. After the friction stir tool 110, that is, the straight pin 100 is moved to the end of processing, the friction stir tool 110 is raised and the straight pin 100 is pulled out. Further, as shown in FIG. 2B, when performing friction stir welding, the shoulder portion 101 of the friction stir tool 110 is subjected to the surface 83 of the first bonding material 80 and the surface of the second bonding material 90 at a predetermined pressure. Since it is pressed against 93, the plastically flowed material does not flow out.

  As described above, as shown in FIG. 2C, the friction diffusion processing unit 130 is formed in the portion where the straight pin 100 has moved. The friction diffusion processing unit 130 is made of an alloy containing copper that forms the first bonding material 80, mainly aluminum that forms the second bonding material 90. In this way, the linear portion 84 of the bonding surface 82 of the first bonding material 80 and the corresponding linear portion 94 of the bonding surface 92 of the second bonding material 90 are friction stir bonded. In this state, the inclined portions 81 and 91 on both edges are hardly joined.

  Subsequently, friction stir welding is performed on the inclined portions 81 and 91 on both edges. As shown in FIG. 2D, the end portion formed by a flat surface of the friction stir tool 140 used for friction stir welding of the inclined portions 81 and 91 on both edges gradually functions toward the tip, which functions as a stirrer. A truncated cone-shaped taper pin 150 having a reduced cross-sectional area is provided. Further, the end surface of the friction stir tool 140 on the side where the taper pin 150 is formed is configured to have a larger area than the end surface of the taper pin 150 that contacts the end surface. A shoulder portion 141 is formed in contact with the surface 83 and the surface 93 of the second bonding material 90. The shoulder portion 141 is basically configured to be a plane parallel to the surface 83 of the first bonding material 80 and the surface 93 of the second bonding material 90, but is not limited to this. Absent. Even if the shoulder portion 141 has a shape that inclines so as to form a concave portion from the peripheral edge toward the tool central portion, like a normal friction stir welding tool, the shoulder portion 141 has a spiral shape from the peripheral edge toward the tool central portion. A spiral concavo-convex structure including a plurality of protrusions may be used.

  2D, an angle θ2 formed between the side surface 151 of the taper pin 150 and the shoulder portion 141 is an angle θ1 formed between the inclined portion 81 in the first bonding material 80 and the surface 83 of the first bonding material 80. It is preferable that it is the same 110-125 degree | times. Further, the height of the taper pin 150, that is, the height of the truncated cone is appropriately set depending on the application to be used. Preferably, the thickness is 5% or more of the thickness of the joining member. It is preferable that the height of the taper pin 150 be in the above-described range. The tensile stress generated at the bonding interface 120 of the dissimilar material is increased on the surface layer, but the treatment with only the extreme surface layer below this increases the strength. This is because the contribution of is small.

  In addition, one end edge 150a of the base portion of the taper pin 150 on the first bonding material 80 side is 0.1 closer to the first bonding material 80 side than the edge 121 of the bonding interface 120 of the inclined portions 81 and 91. It is preferable to arrange the taper pin 150 so as to be positioned at about ˜1.5 mm. It is preferable to arrange the taper pin 150 in this range, when it is less than 0.1 (for example, when the end edge 150a is located at the bonding interface (in the case of 0 mm)), there is a high possibility that a bonding failure will occur. This is because the occurrence of poor bonding disappears with an arrangement of up to about 1.5 mm, and when the thickness exceeds 1.5 mm, the mixing ratio of the first bonding material 80 to the second bonding material 90 increases.

  Subsequently, the friction stir tool 110 is rotated at a predetermined rotation speed (for example, 1000 to 5000 rpm), the friction stir tool 110 is moved downward from the above-described position, and the taper pin 150 is moved to the end of the joining interface 120. The surface 83 of the first bonding material 80 including the edge 121 and the surface 93 of the second bonding material 90 are brought into contact with each other. In this state, after holding for several seconds to several tens of seconds until reaching a temperature at which frictional stirring is satisfactorily performed, as shown in FIG. 2E, a predetermined moving speed (for example, along the edge 121 on one end side of the bonding interface 120) The friction stir tool 110 is moved at 300 to 2000 mm / min. The taper pin 150 is pressed against the bonding material side with a predetermined pressure. After the friction stir tool 110, that is, the taper pin 150 is moved to the end of processing, the friction stir tool 110 is raised and the taper pin 150 is pulled out. Further, as shown in FIG. 2E, when performing friction stir welding, the shoulder portion 141 of the friction stir tool 110 is subjected to a surface 83 of the first bonding material 80 and a surface of the second bonding material 90 at a predetermined pressure. Since it is pressed against 93, the plastically flowed material does not flow out.

  As described above, the frictional diffusion processing unit 160 is formed in the portion where the taper pin 150 has moved, as shown in FIG. 2F. The friction diffusion processing unit 160 is made of an alloy containing copper constituting the first bonding material 10, which is mainly composed of aluminum constituting the second bonding material 90. In this way, the inclined portion 81 of the first bonding material 80 and the corresponding inclined portion 91 of the second bonding material 90 on one end edge side are friction stir welded.

  In addition, the angle θ3 formed between the side surface 161 on the first bonding material 80 side and the surface of the bonding material in the friction diffusion processing unit 160 and the side of the first bonding material 80 is determined by the side surface 151 of the taper pin 150 and the shoulder portion 141. This is almost the same as the angle θ2.

  Subsequently, as shown in FIG. 2G, the friction stir welding is performed on the inclined portions 81 and 91 on the other end edge side which is the back surface side by the same method as described above, using the friction stir tool 140 described above.

  Then, as shown in FIG. 2H, the friction diffusion processing unit 160 is formed on both surfaces, and the first bonding material 10 and the second bonding material 20 are friction stir bonded.

  Here, an example in which copper is used as the first bonding material 80 and aluminum is used as the second bonding material 90 is shown. The combination of different materials is not limited to copper and aluminum, and any combination of materials that can be friction-stirred may be used. For example, copper-titanium, copper-tungsten, copper-molybdenum, copper-steel material, titanium-steel material, etc. are mentioned as an example of a combination. Since the stress singularity at the joint interface edge described above varies depending on the material to be combined, the stress singularity analysis described above is performed for each material to be combined, and the disappearance range of the stress singularity is calculated. The angle θ1 formed by the inclined portion 81 in the first bonding material 80 and the surface 83 of the first bonding material 80 is determined. Further, the shape of the bonding surface 92 of the second bonding material 90 is determined in accordance with the shape of the bonding surface 82 of the first bonding material 80. Further, the shape or the like of the taper pin 150 is determined in accordance with the angle θ1 formed by the inclined portion 81 in the first bonding material 80 and the surface 83 of the first bonding material 80.

  Here, in the pin of the friction stir tool 110 described above, the tip portion may be formed into a cylindrical straight shape, and the friction stir tool 110 side, that is, the base portion side of the pin may be formed into a truncated conical taper shape shown in FIG. 2D. Good. By adopting this composite shape, the friction stir processing shown in FIGS. 2B to 2E can be performed simultaneously. That is, the friction diffusion processing unit 130 and the friction diffusion processing unit 160 can be formed simultaneously.

  Further, when the inclined portion on the other end edge side is eliminated, the butt portion is inclined only at the upper portion, the straight portion is extended to the lower portion, and the straight shape portion of the pin of the friction stir tool 110 becomes the back side of the bonding material. It may be configured to extend to the other end edge. Moreover, when not providing an inclined part in the other end edge side in this way, the thickness of both joining materials may differ. In this case, the surface side into which the friction stir tool is inserted has the same height, and a spacer having a thickness difference or the like may be inserted into the back side of the thin material.

  Furthermore, as shown in FIG. 3, the friction stir tool 110 is provided on both sides of the bonding material, and the cross-sectional area gradually decreases toward the tip at the end portion formed by the flat surface of each friction stir tool 110. A truncated cone-shaped taper pin 150 may be provided, and further, a cylindrical straight pin 100 may be provided between the taper pins 150 to integrally form each. Further, the end surface of the friction stir tool 110 on the side where the taper pin 150 is formed is configured to have a larger area than the end surface of the taper pin 150 that contacts the end surface. A shoulder portion 141 that contacts the surface and the surface of the second bonding material 90 is formed. The shoulder portion 141 is configured to be a plane parallel to the surface of the first bonding material 80 and the surface of the second bonding material 90. Thus, by making the friction stir tool and the pin into a so-called bobbin tool shape, both surfaces of the bonding material can be subjected to friction stir processing simultaneously. Moreover, by using the bobbin tool shape, it is possible to suppress the occurrence of defects that are likely to occur when the friction stir processing is performed from one side of the bonding material.

  As described above, according to the friction stir processing method for joints of different materials according to the second embodiment of the present invention, since all the joint interfaces are joined by friction stir welding, it is easy and reliable. Some bonding can be performed. Further, since the friction stir welding is performed using the pins corresponding to the shape of the joining interface such as the inclined portions 81 and 91, the dissimilar materials mixed in the friction diffusion processing portion can be minimized. As a result, it is possible to prevent the formation of an intermetallic compound at the joint, and to improve the joint strength.

(Third embodiment)
In the third embodiment, a case in which the joining process and the joining edge inclination imparting process are performed simultaneously will be described.

  FIGS. 4A to 4D are diagrams schematically showing a cross section of a joint portion of different materials for explaining the friction stir processing method for the joint portion of different materials according to the third embodiment of the present invention.

  Here, an example is shown in which the first bonding material 180 is formed of a titanium alloy and the second bonding material 190 is formed of an aluminum alloy having a softening temperature different from that of the first bonding material 180. Although the thicknesses of both the bonding materials are the same here, the thicknesses may be different. If the thickness is different, the surface side where the friction stir tool is inserted should be the same surface, and a spacer corresponding to the difference in thickness is inserted on the back side of the thin material to match the thickness of the thin material side. A friction stir tool may be used. Specific examples of the titanium alloy and the aluminum alloy include those exemplified in the first embodiment.

  As shown in FIG. 4A, the bonding surface 181 of the first bonding material 180 is formed so as to intersect the surfaces 182 and 183 of the first bonding material 180 perpendicularly. Further, the bonding surface 191 of the second bonding material 190 is formed so as to intersect the surfaces 192 and 193 of the second bonding material 190 perpendicularly, similarly to the bonding surface 181 of the first bonding material 180.

  First, as shown in FIG. 4B, the bonding surface 181 of the first bonding material 180 and the bonding surface 191 of the second bonding material 190 are brought into contact with each other. At this time, a predetermined pressure is applied in a direction in which the bonding surface 181 of the first bonding material 180 and the bonding surface 191 of the second bonding material 190 are brought into contact with each other.

  Further, as shown in FIG. 4B, a frustoconical taper pin that functions as an agitating portion and gradually decreases in cross-sectional area toward the tip is provided at the end of the friction agitating tool 200 that performs the friction agitating process. 210 is provided. In addition, the end surface of the friction stir tool 200 on the side where the taper pin 210 is formed is configured to have a larger area than the end surface of the taper pin 210 that contacts the end surface. A shoulder portion 201 is formed in contact with the surface 182 and the surface 192 of the second bonding material 190. The shoulder portion 201 is basically configured to be a plane parallel to the surface 182 of the first bonding material 180 and the surface 192 of the second bonding material 190, but is not limited to this. Absent. Even if the shoulder portion 201 has a shape that inclines so as to form a concave portion from the periphery toward the tool center, as in the case of a normal friction stir welding tool, the shoulder portion 201 has a spiral shape from the periphery to the tool center. A spiral concavo-convex structure including a plurality of protrusions may be used. Further, the height of the taper pin 210, that is, the height of the truncated cone is substantially the same as the thickness of the joining member.

  Further, as described above, the angle θ2 formed between the side surface 211 of the taper pin 210 and the shoulder portion 201 is set based on the angle at which the stress singularity disappears at the free edge at the end portion of the joint interface by the analysis of the stress singularity. Has been. Here, as described above, the angle θ2 formed by the side surface 211 of the taper pin 210 and the shoulder portion 201 is set in the range of 120 to 135 degrees based on the analysis result of the stress singularity.

  In addition, the taper pin 210 is disposed so that the central axis of the taper pin 210 is located on the second bonding material 190 side rather than the bonding interface 220 between the first bonding material 180 and the second bonding material 190. The taper pin 210 may be arranged so that the central axis of the taper pin 210 is located on the first bonding material 180 side. That is, the taper pin 210 may be disposed so that the central axis of the taper pin 210 is located on either one of the first bonding material 180 side and the second bonding material 190 side rather than the bonding interface 220.

  For example, when the taper pin 210 is arranged so that the central axis of the taper pin 210 is located closer to the second bonding material 190 than the bonding interface 220 between the first bonding material 180 and the second bonding material 190, As shown in FIG. 4B, one end edge 210a on the first bonding material 180 side of the tip portion of the taper pin 210 is 0.1 on the bonding interface 220 or closer to the first bonding material 180 side than the bonding interface 220. It is preferable to arrange the taper pin 210 so as to be positioned at about ˜1.5 mm. In this case, since the aluminum alloy is mainly frictionally stirred, the mixing of the titanium alloy into the portion where the friction diffusion treatment is performed (the portion corresponding to the friction diffusion treatment portion 230 described later) can be suppressed to a minimum amount. The mechanical properties of the part are improved. Further, since the soft aluminum alloy is mainly frictionally stirred, friction stirring is easy and consumption of the taper pin 210 can be suppressed. Further, the taper pin 210 may be a threaded one that is generally used for friction stir welding, but a screwless pin can be used to mainly friction stir a soft aluminum alloy.

  On the other hand, when the taper pin 210 is arranged so that the central axis of the taper pin 210 is located on the first bonding material 180 side, the other edge 210b on the second bonding material 190 side of the tip of the taper pin 210 is It is preferable to arrange the taper pin 210 so as to be positioned about 0.1 to 1.5 mm on the bonding interface 220 or on the second bonding material 190 side with respect to the bonding interface 220.

  As described above, the taper pin 50 is disposed so that the central axis of the taper pin 210 is located on either one of the first bonding material 180 side and the second bonding material 190 side rather than the bonding interface 220. This is because, in the portion subjected to the frictional diffusion treatment (the portion corresponding to the frictional diffusion treatment unit 230 described later), either one of the first bonding material 180 and the second bonding material 190 is more than 50% by volume. This is to increase the number.

  Then, the friction stir tool 200 is rotated at a predetermined rotation speed (for example, 1000 to 5000 rpm). Subsequently, the friction stir tool 200 is moved downward from the disposed position, and the taper pin 210 is moved to the surface 182 of the first bonding material 180 including the edge 221 on one end side of the bonding interface 220 and the second bonding. Contact surface 192 of material 190. In this state, after holding for several seconds to several tens of seconds until reaching a temperature at which frictional stirring is satisfactorily performed, as shown in FIG. 4C, a predetermined moving speed (for example, along the edge 221 on one end side of the bonding interface 220) The friction stir tool 200 is moved at 300 to 2000 mm / min. The taper pin 210 is pressed against the bonding material side with a predetermined pressure. After the friction stir tool 200, that is, the taper pin 210 is moved to the end of processing, the friction stir tool 200 is raised and the taper pin 210 is pulled out. Further, as shown in FIG. 4C, when the friction stir processing is performed, the shoulder portion 201 of the friction stir tool 200 is subjected to the surface 182 of the first bonding material 180 and the surface of the second bonding material 190 with a predetermined pressure. Since it is pressed against 192, the plastically flowed material does not flow out.

  As described above, the frictional diffusion processing unit 230 is formed in the portion where the taper pin 210 has moved, as shown in FIG. 4D. The friction diffusion processing unit 230 configures the second bonding material 190 when the friction stir processing is performed by bringing the taper pin 210 into contact with the bonding member in a state where the central axis of the taper pin 210 is located on the second bonding material 190 side. It is comprised with the alloy containing the titanium alloy which comprises the 1st joining material 180 which mainly made the aluminum alloy to do. On the other hand, when the friction stir processing is performed by bringing the taper pin 210 into contact with the bonding member in a state where the central axis of the taper pin 210 is located on the first bonding material 180 side, the friction diffusion processing unit 230 causes the first bonding material 180 to be removed. It is comprised with the alloy containing the aluminum alloy which comprises the 2nd joining material 190 which mainly comprised the titanium alloy to comprise.

  Thus, since the friction diffusion process can be performed so as to include the bonding interface 220 over the thickness direction of the bonding member, the bonding process and the inclination imparting process of the bonding edge can be performed at the same time.

  Here, the bonding surface 181 of the first bonding material 180 and the surfaces 182 and 183 of the first bonding material 180 intersect perpendicularly, and the bonding surface 191 of the second bonding material 190 and the second bonding material 190 Although an example using a bonding material in which the surfaces 192 and 193 intersect perpendicularly is shown, the above-described friction diffusion treatment can also be applied to bonding of bonding materials other than these configurations.

  FIG. 5A to FIG. 5D are diagrams schematically showing a cross section of a joint portion of different materials for explaining a friction stir processing method for the joint portion of different materials having other configurations.

  As shown in FIG. 5A, the bonding surface 181 of the first bonding material 180 is configured to have an angle θ <b> 1 formed with the surface 182 of the first bonding material 180. The formed angle θ1 is the angle at which the stress singularity disappears at the free edge at the end of the joint interface according to the analysis of the stress singularity described in the first embodiment. Further, the bonding surface 191 of the second bonding material 190 is configured by an inclined surface corresponding to the bonding surface 181 of the first bonding material 180. Note that here, as in the above-described combination of different materials, the first bonding material 180 is formed of a titanium alloy, and the second bonding material 190 is formed of an aluminum alloy having a softening temperature different from that of the first bonding material 180. An example is shown. Note that the thicknesses of both the bonding materials are the same.

  First, as shown in FIG. 5B, the bonding surface 181 of the first bonding material 180 and the bonding surface 191 of the second bonding material 190 are abutted. At this time, a predetermined pressure is applied in a direction in which the bonding surface 181 of the first bonding material 180 and the bonding surface 191 of the second bonding material 190 are brought into contact with each other.

  The friction stir tool and pin used for friction stir welding have the same configuration as the friction stir tool 200 and the taper pin 210 described above, and the angle θ2 formed between the side surface 211 of the taper pin 210 and the shoulder portion 201 is as described above. The angle θ 1 is the same as the angle θ 1 formed by the bonding surface 181 of the first bonding material 180 and the surface 182 of the first bonding material 180.

  Further, as shown in FIG. 5B, one end edge 210 c of the base portion of the taper pin 210 on the first bonding material 180 side is an end of the bonding interface 220 between the first bonding material 180 and the second bonding material 190. It is preferable to arrange the taper pin 210 so as to be positioned about 0.1 to 1.5 mm closer to the first bonding material 180 than the edge 221. It is preferable to arrange in this range when the distance is less than 0.1 (for example, when the end edge 210c is located at the bonding interface (in the case of 0 mm)), there is a high possibility that bonding failure will occur, and 1.5 mm This is because the occurrence of poor bonding is eliminated with the arrangement up to the extent, and when it exceeds 1.5 mm, the mixing ratio of the first bonding material 180 to the second bonding material 190 increases. In this case, since the aluminum alloy is mainly frictionally agitated, mixing of the titanium alloy into the friction diffusion treatment unit 230 can be suppressed to a minimum amount, and the mechanical characteristics of the joint portion are improved. Further, since the soft aluminum alloy is mainly frictionally stirred, friction stirring is easy and consumption of the taper pin 210 can be suppressed. Further, the taper pin 210 may be a threaded one that is generally used for friction stir welding, but a screwless pin can be used to mainly friction stir a soft aluminum alloy.

  Subsequently, the friction stir tool 200 is rotated at a predetermined rotation speed (for example, 1000 to 5000 rpm), the friction stir tool 200 is moved downward from the arranged position, and the taper pin 210 is connected to one end of the joining interface 220. The surface 182 of the first bonding material 180 including the side edge 221 and the surface 192 of the second bonding material 190 are brought into contact. After being held for several seconds to several tens of seconds until reaching a temperature at which frictional stirring is satisfactorily performed in this state, as shown in FIG. 5C, a predetermined moving speed (for example, along the edge 221 on one end side of the bonding interface 220) The friction stir tool 200 is moved at 300 to 2000 mm / min. The taper pin 210 is pressed against the bonding material side with a predetermined pressure. After the friction stir tool 200, that is, the taper pin 210 is moved to the end of processing, the friction stir tool 200 is raised and the taper pin 210 is pulled out. Further, as shown in FIG. 5C, when the friction stir processing is performed, the shoulder portion 201 of the friction stir tool 200 is subjected to the surface 182 of the first bonding material 180 and the surface of the second bonding material 190 with a predetermined pressure. Since it is pressed against 192, the plastically flowed material does not flow out.

  As described above, the frictional diffusion processing unit 230 is formed in the portion where the taper pin 210 has moved, as shown in FIG. 5D. The friction diffusion processing unit 230 is made of an alloy containing a titanium alloy that constitutes the first bonding material 180, mainly an aluminum alloy that constitutes the second bonding material 190.

  As described above, since the friction diffusion process can be performed so as to include the bonding interface 220 in the thickness direction of the bonding member, the bonding process can be performed simultaneously in the thickness direction.

  As described above, according to the friction stir processing method for joints of different materials according to the third embodiment of the present invention, since all the joint interfaces are joined by friction stir welding, it is easy and reliable. Some bonding can be performed. In addition, since the frictional diffusion process can be performed so as to include the bonding interface 220 over the thickness direction of the bonding member, the bonding process and the inclination imparting process of the bonding edge can be performed simultaneously.

  In addition, since the joining portion of the joining material can be a simple construction such as a straight butt construction, joining of the joining material can be easily performed, and the production time and production cost of the joining material can be reduced. it can.

  Although the present invention has been specifically described above with reference to the embodiments, the present invention is not limited to these embodiments, and various modifications can be made without departing from the scope of the invention. For example, in the above-described embodiment, an example in which the friction stir tool is moved to join the dissimilar materials is shown. However, the dissimilar material may be moved without moving the friction stir tool. In this case as well, the same effects as when the friction stir tool is moved can be obtained.

The figure which shows typically the cross section of the junction part of a dissimilar material for demonstrating the friction stirring process method of the junction part of the dissimilar material of the 1st Embodiment of this invention. The figure which shows typically the cross section of the junction part of a dissimilar material for demonstrating the friction stirring process method of the junction part of the dissimilar material of the 1st Embodiment of this invention. The figure which shows typically the cross section of the junction part of a dissimilar material for demonstrating the friction stirring process method of the junction part of the dissimilar material of the 1st Embodiment of this invention. The figure which shows typically the cross section of the junction part of a dissimilar material for demonstrating the friction stirring process method of the junction part of the dissimilar material of the 1st Embodiment of this invention. The figure which shows typically the cross section of the junction part of a dissimilar material for demonstrating the friction stirring process method of the junction part of the dissimilar material of the 1st Embodiment of this invention. The figure which shows typically the cross section of the junction part of a dissimilar material for demonstrating the friction stirring process method of the junction part of the dissimilar material of the 1st Embodiment of this invention. The figure which shows typically the cross section of the junction part of a dissimilar material for demonstrating the friction stirring process method of the junction part of the dissimilar material of the 1st Embodiment of this invention. The figure which shows typically the cross section of the junction part of a dissimilar material for demonstrating the friction stir welding method of the dissimilar material of the 2nd Embodiment of this invention. The figure which shows typically the cross section of the junction part of a dissimilar material for demonstrating the friction stir welding method of the dissimilar material of the 2nd Embodiment of this invention. The figure which shows typically the cross section of the junction part of a dissimilar material for demonstrating the friction stir welding method of the dissimilar material of the 2nd Embodiment of this invention. The figure which shows typically the cross section of the junction part of a dissimilar material for demonstrating the friction stir welding method of the dissimilar material of the 2nd Embodiment of this invention. The figure which shows typically the cross section of the junction part of a dissimilar material for demonstrating the friction stir welding method of the dissimilar material of the 2nd Embodiment of this invention. The figure which shows typically the cross section of the junction part of a dissimilar material for demonstrating the friction stir welding method of the dissimilar material of the 2nd Embodiment of this invention. The figure which shows typically the cross section of the junction part of a dissimilar material for demonstrating the friction stir welding method of the dissimilar material of the 2nd Embodiment of this invention. The figure which shows typically the cross section of the junction part of a dissimilar material for demonstrating the friction stir welding method of the dissimilar material of the 2nd Embodiment of this invention. The figure which shows typically the cross section of the other form of the tool for friction stirring. The figure which shows typically the cross section of the junction part of a dissimilar material for demonstrating the friction stirring processing method of the junction part of the dissimilar material of the 3rd Embodiment of this invention. The figure which shows typically the cross section of the junction part of a dissimilar material for demonstrating the friction stirring processing method of the junction part of the dissimilar material of the 3rd Embodiment of this invention. The figure which shows typically the cross section of the junction part of a dissimilar material for demonstrating the friction stirring processing method of the junction part of the dissimilar material of the 3rd Embodiment of this invention. The figure which shows typically the cross section of the junction part of a dissimilar material for demonstrating the friction stirring processing method of the junction part of the dissimilar material of the 3rd Embodiment of this invention. The figure which shows typically the cross section of the junction part of a dissimilar material for demonstrating the friction stirring process method of the junction part of the dissimilar material of another structure. The figure which shows typically the cross section of the junction part of a dissimilar material for demonstrating the friction stirring process method of the junction part of the dissimilar material of another structure. The figure which shows typically the cross section of the junction part of a dissimilar material for demonstrating the friction stirring process method of the junction part of the dissimilar material of another structure. The figure which shows typically the cross section of the junction part of a dissimilar material for demonstrating the friction stirring process method of the junction part of the dissimilar material of another structure.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... 1st joining material, 11, 21 ... Joining surface, 12, 13, 22, 23 ... Surface, 20 ... 2nd joining material, 30 ... Joining interface, 31, 32, 50a, 50b ... Edge, 40 ... Friction stirring tool, 41 ... Shoulder part, 50 ... Taper pin, 51, 61, 62 ... Side face, 60 ... Friction diffusion processing part.

Claims (6)

A friction stir processing method for dissimilar material joints in which joints of dissimilar materials having different softening temperatures are processed by friction stirring,
An end face is provided on the flat friction stir tool and the end face of the friction stir tool, and is determined based on the stress singularity disappearance range obtained from the stress singularity analysis of the end face and the joint interface end of the dissimilar material. A friction stirrer including a stirrer having a truncated cone shape having a predetermined angle formed and a cross-sectional area gradually decreasing toward the tip, and rotating at least one of the joints of the different materials The angle formed by the joint surface at the joint edge of the joint and the surface of the dissimilar material is moved relative to the dissimilar material while plastically flowing the dissimilar material along the joint edge. Is a predetermined angle determined based on the stress singularity disappearance range, and a friction stir processing method for a dissimilar material joint portion.   2. The dissimilar material joint according to claim 1, wherein when the stirrer is moved relatively, a central axis of the stirrer is located on one of the dissimilar materials side with respect to the joining edge. The friction stir processing method. A friction stir welding method for different materials in which different materials having different softening temperatures are joined by friction stirring,
An end face is provided on the flat friction stir tool and the end face of the friction stir tool, and is determined based on the stress singularity disappearance range obtained from the stress singularity analysis of the end face and the joint interface end of the dissimilar material. A friction stirrer having a predetermined truncated angle and a stirrer configured in the shape of a truncated cone that gradually decreases in cross-sectional area toward the tip, and joining the dissimilar materials in contact with each other While moving the dissimilar material relative to the dissimilar material while plastically flowing the dissimilar material along at least one interface edge, the agitation unit is moved, and the dissimilar material is joined. An angle formed between a bonding surface at a bonded end edge and a surface of the different material is a predetermined angle determined based on the stress singularity disappearance range. Stir welding method rub.   The friction of dissimilar materials according to claim 3, wherein when the stirrer is moved relatively, the central axis of the stirrer is located on any one dissimilar material side with respect to the interface edge. Stir welding method.   5. The friction stir welding method for dissimilar materials according to claim 3 or 4, wherein the contact surfaces of the dissimilar materials have a straight butted shape.   The edge of the contact surface of the dissimilar material has a butt shape formed of an inclined surface that inclines in the thickness direction of the dissimilar material according to a predetermined angle determined based on the stress singularity disappearance range. 5. The friction stir welding method for dissimilar materials according to claim 3 or 4, wherein the friction stir welding method is used.

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