WO2009119543A1

WO2009119543A1 - Tool for friction stir working comprising ni-base double multiphase intermetallic compound alloy, and friction stir working method

Info

Publication number: WO2009119543A1
Application number: PCT/JP2009/055749
Authority: WO
Inventors: 隆幸高杉; 泰幸金野; 智丈平田; 昇望月; 健司東
Original assignee: アイセル株式会社
Priority date: 2008-03-27
Filing date: 2009-03-24
Publication date: 2009-10-01
Also published as: JP5371139B2; JP2009255170A

Abstract

Disclosed is an inexpensive tool for friction stir working, which is used for workpiece such as iron or iron alloys requiring high working temperatures and can realize friction stir working without significant abrasion and with high efficiency and high productivity. Also disclosed is a friction stir working method. The tool for friction stir working is formed of a Ni-base double multiphase intermetallic compound alloy. The tool for friction stir working comprises a Ni-base double multiphase intermetallic compound alloy as a base metal. The surface of the base metal has been subjected to hardening treatment by at least one of nitriding or carburizing. The friction stir working method comprises pressing the front end of a tool being rotated at a high speed against a workpiece and plasticizing the workpiece by generated frictional heat for stirring to work the workpiece. In the friction stir working method, the tool for friction stir working is used.

Description

Friction stir processing tool and friction stir processing method comprising Ni-based dual-phase intermetallic compound alloy

The present invention relates to a friction stir processing tool, in particular, a friction stir processing tool comprising a Ni-based dual-phase intermetallic compound alloy suitable when the workpiece is iron or an iron alloy, and friction stir processing using the same. Regarding the method. Here, the friction stir processing means that a rotating tool such as friction stir welding, friction stir reforming, or friction point welding is pressed against the work material with a strong force, and the work material is plasticized by the generated frictional heat. Processing in a solid phase state.

When joining materials to be joined such as an aluminum alloy plate, a rod-shaped stirring tool (a shoulder portion having a large diameter and its tip are rotated at one end of a joining line formed by abutting the joining surfaces of the materials to be joined together. The tool (made of hard tool steel with a probe) is pressed and inserted with a strong force, and the tool is moved to the other end along the joining line while rotating at high speed. The joining surface is moved by the frictional heat generated at that time. A joining method in which the joining surfaces of the materials to be joined are joined while plasticizing and applying pressure by the shoulder portion of the tool is called friction stir welding (FSW: Friction Stir Welding) and is widely known (for example, Japanese Patent No. 2712838 (Patent Document 1)).

According to the friction stir welding described above, the frictional heat between the tool and the material to be joined is used for joining, so that the highest temperature does not reach the melting point and the joining is performed in a solid state, so compared to fusion welding such as arc welding. There are advantages such as low strength reduction at joints, no joint defects such as pores and cracks, and flat joint surfaces, which have already been put to practical use in the fields of railway vehicles, ships, civil engineering structures, automobiles, etc. Yes.

Also, insert the probe of the tool that rotates at a high speed as described above into the surface of the workpiece such as an aluminum alloy plate with a strong force, move the tool while rotating it at a high speed, and use the frictional heat generated at that time. A modification method that improves the strength, hardness, etc. by reducing the crystal grain size to a certain depth by plasticizing the workpiece material near the shoulder of the tool and the probe is a friction stir modification. Quality (FSP: Friction Stir
It is called “Processing” and is widely known (for example, Japanese Patent Laid-Open No. 2003-64458 (Patent Document 2)).

Furthermore, a point joining process has been developed in which the tool is pressed against the workpiece, but is pulled out after a certain time without lateral movement. Yes.

In these friction stir processing, a steel tool such as SKD steel is used as a tool when aluminum or an aluminum alloy is used as a workpiece. However, when iron or an iron alloy is used as a workpiece, a steel tool such as SKD steel has a problem that the tool is deformed due to wear or the like and cannot be joined. In addition, ceramic tools have a problem that they are expensive and easy to break, and particularly when the work material is stainless steel, they are easily worn. If the fine pieces of ceramic tool material are dispersed in an iron-based workpiece such as stainless steel when the tool is worn by friction stir processing, there may be a problem in mechanical properties and corrosion resistance. is there.

By the way, a Ni-based two-duplex intermetallic compound alloy is known. (For example, International Publication No. 2006/101212 pamphlet (hereinafter referred to as Patent Document 3) and International Publication No. 2007/086185 pamphlet (hereinafter referred to as Patent Document 4). The intermetallic alloy is a Ni ₃ Al—Ni ₃ Ti—Ni ₃ V-based intermetallic compound alloy, and the Ni-based 2-duplex intermetallic alloy disclosed in Patent Document 4 is Ni ₃ Al—Ni _3. Nb-Ni ₃ V-based intermetallic alloys, which have excellent mechanical properties at high temperatures, and are expected to be applied to applications such as jet engines and turbine components of gas turbines. However, there is no application to friction stir processing tools.

Japanese Patent No. 2712838 JP 2003-64458 A International Publication No. 2006/101212 Pamphlet International Publication No. 2007/086185 Pamphlet

The present invention has been made in view of the above-mentioned problems, and the object of the present invention is to reduce friction, high efficiency, and high productivity for workpieces with high processing temperatures such as iron or iron alloys. An object of the present invention is to provide an inexpensive friction stir processing tool and friction stir processing method capable of performing stir processing.

The above object can be achieved by the friction stir processing tool comprising the Ni-based double-duplex intermetallic compound alloy of the present invention and the friction stir processing method using the same. That is, the friction stir processing tool according to the present invention is characterized by comprising a Ni-based double-duplex intermetallic compound alloy.

In the friction stir processing tool according to the present invention, it is preferable that the Ni-based double-duplex intermetallic alloy contains 0.5 to 8 atomic% of Ta and / or W.

Further, in the friction stir processing tool according to the present invention, the Ni-based double-duplex intermetallic compound alloy contains Ni as a main component and Al: 2-9 atomic%, V: 10-17 atomic%, (Ta and / Or W): 0.5 to 8 atomic%, Nb: 0 to 6 atomic%, Co: 0 to 6 atomic%, Cr: 0 to 6 atomic%, and a total weight of a composition of 100 atomic% in total B: It preferably contains a _double- duplex structure containing 10 to 1000 ppm by weight and consisting of a pro-eutectoid L1 ₂ phase and a (L1 ₂ + D0 ₂₂ ) eutectoid structure.

Further, in the friction stir processing tool according to the present invention, the Ni-based double-duplex intermetallic compound alloy contains Ni as a main component and Al: 5.5-13 atomic%, V: 10-17 atomic%, Nb : 0 to 6 atomic%, Ti: 0 to 6 atomic%, Co: 0 to 6 atomic%, Cr: 0 to 6 atomic%, and B: 10 to 1000 weight with respect to the total weight of the total composition of 100 atomic% It preferably has a two-duplex structure containing ppm and consisting of a proeutectoid L1 ₂ phase and a (L1 ₂ + D0 ₂₂ ) eutectoid structure.

In the friction stir processing tool according to the present invention, it is preferable that the surface of the base material is hardened by using the Ni-based double-duplex intermetallic compound alloy described above as a base material.

In the friction stir processing tool according to the present invention, it is preferable that the hardening treatment is at least one of nitriding treatment or carburizing treatment.

The friction stir processing method according to the present invention is a friction stir processing for processing a workpiece by pressing the tip of a tool that rotates at high speed against the workpiece and plasticizing and stirring the workpiece by the generated frictional heat. In the processing method, the friction stir processing tool described in any one of the above is used.

Since the friction stir processing tool of the present invention is made of a Ni-based double-duplex intermetallic compound alloy, the impact and strong pressing load are applied to the probe tip when the tool is applied to the workpiece while rotating. Is less likely to deform, break or break. Furthermore, it is necessary even at high temperatures (800 ° C or higher) that cause the tool side surface to emit orange light due to frictional heat between the shoulder surface of the tool and the workpiece surface and the probe surface embedded in the workpiece. Since it has a high hardness, it is suitable for friction stir processing of high-temperature materials. In particular, the joining material is less worn and hard to break with respect to workpieces such as iron or iron alloy, and can be friction stir processed at low cost.

Since the tool material is made of a Ni-based two-phase intermetallic compound alloy, when the tool is worn by friction stir processing, it is difficult to cause problems even if the tool material is dispersed in a ferrous material such as stainless steel. .

One preferred friction stir processing tool of the present invention is made of a Ni-based double-duplex intermetallic compound alloy containing 0.5 to 8 atomic% of Ta and / or W. In addition to all the effects of the present invention, the risk of the tool being deformed, broken or broken is further reduced.

In another preferred friction stir processing tool of the present invention, the Ni-based double-duplex intermetallic alloy is mainly composed of Ni and Al: 2 to 9 atomic%, V: 10 to 17 atomic%, (Ta and / Or W): 0.5 to 8 atomic%, Nb: 0 to 6 atomic%, Co: 0 to 6 atomic%, Cr: 0 to 6 atomic%, and a total weight of a composition of 100 atomic% in total B: Since it has a _two- duplex structure containing 10 to 1000 ppm by weight and consisting of a pro-eutectoid L1 ₂ phase and a (L1 ₂ + D0 ₂₂ ) eutectoid structure, the hardness is further increased. In addition to all of the effects of the preferred friction stir processing tool, there is even less risk of the tool being deformed, broken or broken.

According to still another preferred friction stir processing tool of the present invention, the Ni-based dual-duplex intermetallic compound alloy is mainly composed of Ni and Al: 5.5 to 13 atomic%, V: 10 to 17 atomic%, B: 10 to 1000 with respect to the total weight of the composition of a total of 100 atom% including Nb: 0 to 6 atom%, Ti: 0 to 6 atom%, Co: 0 to 6 atom%, Cr: 0 to 6 atom% Since it has a _double- duplex structure containing a weight ppm and consisting of a pro-eutectoid L1 ₂ phase and a (L1 ₂ + D0 ₂₂ ) eutectoid structure, the same effects as those of the above-described invention can be achieved.

Another preferred friction stir processing tool according to the present invention is based on the Ni-based double-duplex intermetallic compound alloy described above, and the surface of the base material is hardened. Since the performance is improved, the impact and strong pressing load are applied to the probe tip when the tool is applied to the workpiece while rotating, but the risk of the tool being deformed, broken or broken is further reduced. Furthermore, it is necessary even at high temperatures (800 ° C or higher) that cause the tool side surface to emit orange light due to frictional heat between the shoulder surface of the tool and the workpiece surface and the probe surface embedded in the workpiece. Since it has a high hardness, it is suitable for friction stir processing of high-temperature materials. In particular, the joining material is less worn and hard to break with respect to workpieces such as iron or iron alloy, and can be friction stir processed at low cost.

In another preferable friction stir processing tool described above, when the base material is made of a Ni-based double-duplex intermetallic compound alloy containing 0.5 to 8 atomic% of Ta and / or W, the surface of the base material is hardened. Therefore, since the hardness of the base material itself is high and the wear resistance of the surface is enhanced by the curing treatment, the same effect as described as another advantageous effect of the friction stir processing tool of the present invention is used. The effect is further enhanced.

In another preferred friction stir processing tool of the present invention, the base material is mainly composed of Ni and Al: 2 to 9 atomic%, V: 10 to 17 atomic%, (Ta and / or W): 0.5 to Including B: 10 to 1000 ppm by weight with respect to the total weight of the composition of 100 atom% including 8 atom%, Nb: 0 to 6 atom%, Co: 0 to 6 atom%, Cr: 0 to 6 atom% In addition, since the surface of the base material is hardened when it is made of a Ni-based double-duplex intermetallic compound alloy having a double-phase structure composed of a pro-eutectoid L1 ₂ phase and a (L1 ₂ + D0 ₂₂ ) eutectoid structure. Furthermore, since the hardness of the base material itself is higher and the wear resistance of the surface is enhanced by the curing process, the same effect as that described as another advantageous effect of the friction stir processing tool of the present invention is obtained. Increased further.

In another preferable friction stir processing tool of the present invention, the base material is mainly composed of Ni and Al: 5.5 to 13 atomic%, V: 10 to 17 atomic%, Nb: 0 to 6 atomic%, Ti: B: 10 to 1000 ppm by weight with respect to the total weight of the composition of a total of 100 atom% including 0 to 6 atom%, Co: 0 to 6 atom%, Cr: 0 to 6 atom%, and proeutectoid L1 ₂ phase And (L1 ₂ + D0 ₂₂ ) Ni-base dual-phase intermetallic compound alloy having a double-phase structure consisting of a eutectoid structure, the hardness of the base material itself is higher, and the wear resistance of the surface is increased by hardening treatment. Since the property is enhanced, the invention similar to that described as the effect of another preferable tool for friction stir processing of the above invention is produced.

Still another preferable friction stir processing tool of the present invention is the other preferable friction stir processing tool of the present invention, since the hardening treatment is at least one of nitriding treatment or carburizing treatment, so that the surface wear resistance is further improved. Since it is further enhanced, in addition to the effect of another preferred friction stir processing tool of the present invention, the tool is less likely to be worn or damaged, and the risk of the tool being deformed, broken, broken is further reduced, As a result, the tool life is increased.

The friction stir processing method of the present invention is a friction stir processing method for processing a workpiece by pressing the tip of a tool that rotates at high speed against the workpiece and plasticizing and stirring the workpiece by the generated frictional heat. In the above, since the friction stir processing tool described in any one of the above is used, the friction stir processing can be performed at a low cost with little wear against the workpiece such as iron or iron alloy and less breakage.

They are a TEM photograph (a) and a mimetic diagram (b) for explaining the double phase structure of the intermetallic compound alloy of one embodiment of the present invention, respectively. It is a block diagram which shows an example of the plasma nitriding or carburizing apparatus in which the plasma nitriding or carburizing process of one Embodiment of this invention is possible. It is explanatory drawing of a friction stir welding (FSW) method. It is the photograph which image | photographed the front side (side in which the tool was inserted) of the workpiece obtained by the friction stir processing of Example 1. It is the photograph which image | photographed the back side (opposite side where the tool was inserted) of the workpiece obtained by the friction stir processing of Example 1. It is the photograph which image | photographed the front side (side in which the tool was inserted) of the workpiece obtained by the friction stir processing of Example 3. It is the photograph which image | photographed the back side (opposite side where the tool was inserted) of the workpiece obtained by the friction stir processing of Example 3. It is the photograph which image | photographed the front side (side in which the tool was inserted) of the workpiece obtained by the friction stir processing of Example 4. It is the photograph which image | photographed the front side (side in which the tool was inserted) of the workpiece obtained by the friction stir processing of Example 5. It is the photograph which image | photographed the front side (side in which the tool was inserted) of the joined body obtained by the friction stir welding of Example 6. It is the photograph which image | photographed the back side (opposite side where the tool was inserted) of the joined body obtained by the friction stir welding of Example 6. It is the photograph which image | photographed the front side (side in which the tool was inserted) of the workpiece obtained by the friction stir processing of Example 7. It is the photograph which image | photographed the front side (side in which the tool was inserted) of the workpiece obtained by the friction stir processing of Example 8. It is the photograph which image | photographed the back side (opposite side where the tool was inserted) of the workpiece obtained by the friction stir processing of Example 8. It is the photograph which image | photographed the front side (side in which the tool was inserted) of the workpiece obtained by the friction stir processing of Example 9. It is the photograph which image | photographed the front side (side in which the tool was inserted) of the workpiece obtained by the friction stir processing of Example 10. It is the photograph which image | photographed the front side (side in which the tool was inserted) of the joined body obtained by the friction stir welding of Example 11. It is the photograph which image | photographed the front side (side in which the tool was inserted) of the joined body obtained by the friction stir welding of Comparative Example 1. It is a photograph which shows the test piece after the tension test of the conjugate | zygote obtained in Example 6, Example 11, and Comparative Example 1. FIG. The center part is Example 6, the uppermost part is Example 11, and the lowermost part is the test piece of Comparative Example 1. 6 is a load-displacement curve during a tensile test of the joined bodies obtained in Example 6, Example 11, and Comparative Example 1. FIG. 1 is Comparative Example 1, 2 is Example 6, and 3 is Example 11. It is the microscope picture which cut | disconnected the junction part obtained in Example 6 perpendicularly | vertically with respect to the joining direction, and observed the cross section with the optical microscope. It is the microscope picture which cut | disconnected the junction part obtained by the comparative example 1 perpendicularly | vertically with respect to the joining direction, and observed the cross section with the optical microscope. It is the photograph which image | photographed the front side (side in which the tool was inserted) of the joined body obtained by the friction stir welding of Example 12. It is the microscope picture which cut | disconnected the junction part obtained in Example 12 perpendicularly | vertically with respect to the joining direction, and observed the cross section with the optical microscope. It is the photograph which image | photographed the front side (side in which the tool was inserted) of the joined body obtained by the friction stir welding of Example 13. It is the microscope picture which cut | disconnected the junction part obtained in Example 13 perpendicularly | vertically with respect to the joining direction, and observed the cross section with the optical microscope. It is the photograph which image | photographed the front side (side in which the tool was inserted) of the joined body obtained by the friction stir welding of Example 14. It is the microscope picture which cut | disconnected the junction part obtained in Example 14 perpendicularly | vertically with respect to the joining direction, and observed the cross section with the optical microscope. It is the photograph which image | photographed the front side (side in which the tool was inserted) of the joined body obtained by the friction stir welding of Example 15. It is the microscope picture which cut | disconnected the junction part obtained in Example 15 perpendicularly | vertically with respect to the joining direction, and observed the cross section with the optical microscope. It is the photograph which image | photographed the front side (side in which the tool was inserted) of the joined body obtained by the friction stir welding of Example 16. It is the photograph which image | photographed the front side (side in which the tool was inserted) of the joined body obtained by the friction stir welding of Example 17. It is the microscope picture which cut | disconnected the junction part obtained in Example 17 perpendicularly | vertically with respect to the joining direction, and observed the cross section with the optical microscope. It is the photograph which image | photographed the front side (side in which the tool was inserted) of the joined body obtained by the friction stir welding of Example 18. It is the photograph which image | photographed the front side (side in which the tool was inserted) of the joined body obtained by the friction stir welding of Example 19. It is the microscope picture which cut | disconnected the junction part obtained in Example 19 perpendicularly | vertically with respect to the joining direction, and observed the cross section with the optical microscope. It is the photograph which image | photographed the front side (side in which the tool was inserted) of the joined body obtained by the friction stir welding of Example 20. It is the photograph which image | photographed the front side (side in which the tool was inserted) of the joined body obtained by the friction stir welding of Example 21. It is the microscope picture which cut | disconnected the junction part obtained in Example 21 perpendicularly | vertically with respect to the joining direction, and observed the cross section with the optical microscope. 22 is a photograph of the tool used in Example 22. It is a figure which shows the relationship between the Vickers hardness of tool material, and measurement temperature.

Explanation of symbols

1: vacuum furnace body, 2: hearth, 3: electrode (cathode), 4: process gas introduction section, 5: gas exhaust section, 6: vacuum pump, 7: plasma power source, 8: workpiece, 9: heater 10: backing jig, 20: backing material, 31: material to be joined, 32: material to be joined, 33: joining line, 34: machining trace, 40: tool, 41: probe of tool, 42: tool Shoulder club.

Hereinafter, an embodiment of a friction stir processing tool made of the Ni-based two-phase intermetallic compound alloy of the present invention will be described in detail. The friction stir processing tool of the present invention is made of a Ni-based double-duplex intermetallic compound alloy. Although it will not specifically limit if it is an alloy which has a Ni group 2 double phase intermetallic compound as said Ni group 2 double phase intermetallic compound, For example, it is disclosed by patent document 3, Al: Greater than 5 atomic% and 13 atomic% or less, V: 9.5 atomic% or more and less than 17.5 atomic%, Ti: 0 atomic% or more and 3.5 atomic% or less, B: 1000 ppm by weight or more Examples include a Ni ₃ Al-based intermetallic compound having a weight ppm or less and the balance being made of Ni excluding impurities and having a _two- phase structure of an eutectoid L1 ₂ phase and a (L1 ₂ + D0 ₂₂ ) eutectoid structure.

Such intermetallic compounds are Al: greater than 5 atomic% and 13 atomic% or less, V: 9.5 atomic% or more and less than 17.5 atomic%, Ti: 0 atomic% or more and 3.5 atomic% hereinafter, B: 0 1000 ppm by weight ppm or greater or less, the balance being the alloy material consisting of Ni remove impurities, performing a first heat treatment at a temperature at which coexist with proeutectoid L1 ₂ phase and Al phase, then L1 or a _2-phase and D0 ₂₂ phase is cooled to a temperature to coexist, by a the L1 ₂ phase and D0 ₂₂ phase performs a second heat treatment at a temperature coexist, Al phase (L1 ₂ + D0 ₂₂₎ eutectoid tissue It can be produced by a method comprising a step of forming a double-duplex structure by changing to the above. Or it can manufacture also by the method of providing the process of forming a double-duplex structure | tissue by slowly cooling the alloy of the said composition from high temperature A1 single phase area | region.

Examples of the Ni-based two-duplex intermetallic compound alloy are those disclosed in Patent Document 4, for example, Al: greater than 5 atomic% and not more than 13 atomic%, and V: not less than 9.5 atomic%. Less than 17.5 atomic%, Nb: 0 atomic% or more and 5 atomic% or less, B: 50 weight ppm or more and 1000 weight ppm or less, the balance is made of Ni except impurities, and the pro-eutectoid L1 ₂ phase and (L1 ₂ + D0 ₂₂ ) Ni ₃ Al-based intermetallic compounds having a double-duplex structure with a eutectoid structure.

Such intermetallic compounds include Al: greater than 5 atomic% and 13 atomic% or less, V: 9.5 atomic% or more and less than 17.5 atomic%, Nb: 0 atomic% or more and 5 atomic% or less, B: 50 ppm or greater at 1000 ppm by weight or less, the balance being the alloy material consisting of Ni remove impurities, and pro-eutectoid L1 ₂ phase and Al phase and the temperature to coexist, or the pro-eutectoid L1 ₂ phase and Al phase The first heat treatment is performed at a temperature at which D0 _a coexists, and then the Al phase is reduced to (L1 ₂ + D0) by cooling to a temperature at which the L1 ₂ phase and the D0 ₂₂ phase coexist or by performing the second heat treatment at that temperature. ₂₂ ) It can be produced by a process of changing to a eutectoid structure to form a double-phase structure. Or it can manufacture also by the method of providing the process of forming a double-duplex structure | tissue by slowly cooling the alloy of the said composition from high temperature A1 single phase area | region.

The friction stir processing tool may also be made of a Ni-based two-phase intermetallic alloy containing 0.5 to 8 atomic% of Ta and / or W.

The friction stir processing tool also includes, for example, Ni as a main component and Al: 2 to 9 atomic%, V: 10 to 17 atomic%, (Ta and / or W): 0.5 to 8 atomic%, Nb : Ni-based intermetallic compound containing B: 10 to 1000 ppm by weight with respect to the total weight of the composition of a total of 100 atom% including 0 to 6 atom%, Co: 0 to 6 atom%, and Cr: 0 to 6 atom% It may be made of an alloy. In the present specification, “˜” includes the composition of both ends. The content of Ta and / or W means the content of Ta or W when only one of Ta and W is included, and when both Ta and W are included, the content of Ta and W It means the total content. The reason why the content of Ta and / or W is within the above range is that if it is within this range, the effect of improving hardness can be obtained by the addition of Ta and / or W, and the upper limit is 8 atoms. This is because even if an amount exceeding% is added, it does not greatly contribute to the improvement of hardness.

Nb, Co, and Cr are optional components and may or may not be included. This is because the hardness is improved by the addition of Ta or W regardless of whether Nb, Co, or Cr is contained. Nb is added to improve the strength of the two-phase structure. Co and Cr are added to improve oxidation resistance.

B is added to improve the ductility of the resulting alloy.

The above Ni-based intermetallic alloy has Al: 2.5 to 8 atomic%, V: 10 to 14.5 atomic%, (Ta and / or W): 1 to 5 atomic%, Nb: 0 to 4 atomic% It is preferable that

The Ni-based intermetallic compound alloy is preferably Ta: 0.5 atomic% or more.

The Ni-based intermetallic compound alloy is preferably W: 0.5 atomic% or more.

The Ni-based intermetallic compound alloy preferably has a double-duplex structure composed of a proeutectoid L1 ₂ phase and a (L1 ₂ + D0 ₂₂ ) eutectoid structure. This is because an intermetallic compound alloy having a two-phase structure is excellent in mechanical properties such as tensile strength and creep resistance. In this case, Ni, Al, and V are added for the formation of a two-phase structure. When Ni, Al, and V are in the above ranges, a two-phase structure is likely to be formed at least partially. A friction stir processing tool made of this alloy is, as one preferred embodiment of the present invention, a friction stir processing tool made of a Ni-based double-duplex intermetallic compound alloy, and comprising a Ni-based double-duplex intermetallic compound This is an example of a friction stir processing tool characterized in that the alloy contains 0.5 to 8 atomic% of Ta and / or W.

The two-duplex structure first forms an upper double-phase structure composed of a proeutectoid L1 ₂ phase and an A1 phase at a relatively high temperature, and then lowers the temperature to change the A1 phase into the L1 ₂ phase and the D0 ₂₂ phase. It can be formed by decomposing it. As a result, a _double- phase structure composed of a proeutectoid L1 ₂ phase and a (L1 ₂ + D0 ₂₂ ) eutectoid structure as shown in the TEM photograph of FIG. 1A and the schematic diagram of FIG. 1B is formed. . The L1 ₂ phase is a Ni ₃ Al intermetallic compound phase, the A1 phase is an fcc solid solution phase, and the D0 ₂₂ phase is a Ni ₃ V intermetallic compound phase.

An intermetallic compound alloy having a two-duplex structure can be produced by the method described in Patent Document 4. However, in Patent Document 4, an upper multiphase structure is formed by performing a heat treatment at a temperature at which the proeutectoid L1 ₂ phase and the A1 phase coexist as an independent process. When producing an ingot of a compound alloy, the upper multiphase structure can also be formed by slow cooling during solidification. When performing the slow cooling, the melt is to stay relatively long time to a temperature that coexist with proeutectoid L1 ₂ phase and A1 phase after coagulation, similar to the case of performing the heat treatment proeutectoid L1 ₂ This is because an upper multiphase structure composed of a phase and an A1 phase is formed.

The Ni-based intermetallic compound alloy preferably has a Vickers hardness of 550 to 1000 at room temperature. In the present invention, “Vickers hardness” means a value measured under conditions of a load of 300 g and a holding time of 20 seconds unless otherwise specified.

In a friction stir processing tool such as iron or iron alloy, since the processing temperature becomes high, it is desirable that the hardness at high temperature is high. For example, at 800 ° C., the Vickers hardness is 400 or more, more preferably 450 or more, and still more preferably. It is preferable that there are 500 or more.

In the Ni-based intermetallic compound alloy having a Vickers hardness of 550 to 1000 at room temperature, the difference between the Vickers hardness at room temperature and 900 ° C. is preferably within 0 to 300, more preferably within 0 to 150.

Ni as a main component and Al: 2-9 atomic%, V: 10-17 atomic%, (Ta and / or W): 0.5-8 atomic%, Nb: 0-6 atomic%, Co A Ni-based intermetallic alloy containing B: 10 to 1000 ppm by weight with respect to the total weight of the composition of a total of 100 atom% including: 0 to 6 atom% and Cr: 0 to 6 atom% is disclosed in Patent Document 4 Ni ₃ Al—Ni ₃ Nb—Ni ₃ V-based intermetallic compound alloy is superior in hardness and suitable as a material for a friction stir processing tool that requires wear resistance.

Further, the Ni-based dual-duplex intermetallic compound alloy used in the present invention is mainly composed of Ni and Al: 5.5 to 13 atomic%, V: 10 to 17 atomic%, Nb: 0 to 6 atomic%, B: 10 to 1000 ppm by weight and proeutectoid L1 with respect to the total weight of the composition of a total of 100 atom% including Ti: 0 to 6 atom%, Co: 0 to 6 atom%, and Cr: 0 to 6 atom% A Ni-based double-duplex intermetallic compound alloy having a double-duplex structure composed of _two phases and a (L1 ₂ + D0 ₂₂ ) eutectoid structure is also preferable. The tool may be produced by melting / casting, casting the cast material by hot forging, plastic working, powder metallurgy, or the like.

As described above in part, the manufacture of the Ni-based double-duplex intermetallic alloy tool can be performed by various manufacturing methods. An ingot is prepared by melting and casting a product obtained by weighing B and having a purity of 99.9% by weight or more) and a vacuum induction melting method or an arc melting method. A tool is manufactured by processing the ingot into a predetermined shape by appropriately using electric discharge machining, cutting, grinding, polishing, or the like.

In the friction stir processing tool according to the present invention, it is preferable that any of the above-described Ni-based double-duplex intermetallic alloys is used as a base material and the surface of the base material is hardened. Hereinafter, preferred embodiments of the present invention will be described.

As the Ni-based double-duplex intermetallic compound alloy, a Ni-based double-duplex intermetallic compound alloy containing Ta and / or W in an amount of 0.5 to 8 atomic% is preferable, and Ni is the main component and Al: 2 to 9 atomic%. V: 10-17 atomic%, (Ta and / or W): 0.5-8 atomic%, Nb: 0-6 atomic%, Co: 0-6 atomic%, Cr: 0-6 atomic% Ni-base double overlap with B: 10 to 1000 ppm by weight with respect to the total weight of the composition of a total of 100 atomic% and having a double-phase structure composed of a pro-eutectoid L1 ₂ phase and a (L1 ₂ + D0 ₂₂ ) eutectoid structure A phase intermetallic alloy is particularly preferred.

Further, it is mainly composed of Ni and Al: 5.5 to 13 atom%, V: 10 to 17 atom%, Nb: 0 to 6 atom%, Ti: 0 to 6 atom%, Co: 0 to 6 atom, Cr : B: 10 to 1000 ppm by weight with respect to the total weight of the composition of 100 atom% including 0 to 6 atom%, and two overlaps consisting of the proeutectoid L1 ₂ phase and the (L1 ₂ + D0 ₂₂ ) eutectoid structure A Ni-based double-duplex intermetallic compound alloy having a phase structure is also particularly preferred.

The above double-phase structure first forms an upper double-phase structure composed of a proeutectoid L1 ₂ phase and an A1 phase at a relatively high temperature, and then lowers the temperature to convert the A1 phase into the L1 ₂ phase and D0 _22. It can be formed by decomposing into phases. As a result, a _double- phase structure composed of a proeutectoid L1 ₂ phase and a (L1 ₂ + D0 ₂₂ ) eutectoid structure as shown in the TEM photograph of FIG. 1A and the schematic diagram of FIG. 1B is formed. . The L1 ₂ phase is a Ni ₃ Al intermetallic compound phase, the A1 phase is an fcc solid solution phase, and the D0 ₂₂ phase is a Ni ₃ V intermetallic compound phase.

The intermetallic compound alloy having the above two-phase structure can be produced by the methods described in

Patent Documents

3 and 4. However, in

Patent Documents

3 and 4, the upper multiphase structure is formed by performing heat treatment at a temperature at which the pro-eutectoid L1 ₂ phase and the A1 phase coexist as an independent process, but instead of performing this heat treatment When producing an ingot of an intermetallic compound alloy, the upper multiphase structure can be formed also by slow cooling during solidification. When performing the slow cooling, the melt is to stay relatively long time to a temperature that coexist with proeutectoid L1 ₂ phase and A1 phase after coagulation, similar to the case of performing the heat treatment proeutectoid L1 ₂ This is because an upper multiphase structure composed of a phase and an A1 phase is formed.

The alloy after the above-mentioned hardening treatment preferably has a Vickers hardness of 500 to 1400 at room temperature measured from the surface with a load of 50 g. Further, the alloy after the hardening treatment preferably has a Vickers hardness of 500 to 1400 measured at a load of 10 g at a position where the depth from the surface is 20 μm.

As the curing treatment, surface treatment by at least one of nitriding treatment or carburizing treatment is preferable.

The nitriding treatment is a treatment for increasing the amount of nitrogen in the base material surface layer. As the nitriding treatment, salt bath nitriding treatment (mainly treatment for heating and nitriding in a cyan salt bath), gas nitriding treatment (heating the treatment subject in ammonia (NH ₃ ) gas for nitriding) Treatment), plasma nitridation treatment (treatment performed using plasma caused by glow discharge generated between an anode to be treated and an anode in a reduced-pressure nitriding atmosphere), etc., from the viewpoint of treatment efficiency, etc. Plasma nitriding is preferred. The temperature of the plasma nitriding treatment is not particularly limited, but it is preferably 400 to 900 ° C. in order to efficiently cure the surface.

The carburizing process is a process for increasing the carbon content of the base material surface layer. As carburizing treatment, gas carburizing treatment (treatment of heating a carburizing gas in a carburizing gas and carburizing), vacuum carburizing treatment (treating the treatment object in a carburizing gas reduced in a vacuum furnace) Heating and carburizing treatment), plasma carburizing treatment (treatment performed using plasma by glow discharge generated between the workpiece to be treated as the cathode and the anode in a reduced carburizing atmosphere), etc. Plasma carburizing treatment is preferable from the viewpoint of treatment efficiency and the like. The temperature of the plasma carburizing treatment is not particularly limited, but is preferably 400 to 900 ° C. in order to efficiently cure the surface.

Hereinafter, an example of a plasma nitriding or carburizing apparatus, a plasma nitriding process, a plasma carburizing process, and a combination of a plasma nitriding process and a plasma carburizing process will be described.

(1) Plasma nitriding or carburizing apparatus An example of a plasma nitriding or carburizing apparatus will be described with reference to FIG. The plasma nitriding or carburizing apparatus in FIG. 2 includes a vacuum furnace body 1, a hearth 2 disposed in the vacuum furnace body 1, an electrode 3 electrically connected to the hearth 2, and a vacuum furnace body 1. A process gas introduction part 4 for introducing process gas, a gas exhaust part 5 for exhausting the inside of the vacuum furnace body 1, a vacuum pump 6 connected to the gas exhaust part 5, the vacuum furnace body 1 serves as an anode, and an electrode 3 A plasma power source 7 connected to be a cathode and a heater 9 for heating the workpiece 8 disposed on the hearth 2 are provided. The electrode 3 and the vacuum furnace body 1 are electrically insulated. When the electrode 3 becomes a cathode, the hearth 2 and the workpiece 8 electrically connected thereto also become cathodes.

Hereinafter, the outline of the plasma nitriding or carburizing process using this apparatus will be described.

First, the workpiece 8 is placed on the hearth 2. Next, the vacuum pump 6 is operated to evacuate the vacuum furnace body 1. Next, the heater 9 is operated to heat the inside of the vacuum furnace body 1 and the workpiece 8. Next, a process gas is introduced into the vacuum furnace body 1 from the process gas introduction unit 4 and a plasma power source 7 is operated to generate plasma by glow discharge between the vacuum furnace body 1 and the workpiece 8. Plasma nitriding or carburizing of the workpiece 8 is performed by the plasma.

(2) Plasma nitriding treatment Next, the plasma nitriding treatment will be described. The process gas used for the plasma nitriding treatment includes a nitrogen source gas. Examples of the nitrogen source gas include N ₂ and NH ₃ , and N ₂ is preferable. The process gas may contain only the nitrogen source gas, but preferably contains a diluent gas composed of an inert gas such as H ₂ or Ar. In this case, excessive generation of thin and hard nitride on the sample surface is suppressed, and a relatively uniform nitride layer can be formed deeper. The flow rate ratio of nitrogen source gas / dilution gas is not particularly limited, but in one example, it is 0.1 to 10 (preferably 0.5 to 2). The process gas may include a gas (for example, a carbon source gas) other than the nitrogen source gas and the dilution gas. The atmospheric pressure may be any pressure that can generate plasma by glow discharge, and is, for example, 50 to 2000 Pa (preferably 100 to 1000 Pa).

The temperature of the plasma nitriding treatment is 400 to 900 ° C., preferably 500 to 800 ° C., more preferably 550 to 700 ° C. This is because when the plasma nitriding treatment is performed at such a temperature, the hardness of the surface is particularly greatly improved. The plasma nitriding time is, for example, 1 to 200 hours.

When the effect of improving the surface hardness by plasma nitriding treatment is seen in terms of Vickers hardness, a Ni-based dual phase intermetallic compound alloy containing 0.5 to 8 atomic% of Ta and / or W is obtained at 575 ° C. for 48 hours. When plasma nitriding is performed under conditions, the Vickers hardness at normal temperature is 900 to 1200 at a depth of 5 μm from the surface of the object to be processed, 700 to 900 at a depth of 10 μm, and a depth of 700 to 900 μm. And about 560 to 650 at a depth of 600 to 700 and 20 μm.

(3) Plasma carburizing process Next, the plasma carburizing process will be described. The process gas used for the plasma carburizing process includes a carbon source gas. Examples of the carbon source gas include hydrocarbon gases such as methane, propane, and acetylene. The process gas preferably includes a dilution gas composed of an inert gas such as H ₂ or Ar. In this case, it is possible to suppress soot from adhering to the sample surface. The flow rate ratio of the carbon source gas / dilution gas is not particularly limited, but in one example, is 0.01 to 1 (preferably 0.05 to 0.2). The process gas may include a gas (for example, nitrogen source gas) other than the carbon source gas and the dilution gas. The atmospheric pressure may be any pressure that enables plasma generation by glow discharge, and is, for example, 50 to 1000 Pa (preferably 100 to 500 Pa).

The temperature of the plasma carburizing treatment is 400 to 900 ° C., preferably 680 to 850 ° C., and more preferably 700 to 800 ° C. This is because when the plasma carburizing process is performed at such a temperature, the surface hardness is particularly improved. The plasma carburizing time is, for example, 1 to 200 hours.

When the effect of improving the hardness of the surface by plasma carburizing treatment is seen in terms of Vickers hardness, Ni-based double-duplex intermetallic alloy containing 0.5 to 8 atomic% of Ta and / or W can be obtained at 750 ° C. for 48 hours. When plasma carburizing treatment is performed under the conditions, the Vickers hardness at normal temperature is 700 to 850 at a depth of 10 μm from the surface of the workpiece, and a depth of 700 to 850 and 30 μm at a depth of 20 μm. At a depth of 650 to 850 and 50 μm, 600 to 700, and at a depth of 100 μm, about 600 to 650.

(4) Combination of plasma nitriding treatment and plasma carburizing treatment Next, a combination of plasma nitriding treatment and plasma carburizing treatment will be described.

As a combination of the plasma nitriding treatment and the plasma carburizing treatment, when the plasma carburizing treatment is performed after the plasma nitriding treatment, when performing the plasma nitriding treatment after the plasma carburizing treatment, the case where the plasma nitriding treatment and the plasma carburizing treatment are simultaneously performed may be considered. . The plasma nitriding treatment and the plasma carburizing treatment can each be performed under the above conditions.

When plasma nitriding is performed after plasma carburizing, the hardness at the outermost surface can be further improved and the hardness distribution can be made gentle. When plasma carburizing is performed after plasma nitriding, the hardness at the outermost surface is low, but a hardness distribution can be formed gently and even inside.

Further, by including both the nitrogen source gas and the carbon source gas in the process gas, the plasma nitriding treatment and the plasma carburizing treatment can be performed simultaneously. However, since the optimum temperature differs between the plasma nitriding treatment and the plasma carburizing treatment, it is considered that an excellent result can be obtained by selecting an appropriate temperature for both the plasma nitriding treatment and the plasma carburizing treatment.

The method for producing the friction stir processing tool of the present invention is performed, for example, as follows.
(1) Ingot production process First, after weighing ingots of predetermined elements (purity 99.9% by weight) and B so as to have a predetermined composition in a crucible, the mold or ceramic mold is used. A sample made of an ingot is produced by solidifying the molten metal. The size of the ingot produced here is, for example, 83 mmφ × 700 mm. A predetermined tool is cut out from the ingot.

(2) Heat treatment step Next, for example, vacuum heat treatment (furnace cooling) is performed on the tool at 1000 ° C. for 10 hours. 1000 ° C. is the coexistence temperature of the L1 ₂ phase and the D0 ₂₂ phase, and the lower multiphase structure composed of the (L1 ₂ + D0 ₂₂ ) eutectoid structure is more reliably formed by this heat treatment. The sample after the heat treatment becomes an intermetallic compound alloy base material. However, in an ingot of an intermetallic compound alloy that is gradually cooled after solidification, a double-duplex structure may be formed.

(3) Surface treatment process Next, surface treatment like the above-mentioned nitriding treatment or carburizing treatment is performed on the tool after the heat treatment.

As used herein, an iron alloy refers to an alloy containing iron as a main component and one or more other elements. Examples thereof include carbon steel and stainless steel.

The shape of the workpiece as defined in claim 6 of the present invention is not particularly limited, and examples thereof include a thin plate, a thick plate, and a lump, and in the case of friction stir welding, a thin plate and a thick plate are particularly preferable.

The friction stir processing method of the present invention will be described in detail. In butt friction stir welding, the materials to be joined are placed and fixed on a surface plate or a backing jig placed on the surface plate by butt. At this time, because there is a problem such as contamination from the back side due to the stir welding, there is a case where a backing material is placed on the joining portion and then the joining process is performed, but this method is also useful in the processing by the tool of the present invention. It is. The backing material preferably has heat resistance, nonflammability, strength, non-contamination, surface smoothness, etc., and foils, plates, molded articles, etc. made of a material such as a refractory metal or ceramics are used.

A method of performing friction stir welding (FSW) using the above backing material as a friction stir processing method of the present invention will be described with reference to FIG.

In FIG. 3, first, the backing material 20 is arranged at a desired position on the surface plate.

Next, the plate-shaped

workpieces

31 and 32 are arranged and fixed so that the bonding line 33 of the plate-shaped

workpieces

31 and 32 is located at the center on the backing material 20. As the materials to be bonded 31 and 32, plate-shaped materials made of iron or iron alloy are mainly used. These materials to be joined 31 and 32 may be flat or simple plate-like or plate-like having a simple curved surface such as a cylindrical shape corresponding to the shape of the backing jig 10. Further, it may be a plate having a three-dimensional curved surface.

In order to interpose the backing material between the materials to be joined 31 and 32 and the backing jig 10, the thin-layer body 20 having a smooth surface is simply placed along the joining line 33 of the materials to be joined 31 and 32. However, in order to facilitate the clamping operation, the backing material 20 may be pasted on the backing jig 10 with an adhesive or an adhesive in advance. Good.

After that, at one end of the joining line 33 of the plate-

like workpieces

31 and 32, a joining rotary tool 40 (a tool made of an alloy of the present invention having a shoulder portion 42 having a large diameter and a probe 41 at the tip thereof). The probe 41 of 40) is pressed and inserted with a strong force while rotating at high speed, and the tool 40 is moved to the other end along the joining line 33 while applying pressure by the shoulder portion 42 to generate frictional heat. The vicinity of the tool is plasticized and joined in a solid state. It should be noted that the tool is inserted from the substantially normal direction of the surface in the vicinity of the joint portion of the material to be joined and is moved while maintaining the substantially normal direction.

Here, the joining rotary tool (tool) will be described. The joining rotary tool (tool) 40 includes a shoulder portion 42 having a large diameter and a probe 41 provided to protrude from the shoulder portion 42. The probe 41 may be threaded or unthreaded. Further, when using a material to be joined (31 and 32) having a thickness of about 6 mm or less, the diameter of the shoulder portion 42 of the tool 40 is about 12 to 15 mm, and the diameter of the probe 41 is about 3 to 6 mm. Preferably used.

The surface of the shoulder portion 42 needs to press the materials to be joined 31 and 32 along the joining line 33. Usually, the shoulder surface contacting the materials to be joined 31 and 32 is a flat surface or a concave surface having a large curvature radius. Is preferred. Depending on the case, it is also possible to use a slightly arcuate or conical convex surface. A flat plate is preferable because it is easy to process. In general, the length of the probe 41 is shorter than the thickness of the materials to be joined 31 and 32 to be joined so as not to contact the backing jig 10. The rotation speed of the tool 40 is generally several hundred to several thousand revolutions / minute, and the joining speed is generally several tens to several hundreds mm / minute, but it can be 1 to 2 m / minute depending on conditions.

The probe 41 is provided so as to protrude from the shoulder surface, but the position is preferably on the rotation axis of the tool.

The probe should start from the shoulder surface and taper, that is, the tip should gradually narrow.
The tip of the probe is preferably a flat surface or a curved surface having a large turning radius, for example, a spherical surface, in order to prevent stress concentration and damage. The ratio of the probe height to the probe root radius is preferably 1 or smaller than 1. For example, the hemisphere is preferably formed in a shape in which a bottom portion is partially buried in the shoulder surface. When the tool at the tip of the rotated tool is strong against impact when it hits the workpiece, is not easily broken, and when the workpiece is not sufficiently plasticized when moving the tool after plasticizing by friction due to rotation This is because it is difficult to break. Moreover, it can have a sufficient depth to stir the plasticized part in the joining, and even if the probe is gradually worn out from the surface by the friction stir processing, the influence of the shape of the probe on the joining is small.

The tool 40 is used by being attached to a known friction stir welding apparatus having three axes of a platen axis (X), a transverse axis (Y), and a lifting / lowering axis (Z). In addition, a known 5-axis frame type consisting of a platen axis (X), a transverse axis (Y), a lifting / lowering axis (Z), three axes, and a swing axis (A) and a swivel axis (C), two tool axes. It is also used when attached to a friction stir welding apparatus. Moreover, although it may be attached and used for the machine head mounted in the front-end | tip of the well-known robot arm provided with three joint axes and two rotating shafts, it is not limited to these.

Thus, a joined body of the materials to be joined 31 and 32 is obtained.

In the above example, the friction stir welding (FSW) for joining the materials to be joined 31 and 32 has been described. However, the present invention replaces the two materials to be joined 31 and 32, and the same 1 By using a single workpiece and inserting the probe 41 of the tool 40 rotating at a high speed on the surface of the workpiece with a strong force, the friction stir reforming (FSP) for modifying the workpiece by the frictional heat generated at that time is used. Is also applicable.

Also, the probe can be inserted into the surface of the workpiece, but it can also be applied to a joining technique and a reforming technique in which point machining is performed by pulling out the probe after a certain time without lateral movement.

Hereinafter, the present invention will be described in detail with reference to examples.
Example 1

(Production of friction stir processing tool)
Metals of Ni, Al, V, and Nb to have a composition of Ni: 75 atomic%, Al: 8.75 atomic%, V: 13.25 atomic%, Nb: 3 atomic%, B: 50 ppm by weight (Weighing 99.9% by weight) and B were weighed in a vacuum induction melting furnace, and then the molten metal was solidified with a mold to prepare a 5 kg ingot.

This hot ingot was subjected to hot forging at 1300 ° C. with a total reduction of about 60% in order to refine the cast structure composed of coarse crystal grains and to eliminate casting defects such as pores. At this time, hot forging did not apply a reduction rate of 60% at a time, but was divided into a plurality of times, and the sample was heated to 1300 ° C. for each forging.

The tool of the present invention was manufactured from this ingot by cutting into the shape shown below. The material of this tool will be called “H # 1”.

(Shape of friction stir processing tool)
The shoulder surface is a circular plane having a diameter of 12 mm, and the probe provided at the center has a spherical surface with a radius of 2 mm partially protruding from the shoulder surface. The bottom diameter of the probe is about 4 mm, and the length from the shoulder surface to the tip of the probe (projection height, probe length) is 0.90 mm.

(Friction stir processing)
Using the friction stir processing tool, the friction stir processing was performed by the method shown in FIG. However, in the method shown in FIG. 3, the friction stir welding is performed using the two flat plate-

like workpieces

31 and 32. In Example 1, one flat plate is used as the workpiece. A bead-on (or star-in-plate, also referred to as a stir-in-plate) friction stir processing test was performed.

The tool 40 was attached to a friction stir welding apparatus composed of three axes: a platen axis (X), a transverse axis (Y), and a lifting / lowering axis (Z). At the time of friction stir processing, argon gas flows along the side of the tool and wraps around the tool (the same applies to the following examples and comparative examples).

As shown in FIG. 3, a 99.5% pure aluminum oxide flat plate (15 cm square, 2.5 mm thickness) having a smooth surface is applied to the surface of a flat steel (S50C) backing jig 10. Fixed as 20.

On the aluminum oxide backing material 20, a flat plate-shaped workpiece (15 cm square, 1.5 mm thickness) made of one SUS430 was placed and fixed.

The tool 40 was inserted on the SUS430 flat plate while rotating at a forward angle of 3 degrees and 1200 rpm, and was moved 250 mm linearly at a feed rate of 100 mm / min, and a bead-on friction stir processing test was performed by friction stir processing. The load on the tool 40 was set to about 29400N. The side of the tool emitted orange during processing. According to the visual observation after the processing, as shown in the photograph of FIG. 4, the working state of the SUS430 flat plate is good although there is a processing mark 34 by the tool 40 on the surface of the processing portion, and the back surface photograph is shown in FIG. As shown, it was smooth. However, since the backing aluminum oxide plate 20 was cracked during processing, SUS plasticized into the cracks entered and cooled and solidified was seen as convex fine streaks.

Table 1 summarizes the tool material, workpiece material, FSW machining format, FSW machining conditions, and tool size in Example 1. In Table 1, the tool size refers to the size of the tool before being used for FSW processing. Table 1 also shows the same items for Examples 2 to 11 and Comparative Example 1 described later.

(Example 2)

In the same manner as in Example 1, a friction stir processing tool having the same shape as in Example 1 was produced. Using the obtained tool, instead of the workpiece made of SUS430, the plate-like workpiece (15 cm square, 1.5 mm thickness) made of titanium (2 types of pure titanium (JIS symbol: TB340H)) is used. The bead-on friction stir processing test was carried out in the same manner as in Example 1 except that the movement distance of the tool during processing was set to 120 mm.

According to the visual observation after the machining, the titanium flat plate was subjected to the machining mark 34 by the tool 40 on the surface of the machined portion, but there were no defects such as burrs, and the back surface was smooth. Further, the tool 40 was slightly worn out in appearance.
(Example 3)

Using the friction stir processing tool used in Example 2, a plate-shaped workpiece (15 cm square, 1.5 mm) made of titanium (two types of pure titanium (JIS symbol: TB340H)) different from Example 2 A bead-on friction stir processing test was conducted in the same manner as in Example 2 except that the thickness) was used.

According to the visual observation after processing, as shown in the photograph of FIG. 6, the titanium flat plate has a processing mark 34 due to the tool 40 on the surface of the processing portion, but there are no defects such as burrs, and a back surface photograph thereof. As shown in FIG. 7, it was smooth. However, since the backing aluminum oxide plate 20 was cracked during processing, the portion where the plasticized titanium entered the cracks and cooled and solidified appeared as convex fine streaks. Further, the tool 40 was slightly worn out in appearance.
Example 4

(Production of friction stir processing tool)
Ni: 71.5 atomic%, Al: 7 atomic%, V: 10.5 atomic%, Nb: 3 atomic%, Co: 3 atomic%, Cr: 3 atomic%, Ta: 2 atomic%, B: 50 weight After weighing ingots of Ni, Al, V, Nb, Co, Cr and Ta ingots (purity 99.9% by weight) and B so as to have a composition of ppm in a vacuum induction melting furnace, ceramic A 10 kg ingot was produced by solidifying the molten metal with a mold. When the ingot was produced, since it was gradually cooled during solidification, a _double- duplex structure composed of a proeutectoid L1 ₂ phase and a (L1 ₂ + D0 ₂₂ ) eutectoid structure was formed in the ingot. The tool of the present invention was manufactured by cutting this ingot into a shape similar to the shape of the friction stir processing tool shown in Example 1. The material of this tool will be called “Ta # 1”.

like workpieces

31 and 32, but in Example 4, one flat plate is used as the workpiece. A bead-on friction stir processing test was conducted.

The tool 40 was attached to a friction stir welding apparatus composed of three axes: a platen axis (X), a transverse axis (Y), and a lifting / lowering axis (Z). At the time of friction stir processing, argon gas flows along the side of the tool and wraps around the tool.

The tool 40 was inserted on the SUS430 flat plate while rotating at a forward angle of 3 degrees and 600 rpm, and the SUS430 was softened. Next, a bead-on friction stir processing test was conducted by friction stir processing by moving the tool 40 90 mm linearly at a feed rate of 150 mm / min while rotating the tool 40 at a forward angle of 3 degrees and 900 rpm. The load on the tool 40 was set to about 9800N. The side of the tool emitted orange during processing. According to the visual observation after the processing, as shown in the photograph of FIG. 8, the construction state of the SUS430 flat plate was good although there was a processing mark 34 by the tool 40 on the surface of the processing portion.
(Example 5)

(Production of friction stir processing tool)
Ni: 71.5 atomic%, Al: 7 atomic%, V: 10.5 atomic%, Nb: 3 atomic%, Co: 3 atomic%, Cr: 3 atomic%, W: 2 atomic%, B: 50 weight After a Ni, Al, V, Nb, Co, Cr, and W bullion (purity 99.9% by weight) and B were weighed in a vacuum induction melting furnace so as to have a ppm composition, A 10 kg ingot was produced by solidifying the molten metal with a mold. When the ingot was produced, since it was gradually cooled during solidification, a _double- duplex structure composed of a proeutectoid L1 ₂ phase and a (L1 ₂ + D0 ₂₂ ) eutectoid structure was formed in the ingot.

The tool of the present invention was manufactured by cutting this ingot into a shape similar to the shape of the friction stir processing tool shown in Example 1. The material of this tool will be called “W # 1”.

(Friction stir processing)
Using the above friction stir processing tool, a bead-on friction stir processing test was performed in the same manner as in Example 4 except that the following description differs from that in Example 4.

The tool 40 was inserted on the SUS430 flat plate while rotating at 400 rpm with an advance angle of 3 degrees to soften the SUS430. Next, a bead-on friction stir processing test by friction stir processing was performed by moving the tool 40 linearly by 90 mm on the SUS430 flat plate at a feed rate of 150 mm / min while rotating the tool at a forward angle of 3 degrees and 1200 rpm. The load on the tool 40 was set to about 9800N. The side of the tool emitted orange during processing. According to the visual observation after the processing, as shown in the photograph of FIG. 9, the construction state of the SUS430 flat plate was good although the processing marks 34 by the tool 40 exist on the surface of the processing portion.
(Example 6)

(Production of friction stir processing tool)
In the same manner as in Example 5, a friction stir processing tool made of the tool material “W # 1” was produced.

(Friction stir processing (friction stir welding))
Using the friction stir processing tool, friction stir processing (friction stir welding by butt joining) was performed by the method shown in FIG. The tool 40 was attached to a friction stir welding apparatus consisting of three axes, a platen axis (X), a transverse axis (Y), and a lift axis (Z). During friction stir welding, argon gas flows along the side of the tool and wraps around the tool.

On the aluminum oxide backing material 20, two flat plate-like materials 31 and 32 (15 cm square, 1.5 mm thickness) made of SUS430 were put in contact with each other and fixed.

The tool 40 was inserted on the joining line 33 while rotating at a forward angle of 3 degrees and 700 rpm, and the surrounding SUS430 including the joining line 33 was softened. Next, the tool 40 is moved about 90 mm along the joining line 33 of the materials to be joined 31 and 32 at a feed rate of 150 mm / min while rotating at a forward angle of 3 degrees and 1200 rpm, and friction stir welding is performed. A joined body of 31 and 32 was produced. The load on the tool 40 was set to about 9800N. The side of the tool emitted orange during processing.

As shown in the photograph of FIG. 10, the joined body of the materials to be joined 31 and 32 obtained by the friction stir welding has a processing mark 34 due to the tool 40 on the surface of the joined portion, which is good. The back surface photograph is shown in FIG. 11 and was smooth. However, since the backing aluminum oxide plate 20 was cracked during processing, SUS plasticized into the cracks entered and cooled and solidified was seen as convex fine streaks.

In order to examine the strength of the above-mentioned joint part, a sample was produced from the butt-joined flat plate in a direction orthogonal to the joining direction, and a tensile test was performed according to JIS Z 2241 “Tensile test method for metal material”. The sample had a width of 24.6 mm and a parallel part length of 50 mm in accordance with the shape of the JIS Z 2201 No. 5 test piece. The thickness was 1.46 mm. The crosshead speed at the time of measurement was 20 mm / min. As a result, the tensile strength was 505 MPa. As for the tensile strength of the SUS430 base material measured under the same conditions, the average of n = 3 was 519 MPa. Therefore, it was found that the tensile strength of the above-mentioned joint portion is almost the same as that of the base material. Moreover, although the photograph of the fractured test piece is shown in FIG. 19, the test piece located at the center in FIG. 19 (represented by reference numeral 2 in the figure) is not the joint but the base material portion. It showed what happened. Further, the load-displacement curve is shown in FIG. 20. In FIG. 20, it can be seen that the present test piece represented by reference numeral 2 is well stretched before breaking.

Moreover, the said junction part was cut | disconnected perpendicularly | vertically with respect to the joining direction, and the cross section was observed with the stereomicroscope. The micrograph is shown in FIG. In FIG. 21, the thickness of this cross section is 1.46 mm as described above. As can be seen from this photograph, the original butt interface disappears completely by friction stir and can be joined.
(Example 7)

(Production of friction stir processing tool)
In the same manner as in Example 4, a friction stir processing tool made of the tool material “Ta # 1” was produced.

(Plasma nitriding (PN) treatment)
The obtained tool for friction stir processing was put into the plasma nitriding apparatus shown in FIG. 2, and heated to 575 ° C. under a pressure of 0.05 Pa for about 60 minutes. Next, a mixed gas of N ₂ / H ₂ = 1/1 was supplied, and plasma nitriding was performed at a pressure of 180 Pa and a temperature of 575 ° C. for 48 hours. Then cooled to room temperature by introducing N ₂ gas into the apparatus. The obtained tool will be called “Ta # 1-PN”.

The tool 40 was inserted on the SUS430 flat plate while rotating at 400 rpm with an advance angle of 3 degrees to soften the SUS430. Next, a bead-on friction stir processing test by friction stir processing was performed by moving the tool 40 linearly by 90 mm on the SUS430 flat plate at a feed rate of 150 mm / min while rotating the tool at a forward angle of 3 degrees and 1200 rpm. The load on the tool 40 was set to about 9800N. The side of the tool emitted orange during processing. According to the visual observation after the processing, as shown in the photograph of FIG. 12, the construction state of the SUS430 flat plate was good although there was a processing mark 34 by the tool 40 on the surface of the processing portion.
(Example 8)

(Plasma carburizing (PC) treatment)
The obtained tool for friction stir processing was put into the plasma carburizing apparatus shown in FIG. 2, and heated to 750 ° C. under a pressure of 0.05 Pa for 75 minutes. Next, a mixed gas of C ₃ H ₈ / H ₂ = 1/10 was supplied, and plasma carburization was performed at a pressure of 130 Pa and a temperature of 750 ° C. for 48 hours. Thereafter, N ₂ gas was introduced into the apparatus and cooled to room temperature. The obtained tool is called “Ta # 1-PC”.

The tool 40 was inserted onto the SUS430 flat plate while being rotated at 700 rpm with an advance angle of 3 degrees, and the SUS430 was softened. Next, a bead-on friction stir processing test was performed by friction stir processing by moving the tool 40 linearly by 200 mm on the SUS430 flat plate while rotating the tool 40 at a forward angle of 3 degrees and 1200 rpm. The load on the tool 40 was set to about 9800N. The side of the tool emitted orange during processing. According to the visual observation after the processing, as shown in the photograph of FIG. 13, the construction state of the SUS430 flat plate is good although the processing marks 34 by the tool 40 are present on the surface of the processing portion, and the back surface photograph is shown in FIG. 14. However, it was smooth. However, since the backing aluminum oxide plate 20 was cracked during processing, SUS plasticized into the cracks entered and cooled and solidified was seen as convex fine streaks.
Example 9

(Plasma nitriding (PN) treatment)
The obtained tool for friction stir processing was put into the plasma nitriding apparatus shown in FIG. 2, and heated to 575 ° C. under a pressure of 0.05 Pa for about 60 minutes. Next, a mixed gas of N ₂ / H ₂ = 1/1 was supplied, and plasma nitriding was performed at a pressure of 180 Pa and a temperature of 575 ° C. for 48 hours. Then cooled to room temperature by introducing N ₂ gas into the apparatus. The obtained tool is called “W # 1-PN”.

The tool 40 was inserted onto the SUS430 flat plate while being rotated at 700 rpm with an advance angle of 3 degrees, and the SUS430 was softened. Next, a bead-on friction stir processing test by friction stir processing was performed by moving the tool 40 linearly by 90 mm on the SUS430 flat plate at a feed rate of 150 mm / min while rotating the tool at a forward angle of 3 degrees and 1200 rpm. The load on the tool 40 was set to about 9800N. The side of the tool emitted orange during processing. According to the visual observation after the processing, as shown in the photograph of FIG. 15, the working state of the SUS430 flat plate was good although the processing marks 34 by the tool 40 exist on the surface of the processing portion.
(Example 10)

(Plasma carburizing (PC) treatment)
The obtained tool for friction stir processing was put into the plasma carburizing apparatus shown in FIG. 2, and heated to 750 ° C. under a pressure of 0.05 Pa for 75 minutes. Next, a mixed gas of C ₃ H ₈ / H ₂ = 1/10 was supplied, and plasma carburization was performed at a pressure of 130 Pa and a temperature of 750 ° C. for 48 hours. Then cooled to room temperature by introducing N ₂ gas into the apparatus. The obtained tool is called “W # 1-PC”.

The tool 40 was inserted onto the SUS430 flat plate while being rotated at 700 rpm with an advance angle of 3 degrees, and the SUS430 was softened. Next, a bead-on friction stir processing test by friction stir processing was performed by moving the tool 40 linearly by 90 mm on the SUS430 flat plate at a feed rate of 150 mm / min while rotating the tool at a forward angle of 3 degrees and 1200 rpm. The load on the tool 40 was set to about 9800N. The side of the tool emitted orange during processing. According to the visual observation after the processing, as shown in the photograph of FIG. 16, the construction state of the SUS430 flat plate was good although the processing marks 34 by the tool 40 exist on the surface of the processing portion.
(Example 11)

In the same manner as in Example 10, a “W # 1-PC” tool treated with plasma carburizing (PC) was produced.

(Friction stir processing (friction stir welding))
Using the friction stir processing tool described above, a friction stir processing test by butt joint was performed in the same manner as in Example 6 except that the following description differs from the description of Example 6.

The tool 40 was inserted onto the joining line 33 while rotating at a forward angle of 3 degrees and 700 rpm, and the surrounding SUS430 including the joining line 33 was softened. Next, the tool 40 is moved about 90 mm along the joining line 33 of the materials to be joined 31 and 32 at a feed rate of 150 mm / min while rotating at a forward angle of 3 degrees and 1200 rpm, and friction stir welding is performed. A joined body of 31 and 32 was produced. The load on the tool 40 was set to about 9800N. The side of the tool emitted orange during processing.

The joined body of the materials to be joined 31 and 32 obtained by the friction stir welding was joined well as shown in the photograph of FIG.

In order to examine the strength of the joint part, a sample was prepared from a butt-joined flat plate in a direction orthogonal to the joining direction, and a tensile test was performed. The same as Example 6 except that the thickness of the test piece was 1.43 mm. As a result, the tensile strength was 513 MPa. Since the average of n = 3 tensile strength of the SUS430 base material measured under the same conditions was 519 MPa, it was found that the tensile strength of the above-mentioned joint was almost the same as that of the base material. Further, a photograph of the fractured test piece is shown in FIG. 19, and this test piece located at the top in FIG. 19 (represented by reference numeral 3 in the figure) is not a joint but a base material portion. It showed what happened. Further, the load-displacement curve is shown in FIG. 20. In FIG. 20, it can be seen that the present test piece represented by reference numeral 3 is well stretched before breaking.

(Comparative Example 1)
(Production of friction stir processing tool)
A friction stir processing tool having the shape shown in Example 1 was manufactured by cutting using Inconel alloy # 625.

As shown in the photograph of FIG. 18, the joined body of the materials to be joined 31 and 32 obtained by the friction stir welding has a number of deep hole-like defects with a diameter of several millimeters on the joining line. Bonding was not possible. In addition, wear and wear of the tool was clearly recognized in appearance.

In order to examine the strength of the joint part, a sample was prepared from a butt-joined flat plate in a direction orthogonal to the joining direction, and a tensile test was performed. The same as Example 6 except that the width of the test piece was 24.5 mm. As a result, the tensile strength was 457 MPa. Since the average of n = 3 tensile strength of the SUS430 base material measured under the same conditions was 519 MPa, the tensile strength of the joint was inferior to that of the base material. Further, a photograph of the fractured test piece is shown in FIG. 19, and this test piece located at the bottom in FIG. 19 (represented by reference numeral 1 in the figure) shows that the fracture occurred at the joint. It was. Further, FIG. 20 shows a load-displacement curve. In FIG. 20, it can be seen that the present test piece represented by reference numeral 1 broke before it slightly extended.

Moreover, the said junction part was cut | disconnected perpendicularly | vertically with respect to the joining direction, and the cross section was observed with the stereomicroscope. This micrograph is shown in FIG. In FIG. 22, the thickness of this cross section is 1.46 mm. From this picture, the lower boundary of the friction stir zone was unclear.
Example 12

In Examples 12 to 21 below, the feed rate of the tool during joining was examined under the condition of a high feed rate of 500 mm / min or more. The feed rate of the tool at the time of joining is practically required to be about 500 mm / min.

(Friction stir processing (friction stir welding))
Using the friction stir processing tool, friction stir processing (friction stir welding by butt joining) was performed by the method shown in FIG. The tool 40 was attached to a friction stir welding apparatus consisting of three axes, a platen axis (X), a transverse axis (Y), and a lift axis (Z). As shown in FIG. 3, on the surface of a flat steel (S50C) backing jig 10, surface smooth silicon nitride (90% by weight of Si ₃ N ₄ as a main component, Al ₂ 0 ₃ 4-5) ₃ % square column (30 mm square, 100 mm length) made of 4% by weight, 4% to 5% by weight of Y ₂ O _{3, etc. The} same applies hereinafter.

On the silicon nitride backing material 20, the joining surfaces of two plate-like materials to be joined (300 × 150 mm, 1.5 mm thickness) 31 and 32 made of SUS430 were placed against each other and fixed.

The tool 40 was inserted onto the joining line 33 while rotating at a forward angle of 3 degrees and 600 rpm, and the surrounding SUS430 including the joining line 33 was softened. Next, friction stir welding is performed by moving the tool 40 about 250 mm along the bonding line 33 of the materials to be bonded 31 and 32 at a feed rate of 550 mm / min while rotating at a forward angle of 3 degrees and 800 rpm. A joined body of 31 and 32 was produced. The load on the tool 40 was set to about 9800N.

(Friction stir processing (bead-on friction stir processing))
The friction stir processing was performed by the method shown in FIG. 3 using the friction stir processing tool used in the friction stir welding. However, in the method shown in FIG. 3, the friction stir welding is performed using the two flat plate-

like workpieces

31 and 32. In this embodiment, a single flat plate is used as the workpiece. A bead-on friction stir processing test was conducted.

Specifically, the tool 40 was attached to a friction stir welding apparatus composed of three axes: a platen axis (X), a transverse axis (Y), and a lift axis (Z). At the time of friction stir processing, argon gas flows along the side of the tool and wraps around the tool.

As shown in FIG. 3, on the surface of a flat steel (S50C) backing jig 10, three smooth silicon nitride square columns (30 mm square, 100 mm length) are connected in the length direction. Fixed as a side backing material 20.

On the silicon nitride backing material 20, a flat plate-shaped workpiece (300 × 150 mm, 1.5 mm thickness) made of one SUS430 was placed and fixed.

The tool 40 was inserted on the SUS430 flat plate while rotating at 600 rpm with a forward angle of 3 degrees, and the SUS430 was softened. Next, a bead-on friction stir processing test was performed by friction stir processing by moving the tool 40 linearly 250 mm on the SUS430 flat plate at a feed rate of 550 mm / min while rotating the tool 40 at an advance angle of 3 degrees and 800 rpm. The load on the tool 40 was set to about 9800N.

(Friction stir processing (bead-on friction stir processing))
Using the friction stir processing tool used in the bead-on friction stir processing test, a bead on friction stir processing test was performed in the same manner as described above.

(Friction stir processing (friction stir welding))
Friction stir welding was performed in the same manner as the friction stir welding performed at the beginning of this example, except that the feed rate was set to 500 mm / min using the friction stir processing tool used in the above bead-on friction stir processing test. It was.

As a result, in this embodiment, the total construction distance in which the friction stir processing is performed using this tool is 250 mm × 4 = 1000 mm.

The joined body of the materials to be joined 31 and 32 obtained by the above friction stir welding was well joined as shown in the photograph of FIG.

In order to examine the strength of the joint, a sample was prepared from a butt-joined flat plate in a direction orthogonal to the joining direction, and a tensile test was performed in the same manner as in Example 6. As a result, the tensile strength was 466 MPa, and the tensile strength of the joint was slightly inferior to that of the base material. The fracture occurred at the joint.

Further, the joint was cut perpendicular to the joining direction, and the cross section was observed with a stereomicroscope. The micrograph is shown in FIG. In FIG. 24, the thickness of this cross section is 1.43 mm. As can be seen from this photograph, the original butt interface had almost completely disappeared by friction stirring.

Table 2 summarizes the friction stir welding tool material, workpiece material, FSW machining type, and FSW machining conditions in Example 12. In Table 2, the tool size refers to the size of the tool before being used for FSW processing. Table 2 shows the final friction stir welding conditions among the friction stir welding described above. However, the construction distance in Table 2 indicates the total construction distance. Table 2 summarizes the same matters for Examples 13 to 22 described later.

In addition, as for the construction distance, every trial of FSW processing, the processing was performed smoothly, the appearance of the surface of the processed material after processing (there is no depression-like defect in the joint or bead-on part, The tool is used from the viewpoints of whether the scar of the shape remains beautiful, the scar of the circular shape itself is not fuzzy, etc., the appearance of the back surface of the work material, and whether there is any significant deformation of the tool. It was then determined whether further FSW processing would be performed.

(Example 13)

On the silicon nitride backing material 20, two flat plate-like materials 31 and 32 (300 × 150 mm, 1.5 mm thickness) made of SUS430 were put in contact with each other and fixed.

like workpieces

The bonded body of the materials to be bonded 31 and 32 obtained by the friction stir welding was bonded well as shown in the photograph of FIG.

In order to examine the strength of the joint, a sample was prepared from a butt-joined flat plate in a direction orthogonal to the joining direction, and a tensile test was performed in the same manner as in Example 6. As a result, it was found that the tensile strength was 526 MPa, and the tensile strength of the above-mentioned joint was almost the same as that of the base material. The fracture occurred at the joint.

Moreover, the said junction part was cut | disconnected perpendicularly | vertically with respect to the joining direction, and the cross section was observed with the stereomicroscope. This micrograph is shown in FIG. In FIG. 26, the thickness of this cross section is 1.43 mm. As can be seen from this photograph, the original butt interface disappears completely by friction stir and can be joined.
(Example 14)

(Production of friction stir processing tool)
Ni, Al, Ni: 76 atomic%, Al: 5.5 atomic%, V: 13.5 atomic%, Nb: 3 atomic%, Ta: 2 atomic%, B: 50 ppm by weight An ingot of about 10 kg was produced by melting a V, Nb, Ta ingot (purity 99.9% by weight) and B in a vacuum induction melting furnace and solidifying the molten metal with a ceramic mold. . When the ingot was produced, since it was gradually cooled during solidification, a _double- duplex structure composed of a proeutectoid L1 ₂ phase and a (L1 ₂ + D0 ₂₂ ) eutectoid structure was formed in the ingot. The tool of the present invention was manufactured by cutting this ingot into a shape similar to the shape of the friction stir processing tool shown in Example 1.
The material of this tool will be referred to as “Ta # 2”.

On the silicon nitride backing material 20, the joining surfaces of two flat plate-like materials 31 and 32 (300 mm × 150 mm, 1.5 mm thickness) made of SUS430 were placed in contact with each other and fixed.

like workpieces

On the silicon nitride backing material 20, a flat plate-shaped workpiece (300 mm × 150 mm, 1.5 mm thickness) made of one SUS430 was placed and fixed.

Using the friction stir processing tool used in the above bead-on friction stir processing test, the bead on friction stir processing test was performed twice in the same manner as described above, and then the same friction stir processing tool used was not changed. Using the tool, the friction stir welding was performed once in the same manner as the friction stir welding performed at the beginning of this example, then the same bead-on friction stir processing test was performed three times, and then the same friction stir welding was performed once. Then, the same bead-on friction stir processing test was performed three times, then the same friction stir welding test was performed once, then the same bead-on friction stir processing test was performed three times, and finally the feed rate was 500 mm / min. The same friction stir welding as described above was performed. As a result, in this embodiment, the total construction distance when the friction stir processing is performed using this tool is 250 mm × 17 = 4250 mm.

The joined body of the materials to be joined 31 and 32 obtained by the final friction stir welding as described above was satisfactorily joined as shown in the photograph of FIG.

In order to examine the strength of the joint, a sample was prepared from the butt-joined flat plate in a direction orthogonal to the joining direction, and a tensile test was performed in the same manner as in Example 6. As a result, the tensile strength was 533 MPa, the tensile strength of the above-mentioned joint portion exceeded the tensile strength of the base material, and the fracture occurred in the base material.

Moreover, the said junction part was cut | disconnected perpendicularly | vertically with respect to the joining direction, and the cross section was observed with the stereomicroscope. This micrograph is shown in FIG. In FIG. 28, the thickness of this cross section is 1.45 mm. As can be seen from this photograph, the original butt interface disappears completely by friction stir and can be joined.
(Example 15)

(Production of friction stir processing tool)
In the same manner as in Example 14, an ingot made of the tool material “Ta # 2” was produced. The tool of the present invention was manufactured from this ingot by cutting into the shape shown below.

(Shape of friction stir processing tool)
The shoulder surface is a circular plane having a diameter of 12 mm, and the probe provided at the center has a spherical surface with a radius of 4.7 mm partially protruding from the shoulder surface. The bottom diameter of the probe is about 6 mm, and the length from the shoulder surface to the tip of the probe (projection height, probe length) is 0.90 mm.

The tool 40 was inserted onto the joining line 33 while rotating at a forward angle of 3 degrees and 1000 rpm, and the surrounding SUS430 including the joining line 33 was softened. Next, friction stir welding is performed by moving the tool 40 about 250 mm along the joining line 33 of the materials to be joined 31 and 32 at a feed rate of 700 mm / min while rotating at a forward angle of 3 degrees and 1200 rpm. A joined body of 31 and 32 was produced. The load on the tool 40 was set to about 9800N.

like workpieces

Specifically, the tool 40 was attached to a friction stir welding apparatus composed of three machine axes: a platen axis (X), a transverse axis (Y), and a lifting axis (Z). At the time of friction stir processing, argon gas flows along the side of the tool and wraps around the tool.

The tool 40 was inserted on the SUS430 flat plate while rotating at a forward angle of 3 degrees and 1000 rpm, and the SUS430 was softened. Next, a bead-on friction stir processing test was performed by friction stir processing by moving the tool 40 linearly 250 mm on the SUS430 flat plate at a feed rate of 700 mm / min while rotating the tool at a forward angle of 3 degrees and 1200 rpm. The load on the tool 40 was set to about 9800N.

(Friction stir processing (friction stir welding))
Using the friction stir processing tool used in the bead-on friction stir processing test, friction stir welding was performed in the same manner as the friction stir welding performed at the beginning of this example.

In order to examine the strength of the joint, a sample was prepared from a butt-joined flat plate in a direction orthogonal to the joining direction, and a tensile test was performed in the same manner as in Example 6. As a result, the tensile strength was 534 MPa, the tensile strength of the above-mentioned joint portion exceeded the tensile strength of the base material, and the fracture occurred in the base material.

Moreover, the said junction part was cut | disconnected perpendicularly | vertically with respect to the joining direction, and the cross section was observed with the stereomicroscope. The micrograph is shown in FIG. In FIG. 30, the thickness of this cross section is 1.45 mm. As can be seen from this photograph, the original butt interface disappears completely by friction stir and can be joined.
(Example 16)

(Production of friction stir processing tool)
In the same manner as in Example 8, a “Ta # 1-PC” tool was produced.

The joined body of the materials to be joined 31 and 32 obtained by the friction stir welding was well joined as shown in the photograph of FIG.

In order to examine the strength of the joint, a sample was prepared from the butt-joined flat plate in a direction orthogonal to the joining direction, and a tensile test was performed in the same manner as in Example 6. As a result, the tensile strength was 541 MPa, the tensile strength of the above-mentioned joint portion exceeded the tensile strength of the base material, and the fracture occurred in the base material.
(Example 17)

(Production of friction stir processing tool)
A “W # 1-PC” tool was fabricated in the same manner as in Example 10.

(Friction stir processing (friction stir welding))
Using the friction stir processing tool, friction stir processing (friction stir welding by butt joining) was performed by the method shown in FIG. The tool 40 was attached to a friction stir welding apparatus composed of three machine axes including a platen axis (X), a transverse axis (Y), and a lifting / lowering axis (Z). During friction stir welding, argon gas flows along the side of the tool and wraps around the tool.

like workpieces

The joined body of the materials to be joined 31 and 32 obtained by the final friction stir welding as described above was well joined as shown in the photograph of FIG.

In order to examine the strength of the joint, a sample was prepared from a butt-joined flat plate in a direction orthogonal to the joining direction, and a tensile test was performed in the same manner as in Example 6. As a result, the tensile strength was 544 MPa, the tensile strength of the above-mentioned joint portion exceeded the tensile strength of the base material, and the fracture occurred in the base material.

Moreover, the said junction part was cut | disconnected perpendicularly | vertically with respect to the joining direction, and the cross section was observed with the stereomicroscope. This micrograph is shown in FIG. In FIG. 33, the thickness of this cross section is 1.43 mm. As can be seen from this photograph, the original butt interface disappears completely by friction stir and can be joined.
(Example 18)

(Production of friction stir processing tool)
In the same manner as in Example 14, a friction stir processing tool made of the tool material “Ta # 2” was produced.

(Plasma carburizing (PC) treatment)
The produced tool for friction stir processing was put in the plasma carburizing apparatus shown in FIG. 2 and heated to 750 ° C. under a pressure of 0.05 Pa for 75 minutes. Next, a mixed gas of C ₃ H ₈ / H ₂ = 1/10 was supplied, and plasma carburization was performed at a pressure of 130 Pa and a temperature of 750 ° C. for 48 hours. Thereafter, N ₂ gas was introduced into the apparatus and cooled to room temperature. The tool obtained by the plasma carburizing process will be referred to as “Ta # 2-PC”.

(Friction stir processing (friction stir welding))
Friction stir processing (friction stir welding) was performed in the same manner as in Example 16 except that the above friction stir processing tool was used.

34. The joined body of the materials to be joined 31 and 32 obtained by the friction stir welding was joined well as shown in the photograph of FIG.

In order to examine the strength of the joined portion, a sample was prepared from the butt-joined flat plate in a direction orthogonal to the joining direction, and a tensile test was performed in the same manner as in Example 6. As a result, the tensile strength was 545 MPa, the tensile strength of the joint portion exceeded the tensile strength of the base material, and the fracture occurred in the base material.
(Example 19)

(Production of friction stir processing tool)
In the same manner as in Example 7, a “Ta # 1-PN” tool was produced.

(Friction stir processing (friction stir welding-bead-on friction stir-bead-on friction stir-friction stir welding))
Except for using the friction stir processing tool, the same as in Example 17,
Friction stir processing (friction stir welding-bead-on friction stirring-bead-on friction stirring-friction stir welding) was performed.

In order to examine the strength of the joint, a sample was prepared from a butt-joined flat plate in a direction orthogonal to the joining direction, and a tensile test was performed in the same manner as in Example 6. As a result, the tensile strength was 542 MPa, the tensile strength of the above joint exceeded the tensile strength of the base material, and the fracture occurred in the base material.

Moreover, the said junction part was cut | disconnected perpendicularly | vertically with respect to the joining direction, and the cross section was observed with the stereomicroscope. This micrograph is shown in FIG. In FIG. 36, the thickness of this cross section is 1.43 mm. As can be seen from this photograph, the original butt interface disappears completely by friction stir and can be joined.
(Example 20)

(Production of friction stir processing tool)
A “W # 1-PN” tool was produced in the same manner as in Example 9.

In order to examine the strength of the joined portion, a sample was prepared from the butt-joined flat plate in a direction orthogonal to the joining direction, and a tensile test was performed in the same manner as in Example 6. As a result, the tensile strength was 544 MPa, the tensile strength of the above-mentioned joint portion exceeded the tensile strength of the base material, and the fracture occurred in the base material.
(Example 21)

(Plasma nitriding (PN) treatment)
The produced tool for friction stir processing was put in the plasma nitriding apparatus shown in FIG. 2, and heated to 575 ° C. under a pressure of 0.05 Pa for about 60 minutes. Next, a mixed gas of N ₂ / H ₂ = 1/1 was supplied, and plasma nitriding was performed at a pressure of 180 Pa and a temperature of 575 ° C. for 48 hours. Then cooled to room temperature by introducing N ₂ gas into the apparatus. The tool obtained by the above plasma treatment will be referred to as “Ta # 2-PN”.

(Friction stir processing (friction stir welding-bead-on friction stir-bead-on friction stir-friction stir welding))
Friction stir processing (friction stir welding-bead-on friction stirring-bead-on friction stirring-friction stir welding) was performed in the same manner as in Example 15 except that the above friction stir processing tool was used.

38. The joined body of the materials to be joined 31 and 32 obtained by the final friction stir welding was satisfactorily joined as shown in the photograph of FIG.

In order to examine the strength of the joint, a sample was prepared from a butt-joined flat plate in a direction orthogonal to the joining direction, and a tensile test was performed in the same manner as in Example 6. As a result, the tensile strength was 538 MPa, the tensile strength of the above-mentioned joint portion exceeded the tensile strength of the base material, and the fracture occurred in the base material.

Moreover, the said junction part was cut | disconnected perpendicularly | vertically with respect to the joining direction, and the cross section was observed with the stereomicroscope. This micrograph is shown in FIG. In FIG. 39, the thickness of this cross section is 1.44 mm. As can be seen from this photograph, the original butt interface disappears completely by friction stir and can be joined.
(Example 22)

(Production of friction stir processing tool)
Ni: 70.5 atomic%, Al: 10 atomic%, V: 10.5 atomic%, Nb: 3 atomic%, Co: 3 atomic%, Cr: 3 atomic%, B: 500 ppm by weight In addition, Ni, Al, V, Nb, Co, Cr ingots (purity 99.9% by weight) and B were weighed in a vacuum induction melting furnace, and then the molten metal was solidified with a ceramic mold. An ingot of 83 mmφ × 700 mm was produced. When the ingot was produced, since it was gradually cooled during solidification, a _double- duplex structure composed of a proeutectoid L1 ₂ phase and a (L1 ₂ + D0 ₂₂ ) eutectoid structure was formed in the ingot. A tool for friction stir processing having a shape shown in FIG. 40 was manufactured by cutting from the ingot. The material of this tool will be called “H # 2”.

(Shape of friction stir processing tool)
The tool shown in FIG. 40 will be described in detail. The shoulder consists of a plane perpendicular to the rotational axis of a 24 mmφ right cylinder and an inverted frustoconical concave surface that is recessed toward the center with an inclination of 7 °. The probe protrudes in the shape of a right truncated cone with a half apex angle of 7 ° at the center of the shoulder surface, and the protrusion height from the plane orthogonal to the rotation axis intersecting the outer periphery of the shoulder surface is 0.9 mm. The tip of the probe has a 120 ° rotationally symmetric shape chamfered parallel to the side of the truncated cone with a distance of 0.55 mm between the center of the arcuate chord having a central angle of 60 ° and the center of the arc with respect to a circle having a radius of 4.55 mm. Eggplant.

(Friction stir processing (friction stir welding))
Using the friction stir processing tool, friction stir processing (friction stir welding by butt joining) was performed by the method shown in FIG. The tool 40 was attached to a friction stir welding apparatus consisting of three axes, a platen axis (X), a transverse axis (Y), and a lift axis (Z). During friction stir welding, argon gas flows along the side of the tool and wraps around the tool. As shown in FIG. 3, a 99.5% pure aluminum oxide flat plate (15 cm square, 2.5 mm thick) having a smooth surface is applied to the surface of a flat steel (S50C) backing jig 10. Fixed as 20. Since the probe length was large with respect to the plate thickness, the backing material 20 was greatly damaged, so a metal foil was laid between the backing material 20 and the material to be joined.

On the metal foil, the joining surfaces of two flat plate materials 31 and 32 (300 mm × 75 mm, 1.0 mm thickness) made of SUS430 were placed against each other and fixed.

The tool 40 was inserted on the joining line 33 while rotating at 800 rpm with an advance angle of 3 degrees, and the surrounding SUS430 including the joining line 33 was softened. Next, friction stir welding is performed by moving the tool 40 about 120 mm along the joining line 33 of the materials to be joined 31 and 32 at a feed rate of 100 mm / min while rotating at an advance angle of 3 degrees and 800 rpm, A joined body of 31 and 32 was produced. The load on the tool 40 was set to about 9800N. The side of the tool emitted orange during processing.

The joined body of the materials to be joined 31 and 32 obtained by the above friction stir welding seemed to be joined in appearance, but the machining traces were dirty, and after 120 mm machining, the probe was heavily worn out. It was.

(Reference example)
Relationship between Vickers hardness of tool material and measurement temperature Ingot production process Example 4 (tool material Ta # 1), Example 5 (tool material W # 1), Example 14 (tool material Ta # 2) and Example 22 (tool material H # 2) After melting in a vacuum induction melting furnace, weighed ingots of each element (purity 99.9% by weight) and B so as to have the composition described in the section of making a friction stir processing tool, and then ceramic A sample made of an ingot was prepared by solidifying the molten metal with a mold. The sizes of the ingots produced were 83 mmφ × 700 mm for the ingots of Example 4 (tool material Ta # 1), Example 5 (tool material W # 1) and Example 22 (tool material H # 2), The ingot of Example 14 was 77 mmφ × 280 mm.

2. Vickers hardness measurement A test piece of 10 mmφ × 5 mm was cut out from this ingot as a sample for measuring Vickers hardness. Using this sample, Vickers hardness measurement was performed at normal temperature and high temperature (300 ° C, 500 ° C, 600 ° C, 800 ° C, 900 ° C). For the measurement of samples of Example 4 (tool material Ta # 1), Example 5 (tool material W # 1) and Example 22 (tool material H # 2), heat treatment (furnace cooling) at 1280 ° C. for 3 hours The sample after performing was used. In the measurement of the sample of Example 14 (tool material Ta # 2), a sample that was not heat-treated was used after the casting. The load was 1 kg and the holding time was 20 seconds. The measurement was performed in a reducing atmosphere (Ar + about 10% H ₂ ), and the heating rate was 10 ° C. per minute.

The measurement results are shown in FIG. In FIG. 41, 1 is Example 4 (tool material Ta # 1), 2 is Example 5 (tool material W # 1), 3 is Example 14 (tool material Ta # 2), and 4 is Example 22 (tool). This is the Vickers hardness of the sample of material H # 2). FIG. 41 also shows the Vickers hardness data for SUS440C, which is the material generally used in applications where wear resistance is required, showing the highest hardness in stainless steel. This data is actually measured under the same measurement conditions using a sample having the same size as the above Vickers hardness measurement.

Referring to FIG. 41, in Example 4 (tool material Ta # 1), Example 5 (tool material W # 1) and Example 14 (tool material Ta # 2), Example 22 was measured in the entire temperature range measured. It can be seen that the value of Vickers hardness was higher than that of (tool material H # 2). Therefore, it can be seen that the effect of improving the Vickers hardness by adding Ta or W extends to the entire temperature range measured.

In SUS440C, the value of Vickers hardness sharply decreases as the measurement temperature increases, whereas Example 4 (tool material Ta # 1), Example 5 (tool material W # 1), and Example 14 ( It can be seen that in the samples of the tool material Ta # 2) and Example 22 (tool material H # 2), the decrease in the value of the Vickers hardness accompanying the temperature rise is very small. When the measurement temperature is 500 ° C. or higher, the Vickers hardness of the samples of Example 4 (tool material Ta # 1), Example 5 (tool material W # 1) and Example 14 (tool material Ta # 2) is measured. It can be seen that the value is larger than SUS440C.

The following can be said from FIG. Although the hardness of the medium temperature range of the alloy used in the present invention is inferior to that of SUS440C, it is higher than that in the high temperature range, and the alloy used in the present invention exhibits excellent high temperature characteristics. In the friction stir processing, the temperature of the FSW tool at the time of joining stainless steel is estimated to be about 600 ° C. or higher, so it is considered that hardness at 600 ° C. or higher is important.

As for the Vickers hardness of Inconel, according to “Turning of Inconel 713C” by Yamaguchi Prefectural Industrial Technology Center (Masanobu Kagawa, Hideharu Maeda, Satoru Ikeda), for example, A graph is shown in which Vickers hardness is measured using a sample size of φ10 mm × 5 mm and a load of 5 kgf. From the graph, it can be seen that the ambient temperature to 600 ° C. is about Hv 350, the 800 ° C. is about Hv 300, and the 1000 ° C. is about Hv 220. On the other hand, the Vickers hardness of the alloy used in the present invention is higher than that of Inconel at any temperature from room temperature to 800 ° C., and Example 4 (tool material Ta # 1) and Example 5 (tool material W # 1). And the alloy used in Example 14 (tool material Ta # 2) is particularly higher than Inconel.

Regarding the Vickers hardness of WC-based cemented carbide, for example, a material according to the standards of the Cemented Carbide Tool Association (CIS019D-2005, cemented carbide for wear and impact resistant tools, and grade selection criteria for ultrafine cemented carbide) In a cemented carbide of the type classification symbol VC-50 (trade name “Fuji Roy C50” manufactured by Fuji Dice Co., Ltd., sintered using coarse grain tungsten carbide and Co as a binder metal), Vickers hardness of 800 ° C. 330 , Vickers hardness 210 of 900 ° C. is disclosed. In contrast, the alloys used in Example 4 (tool material Ta # 1), Example 5 (tool material W # 1) and Example 14 (tool material Ta # 2) of the present invention have a Vickers hardness of 800 ° C. The Vickers hardness at around 500 and 900 ° C. is 450 or more, which is much higher than that of the WC cemented carbide in the high temperature region.

The friction stir processing tool comprising the Ni-based double-duplex intermetallic compound alloy of the present invention can be effectively used for friction stir processing using iron or an iron alloy as a workpiece. The friction stir processing method of the present invention can be effectively used for friction stir processing using iron or an iron alloy as a workpiece.

Claims

A friction stir processing tool characterized by comprising a Ni-based dual-phase intermetallic compound alloy.
The friction stir processing tool according to claim 1, wherein the Ni-based two-phase intermetallic compound alloy contains 0.5 to 8 atomic% of Ta and / or W.
The Ni-based two-phase intermetallic compound alloy is mainly composed of Ni and Al: 2 to 9 atomic%, V: 10 to 17 atomic%, (Ta and / or W): 0.5 to 8 atomic%, B: 10 to 1000 ppm by weight and proeutectoid L1 with respect to the total weight of the composition of a total of 100 atom% including Nb: 0 to 6 atom%, Co: 0 to 6 atom%, Cr: 0 to 6 atom% 2. The friction stir processing tool according to claim 1, wherein the friction stir processing tool has a two-phase structure composed of two phases and a (L1 2 + D0 22 ) eutectoid structure.
The Ni-based double-duplex intermetallic compound alloy is mainly composed of Ni and Al: 5.5 to 13 atom%, V: 10 to 17 atom%, Nb: 0 to 6 atom%, Ti: 0 to 6 atom %, Co: 0 to 6 atom%, Cr: 0 to 6 atom%, and B: 10 to 1000 ppm by weight with respect to the total weight of the composition of 100 atom% in total and the proeutectoid L1 2 phase (L1 2 The tool for friction stir processing according to claim 1, wherein the tool has a double-phase structure composed of + D0 22 ) a eutectoid structure.
The friction stirrer according to any one of claims 1 to 4, wherein the Ni-based two-phase intermetallic compound alloy is used as a base material, and a surface of the base material is hardened. Tool for processing.
The friction stir processing tool according to claim 5, wherein the hardening treatment is at least one of nitriding treatment or carburizing treatment.
The friction stir processing method for processing a workpiece by pressing the tip of a tool rotating at a high speed against the workpiece and plasticizing and stirring the workpiece by the generated frictional heat. A friction stir processing method using the tool for friction stir processing according to any one of the above.