KR20130036064A - Rotating tool for forming voids and void-formation method - Google Patents

Abstract

When forming a space | gap in a metal member by friction stirring, the space | gap becomes difficult to be crushed and the rotation tool for air gap formation and the method for forming a space which are hard to produce surface defects are provided. As the rotation tool 1 for forming a space which moves relatively with respect to the metal member Z, and forms the space | gap M in this metal member Z, the shoulder part 2 and this shoulder part ( 2) having a stirring pin 3 vertically descending from (2), a spiral groove 3a is formed on the outer circumferential surface of the stirring pin 3, and a value obtained by dividing the outer diameter of the shoulder portion by the outer diameter of the tip of the stirring pin is 1.4 or more 2.2. It is characterized by the following.

Description

Rotary tools for forming voids and methods for forming voids {ROTATING TOOL FOR FORMING VOIDS AND VOID-FORMATION METHOD}

The present invention relates to a pore forming rotary tool for forming voids in a metal member by friction stirring and a void forming method using the same.

Patent Literature 1 describes a rotary tool for forming a gap having a shoulder portion and a stirring pin vertically lowered to the bottom of the shoulder portion. Screw grooves are squared on the outer circumferential surface of the stirring pin. When forming voids in the metal member, the void-forming rotary tool rotated in the retraction direction of the screw groove is pressed against the surface of the flat metal member, and moved relatively to the metal member while maintaining a constant height. Let's do it. As a result, the plastically fluidized metal is pumped out near the bottom of the shoulder portion by the helical induction of the screw groove, and a part of the metal to be pushed out is pressed by the bottom of the shoulder portion. Therefore, since the upper part of the space | gap is covered by the metal member baked by friction stirring, a tunnel-shaped space | gap can be formed in the inside of a metal member.

Japanese Unexamined Patent Application Publication No. 11-47961

However, depending on the structure of the rotation tool for forming a space | gap, the space | gap may be crushed and the hole (henceforth "surface defect") which communicates with the surface of a space | gap and a metal member may be formed.

In view of this, it is an object of the present invention to provide a rotary tool for forming voids and a method for forming voids, when the voids are formed inside the metal member by friction stirring, the voids are less likely to be crushed and surface defects are less likely to occur. It is a task.

The present invention which solves such a problem is a rotary tool for forming voids used when forming voids in a metal member by friction stirring, and has a shoulder portion and a stirring pin vertically descending from the shoulder portion. A spiral groove is squared on the outer circumferential surface of the pin, and a value obtained by dividing the outer diameter of the shoulder portion by the outer diameter of the tip of the stirring pin is 1.4 or more and 2.2 or less.

According to such a structure, since the plastic fluidized metal can be appropriately pumped out, and the pumped metal can be pressed to the bottom of the shoulder portion, voids are less likely to be crushed, and surface defects are less likely to occur in the metal member. If the value obtained by dividing the outer diameter of the shoulder portion by the outer diameter of the tip of the stirring pin is less than 1.4, the metal is not pressed against the bottom of the shoulder portion, and thus surface defects are likely to occur. On the other hand, if the value obtained by dividing the outer diameter of the shoulder portion by the outer diameter of the tip of the stirring pin is larger than 2.2, the metal becomes difficult to be pumped out of the shoulder portion, and thus the voids in the metal member tend to be crushed. In addition, the load on the main shaft motor of the friction stirring device increases.

Moreover, it is preferable that the angle of the said spiral groove with respect to the reference plane which makes the axial direction of the said stirring pin into a normal line is 20 degree | times or more and 40 degrees or less. According to this configuration, the voids are more difficult to crush. If the angle of the spiral groove with respect to the reference plane is less than 20 degrees, the angle is shallow, so that it is difficult to spread metal from the shoulder portion. In addition, when the angle of the spiral groove with respect to the reference plane is greater than 40 degrees, the length of the spiral groove with respect to the stirring pin is shortened, so that it is difficult for metal to be ejected from the shoulder portion. Therefore, in any case, there is a possibility that the voids are crushed.

Moreover, it is preferable that the said helical groove has the said stirring pin wound around 1 week or more, and is turned. If the number of turns of the spiral groove is less than one week, the plastically fluidized metal remains on either sidewall of the void, and the void may be crushed. According to this configuration, the void is crushed because the metal is plastically fluidized in a balanced manner. You can avoid losing.

Moreover, it is preferable that the said stirring pin is provided with the spiral groove part in which the said spiral groove was formed, and the flat surface part in which the said spiral groove is not formed, and the said spiral groove part is squared off from the front-end | tip of the said stirring pin. According to such a structure, a space | gap can be formed in the deep position of a metal member.

Moreover, it is preferable that a protrusion protrudes from the bottom face of the said shoulder part, and the said protrusion is formed in the vortex shape around the said stirring pin. According to such a structure, the space | gap formed becomes a relatively ordered shape.

Moreover, it is preferable that the notch cut | disconnected in the radial direction of the bottom face of the said shoulder part is formed in the said protrusion. According to such a structure, the plastically fluidized metal collects around the base end part of a stirring pin, and it is easy to make it out of a cutout part. As a result, a relatively large gap can be formed.

It is preferable that the said stirring pin consists of fixed outer diameter from a front-end | tip to a base end part. According to such a structure, the width | variety of a space | gap can be made constant.

Moreover, as a space | gap formation method which forms a space | gap inside a metal member using the space | gap formation rotation tool, the said space | gap formation rotation tool has a shoulder part and the stirring pin which descend | falls vertically in this shoulder part, The said stirring pin Spiral grooves are squared on the outer circumferential surface thereof, and the outer diameter of the shoulder portion divided by the outer diameter of the tip of the stirring pin is 1.4 or more and 2.2 or less, and is relatively moved relative to the metal member while rotating the pore forming rotating tool. At this time, it is characterized by rotating the pore-forming rotary tool in a direction in which the metal fluidized by friction stirring is scraped up to the surface of the metal member by the spiral groove.

According to such a method, since the plasticized fluidized metal can be properly pumped out, and the pumped metal can be pressed to the bottom of the shoulder portion, voids are less likely to be crushed, and surface defects are less likely to occur in the metal member. If the value obtained by dividing the outer diameter of the shoulder portion by the outer diameter of the tip of the stirring pin is less than 1.4, the surface metal is likely to occur because the metal is not pressed against the bottom of the shoulder portion. On the other hand, if the value obtained by dividing the outer diameter of the shoulder portion by the outer diameter of the tip of the stirring pin is larger than 2.2, the plastically fluidized metal in the shoulder portion is less likely to be scooped out, so that the voids in the metal member tend to be crushed. In addition, the load on the main shaft motor of the friction stirring device increases.

Moreover, it is preferable to set the distance of the surface of the said metal member and the bottom face of the said shoulder part to 0-3.0 mm.

According to such a method, a relatively large void can be formed. When the bottom face of the shoulder portion is pressed in from the surface of the metal member, the voids tend to be crushed because the plastically fluidized metal is less likely to be spread out. On the other hand, when the distance between the surface of the metal member and the bottom face of the shoulder portion is larger than 3.0 mm, the surface metal is likely to be caused in the metal member because the metal is not pressed against the bottom face of the shoulder portion. In addition, the "surface" of the metal member here means the surface of the metal member before friction stirring.

According to the rotary tool for forming a void and the method for forming a void according to the present invention, when the void is formed inside the metal member by friction stirring, the void is hardly crushed, and surface defects are less likely to occur in the metal member.

1: is a figure which shows the rotation tool for air gap formation which concerns on this embodiment, (a) is a side view, (b) shows a bottom view.
FIG. 2 is a diagram showing a void forming method according to the present embodiment, (a) is a side cross-sectional view, and (b) is a II longitudinal cross-sectional view of (a).
(A) is a side view which shows a 1st modification, (b) is a bottom view of the shoulder part which shows a 2nd modification.
4 is a side view illustrating a third modification.
Fig. 5 is a rotary tool for forming voids used in the spiral groove angle test, (a) shows tool NO.S1, (b) tool NO.S2, and (c) shows side and bottom views of the tool NO.S3. .
6 is a plan view of a metal member showing the test result of the spiral groove angle test, (a) is the result of tool NO.S1, (b) is the result of tool NO.S2, and (c) is of tool NO.S3. Show the results.
FIG. 7A is a II-II cross-sectional view of FIG. 6A, (B) is a II-II cross-sectional view of FIG. 6B, and (c) is a II-II cross-sectional view of FIG. 6C. It is a cross section.
FIG. 8 is a graph showing the relationship between the void area and the gap in the spiral groove angle test for each tool. FIG.
Fig. 9 is a graph showing the relationship between the void area and the gap in each spiral speed in the spiral groove angle test.
10 is a graph showing the relationship between the void area and the moving speed in the spiral groove angle test for each gap.
Fig. 11 is a void forming rotary tool used in shoulder portion outer diameter test, (a) shows tool NO.T1, (b) tool NO.T2, and (c) shows side and bottom views of tool NO.T3. .
12 is a plan view of a metal member showing the test results of the shoulder portion outer diameter test, (a) is the result of tool NO.T1, (b) is the result of tool NO.T2, (c) is of tool NO.T3 Show the results.
Fig. 13 is a sectional view taken along line III-III of Fig. 12 (a), Fig. 13 (b) is a sectional view taken along the line III- to be.
It is a graph which shows the relationship between a space | gap area and a gap in a tool in the shoulder part outer diameter test.
FIG. 15 is a graph showing the relationship between the void area and the gap in each shoulder in the outer diameter test for each tool. FIG.
It is a graph which shows the relationship of the space | gap area in the shoulder part outer diameter test and the outer diameter of a shoulder part for every clearance gap.
It is a graph which shows the relationship between the space | gap area in the shoulder part outer diameter test, and the outer diameter of a shoulder part for every clearance gap.
Fig. 18 is a rotary tool for forming voids used in the stone test, (a) tool NO.S3-1, (b) tool NO.S3-2, and (c) side view and bottom of tool NO.S3-3. Shows a figure.
19 is a cross-sectional view of a metal member showing a test result of a protrusion test, (a) is a result of tool NO.S3-1, (b) is a result of tool NO.S3-2, (c) is a tool NO. The result of S3-3 is shown.
20 is a graph showing the relationship between the void area and the gap in the protrusion test for each tool.
Fig. 21 is a rotary tool for forming voids used in the stirring pin outer diameter test, (a) tool NO.U1, (b) tool NO.U2, (c) tool NO.U3, and (d) tool NO. A side view and a bottom view of U4 are shown.
22 is a cross-sectional view showing the test result of the stirring pin outer diameter test, (a) is the result of tool NO.U1, (b) is the result of tool NO.U2, (c) is the result of tool NO.U3, ( d) shows the result of tool NO.U4.
FIG. 23 is a graph showing the relationship between the void area and the gap in the stirring pin outer diameter test for each tool. FIG.
It is a graph which shows the relationship between a void area and a gap in a stirring pin outer diameter test for every tool.
It is a graph which shows the relationship between the space | gap area in the stirring pin outer diameter test, and the outer diameter of a stirring pin for every clearance gap.
Fig. 26 is a pore forming rotary tool used in the void depth test, (a) tool NO.T2, (b) tool NO.T2-1, and (c) side view and bottom view of tool NO.T2-2. Shows.
27 is a cross-sectional view showing the test results of the void depth test, (a) and (b) show the result of the tool NO.T2, and (c) and (d) show the result of the tool NO.T2-1.
28 is a cross-sectional view showing the test results of the void depth test, and (a) and (b) show the results of the tool NO.T2-2.
Fig. 29 is a graph showing the relationship between the gap depth and the height of the flat surface portion in the gap depth test for each gap.
30 is a graph showing the relationship between the gap depth and the height of the flat surface portion in the gap depth test for each gap.
Fig. 31 is a graph showing the relationship between the void area and the gap in the gap depth test for each height of the spiral groove portion.
32 is a graph showing the relationship between the void area and the gap in the gap depth test for each height of the helical groove.
It is a table which shows the situation of the space | gap formed with each tool in the Example.
It is a table which shows the situation of the space | gap formed with each tool in the Example.

EMBODIMENT OF THE INVENTION Embodiment of this invention is described in detail with reference to drawings. As shown in FIG. 1, the space | gap formation rotation tool 1 which concerns on this embodiment has the shoulder part 2 and the stirring pin 3. As shown in FIG. The rotation tool 1 for air gap formation is formed, for example from tool steel. The pore-forming rotation tool 1 is a tool for forming tunnel-shaped voids inside the metal member by moving while rotating in the metal member. By flowing a fluid such as gas or liquid into the tunnel-shaped void formed by the tool, for example, a metal member can be used as a cooling plate.

The shoulder part 2 has a cylinder shape and is connected to the friction stirring apparatus which is not shown in figure. A projection 2b is formed on the bottom face 2a of the shoulder portion 2. As shown in Fig. 1B, the protrusion 2b is formed in a vortex around the stirring pin 3. The cross-sectional shape of the projections 2b is not particularly limited, but is rectangular in this embodiment. The number of turns of the protrusions 2b is not particularly limited, but in the present embodiment, the number of turns is about one and a half turns. By providing the projection 2b, the metal (base material) plastically fluidized at the time of friction stirring will flow easily around the base end side of the stirring pin 3.

Starting position of the protrusion 2b (distance P1 from the base end of the stirring pin 3 to the starting position of the protrusion 2b) or scroll pitch of the protrusion 2b (distance P2 between the protrusions 2b) Is not particularly limited and may be appropriately set. In addition, the protrusion 2b does not need to be provided.

The stirring pin 3 is concentric with the shoulder part 2 and descends perpendicularly to the bottom face 2a of the shoulder part 2. In addition, in the present embodiment, the stirring pin 3 is tapered. The length of the stirring pin 3 is not specifically limited, What is necessary is just to set it suitably.

In this embodiment, the outer diameter X1 of the shoulder part 2 and the outer diameter Y2 of the tip of the stirring pin 3 are set so that X1 / Y2 may be 1.4-2.2. In this case, when the voids are formed inside the metal member by friction stirring, the voids are less likely to be crushed, and surface defects are less likely to occur in the metal members. In addition, the load applied to the friction stirring device can be reduced. Later on the evidence.

On the outer circumferential surface of the stirring pin 3, the spiral groove 3a is formed from the front end to the base end of the stirring pin 3. In the present embodiment, the spiral groove 3a is grooved and formed by a ball end mill. Although the cross-sectional shape of the spiral groove 3a is not specifically limited, In this embodiment, it is a semicircle. In the present embodiment, the spiral groove 3a is formed to be turned right when it fumbles from the top to the bottom (right screw).

It is preferable that the angle (lead angle) (alpha) of the spiral groove 3a with respect to the reference plane which makes the axial direction of the stirring pin 3 normal is set suitably between 20-40 degrees. When the angle α of the spiral groove 3a is less than 20 degrees, the angle is too shallow, so that the plastically fluidized metal from the shoulder portion 2 is hard to be pumped out. On the other hand, when the angle α of the spiral groove 3a is larger than 40 degrees, the length of the spiral groove 3a with respect to the stirring pin 3 is shortened, so that the plastically fluidized metal from the shoulder portion 2 is hard to be spread out. Lose. Thus, in any case, the voids tend to be crushed.

The number of turns of the spiral groove 3a in the axial direction is not particularly limited, but it is preferable that the spiral groove 3a is wound at least one week or more. If it winds around one week or more, a space | gap can be formed large. If the number of turns of the spiral grooves 3a is less than one week, since the bias occurs at the position of the spiral grooves 3a with respect to the stirring pin 3, the plastic fluidized metal may remain on either sidewall of the formed voids. There is this.

In addition, in this embodiment, although the spiral groove 3a was comprised as mentioned above, you may form in the left turn when it traces from the upper side to the lower side (left screw).

Next, the void formation method which concerns on this embodiment is demonstrated. As shown in FIG. 2, in this embodiment, the case where the flat metal member Z is processed is illustrated. The material of the metal member Z is not particularly limited, but may be selected from friction-stirrable metals such as aluminum, aluminum alloy, copper, copper alloy, titanium, titanium alloy, magnesium, and magnesium alloy.

By rotating the rotary tool 1 for forming a space | gap above the metal member Z, the stirring pin 3 is press-fitted into the surface Za of the metal member Z, and the metal member ( The rotary tool 1 for forming a void is moved relative to Z). Although the rotation speed of the rotation tool 1 for air gap formation is not specifically limited, For example, it sets between 700-1300 rpm. In addition, the moving speed of the rotation tool 1 for air gap formation is set, for example between 200-400 mm / min. The bottom face 2a of the shoulder part 2 and the surface Za of the metal member Z may be moved, making contact, and may be moved with a clearance gap. What is necessary is just to set the clearance gap (distance) K between the bottom face 2a of the shoulder part 2 and the surface Za of the metal member Z suitably between 0-3.0 mm, for example.

As shown in Fig. 2 (a), in the present embodiment, since the spiral grooves 3a are formed in the right direction from the top to the bottom, the void formation method is for forming the voids in the right direction when viewed from above. Rotate the rotation tool 1. That is, it moves, rotating the rotating tool 1 for air gap formation in the direction in which the metal plastically plasticized by the spiral groove 3a is scraped up on the surface Za of the metal member Z.

Incidentally, in the case where the spiral groove 3a is formed to the left as it goes upward from below, the voids are formed in the direction in which the plastically fluidized metal can be rolled up on the surface Za of the metal member Z, that is, in the left rotation. The rotary rotation tool 1 is rotated.

In the space | gap formation method, the metal member Z is friction-stirred by the rotational tool 1 for space | gap formation, and the plastic flow upwards is generated by the spiral groove 3a. As a result, the fluidized metal is guided to the spiral groove 3a and is pumped out toward the surface Za of the metal member Z. The metal which has been excavated is pressed by the pressing force of the rotary tool 1 for forming a void while being in contact with the bottom face 2a. In the trace through which the pore-forming rotary tool 1 has passed, a tunnel-shaped void M formed by metal is formed and a plasticized region Z2 is formed on the void M. As shown in FIG.

Here, as shown in FIG. 2B, the metal member Z after friction stir has a main body portion Z1, a space M formed inside the main body portion Z1, and a space M. FIG. It consists of the plasticization area | region Z2 which covers the upper part of the. The plasticization region Z2 is a portion formed by hardening after the metal is plastically fluidized by friction stirring. In the present embodiment, the plasticized region Z2 has an inverted trapezoidal shape in cross section and is formed so as to cover the upper portion of the space M. As shown in FIG. The plasticization region Z2 is formed by the metal that is frictionally agitated by the stirring pin 3 being pressed by the bottom face 2a of the shoulder portion 2. Among the friction-stirred metals, the metal overflowing from the bottom face 2a of the shoulder portion 2 becomes the burr V and is exposed to the surface Za. The burr V is preferably removed by cutting or the like.

The space | gap M is formed in substantially rectangular shape at the cross section in this embodiment. In this embodiment, the space | gap M becomes a sealed space and communicates with the space | gap M in the inside of the plasticization area | region Z2, and the boundary part of main-body part Z1 and the plasticization area | region Z2. Surface defects are not formed. In addition, the distance from the upper end of the space | gap M to the surface Za is called "gap depth D."

Depending on the shape of the cavity-forming rotary tool 1, the metal may not be properly excavated and the void M may be crushed. On the other hand, the metal is excessively pumped out, so that the plasticized region Z2 becomes thin and communicates with the space M in the interior of the plasticized region Z2 and the boundary between the main body portion Z1 and the plasticized region Z2. Surface defects may be formed.

However, according to the rotation tool 1 for forming a space | gap, since the metal can be scooped out appropriately and the pressed metal can be pressed to the bottom face 2a of the shoulder part 2, the space | gap M is hard to be crushed, In addition, surface defects are less likely to occur in the metal member Z. In addition, the load applied to the friction stirring device can be reduced. The conditions such as the ratio of the outer diameter X1 of the shoulder portion 2 to the outer diameter Y2 of the front end of the stirring pin 2 and the numerical value of the angle alpha of the helical groove will be described in the embodiment.

Moreover, since the stirring pin 3 which concerns on this embodiment is a shape where a tip is tapered, the press-in resistance at the time of press-fitting into the metal member Z can be made small.

<1st modification>

Next, a first modification of the present invention will be described. In 1 A of air gap forming rotary tools which concern on a 1st modification, it differs from the above-mentioned embodiment in that the stirring pin 3 is equipped with the flat surface part 11 and the spiral groove part 12. As shown in FIG.

On the outer circumferential surface of the stirring pin 3 according to the first modified example, as shown in Fig. 3A, a flat surface portion 11 in which no groove is formed and a spiral groove portion in which the spiral groove 3a is formed ( 12). The outer peripheral surface of the flat surface part 11 is flattened, and is formed from the base end of the stirring pin 3 to the substantially center of the stirring pin 3.

On the other hand, on the outer circumferential surface of the spiral groove portion 12, the spiral groove 3a is formed from the tip to the center (up to the flat surface portion 11). It is preferable that the spiral groove 3a is wound around at least one week or more. Although the height H1 of the spiral groove part 12 may be set suitably according to the depth of the clearance gap M to be formed with respect to the metal member Z, For example, the height H1 is the stirring pin 3 It is preferable to set it as the length of 30 to 70% (the height of the flat surface part 11 is 70% to 30% with respect to the length of the stirring pin 3) with respect to the length of the.

In the cavity forming rotary tool 1 shown in FIG. 1, since the spiral groove | channel 3a is formed from the front-end | tip to the base end of the stirring pin 3, metal is comparatively easy to spread | diffuse, and the void depth D is comparatively It tends to be small.

However, according to the pore-forming rotary tool 1A according to the first modification, the metal is scooped out by the spiral groove 12 to form the void M, but the metal frictionally stirred to the flat surface portion 11 is a shoulder. It is hard to spread out from the part 2 to the outside. Therefore, since the thickness of the plasticization area | region Z2 becomes large, the space | gap depth D can be enlarged (deep). Thereby, large void | gap M can be formed in the deep position of the metal member Z, and at the inside of the plasticization area | region Z2, or in the boundary part of the main-body part Z1 and the plasticization area | region Z2, Surface defects are more difficult to form.

Second Modification

Next, a second modification of the present invention will be described. As shown in FIG.3 (b), in the space | gap formation rotation tool 1B which concerns on a 2nd modified example, the protrusion 2b formed in the bottom face 2a of the shoulder part 2 is formed intermittently. It differs from embodiment mentioned above in a point.

The protrusion 2b which concerns on a 2nd modification is provided with the some notch part 2c which divides the protrusion 2. By providing the notch part 2c, since the plastic fluidized metal passes through the notch part 2c, it is easy to flow plastically fluidized metal in the radial direction of the bottom face 2a of the shoulder part 2. As shown in FIG. Thereby, metal collects easily around the base end part of the stirring pin 3, and the metal which plasticized and fluidized from the notch part 2c becomes easy to spread out. Thereby, comparatively large space | gap M can be formed. In addition, what is necessary is just to set the number and size of the notch parts 2c suitably.

<Third Modification>

Next, a third modification of the present invention will be described. As shown in FIG. 4, in the cavity forming rotary tool 1C according to the third modification, the outer diameter of the stirring pin 3 is different from the above-described embodiment in that the constant diameter is constant.

The outer diameter Y1 of the base end of the stirring pin 3 of the rotation tool 1C for air gap formation, and the outer diameter Y2 of the front end are equal. Thus, the outer diameter of the stirring pin 3 may be made constant. Thereby, the space | gap M formed by the space | gap formation method can be formed in fixed width | variety.

As mentioned above, although embodiment and the modified example of this invention were described, a design change is possible suitably in the range which does not contradict the meaning of this invention.

Example

<Test summary>

Next, the Example of this invention is described. In the Example, the space | gap formation method was performed by changing the shape, size, ratio, etc. of each element which comprise the rotation tool for air gap formation, and observed the formed space | gap. In addition, for the convenience of description, the rotation tool for air gap formation is hereafter simply called a "tool."

In the Examples, five types of tests were conducted. "Spiral groove angle test" which examines influence of angle (lead angle) of spiral groove of tool, "shoulder part outer diameter test" which examines influence of outer diameter of shoulder part, "protrusion test which examines influence of protrusion of bottom of shoulder part "The stirring pin outer diameter test" which examines the influence of the outer diameter of a stirring pin, and the "pore depth test" which examines the space | gap depth of the formed plasticization area | region were performed.

In the gap depth test, an A1050 alloy plate was used, and in another test, an A1100 alloy plate was used. The cross-sectional shape of the spiral groove formed in the stirring pin has a semicircle shape, and the radius is 1.5 mm. The start position (distance P1 of FIG. 1 (b)) of a protrusion was 3.0 mm, and scroll pitch (distance P2 of FIG. 1 (b)) was 2.5 mm.

In the void formation method, the tool rotated to the said alloy plate was pressed in, and the predetermined distance was moved. The rotation speed of the tool was based on 800 RPM, and in the air gap test, friction stirring was also performed at 1275 RPM to investigate the influence of the rotation speed of the tool.

The moving speed of the tool was 100 mm / min or 300 mm / min. Moreover, in the spiral groove angle test, the influence of the movement speed was examined by changing the movement speed between 50 and 300 mm / min.

In each test, the gap from the surface of the metal member to the bottom surface of the shoulder portion (the distance K in FIG. 2A) was changed to 0 mm, 1.0 mm, 2.0 mm, and 3.0 mm to form a single metal. Friction stirring was performed on the members to compare the voids formed respectively. Also in any alloy plate (test body), after cutting the center part of the alloy plate, grinding | polishing, and etching, the shape of the formed space | gap was observed. Moreover, the cross-sectional area of the space | gap formed using the imaging device was measured.

Spiral groove angle test

In the spiral groove angle test, the influence of the angle of the spiral groove 3a of the stirring pin 3 was investigated. As shown in Fig. 5, three types of tools NO.S1 to S3 were used in this test. The angle with the horizontal surface of the spiral groove 3a was set to 40 degrees with tool NO.S1, 30 degree with tool NO.S2, and 20 degree with tool NO.S3. The number of windings in the axial direction of the stirring pin 3 of the spiral groove of each tool is about 0.8 weeks in tool NO.S1, about 1.3 weeks in tool NO.S2, and about 2.3 weeks in tool NO.S3. .

The configuration other than the angle of the spiral groove 3a is equivalent to all three types, and the outer diameter of the shoulder portion 2 is 22 mm, the outer diameter of the proximal end of the stirring pin 3 is 10 mm, the outer diameter of the tip is 7 mm, and stirring The length of the pin 3 was set to 11 mm. Moreover, all the tools are provided with the spiral protrusion 2b in the bottom face 2a of the shoulder part 2. As shown in FIG. The height of the projection 2b was 1 mm.

Fig. 6 is a plan view of a metal member showing the test results of the spiral groove angle test, (a) is the result of tool NO.S1, (b) is the result of tool NO.S2, and (c) is tool NO.S3. Shows the result. Four (a), (b), and (c) of FIG. 6 are formed with four plasticization regions Z2 on the surface Za of the metal member Z (main part Z1). The plasticization area | region Z2 is 2.0 in the case of 1.0 mm, when the clearance gap from the surface Za of the metal member Z to the bottom face 2a of the shoulder part 2 is 0 mm in order from the figure. In the case of mm, the result in the case of 3.0 mm is shown.

(A) is sectional drawing II-II of FIG. 6 (a), (b) is sectional drawing II-II of FIG. 6 (b), (c) is II-II of FIG. 6 (c) It is a cross section.

As shown in (a) to (c) of FIG. 6, under the condition of a gap of 0 mm and 1.0 mm, the entire surface of the bottom face 2a of the shoulder portion 2 is in contact with the plastically fluidized metal and has a large burr ( V) is occurring. In the gap 2.0 mm, although the whole surface of the bottom face 2a of the shoulder part 2 was in contact with the plastically fluidized metal, the burr V was comparatively small. In the gap of 3.0 mm, the width of the plasticized region Z2 formed by plasticizing and fluidizing was shorter than the outer diameter X1 (see FIG. 1A) of the shoulder portion 2.

6 and 7, the side where the tool movement speed is added to the tool rotational speed is &quot; Advancing 'side &quot; (hereinafter also referred to as the &quot; Ad side &quot;) and the tool movement to the tool rotational speed. The side at which the speed is subtracted is called "Retreating side" (hereinafter also referred to as "Re side"). In this embodiment, since the tool is moved from the left side to the right side of FIG. 6 while the tool is rotated to the right, the advancing left side is the Ad side and the right side is the Re side.

As shown to Fig.7 (a), the space | gap M in the tool NO.S1 has a rectangular shape long and thin. Although the plasticization area | region Z2 has covered the upper direction of the space | gap M, the one part remains in the side wall of Re side of the space | gap M. As shown to FIG.

On the other hand, in tool NO.S2 and tool NO.S3, the space | gap M of substantially the same shape is formed on the conditions of the gap 1.0-3.0, and the plastically fluidized metal does not remain in the side wall of the space | gap M. It is discharged to the outside.

In tools NO.S1 to S3, it was found that as the gap increases, the height position of the gap M moves upward of the metal member Z, and the height of the gap M also increases. In addition, as the gap increases with the tools NO. S1 to S3, the cross-sectional area of the plasticization region Z2 decreases, and the void depth D from the upper end of the void M to the surface Za of the metal member Z. I noticed) getting smaller.

Moreover, in tool NO.S2 and tool NO.S3, the width | variety of the formed space | gap M and the outer diameter of the front-end | tip of the stirring pin 2 were nearly equal, but in tool NO.S1, the width | variety of the formed space | gap was the stirring pin 2 Was smaller than the outer diameter of the tip. As shown to Fig.7 (a), a part of plasticization area | region Z2 remains in the side wall of Re side of the space | gap M. As shown to FIG. This is considered to be due to the angle and the number of turns of the spiral groove 3a of the NO.S1 tool.

Since the angle of the spiral groove 3a is 40 degrees deep, the tool NO.S1 has a short length of the spiral groove with respect to the stirring pin 3. Therefore, it is thought that the plastic fluidized metal is difficult to be discharged. Moreover, in tool NO.1, since the number of turns of the spiral groove 3a is less than one week, the bias generate | occur | produces in the position of the spiral groove 3a with respect to the stirring pin 3. For this reason, it is thought that the plasticized metal remains in one side wall of the formed space | gap M (here, Re side).

8 is a graph showing the relationship between the void area and the gap in the spiral groove angle test for each tool. As shown in FIG.7 and FIG.8, although the space | gap area of the space | gap M formed by tool NO.S2 and tool NO.S3 was substantially equal, the space | gap area obtained by tool NO.S1 was tool NO.S2. And the void area of the tool NO.S3.

As shown in FIG. 8, as the gap increases with the tools NO. S1 to S3, the void area (cross-sectional area of the void M) increases. As a result, it was found that if the tool is separated from the metal member Z and the plastic fluidized metal is easily pumped out, the void area of the void M can be increased. The rate of increase of the void area (inclination of the graph) of the tools NO. S1 to S3 was approximately 7 mm 2 / mm and became almost equal to the outer diameter of the tip of the stirring pin 3.

9 is a graph showing the relationship between the void area and the gap in each spiral speed in the spiral groove angle test. Since the results of tools NO. S1 to S3 were almost the same, the result of tool NO. S2 is shown in FIG. 9 as a representative example.

10 is a graph showing the relationship between the void area and the moving speed in the spiral groove angle test for each gap. In FIG. 10, the relationship between the space | gap area obtained with tool NO.S3, and a moving speed is shown.

As apparent from FIG. 9 and FIG. 10, it was found that the void area was not affected much by the change of the moving speed.

<Shoulder part outer diameter test>

In the shoulder part outer diameter test, the influence of the outer diameter of the shoulder part 2 was investigated. As shown in FIG. 11, three types of tools NO.T1 to T3 were used in this test. The outer diameter of the shoulder part 2 was set to 20 mm with tool NO.T1, 18 mm with tool NO.T2, and 16 mm with tool NO.T3. All three types of structures other than the outer diameter of the shoulder part 2 are equivalent, The outer diameter of the base end part of the stirring pin 3 is set to 10 mm, the outer diameter of the front end is 7 mm, and the length of the stirring pin 3 is set to 11 mm. did. Moreover, all the tools are provided with the spiral protrusion 2b in the bottom face 2a of the shoulder part 2. As shown in FIG. The height of the projection 2b was 1 mm.

12 is a plan view of a metal member showing the test results of the shoulder portion outer diameter test, (a) is the result of tool NO.T1, (b) is the result of tool NO.T2, and (c) is tool NO.T3. Shows the result. 13A is a III-III cross section of FIG. 12A, (B) is a III-III cross section of FIG. 12B, and (c) is a III-III cross section of FIG. 12C. III section. In addition, as shown in FIG.5 (c), since the outer diameter of the shoulder part 2 is 22 mm of said tool NO.S3, and the other structure is equivalent to tools NO.T1 to T3, it is the same as that of FIG. Consider both (c) and FIG. 7 (c) in preparation.

By reducing the outer diameter of the shoulder portion 2, it was found that even when the gap was 2.0 mm, the plastically fluidized metal contacted the bottom face 2a of the shoulder portion 2, and much burr V was discharged from the Re side. Although burr V was discharge | released to Re side in the clearance 3.0mm, the surface defect E which communicates with the space | gap M by lack of the metal of the plasticization area | region Z2 in tool NO.T1 and tool NO.T3 is Formed.

On the other hand, as the outer diameter of the shoulder part 2 became small, the height of the space | gap M increased. By making the outer diameter of the shoulder part 2 small, the metal which can be suppressed by the bottom face 2a of the shoulder part 2 reduces. For this reason, it is thought that the plastically fluidized metal was easy to be spread out, and it led to the increase of the height of the space | gap M. As shown to FIG.

Fig. 14 and Fig. 15 are graphs showing the relationship between the void area and the gap in the shoulder portion outer diameter test for each tool, and Fig. 14 shows the moving speed at 100 mm / min, and Fig. 15 at 300 mm /. The result of setting min is shown.

As shown in Fig. 14 and Fig. 15, as the gap became larger in all the tools, the void area increased. As a result, it was found that if the tool is separated from the metal member Z and the plastic fluidized metal is easily pumped out, the void area of the void M can be increased. The tool NO.S3 and the tool NO.T1 to T3 increased the rate of increase of the void area (inclination of increase) at about 7 mm 2 / mm and became equal to the outer diameter of the tip of the stirring pin 3.

16 and 17 are graphs each showing the relationship between the void area and the outer diameter of the shoulder portion in the shoulder portion outer diameter test for each gap, and FIG. 16 shows a moving speed of 100 mm / min, and FIG. 17 shows a moving speed of 300. FIG. The result at the time of setting to mm / min is shown.

As shown in FIG. 16 and FIG. 17, under the condition of a gap of 2.0 mm, the void area obtained by the outer diameter of the shoulder portion 2 to 22 mm and the void area obtained by the outer diameter of the shoulder portion 2 to 20 mm are almost the same. Was equivalent. In the range of 20 mm to 16 mm in the outer diameter of the shoulder portion 2, the void area increased as the outer diameter of the shoulder portion 2 decreased. The rate of increase (slope of increase) of the void area was about 5 mm 2 / mm.

As shown in FIG. 16, under the conditions of a movement speed of 100 mm / min and a clearance of 3.0 mm, as the outer diameter of the shoulder part 2 becomes small in the range of 22 mm to 16 mm, as the outer diameter of the shoulder part 2 becomes small. , The void area increased linearly. This is considered to be because the pressurization from the shoulder portion 2 decreases as the outer diameter of the shoulder portion 2 decreases, and the metal discharged increases.

On the other hand, as shown in FIG. 17, since the outer diameter of the shoulder part 2 was 16 mm and 18 mm on the conditions of a clearance gap of 3.0 mm on the conditions of the movement speed of 300 mm / min, the surface defect generate | occur | produced in the plasticization area | region The void area is reduced.

<Stone Test>

In the protrusion test, the influence of the protrusion 2b formed on the bottom face 2a of the shoulder part 2 was investigated. As shown in FIG. 18, three types of rotation tool tools NO.S3-1 to S3-3 for forming a space | gap were used for this test. The width | variety of the notch 2c of the protrusion 2b was set to 2 mm in tool NO.S3-1, and 6 mm in tool NO.S3-2. In tool NO.S3-3, no stone was installed. All three types of structures other than the protrusion 2b are equivalent, and the outer diameter of the shoulder part 2 is 22 mm, the outer diameter of the base end part of the stirring pin 3 is 10 mm, the outer diameter of the tip is 7 mm, and the length of the stirring pin. Was set to 11 mm.

19 is a cross-sectional view of the metal member showing the test result of the protrusion test, (a) is the result of tool NO.S3-1, (b) is the result of tool NO.S3-2, and (c) is tool NO. The result of .S3-3 is shown. 20 is a graph showing the relationship between the void area and the gap in the protrusion test for each tool. In addition, as shown in FIG.5 (c), the said gap-forming rotation tool tool NO.S3 is provided with the protrusion 2b without the notch 2c, The other structure is tool NO.S3 Since it is equivalent to -1 to S3-3, both (c) of FIG. 6 and (c) of FIG. 7 are considered compared.

As shown in FIG.7 (c), FIG.19 (a), and FIG.20, each void area of the tool NO.3, the tool NO.3-1, and the tool NO.3-3 was nearly equivalent. In comparison with the result of tool NO.3 and the result of tool NO.3-3, it turned out that the presence or absence of the protrusion 2b does not affect the result of the void area. However, in contrast to FIG. 7C and FIG. 19C, it was found that the air gap M of the tool NO. 3 having the protrusion 2b has an orderly shape. It is thought that this is due to the presence of the projections 2b, and the metals plasticized and fluidized around the base end side of the stirring pin 3 are likely to collect.

Like tool NO.3-2, when the length of the notch 2c was 6 mm and the length was comparatively large, the space area was also large. This is considered to be due to the fact that when the length of the cutout portion 2c is large, the plastically fluidized metal easily flows in the radial direction of the bottom face 2a of the shoulder portion 2, and the metal is easily spread out.

<Stirring Pin Outer Diameter Test>

In the stirring pin outer diameter test, while using the shoulder part 2 of the same outer diameter, the outer diameter from the base end of the stirring pin 3 to the front-end | tip is set to become constant, and it changes stirring the outer diameter of each stirring pin 3, and stirs. The influence of the outer diameter of the pin 3 was investigated. As shown in FIG. 21, four types of rotary tool tools NO.U1 to U4 for forming voids were used in this test. The outer diameter of the stirring pin 3 was set to 10 mm in tool NO.U1, 12 mm in tool NO.U2, 14 mm in tool NO.U3, and 16 mm in tool NO.U4. All four types of structures other than the outer diameter of the stirring pin 3 were equivalent, and the outer diameter of the shoulder part 2 set the length of 22 mm and the stirring pin 3 to 11 mm. Moreover, all the tools are provided with the spiral protrusion 2b in the bottom face 2a of the shoulder part 2. As shown in FIG. The height of the projection 2b was 1 mm.

As shown in FIG.22 (d), it turned out that surface defect E generate | occur | produces on the conditions of 3.0 mm of gaps of the tool NO.U4. As shown in FIG. 22 and FIG. 23, it turns out that the space | gap area also becomes large as the clearance gap becomes large in the tools NO.U1-U4. The rate of increase (inclination of the graph) of the void areas of the tools NO.U1 to U3 became a value close to the outer diameter of the stirring pin 3 of each tool.

That is, the increase rate of the void area of the tool NO.U1 (the slope of the graph) is 10 mm 2 / mm in FIG. 23, 10.7 mm 2 / mm in FIG. 24, and the increase rate of the void area of the tool NO.U 2 is 12.6 mm 2 in FIG. 23. / Mm, the increase rate of the space area of 12.5mm <2> / mm in FIG. 24, and tool NO.U3 was 13.7mm <2> / mm in FIG. 23, and 14.4mm <2> / mm in FIG. This is considered to be that the void space M increases as much as the outer diameter of the stirring pin 3 when the gap is increased by 1 mm for each tool. Therefore, it is considered that the formed void area is also larger as the outer diameter of the stirring pin 3.

Moreover, as shown in FIG. 23 and FIG. 24, it turned out that the difference of the moving speed does not affect the space area. As shown in FIG. 25, as the outer diameter of the stirring pin 3 increases, the void area also increases, but it is found that the increase tendency is quadratic.

<Pore depth test>

In the gap depth test, as shown in Fig. 3A, the gap M is formed by using a void forming rotary tool provided with the flat surface portion 11 on which the spiral grooves 3a are not formed. The depth position of the was investigated. As shown in FIG. 26, three types of rotation tools for forming voids were used in this test. Tool NO.T2 is a comparative example and is equivalent to the tool shown in FIG.

As shown to Fig.27 (a), the height of the spiral groove part 12 of tool NO.T2 is equal to the length of the stirring pin 3, and is 11.0 mm. As shown in FIG. 27C, the height of the flat surface portion 11 of the tool NO.T2-1 is 3.5 mm, and the height of the spiral groove portion 12 is 7.5 mm. As shown in Fig. 28A, the height of the flat surface portion 11 of the tool NO.T2-2 is 6.0 mm and the height of the spiral groove portion 12 is 5.0 mm.

All three types of structures other than the height of the spiral groove part 12 were equal, and the outer diameter of the shoulder part 2 was 18 mm, the outer diameter of the base end part of the stirring pin 3 was 10 mm, and the outer diameter of the tip was 7 mm. . Both tools are provided with the spiral protrusion 2b in the bottom face 2a of the shoulder part 2. As shown in FIG. The height of the projection 2b was 1 mm. In addition, in the space | gap depth test, the clearance gap from the surface Za of the metal member Z to the bottom face 2a of the shoulder part 2 was made into three types of 0 mm, 1.0 mm, and 2.0 mm. Moreover, in each tool, it tested by two types of rotation speeds, 800 RPM and 1275 RPM.

27 is a cross-sectional view showing the test results of the void depth test, (a) and (b) show the results of the tool NO.T2, and (c) and (d) show the results of the tool NO.T2-1. . 28 is a cross-sectional view showing the test result of the void depth test, and (a) and (b) show the result of the tool NO.T2-2. Fig. 29 is a graph showing the relationship between the gap depth and the height of the flat surface portion in the gap depth test for each gap. 30 is a graph showing the relationship between the gap depth and the height of the flat surface portion in the gap depth test for each gap. 29 and 30 have different rotation speeds of the tool, the rotation speed of the test according to FIG. 29 is 800 RPM, and the rotation speed of the test according to FIG. 30 is 1275 RPM.

As shown in FIG. 29 and FIG. 30, it turned out that the clearance depth D also becomes large, so that the height of the flat surface part 11 (the height of the length-helix groove part 12 of the stirring pin 3) becomes large. Moreover, it turned out that the gap depth D becomes large, so that a clearance gap becomes small. As compared with FIG. 29 and FIG. 30, it was found that the higher the rotational speed of the tool, the larger the air gap depth D is.

FIG. 31 is a graph showing the relationship between the void area and the gap in the gap depth test for each height of the spiral groove portion. FIG. FIG. 32 is a graph showing the relationship between the void area and the gap in the gap depth test for each height of the spiral groove portion. FIG. 31 and 32 are different in rotation speed of the tool, the rotation speed of the test in FIG. 31 is 800 RPM, and the rotation speed of the test in FIG. 32 is 1275 RPM.

As shown in FIG. 31, 32 and FIG. 27, 28, it turned out that the space | gap area becomes large, so that the height of the spiral groove part 11 increases. As compared with FIG. 31 and FIG. 32, it was found that the rotational speed of the tool had little effect on the increase and decrease of the void area.

As mentioned above, according to the space | gap test, when the height of the flat surface part 11 was enlarged, it turned out that the space | gap M can be formed in a deep position. On the other hand, it turned out that when the height of the flat surface part 11 is made too large, the space area of the space | gap M will become small.

<Contrast between the outer diameter of the shoulder part and the tip of the stirring pin and the test result>

33 and 34 are tables showing the situations of the gaps formed with the respective tools in the examples. "○" in the item "Situation" shows that the state of the space | gap M is favorable, and "x" shows the state in which the surface defect E has generate | occur | produced.

33 and 34, when the value obtained by dividing the outer diameter of the shoulder portion by the outer diameter of the tip of the stirring pin is 1.4 to 2.2, no surface defect E occurs and the state of the void M is roughly good. did. If this value is less than 1.4, since the metal to be spread cannot be pressed to the bottom face 2a of the shoulder portion 2, surface defects E are likely to occur. On the other hand, when this value is larger than 2.2, since the plastically fluidized metal from the shoulder part 2 becomes hard to be spread out, a space | gap tends to be crushed. Moreover, when this value is larger than 2.2, since the load on the main shaft motor of a friction stirring apparatus becomes large, it is unpreferable.

1 Rotating tool for forming voids
2 shoulder parts
2a bottom
2b stone
2c cutout
3 stirring pins
3a helix groove
D void depth
K gap
M air gap
V burr
Z metal parts
Z1 main body
Z2 plasticization zone
Za surface

Claims (9)

It is a rotation tool for forming a space | gap used when forming a space | gap inside a metal member by friction stirring,
With a shoulder part and the stirring pin which descends perpendicularly from this shoulder part,
On the outer circumferential surface of the stirring pin is formed a spiral groove,
A value obtained by dividing the outer diameter of the shoulder portion by the outer diameter of the tip of the stirring pin is 1.4 or more and 2.2 or less, wherein the air gap forming rotary tool is used. The rotation tool for forming voids according to claim 1, wherein an angle of the spiral groove with respect to a reference plane whose normal direction is the axial direction of the stirring pin is 20 degrees or more and 40 degrees or less. The said spiral groove is wound around the said stirring pin for one week or more, and is turned, The rotation tool for air gap formation of Claim 1 characterized by the above-mentioned. The said stirring pin is provided with the spiral groove part in which the said spiral groove was formed, and the flat surface part in which the said spiral groove is not formed,
The said spiral groove part is squared out from the front-end | tip of the said stirring pin, The tool for forming gaps. The projection according to claim 1, wherein a protrusion is provided on the bottom of the shoulder portion.
The projection is formed in a vortex shape around the stirring pin, the tool for forming voids. The said protrusion is provided with the notch part cut | disconnected in the radial direction of the bottom face of the said shoulder part, The rotation tool for air gap formation of Claim 5 characterized by the above-mentioned. The rotary tool for forming voids according to claim 1, wherein the stirring pin has a constant outer diameter from the leading end to the proximal end. It is a space | gap formation method which forms a space | gap inside a metal member using the rotational tool for space | gap formation,
The void forming rotary tool,
With a shoulder part and the stirring pin which descends perpendicularly from this shoulder part,
On the outer circumferential surface of the stirring pin is formed a spiral groove,
The value obtained by dividing the outer diameter of the shoulder portion by the outer diameter of the tip of the stirring pin is 1.4 or more and 2.2 or less,
For rotating the pore-forming rotary tool while moving relatively to the metal member, the metal fluidized by friction stir is scraped up to the surface of the metal member by the spiral groove for forming the void. A method for forming voids, characterized by rotating a rotating tool. The gap formation method of Claim 8 which sets the distance of the surface of the said metal member and the bottom face of the said shoulder part to 0-3.0 mm.

Images