JP7272153B2 - Joining method and manufacturing method of composite rolled material - Google Patents

Description

TECHNICAL FIELD The present invention relates to a joining method and a manufacturing method of a composite rolled material.

For example, Patent Literature 1 discloses a technique of friction stir welding metal members made of different materials with a rotary tool.

JP 2016-150380 A

In a conventional joining method, inclined surfaces are provided at both ends of the first metal member and the second metal member, and these inclined surfaces are brought into surface contact with each other to butt each other. Therefore, there is a problem that it is complicated to form the inclined surface, and that the preparation process and the butting process become complicated because the surface contact does not occur unless the inclination angles of the two metal members match.

From such a point of view, an object of the present invention is to provide a joining method and a method for manufacturing a composite rolled material that can easily join different kinds of metal members.

In order to solve such problems, the present invention provides a joining method for joining a pair of metal members made of different materials using a rotary tool having a proximal pin and a distal pin, wherein the proximal pin is larger than the taper angle of the distal pin, the proximal pin has a stepped portion on its outer peripheral surface, and the first pin has a vertical surface at its end. a metal member, a second metal member having a first inclined surface at the end on the back side and a second inclined surface at the end on the front side, and having a higher melting point and a smaller plate thickness than the first metal member; a preparation step of preparing the first metal member and the second metal member, abutting step of forming a butt portion having a V-shaped gap by butting the ends of the first metal member and the second metal member, and The first metal member is inserted only from the surface of the first metal member, and the first metal member is caused to flow into the gap while the outer peripheral surfaces of the distal side pin and the proximal side pin are in contact with at least the first metal member. and a joining step of joining the first metal member and the second metal member by relatively moving the rotating tool along the butting portion, wherein the joining step includes: Let γ be the angle of inclination with respect to the vertical plane, let β be the angle of inclination of the first inclined surface with respect to the vertical plane, let β be the angle of inclination of the second inclined surface with respect to the vertical plane, and let β′ be the angle of inclination of the second inclined surface with respect to the vertical plane. Let α be the angle of inclination with respect to the central axis, and let α′ be the angle of inclination of the outer peripheral surface of the proximal pin with respect to the central axis of rotation. characterized by performing

The present invention also provides a joining method for joining a pair of metal members made of different materials using a rotary tool having a proximal pin and a distal pin, wherein the taper angle of the proximal pin is equal to the distal end. The taper angle of the side pin is larger than the taper angle of the side pin, and a stepped stepped portion is formed on the outer peripheral surface of the base side pin. a preparation step of preparing a second metal member having a first inclined surface at an end portion and a second inclined surface at an end portion on the surface side, and having a higher melting point and a smaller plate thickness than the first metal member; a butting step of butting ends of the first metal member and the second metal member to form a butting portion having a V-shaped gap; While the outer peripheral surface of the proximal side pin is in contact with the surface of the first metal member, the outer peripheral surfaces of the distal side pin and the proximal side pin are in contact with at least the first metal member a joining step of joining the first metal member and the second metal member by relatively moving the rotating tool along the butted portion while allowing the first metal member to flow into the gap in the above state; and a rolling step of rolling the metal members joined in the step with the joining line as the rolling direction, and in the joining step, the inclination angle of the rotation center axis of the rotary tool with respect to the vertical plane is γ, and the second Let β be the inclination angle of one inclined surface with respect to the vertical plane, β′ be the inclination angle of the second inclined surface with respect to the vertical plane, α be the inclination angle of the outer peripheral surface of the tip side pin with respect to the rotation center axis, and Assuming that the inclination angle of the outer peripheral surface of the end-side pin with respect to the rotation center axis is α', the welding is performed in a state of γ=α-β and γ=α'-β'.

According to this joining method or manufacturing method, only the second metal member is required to form the inclined surface. In addition, since the two metal members are butted with a V-shaped gap, high accuracy is not required and the butting work can be easily performed. Also, for example, if the rotating tool is inserted so as to contact only the first metal member, the welding conditions can be adjusted according to the first metal member having a low softening temperature, and the amount of heat input can be suppressed. Therefore, it is possible to prevent the first metal member from being greatly softened and excessive burrs to be generated, and it is possible to prevent defective bonding due to lack of metal. Further, the inclination angle γ with respect to the vertical plane of the rotation center axis of the rotating tool is obtained by subtracting the inclination angle β of the first inclined surface with respect to the vertical direction from the inclination angle α of the outer peripheral surface of the tip side pin with respect to the rotation center axis, and the base end The inclination angles α, β, α', β' are optimized by matching the value obtained by subtracting the inclination angle β' of the second inclined surface with respect to the vertical surface from the inclination angle α' with respect to the rotation center axis of the outer peripheral surface of the side pin. can be selected, and the outer peripheral surface of the distal side pin and the first inclined surface and the outer peripheral surface of the proximal side pin and the second inclined surface are parallel to each other, and the distal side pin and the proximal side pin While avoiding excessive contact between the outer peripheral surface and each inclined surface, the outer peripheral surfaces of the distal side pin and the proximal side pin and each inclined surface can be brought as close to each other as possible over the height direction. Further, by making the plate thickness of the first metal member larger than the plate thickness of the second metal member, it is possible to prevent metal shortage at the joint portion.

Moreover, in the butting step, it is preferable that the first metal member and the second metal member are butted together in a state where the back surfaces of the first metal member and the second metal member are flush with each other.

According to such a joining method, the rear surfaces of the metal members can be made flush with each other.

In addition, in the butting step, the back surface of the first metal member is positioned lower than the back surface of the second metal member, and the front surface of the first metal member is positioned higher than the front surface of the second metal member. The first metal member and the second metal member are butted against each other, and in the joining step, the tip of the tip side pin is positioned below the height of the back surface of the second metal member. It is preferable to set the insertion depth.

According to such a joining method, friction welding can be performed over the entire depth direction of the second metal member.

Further, in the joining step, the rotating tool is rotated so that the second metal member side is the shear side and the first metal member side is the flow side in the plasticized region formed in the moving locus of the rotating tool. It is preferable to set the direction and direction of travel.

If the second metal member side, which has a higher melting point, becomes the flow side of the plasticized region, the temperature of the first metal member at the butted portion decreases, and mutual diffusion at the interface between different metals is not promoted, resulting in poor bonding. may become However, according to such a joining method, by setting the second metal member having a higher melting point to be the shear side, it is possible to keep the temperature of the first metal member at the butted portion relatively high. Mutual diffusion at the interface between metals is promoted, and poor bonding can be prevented.

The shear side is the side where the relative speed of the outer circumference of the rotary tool with respect to the joint portion is a value obtained by adding the magnitude of the tangential speed at the outer circumference of the rotary tool to the magnitude of the movement speed. The flow side is the side where the relative speed of the outer circumference of the rotary tool with respect to the joint portion is the value obtained by subtracting the magnitude of the movement speed from the magnitude of the tangential speed at the outer circumference of the rotary tool.

In the preparing step, the first metal member is made of aluminum or an aluminum alloy, and the second metal member is made of copper or a copper alloy. While contacting only the surface of the first metal member, the outer peripheral surface of the tip side pin is not contacted with the second metal member, and the first metal member is caused to flow into the gap and is moved along the butted portion. It is preferable to join the first metal member and the second metal member by relatively moving a rotating tool.

According to such a joining method, a metal member made of copper or a copper alloy and a metal member made of aluminum or an aluminum alloy can be preferably joined.

Further, in the joining step, when a counterclockwise spiral groove is formed on the outer peripheral surface of the distal end side pin from the proximal end toward the distal end, the rotating tool is rotated clockwise to allow the outer peripheral surface of the distal end side pin to move toward the outer peripheral surface of the distal end side pin. When a clockwise spiral groove is cut from the end to the tip, it is preferable to rotate the rotary tool counterclockwise.

According to such a joining method, the plastically fluidized metal is guided by the spiral grooves and flows to the tip side of the rotating tool, so it is possible to suppress the occurrence of burrs.

According to the joining method and the method for producing a composite rolled material according to the present invention, different kinds of metal members can be preferably joined.

1 is a side view of a rotary tool according to an embodiment of the invention; FIG. FIG. 4 is an enlarged cross-sectional view of the rotary tool; It is a cross-sectional view showing a first modification of the rotary tool. It is a sectional view showing the second modification of the rotary tool. It is a sectional view showing the third modification of a rotation tool. It is sectional drawing which shows the preparation process and butting process which concern on 1st embodiment of this invention. It is a perspective view which shows the joining process which concerns on 1st embodiment. It is sectional drawing which shows the joining process which concerns on 1st embodiment. It is sectional drawing which shows after the joining process which concerns on 1st embodiment. It is a perspective view which shows the rolling process which concerns on 1st embodiment. It is sectional drawing which shows after the rolling process which concerns on 1st embodiment. It is sectional drawing which shows the preparation process and butting process which concern on 2nd embodiment of this invention. It is sectional drawing which shows the joining process which concerns on 2nd embodiment. It is sectional drawing which shows after the joining process which concerns on 2nd embodiment.

Embodiments of the present invention will be described with reference to the drawings as appropriate. First, the rotary tool used in the joining method according to this embodiment will be described. A rotating tool is a tool used for friction stir welding. As shown in FIG. 1, the rotating tool F is made of, for example, tool steel, and is mainly composed of a base shaft portion F1, a proximal pin F2, and a distal pin F3. The base shaft portion F1 has a cylindrical shape and is a portion connected to the main shaft of the friction stirrer.

The base end pin F2 is continuous with the base shaft portion F1 and tapers toward the tip. The proximal pin F2 has a truncated cone shape. The taper angle A of the proximal pin F2 may be set appropriately, and is, for example, 135 to 160°. If the taper angle A is less than 135° or exceeds 160°, the joint surface roughness after friction stir increases. The taper angle A is larger than the taper angle B of the distal pin F3, which will be described later. As shown in FIG. 2, a stepped pin stepped portion F21 is formed over the entire height direction on the outer peripheral surface of the base end side pin F2. The pin stepped portion F21 is spirally formed clockwise or counterclockwise. That is, the pin stepped portion F21 has a spiral shape when viewed from above, and has a stepped shape when viewed from the side. In this embodiment, since the rotary tool F is rotated rightward, the pin step portion F21 is set counterclockwise from the base end side toward the tip end side.

When rotating the rotating tool F to the left, it is preferable to set the pin stepped portion F21 clockwise from the proximal side to the distal side. As a result, the plastic flow material is guided to the tip end side by the pin stepped portion F21, so that the amount of metal overflowing to the outside of the metal members to be joined can be reduced. The pin step portion F21 is composed of a step bottom surface F21a and a step side surface F21b. The distance X1 (horizontal distance) between the vertices F21c, F21c of the adjacent pin stepped portions F21 is appropriately set according to the stepped angle C and the height Y1 of the stepped side surface F21b, which will be described later.

The height Y1 of the stepped side surface F21b may be set as appropriate, and is set to 0.1 to 0.4 mm, for example. If the height Y1 is less than 0.1 mm, the joint surface roughness becomes large. On the other hand, when the height Y1 exceeds 0.4 mm, the joint surface roughness tends to increase, and the number of effective stepped portions (the number of pin stepped portions F21 in contact with the metal members to be joined) also decreases.

The step angle C between the step bottom surface F21a and the step side surface F21b may be set appropriately, but is set to 85 to 120°, for example. The stepped bottom surface F21a is parallel to the horizontal plane in this embodiment. The stepped bottom surface F21a may be inclined in the range of −5° to 15° with respect to the horizontal plane toward the outer peripheral direction from the rotation axis of the tool (minus is downward with respect to the horizontal plane, plus is with respect to the horizontal plane above). The distance X1, the height Y1 of the stepped side surface F21b, the stepped angle C, and the angle of the stepped bottom surface F21a with respect to the horizontal plane are such that the plastic flow material does not stay inside the pin stepped portion F21 and adhere to the outside when performing friction stir. In addition, the step bottom F21a presses the plastic flow material to reduce the joint surface roughness.

As shown in FIG. 1, the distal pin F3 is formed continuously with the proximal pin F2. The distal pin F3 has a truncated cone shape. The tip of the tip side pin F3 is a flat surface F4 perpendicular to the rotation axis. A taper angle B of the distal pin F3 is smaller than a taper angle A of the proximal pin F2. As shown in FIG. 2, a spiral groove F31 is engraved on the outer peripheral surface of the tip side pin F3. The spiral groove F31 may be either clockwise or counterclockwise, but in this embodiment, it is engraved counterclockwise from the proximal side toward the distal side in order to rotate the rotary tool F clockwise.

In addition, when rotating the rotating tool F counterclockwise, it is preferable to set the spiral groove F31 clockwise from the base end side to the tip end side. As a result, the plastic flow material is guided to the tip side by the spiral groove F31, so that the amount of metal overflowing to the outside of the metal members to be joined can be reduced. The spiral groove F31 is composed of a spiral bottom surface F31a and a spiral side surface F31b. The distance (horizontal distance) between the apexes F31c, F31c of the adjacent spiral grooves F31 is defined as length X2. Let the height of the spiral side surface F31b be a height Y2. A spiral angle D formed by the spiral bottom surface F31a and the spiral side surface F31b is, for example, 45 to 90°. The spiral groove F31 has the role of increasing the frictional heat by coming into contact with the metal members to be joined and guiding the plastic flow material to the tip side.

The design of the rotating tool F can be changed as appropriate. FIG. 3 is a side view showing a first modification of the rotary tool of the invention. As shown in FIG. 3, in the rotary tool FA according to the first modified example, the step angle C between the step bottom surface F21a and the step side surface F21b of the pin step portion F21 is 85°. The stepped bottom surface F21a is parallel to the horizontal plane. In this way, the stepped bottom surface F21a is parallel to the horizontal surface, and the stepped angle C may be an acute angle within a range in which the plastic flow material stays and adheres to the pin stepped portion F21 during friction stirring and escapes to the outside. .

FIG. 4 is a side view showing a second modification of the rotary tool of the invention. As shown in FIG. 4, in the rotary tool FB according to the second modification, the step angle C of the pin step portion F21 is 115°. The stepped bottom surface F21a is parallel to the horizontal plane. In this manner, the stepped bottom surface F21a may be parallel to the horizontal plane, and the stepped angle C may be an obtuse angle within the range of functioning as the pin stepped portion F21.

FIG. 5 is a side view showing a third modification of the rotary tool of the invention. As shown in FIG. 5, in the rotary tool FC according to the third modification, the stepped bottom surface F21a is inclined upward by 10° with respect to the horizontal plane from the rotation axis of the tool toward the outer peripheral direction. The stepped side surface F21b is parallel to the vertical plane. In this manner, the stepped bottom surface F21a may be formed so as to be inclined upward from the horizontal surface toward the outer peripheral direction from the rotating shaft of the tool within a range where the plastic flow material can be pressed during friction stirring. The first to third modifications of the rotating tool described above can also produce effects equivalent to those of the following embodiments.

[First embodiment]
Next, a method for producing a composite rolled material according to the first embodiment of the present invention will be described. In the method for manufacturing a composite rolled material according to this embodiment, a pair of metal members are joined together by a rotating tool F and then rolled to obtain a composite rolled material. In addition, below, let the surface of the opposite side of a "back surface" be a "front surface."

As shown in FIG. 6, the first metal member 1 has a plate shape. The end surface 1a of the first metal member 1 is a vertical surface perpendicular to the front surface 1b and the rear surface 1c. The first metal member 1 is made of an aluminum alloy in this embodiment, but may be made of a metal material that can be friction-stirred, such as aluminum, copper, copper alloy, titanium, titanium alloy, magnesium, or magnesium alloy.

The second metal member 2 has a plate shape. The plate thickness of the second metal member 2 is smaller than the plate thickness of the first metal member 1 . The end surface 2a of the second metal member 2 has a first inclined surface 2a1 inclined with respect to the vertical plane at the end on the back surface 2c side and a second inclined surface 2a2 inclined with respect to the vertical plane at the end on the front surface 2b side. ing. The inclination angle β of the first inclined surface 2a1 with respect to the vertical plane may be appropriately set, but in the present embodiment, the inclination angle β is larger than the inclination angle α (FIG. 1) with respect to the vertical surface of the tip side pin F3. The inclination angle β' of the second inclined surface 2a2 with respect to the vertical plane may be set as appropriate, but in this embodiment, the angle is larger than the inclination angle α' (FIG. 1) of the distal pin F3 with respect to the vertical plane. . The second metal member 2 is made of a material that has a higher melting point than the first metal member 1 and that can be friction-stirred. The second metal member 2 may be made of copper or a copper alloy, for example.

The method for manufacturing a composite rolled material according to this embodiment includes a preparation process, a butting process, a joining process, and a rolling process. In addition, the joining method in the scope of claims is a step of performing a preparation step, a matching step, and a joining step. The preparation step is a step of preparing the first metal member 1, the second metal member 2 and the rotary tool F described above.

The butting step is, as shown in FIG. 6, a step of butting the ends of the first metal member 1 and the second metal member 2 with each other. In the butting step, the end surface 1a of the first metal member 1 and the end surface 2a of the second metal member 2 are butted together to form a butting portion J. As shown in FIG. The abutting portion J is formed with a gap having a substantially V-shaped cross section so that the opening widens toward the surfaces 1b and 2b. The rear surface 1c of the first metal member 1 and the rear surface 2c of the second metal member 2 are flush with each other. The first metal member 1 and the second metal member 2 are fixed to the base K so as not to move.

The joining step is a step of joining the first metal member 1 and the second metal member 2 using the rotary tool F. As shown in FIG. As shown in FIGS. 7 and 8, in the joining step, while rotating the distal end pin F3 of the rotating tool F to the right, the starting point is set on the surface 1b of the first metal member 1 and in the vicinity of the butting portion J. A tip side pin F3 is inserted in the position Sp. Then, the rotating tool F is relatively moved parallel to the extending direction of the butted portion J. A plasticized region W is formed in the movement trajectory of the rotating tool F. As shown in FIG. In the joining step, friction stir welding is performed so that the plastic flow material on the side of the first metal member 1 mainly flows into the gap of the butted portion J. As shown in FIG.

As shown in FIG. 8, in the main joining step, the rotation center axis j of the rotary tool F is inclined toward the second metal member 2 with respect to the vertical plane by an inclination angle γ, so that the tip-side pin F3 is attached to the first metal member. Friction stir is performed in a state of contact with only 1. The inclination angle γ for inclining the rotation center axis j of the rotary tool F with respect to the vertical plane is determined from the inclination angle α ( FIG. It is the same as the value obtained by subtracting the inclination angle β (FIG. 6) of the inclined surface 2a1 (γ=α−β), and the inclination angle α′ (FIG. 1) formed with the outer peripheral surface of the proximal pin F2. is the same as the value obtained by subtracting the inclination angle β' (FIG. 6) of the second inclined surface 2a2 of the second metal member 2 from (γ=α'-β'). Since the value of γ in this case is a negative value, the rotation center axis j is tilted toward the second metal member 2 side. The first inclined surface 2a1 and the outer peripheral surface of the tip side pin F3 facing the first inclined surface 2a1 are parallel to each other. In addition, the second inclined surface 2a2 and the outer peripheral surface of the base end pin F2 facing the second inclined surface 2a2 are parallel to each other.

That is, the direction in which the rotation center axis j of the rotary tool F is tilted is determined by the relationship between the tilt angles α, β, α', and β'. For example, when "α>β, α'>β'", the inclination angle γ takes a positive value, and the rotation center axis j of the rotary tool F is inclined toward the first metal member. In addition, when "α<β, α'<β'", the inclination angle γ takes a negative value, and the rotation center axis j of the rotary tool F is inclined toward the second metal member 2 side. In addition, when "α=β", the tilt angle γ is "0 (zero)", and the rotation center axis j of the rotating tool F is parallel to the vertical plane without being tilted.

In the joining process, in the plasticized region W, the second metal member 2 side (the side closer to the butt portion J) is the shear side, and the first metal member 1 side (the side away from the butt portion J) is the flow side. is set to That is, in the joining process according to the present embodiment, the first metal member 1 is positioned on the right side in the traveling direction, and the rotating tool F is rotated to the right. In the case where the second metal member 2 is positioned on the right side in the traveling direction, by rotating the rotating tool F to the left, the second metal member 2 side (the side close to the butted portion J) of the plasticized region W ) is the shear side.

The insertion depth of the tip side pin F3 may be appropriately set as shown in FIG. In addition, in the bonding process of the present embodiment, the starting position Sp position and movement route are set. Also, the insertion depth is set so that the outer peripheral surface of the proximal pin F2 and the surface 1b of the first metal member 1 are in contact with each other.

Here, if the outer peripheral surface of the tip side pin F3 and the second metal member 2 are separated from each other by a large distance, the first metal and the second metal do not mutually diffuse at the abutting portion J, and the first metal member 1 and the second metal The member 2 cannot be firmly joined. On the other hand, if the tip side pin F3 and the second metal member 2 are brought into contact with each other and friction stir is performed in a state in which the overlapping margin between the two is increased, the welding conditions are adjusted to soften the second metal member 2. It is necessary to increase the amount of heat, which may result in poor bonding. Therefore, the outer peripheral surface of the tip end side pin F3 and the second metal member 2 are joined in a state of slightly contacting each other so that the first metal and the second metal are mutually diffused and joined at the abutting portion J. Alternatively, it is preferable to join the outer peripheral surface of the tip-side pin F3 and the second metal member 2 in a state where they are brought close to each other as much as possible without contacting each other.

Also, as in the present embodiment, when the first metal member 1 is an aluminum or aluminum alloy member and the second metal member 2 is a copper or copper alloy member, in the joining step, the outer peripheral surface of the tip side pin F3 and the It is preferable to join the second metal member 2 in a state in which they are brought as close as possible without contacting each other. Incidentally, if the outer peripheral surface of the tip side pin F3 and the second metal member 2 (copper member) are brought into contact under the joining condition where the heat input becomes large, a small amount of the copper member is stirred and mixed into the aluminum alloy member. , the mutual diffusion of Al/Cu is promoted, the Al--Cu phase dispersed in the aluminum alloy member becomes a liquid phase, and many burrs are generated from the aluminum alloy member side, resulting in poor bonding.

As shown in FIG. 9, burrs are less likely to be formed on the surface of the plasticized region W because the plastic flow material can be pressed by the outer peripheral surface of the proximal pin F2. The plasticized region W and the second metal member 2 are adjacent to each other. In other words, the plasticized region W is not formed on the second metal member 2 side beyond the butted portion J. Since the first metal member 1 is formed thicker than the second metal member 2, the plastic flow material of the first metal member 1 flows into the clearance of the abutment portion J, and the surface of the plasticized region W forms a stepped groove. etc. do not occur. In other words, it is possible to prevent metal shortage at the joint.

The rolling step is a step of rolling the joined first metal member 1 and second metal member 2 . As shown in FIG. 10, in the rolling process, cold rolling is performed using a rolling apparatus having rollers R, R. As shown in FIG. In the rolling process, the joining line (plasticized region W) in the joining process is set in the rolling direction and rolled. As described above, the composite rolled material 10 shown in FIG. 11 is formed. The rolling reduction in the rolling process may be appropriately set according to the materials of the first metal member 1 and the second metal member 2 and the application of the composite rolled material 10 . As shown in FIG. 9, there is a difference in plate thickness between the first metal member 1 and the second metal member 2 after the joining process, but after the rolling process shown in FIG. 11, the difference is negligible. is rolled to

According to the manufacturing method and joining method of the composite rolled material described above, in the joining step, the end surface 1a on the side of the first metal member 1 is perpendicular to the front surface 1b and the back surface 1c. can be prepared for In addition, the second metal member 2 is provided with the first inclined surface 2a1 and the second inclined surface 2a2. can. In addition, since the plate thickness of the first metal member 1 is made larger than the plate thickness of the second metal member 2 and the joint is performed in such a manner that the plastic flow material flows into the gap of the butt joint J in the joint process, Prevent metal shortages.

In addition, since the shoulder portion of the rotary tool is not brought into contact with the first metal member 1 and the second metal member 2, the amount of heat input can be reduced, and the frictional resistance can be reduced. load can be reduced. Further, as in the present embodiment, when the first metal member 1 is an aluminum or aluminum alloy member and the second metal member 2 is a copper or copper alloy member, in the joining step, the proximal pin of the rotary tool F It is preferable to join the outer peripheral surfaces of F2 and the tip side pin F3 and the second metal member 2 (copper member) in a state in which they are brought close to each other as much as possible without contacting each other. In this way, mutual diffusion between the first metal member 1 and the second metal member 2 is promoted at the abutment portion J without excessive burrs being generated from the aluminum alloy member side, thereby firmly joining them. Therefore, the amount of heat input to the first metal member 1 and the second metal member 2 can be suppressed more than before, and the load on the rotating tool F and the friction stirrer can be reduced, and burrs can be removed from the first metal member 1 side. Excessive occurrence can be suppressed. Furthermore, since the shoulder portion is not brought into contact with the first metal member 1 and the second metal member 2, it is possible to prevent the rotary tool F from becoming hot. This facilitates the selection of the material for the rotary tool F and prolongs the life of the rotary tool F.

When the side of the second metal member 2 having a higher melting point in the plasticized region W becomes the flow side, the temperature of the first metal member 1 at the butted portion J decreases, and mutual diffusion at the interface between different metals is not promoted. Poor bonding may occur. If the bonding conditions are adjusted so as to increase the amount of heat input, excessive burrs are generated from the first metal member 1 side, which is the shear side, resulting in bonding defects. However, as in the present embodiment, by setting the joining conditions (rotating direction of the rotating tool F, advancing direction, etc.) so that the second metal member 2 side having a higher melting point becomes the shear side in the plasticized region W , the temperature of the first metal member 1 at the butted portion J can be maintained at a relatively high temperature, promoting mutual diffusion at the interface between different metals and preventing poor bonding.

The outer peripheral surface of the rotating tool F may be brought into slight contact with the second metal member 2, but in the present embodiment, the rotating tool F and the second metal member 2 are set so as not to come into contact with each other. It is possible to prevent the member 1 and the second metal member 2 from being mixed and agitated, and it is possible to more reliably prevent the occurrence of excessive burrs and poor bonding. Further, by bringing the outer peripheral surface of the base end pin F2 into contact with the surface 1b of the first metal member 1, the plastic flow material can be suppressed, thereby suppressing the occurrence of burrs.

The back surfaces 1c and 2c of the first metal member 1 and the second metal member 2 are butted against each other with the back surfaces 1c and 2c flush with each other, and friction stir welding is performed to make the back surfaces 1c and 2c of the metal members flush with each other after welding. can do.

Further, in the present embodiment, the inclination angle γ with respect to the vertical plane of the rotation center axis j of the rotary tool F is changed from the inclination angle α with respect to the rotation center axis of the distal pin F3 to the vertical angle of the first inclined surface 2a1 of the second metal member 2. It matches the value obtained by subtracting the inclination angle β with respect to the surface. Further, the inclination angle γ is made equal to the value obtained by subtracting the inclination angle β' of the second inclined surface 2a2 of the second metal member 2 with respect to the vertical plane from the inclination angle α' with respect to the rotation center axis of the proximal pin F2. . As a result, it is possible to select optimum values for the inclination angles α, β, α', and β'. While the outer peripheral surface of the pin F2 and the second inclined surface 2a2 are parallel to avoid contact between the outer peripheral surface of the tip side pin F3 and the end surface 2a, the outer peripheral surface of the tip side pin F3 and the end surface 2a are aligned in the height direction. can be brought as close to each other as possible.

For example, the inclination angles α and α' are determined by the design concept of the rotating tool in the technical field of friction stir welding (FSW), and the inclination angles β and β' are determined by the casting field (for example, die casting). Determined by the design concept of the mold. In other words, since the inclination angles α, β, α', and β' all have optimum values depending on the design concept, it may be difficult to set "α=β, α'=β'". However, according to the present embodiment, since the inclination angles α and β can be freely selected, optimum values can be selected as the inclination angles α, β, α' and β'. Further, according to the present embodiment, the work of bringing the outer peripheral surface of the rotary tool F and the second metal member 2 as close as possible without contacting each other is facilitated.

In addition, by inclining the rotary tool F toward the second metal member 2, the bonding area between the first metal member 1 and the second metal member 2 increases during the rolling process, and the bonding strength between the two metal members is increased. be able to.

[Second embodiment]
A method for manufacturing a composite rolled material according to the second embodiment of the present invention will be described. The method for manufacturing a composite rolled material according to this embodiment includes a preparation process, a butting process, a joining process, and a rolling process. In the preparation step, as shown in FIG. 12, a stepped frame KA is prepared. The stepped frame KA has a bottom portion K1, a bottom portion K2 positioned one step higher than the bottom portion K1, and a stepped side surface K3.

In the butting step, as shown in FIG. 12, the ends of the first metal member 1 and the second metal member 2 are butted against each other. The first metal member 1 is arranged on the bottom portion K1, and the end surface 1a of the first metal member 1 is brought into contact with the stepped side surface K3. Abutting portion J is formed by butting the first metal member 1 and the second metal member 2 together. A gap having a V-shaped cross section is formed in the butted portion J, as in the first embodiment. When the first metal member 1 and the second metal member 2 are butted against each other, the surface 1b of the first metal member 1 is positioned higher than the surface 2b of the second metal member 2, and the second metal member The rear surface 1c of the first metal member 1 is positioned lower than the rear surface 2c of the first metal member 1.

In the joining step, as shown in FIG. 13, a rotating tool F is used to join the first metal member 1 and the second metal member 2 together. In the joining step, friction stir is performed in the same manner as in the first embodiment. That is, the rotating tool F is inserted into the start position set near the butted portion J on the surface 1b of the first metal member 1 while rotating the distal end side pin F3 of the rotating tool F. Then, the rotary tool F is relatively moved in parallel with the extending direction of the butted portion J in a state where the rotary tool F is inclined at the inclination angle γ toward the first metal member 1 side. The rotating tool F may be brought into slight contact with the second metal member 2, but in the present embodiment, friction stir is performed in a state where only the first metal member 1 is brought into contact. Friction stir is performed while the outer peripheral surface of the proximal pin F2 is in contact with the surface 1b of the first metal member 1. As shown in FIG. A plasticized region W is formed in the movement trajectory of the rotating tool F. As shown in FIG. In the joining step, friction stir welding is performed so that the plastic flow material on the side of the first metal member 1 mainly flows into the gap of the butted portion J. As shown in FIG.

In the joining process according to this embodiment, the tip (flat surface F4) of the tip pin F3 of the rotary tool F is inserted to a depth lower than the back surface 2c of the second metal member 2. set. About a rolling process, it is the same as that of 1st embodiment.

Also in the second embodiment described above, substantially the same effect as in the first embodiment can be obtained. In the first embodiment, as shown in FIG. 8, it is difficult to join the second metal member 2 over the entire height direction. However, in the second embodiment, the friction stir welding is performed in a state in which the distal end side pin F3 is inserted at a position deeper than the back surface 2c of the second metal member 2. Therefore, as shown in FIG. It is possible to join the entire plate thickness direction. Thereby, the bonding strength between the first metal member 1 and the second metal member 2 can be increased.

REFERENCE SIGNS LIST 1 first metal member 2 second metal member F rotary tool F2 proximal pin F3 distal pin J butt portion W plasticized region

Claims (7)

A joining method for joining a pair of metal members made of different materials using a rotating tool having a proximal pin and a distal pin,
A taper angle of the proximal pin is larger than a taper angle of the distal pin, and a stepped portion is formed on an outer peripheral surface of the proximal pin,
A first metal member having a vertical surface at its end, a first inclined surface at the end on the back side and a second inclined surface at the end on the front side, and having a melting point higher than that of the first metal member a preparation step of preparing a second metal member having a small thickness;
a butting step of butting the ends of the first metal member and the second metal member to form a butting portion having a V-shaped gap;
The rotating tip side pin is inserted only from the surface of the first metal member, and in a state in which the outer peripheral surfaces of the tip side pin and the base side pin are in contact with at least the first metal member, they are inserted into the gap. a joining step of joining the first metal member and the second metal member by relatively moving the rotary tool along the butt portion while allowing the first metal member to flow in;
In the joining step, the inclination angle of the rotation center axis of the rotating tool with respect to the vertical plane is γ, the inclination angle of the first inclined surface with respect to the vertical plane is β, and the inclination angle of the second inclined surface with respect to the vertical surface is β. ', the inclination angle of the outer peripheral surface of the distal side pin with respect to the rotation center axis is α, and the inclination angle of the outer peripheral surface of the proximal side pin with respect to the rotation center axis is α', then γ=α−β and A joining method characterized by joining in a state of γ=α'-β'. 2. The method according to claim 1, wherein in the butting step, the first metal member and the second metal member are butted with the back surfaces of the first metal member and the second metal member being flush with each other. Joining method as described. In the butting step, the back surface of the first metal member is positioned lower than the back surface of the second metal member, and the front surface of the first metal member is positioned higher than the front surface of the second metal member. Matching the first metal member and the second metal member,
2. The method according to claim 1, wherein in the joining step, the insertion depth of the tip side pin is set so that the tip of the tip side pin is located below the height of the back surface of the second metal member. joining method. In the joining step, the rotating direction of the rotating tool is set so that the second metal member side is the shear side and the first metal member side is the flow side of the plasticized region formed in the moving locus of the rotating tool. 4. The joining method according to any one of claims 1 to 3, wherein a direction of movement is set. In the preparing step, the first metal member is made of aluminum or an aluminum alloy, the second metal member is made of copper or a copper alloy,
In the joining step, the outer peripheral surface of the proximal side pin is brought into contact only with the surface of the first metal member, and the outer peripheral surface of the distal side pin is not brought into contact with the second metal member, and the gap is filled with the 5. The method according to claim 1, wherein the first metal member and the second metal member are joined by relatively moving the rotating tool along the abutting portion while allowing the first metal member to flow. The joining method according to any one of the items. In the bonding step,
When a counterclockwise spiral groove is engraved on the outer peripheral surface of the tip side pin as it goes from the base end to the tip, the rotating tool is rotated to the right,
6. The rotating tool is rotated counterclockwise when a clockwise spiral groove is engraved on the outer peripheral surface of the distal pin as it goes from the proximal end to the distal end. The joining method described in . A joining method for joining a pair of metal members made of different materials using a rotating tool having a proximal pin and a distal pin,
A taper angle of the proximal pin is larger than a taper angle of the distal pin, and a stepped portion is formed on an outer peripheral surface of the proximal pin,
A first metal member having a vertical surface at its end, a first inclined surface at the end on the back side and a second inclined surface at the end on the front side, and having a melting point higher than that of the first metal member a preparation step of preparing a second metal member having a small thickness;
a butting step of butting the ends of the first metal member and the second metal member to form a butting portion having a V-shaped gap;
While inserting the rotating distal side pin only from the surface of the first metal member and bringing the outer peripheral surface of the proximal side pin into contact with the surface of the first metal member, the distal side pin and the proximal side With the outer peripheral surface of the pin in contact with at least the first metal member, the rotating tool is relatively moved along the abutting portion while the first metal member is allowed to flow into the gap, thereby moving the first metal member and the pin. a joining step of joining the second metal member;
a rolling step of rolling the metal members joined in the joining step with the joining line in the rolling direction;
In the joining step, the inclination angle of the rotation center axis of the rotating tool with respect to the vertical plane is γ, the inclination angle of the first inclined surface with respect to the vertical plane is β, and the inclination angle of the second inclined surface with respect to the vertical surface is β. ', the inclination angle of the outer peripheral surface of the distal side pin with respect to the rotation center axis is α, and the inclination angle of the outer peripheral surface of the proximal side pin with respect to the rotation center axis is α', then γ=α−β and A method for producing a composite rolled material, characterized in that joining is performed in a state of γ=α'-β'.

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