阅读说明：本技术 金属系基材的修补、改性方法 (Method for repairing and modifying metal base material ) 是由 阿野元贵 丸子智弘 宫泽智明 岩本祐一 于 2019-01-23 设计创作，主要内容包括：本公开的目的在于提供一种金属系基材的修补、改性方法,能够抑制例如摩擦搅拌接合用工具所具有的探针带来的杂质混入到结构体内部,并且通过将结构体内部的组织改性,减少结构体内部存在的缺陷,从而减少结构体内部存在的界面区域。本发明的金属系基材的修补、改性方法具有如下步骤：准备金属系基材,该金属系基材具有在基材面内方向上被划分的第1区域,所述第1区域包含缺陷及/或组织的非连续部分；以及使不具有探针的摩擦工具边旋转边压抵于所述第1区域的表面,产生摩擦热的同时按压所述表面,从而将修补所述缺陷及/或将所述组织的非连续部分改性。(The present disclosure aims to provide a method for repairing and modifying a metal base material, which can suppress impurities from entering the inside of a structure due to a probe provided in a friction stir welding tool, and can modify the structure inside the structure to reduce defects in the structure and reduce the interface region in the structure. The method for repairing and modifying a metal base material of the present invention comprises the steps of: preparing a metal-based substrate having a 1 st region divided in an in-plane direction of the substrate, the 1 st region including a discontinuous portion of a defect and/or a structure; and pressing a rubbing tool without a probe against the surface of the No. 1 region while rotating, thereby generating frictional heat while pressing the surface, thereby repairing the defect and/or modifying the discontinuous portion of the tissue.)

1. A method for repairing and modifying a metal base material is characterized by comprising the following steps:

preparing a metal-based substrate having a 1 st region divided in an in-plane direction of the substrate, the 1 st region including a discontinuous portion of a defect and/or a structure; and

pressing a rubbing tool without a probe against the surface of the region 1 while rotating, generating frictional heat while pressing the surface, thereby repairing the defect and/or modifying a discontinuous portion of the tissue.

2. The method of claim 1, wherein:

the metal base material further has a 2 nd region divided in the in-plane direction of the base material, and the 2 nd region is a portion which does not need to be repaired and/or modified.

3. The method for repairing or modifying a metal-based substrate according to claim 1 or 2, wherein:

repairing and/or modifying a portion of the metal base material from the surface to a maximum depth of 20 mm.

4. The method of claim 3, wherein:

the metal base material has a thickness exceeding 20mm, and a portion of the metal base material from the surface to the maximum depth of 20mm is repaired and/or modified.

5. The method of claim 3, wherein:

the metal base material has a thickness of 20mm or less, and the entire thickness direction of the metal base material or a portion of the metal base material from the surface, the thickness of which is thinner than the thickness of the base material, is repaired and/or modified.

6. The method of repairing and modifying a metal-based substrate according to any one of claims 1 to 5, wherein:

the impurities from the rubbing tool are not mixed into the surface of the repaired and/or modified part to a depth of more than 1 mm.

7. The method of repairing and modifying a metal-based substrate according to any one of claims 2 to 6, wherein:

the tensile strength of the base material comprising the repaired and/or modified 1 st area is 60-200% of the tensile strength of the base material comprising the 2 nd area only.

8. The method for repairing or modifying a metal-based substrate according to any one of claims 1 to 7, wherein:

the method further comprises a step of melting at least a part of the 1 st region before repairing and/or modifying the metal base material.

9. The method of repairing or modifying a metal-based substrate according to any one of claims 1 to 8, wherein:

the 1 st region of the metal-based substrate before the repair and/or modification is welded from the front surface to the back surface.

10. The method of repairing and modifying a metal-based substrate according to any one of claims 1 to 9, wherein:

the method further comprises a step of providing or depositing a material having the same composition as that of the metal-based substrate on at least a part of the 1 st region of the metal-based substrate before the repair and/or modification.

11. The method of repairing or modifying a metal-based substrate according to any one of claims 1 to 10, wherein:

in the step of performing the repair and/or modification, the friction tool is pressed until the portion pressed by the friction tool is plastically deformed.

12. The method of repairing or modifying a metal-based substrate according to any one of claims 1 to 11, wherein:

in the step of repairing and/or modifying, the rubbing tool and the metal-based base material are relatively moved only in a depth direction of the base material, an in-plane direction of the base material, or a combined direction of the depth direction of the base material and the in-plane direction of the base material.

13. The method for repairing or modifying a metal-based substrate according to any one of claims 1 to 12, wherein:

a heat source other than frictional heat is used as an auxiliary before or during the repair and/or modification.

14. The method of repairing or modifying a metal-based substrate according to any one of claims 1 to 13, wherein:

the metal-based substrate includes any one of Cu, Ag, Au, Pt, a Cu-based alloy, an Ag-based alloy, an Au-based alloy, or a Pt-based alloy.

15. The method for repairing or modifying a metal-based substrate according to any one of claims 1 to 14, wherein:

the friction tool includes any one of Ir-based alloy, Ni-based alloy, Co-based alloy, super-hard alloy, tool steel, or ceramic.

16. The method of repairing or modifying a metal-based substrate according to any one of claims 1 to 15, wherein:

the metal-based substrate includes any one of Cu, Ag, Au, a Cu-based alloy, an Ag-based alloy, or an Au-based alloy, and the friction tool includes any one of an Ir-based alloy, a Ni-based alloy, a Co-based alloy, a cemented carbide, a tool steel, or a ceramic.

17. The method of repairing or modifying a metal-based substrate according to any one of claims 1 to 16, wherein:

the metal-based substrate includes Pt or a Pt-based alloy, and the friction tool includes any one of an Ir-based alloy, a super-hard alloy, or a ceramic.

18. The method of repairing or modifying a metal-based substrate according to any one of claims 1 to 17, wherein:

the metal-based substrate is a gasket for a pressure vessel, a capsule for a pressure vessel, a sputtering target, or a backing plate for a sputtering target as a whole or a part thereof.

Technical Field

The present disclosure relates to a method for repairing and/or modifying a structure of a metal-based substrate, and for example, relates to the following method: the metal base material is repaired and/or modified by a rubbing tool without a probe (hereinafter, the same shall apply to a non-probe tool), wherein the maximum depth of the repaired and/or modified portion is 20mm or less from the surface to the inside of the repaired and/or modified portion. In addition, the method suppresses the incorporation of impurities into the structure by the probe, and modifies the structure in the structure to reduce defects in the structure, thereby reducing the interface region in the structure.

Background

When a structure made of a metallic material is produced, defects due to fusion bonding, for example, a discontinuous portion of a structure such as a pore or a solidification crack, may be present in addition to casting defects. These defects or discontinuous portions cause deterioration of mechanical properties of the structure. Further, the quality of a product manufactured using a structure having a defect or a discontinuous portion of the structure may be adversely affected.

As one of the joining methods without melting, there is a friction stir joining method. The technique of friction stir welding is as follows: the bonding is performed by rotating a tool having a protrusion called a probe, inserting the probe into the metal base material while rotating the tool, softening the metal base material by frictional heat generated, and plastically fluidizing the softened metal base material. It is widely known that a joint formed by friction stir welding has excellent mechanical properties as compared with fusion welding because the joint does not entrain gas, does not form pores, and has a fine structure (see, for example, patent documents 1 and 2).

As one of the friction stir welding methods, sheet welding using a probe-less tool has been proposed, and it has been reported that welding can be performed only with a sheet of 0.5mm to 5mm (see, for example, patent document 3).

In the art, it has been proposed to effectively use excellent properties of friction stir welding as a surface modification treatment technique, for example, repair of welding defects such as pores and weld cracks, casting defects, structure modification, and improvement of mechanical properties of a construction site (for example, see patent document 4). Patent document 4 discloses a welded joint in which a welded metal portion subjected to fusion welding is friction-stirred using a probe of a friction stir welding tool.

Disclosure of Invention

[ problems to be solved by the invention ]

However, there are several problems in the case of performing friction stir welding using a tool having a probe as in the technique of patent document 1 or 2, or in the case of performing surface modification treatment using a tool having a probe as in the technique of patent document 4.

In the 1 st problem, a hole generated by the probe, a so-called end hole (end hole), remains at the bonding terminal. The end hole portion has a small wall thickness, and the strength of the end hole portion is significantly reduced as compared with the base material or the joint, and therefore, the quality standard of the structure may not be achieved.

As a method for preventing the end hole from remaining in the structure, for example, a method has been proposed in which only the end hole portion is cut after the end hole portion is released to the sacrificial material, or a probe of a tool is driven and joined to a root surface (shank) separately, but the former has a problem of deterioration in material yield, and the latter has a problem of requiring a dedicated device, and thus it takes a high cost to manufacture the structure by friction stir joining.

The 2 nd problem is that the probe is worn by friction with the material, and the material of the probe enters the metal base material. Since elements other than the metal-based base material are mixed into the base material, there is a concern that mechanical properties of the structure may be changed and a product obtained by using the structure may be adversely affected.

As an example of the adverse effect on the product, a pressure vessel used for single crystal growth is cited. When friction stir welding or surface modification treatment is performed using a tool having a probe at the time of producing a liner or a capsule housed inside a pressure vessel, elements other than the mixed base material may infiltrate into the single crystal growth atmosphere and the quality of the produced single crystal may be degraded.

With respect to the problem in friction stir welding using a tool having a probe, it is possible to solve the problem by using the technique of patent document 3. However, if the joining is performed at room temperature using the technique of patent document 3, the joint seems to be firmly joined, but according to the study of the present inventors, the tensile strength is very low as compared with the base material. This is considered to be because the adsorbed gas molecules on the butting faces prevent the metal newly-grown faces from contacting each other. Therefore, patent document 3 describes that a preheating step at 530 to 1600 ℃ is necessary.

In practice, when a large structure is manufactured, it is difficult to maintain the bonded portion at a high temperature of 500 ℃ or higher, and it is difficult to use a material having good conductivity (for example, Cu, Ag, Au, or Pt). Further, since the probe-less tool has a weaker stirring force than the tool having the probe, the abutting surfaces must be brought into contact with each other with high accuracy. Therefore, the larger the structure, the higher the accuracy of the butting of the joined parts is required.

The present disclosure has been made to solve the above-mentioned problems, and an object of the present disclosure is to provide a method for repairing and/or modifying a tissue without mixing impurities from the surface to the inside of a structure. More specifically, the present disclosure provides a method for repairing and modifying a metal-based base material, which can suppress impurities from entering the interior of a structure due to a probe provided in a friction stir welding tool, and can modify the structure of the interior of the structure to reduce defects present in the interior of the structure, thereby reducing the interface region present in the interior of the structure.

[ means for solving problems ]

As a result of intensive studies, the present inventors have found that the above problems can be solved by pressing a friction tool without a probe against the surface of a portion to be repaired or modified of a metal base material while rotating the friction tool, thereby generating frictional heat and pressing the surface, and have completed the present invention. That is, the method for repairing and modifying a metal-based substrate of the present invention is characterized by comprising the steps of: preparing a metal base material having a 1 st region divided in an in-plane direction of the base material, the 1 st region including a discontinuous portion of a defect and/or a structure; and pressing a rubbing tool without a probe against the surface of the 1 st region while rotating, thereby generating frictional heat and simultaneously pressing the surface, thereby repairing the defect and/or modifying the discontinuous portion of the tissue.

The method for repairing and modifying a metal base material of the present invention comprises: the metal base material further has a 2 nd region divided in the in-plane direction of the base material, and the 2 nd region is a portion which does not need to be repaired and/or modified.

The method for repairing and modifying a metal base material of the present invention comprises: repairing and/or modifying a portion of the metal base material from the surface to a maximum depth of 20 mm.

The method for repairing and modifying a metal base material of the present invention comprises: the metal base material has a thickness exceeding 20mm, and a portion of the metal base material from the surface to the maximum depth of 20mm is repaired and/or modified.

The method for repairing and modifying a metal base material of the present invention comprises: the metal base material has a thickness of 20mm or less, and the entire thickness direction of the metal base material or a portion of the metal base material from the surface, the thickness of which is thinner than the thickness of the base material, is repaired and/or modified.

In the method for repairing and reforming a metal base material according to the present invention, it is preferable that the impurities derived from the rubbing tool are not mixed into a portion having a depth of more than 1mm from the surface of the portion subjected to the repair and/or the reforming. By using the probe-less tool, it is possible to prevent impurities brought by the tool from being mixed into the deep portion of the metal base material.

The method for repairing and modifying a metal base material of the present invention comprises: the tensile strength of the base material comprising the repaired and/or modified 1 st area is 60-200% of the tensile strength of the base material comprising the 2 nd area only.

The method for repairing and modifying a metal-based substrate according to the present invention preferably further comprises the steps of: before repairing and/or modifying the metal base material, at least a part of the 1 st region is melted. The metallic base material can be repaired or modified to a deep portion.

The method for repairing and modifying a metal base material of the present invention comprises: the 1 st region of the metal-based substrate before the repair and/or modification is welded from the front surface to the back surface. The fusion bonded portion can be repaired or modified.

The method for repairing and modifying a metal-based substrate according to the present invention preferably further comprises the steps of: at least a portion of the 1 st region of the metal-based substrate before repair and/or modification is provided with or deposited with a material of the same composition as the metal-based substrate. The thickness of the repaired or modified portion can be prevented from being thinner than other portions.

In the method for repairing and reforming a metal base material according to the present invention, it is preferable that, in the step of repairing and/or reforming, the friction tool is pressed until a portion pressed by the friction tool is plastically deformed. The metallic base material can be repaired or modified to a deep portion.

In the method for repairing and reforming a metal base material according to the present invention, it is preferable that, in the step of repairing and/or reforming, the relative movement between the rubbing tool and the metal base material is in a depth direction of the base material only, in-plane direction of the base material only, or in a direction obtained by combining the depth direction of the base material and the in-plane direction of the base material. The metallic base material can be repaired or modified to a deep portion.

In the method for repairing and modifying a metal-based substrate according to the present invention, it is preferable to use a heat source other than frictional heat as an auxiliary before or during the repair and/or modification. The metallic base material can be repaired or modified to a deep portion.

In the method for repairing or modifying a metal-based substrate according to the present invention, the metal-based substrate includes any one of Cu, Ag, Au, Pt, a Cu-based alloy, an Ag-based alloy, an Au-based alloy, and a Pt-based alloy.

In the method for repairing or modifying a metal-based substrate according to the present invention, the friction tool includes any one of an Ir-based alloy, a Ni-based alloy, a Co-based alloy, a cemented carbide, a tool steel, and a ceramic.

In the method for repairing or modifying a metal-based substrate according to the present invention, it is preferable that the metal-based substrate includes any one of Cu, Ag, Au, a Cu-based alloy, an Ag-based alloy, and an Au-based alloy, and the friction tool includes any one of an Ir-based alloy, a Ni-based alloy, a Co-based alloy, a cemented carbide, a tool steel, and a ceramic.

In the method for repairing or modifying a metal-based substrate according to the present invention, it is preferable that the metal-based substrate includes Pt or a Pt-based alloy, and the friction tool includes any one of an Ir-based alloy, a cemented carbide, and a ceramic.

In the method for repairing or modifying a metal-based substrate according to the present invention, the metal-based substrate is a gasket for a pressure vessel, a capsule for a pressure vessel, a sputtering target, or a backing plate for a sputtering target as a whole or a part thereof.

[ Effect of the invention ]

According to the present disclosure, a method of repairing and/or modifying a tissue without mixing impurities from the surface to the inside of a structure can be provided. More specifically, the present disclosure can provide a method for repairing and modifying a metal base material, which can suppress impurities from being mixed into the interior of a structure by a probe provided in a friction stir welding tool, and can reduce defects existing in the interior of the structure by modifying the structure in the interior of the structure, thereby reducing the interface region existing in the interior of the structure.

Further, according to the present disclosure, the following effects can be obtained. (1) The mechanical properties and structure of the modified or repaired portion of the structure are ensured to be equivalent to those of the base material. Therefore, the structure has high quality reliability as compared with an unrepaired or unmodified structure. (2) The casting defect of the structure is repaired, and therefore, the risk of quality failure at the time of manufacturing is improved. That is, manufacturing stability is improved and cost can be reduced. (3) Since the tool used does not have a probe, there is very little risk of contamination of the inside with impurities due to a rejected lot (rejected lot) of the structure or the tool caused by breakage of the probe at the time of repair and/or modification. In addition, since there is no terminal hole, the yield in manufacturing is high. (4) Since the quality of the structure is ensured by repair and/or modification, even when the structure is manufactured using a material that is difficult to weld, special atmosphere control, pretreatment of the abutting surface, or precision is not required, and simplification of equipment or steps can be achieved.

Drawings

Fig. 1 is a schematic view showing the shape of the friction tool according to the present embodiment, wherein (a) is a side view, and (b) is a view of the tip portion (flat shape) as viewed in the axial direction of the friction tool.

Fig. 2 is a schematic view showing the shape of the friction tool according to the present embodiment, where (a) is a side view, and (b) is a view of the tip portion (circular shape without any corner at the tip portion) as viewed from the axial direction of the friction tool.

Fig. 3 is a schematic view showing the shape of the friction tool according to the present embodiment, where (a) is a side view, and (b) is a view of the tip portion (the shape of the flat surface having the spiral cut) when viewed from the axial direction of the friction tool.

Fig. 4 is a schematic view showing the shape of the friction tool according to the present embodiment, wherein (a) is a side view, and (b) is a view of the tip portion (the shape in which numerous convex portions are provided on the flat surface) as viewed in the axial direction of the friction tool.

Fig. 5 is a conceptual diagram illustrating an embodiment of the method for repairing and modifying a metal base material according to the present embodiment.

Fig. 6 is a conceptual diagram illustrating a method of spot construction.

Fig. 7 is a conceptual diagram illustrating a method of line construction.

Fig. 8 is a conceptual diagram showing another embodiment of the line construction method.

Fig. 9 is a conceptual diagram showing another embodiment of the line construction method.

Fig. 10 is a conceptual diagram illustrating a method of constructing a plurality of points.

FIG. 11 is a conceptual diagram illustrating another method of a plurality of point construction.

Fig. 12 is a conceptual diagram illustrating a method of line construction for base materials having non-uniform thicknesses.

Fig. 13 is a schematic view showing a method of line construction for the base material to be deposited.

Fig. 14 is a view showing the cross-sectional shape of the substrate after groove processing in example 1.

Fig. 15 is a cross-sectional image of a microscope of the weld overlay joint.

Fig. 16 is an enlarged image of a frame portion of fig. 15.

Fig. 17 is a cross-sectional image of a microscope of a repaired or modified portion of the weld bead.

Fig. 18 is an enlarged image of an upper frame portion of the solid line of fig. 17.

Fig. 19 is an enlarged image of a lower frame portion of the solid line in fig. 17.

Fig. 20 is an enlarged image of a dotted frame portion of fig. 17.

Fig. 21 is an image showing the result of the composition analysis (BEC) corresponding to the dashed frame portion of fig. 17.

Fig. 22 is an image showing the result of the composition analysis (BEC) corresponding to the dotted frame portion of fig. 17.

FIG. 23 shows S-S curves for example 2(TIG-FSP), reference example 1(BM) and comparative example 1 (TIG).

FIG. 24 is a graph showing a comparison of the maximum tensile strengths in example 2(TIG-FSP), reference example 1(BM) and comparative example 1 (TIG).

FIG. 25 is a graph showing a comparison of the elongation rates in example 2(TIG-FSP), reference example 1(BM) and comparative example 1 (TIG).

Fig. 26 is a sectional image and an enlarged image thereof of example 2.

Fig. 27 is a cross-sectional image of reference example 1 and an enlarged image thereof.

Fig. 28 is a cross-sectional image and an enlarged image thereof of comparative example 1.

Fig. 29 is a sectional image of a portion filled with a material in the terminal hole and an enlarged image thereof.

Fig. 30 is a cross-sectional image of the portion shown in fig. 29 after the portion is repaired and modified, and an enlarged image thereof.

FIG. 31 is a cross-sectional view of the entire repaired and modified sample of example 4 and an enlarged view thereof.

Fig. 32 is a sectional image of the substrate used in example 4.

Fig. 33 is a sectional image of a TIG weld zone before repair and modification in example 5.

Fig. 34 is a cross-sectional image of a portion of the TIG weld deposit repaired and modified in example 5.

Detailed Description

The present invention will be described in detail below with reference to embodiments, but the present invention is not limited to the description. The embodiment may be variously modified as long as the effect of the present invention is exerted.

The method for repairing and modifying a metal base material according to the present embodiment includes the steps of: preparing a metal base material having a 1 st region divided in an in-plane direction of the base material, the 1 st region including a discontinuous portion of a defect and/or a structure (referred to as a 1 st step); and pressing the friction tool without the probe against the surface of the 1 st region while rotating the friction tool, thereby generating frictional heat and pressing the surface, thereby repairing the defect and/or modifying the discontinuous portion of the tissue (referred to as the 2 nd step). The present embodiment includes: the metal base material further has a 2 nd region divided in the in-plane direction of the base material, and the 2 nd region is a portion which does not need to be repaired and/or modified. In the present embodiment, the "in-plane direction" refers to any direction in the X-Y plane when the plane of the surface of the base material is represented by the X-Y coordinate axis, and the "depth direction" refers to an orientation perpendicular to the in-plane direction. Further, the 1 st region and the 2 nd region include the depth direction of the substrate.

(1 st step)

The metal-based substrate is, for example, a substrate containing any one of Cu, Ag, Au, Pt, Cu-based alloy, Ag-based alloy, Au-based alloy, and Pt-based alloy. Examples of the Cu-based alloy include Cu-Zn, Cu-Ni, Cu-Ag, Cu-Sn and Cu-Sn-P, examples of the Ag-based alloy include Ag-Pd, Ag-Pd-Cu-Ge, Ag-In and Ag-Sn, examples of the Au-based alloy include ODS (Oxide Dispersion Strengthened alloy) -Au, Au-Pd, Au-Ag, Au-Cu and Au-Ni, and examples of the Pt-based alloy include ODS-Pt, Pt-Rh, Pt-Ir, Pt-Co and Pt-Cu. Examples of the shape of the base material include a plate shape, a cylindrical shape, a crucible shape, a capsule shape, and a ring shape, but the present embodiment is not limited to these shapes. The thickness (wall thickness) of the base material is not particularly limited, and is, for example, preferably 10mm or less, and more preferably 5mm or less. The lower limit of the thickness of the substrate is preferably 1mm or more. Specific applications of the metal-based base material include a gasket for a pressure vessel, a capsule for a pressure vessel, a sputtering target, and a backing plate for a sputtering target as a whole or in part. In the present embodiment, the term "M-based alloy" (M represents a metal element such as Cu, Ag, Au, Pt, Ir, Ni, or Co) means an alloy having the largest content (mass%) of M among elements constituting the alloy, and preferably an alloy having a content of M of 50 mass% or more. For example, if the alloy is an Ag-based alloy, Ag is preferably 95 mass% or more. In the case of a Cu-based alloy, Cu is preferably 50 mass% or more.

The repair and/or modification is performed on the exposed surface of the metal base material. That is, the processing is performed on at least one of the front surface and the back surface, or both of the front surface and the back surface. The end face of the base material depends on the width of the end face (corresponding to the wall thickness in the case of a plate), but if the end face is 40mm or less, the end face of the base material does not need to be repaired and/or modified. The metal-based base material is roughly classified into a case where the base material needs to be repaired and/or modified in the entire in-plane direction and a case where the base material needs to be repaired and/or modified in a part of the in-plane direction. In this embodiment, a portion requiring repair and/or modification is expressed as a 1 st region, and a portion not requiring repair and/or modification is expressed as a 2 nd region. That is, the metal-based base material has a form having only the 1 st region divided in the in-plane direction of the base material, and a form having the 1 st region and the 2 nd region divided in the in-plane direction of the base material.

In the present embodiment, the repair means that, when there is or is feared that there is a defect due to fusion bonding such as a pore or a solidification crack or a discontinuous portion of a structure such as a casting defect in the metal base material, the defect is eliminated or reduced. The modification means that a molten structure or dendrites are eliminated, crystal grains are equiaxed and granulated, and crystal grains are refined. In the present embodiment, the case where repair and modification are performed simultaneously is also included. In the present specification, "repair and/or modification" may be sometimes referred to as "repair and modification".

The friction tool is, for example, a friction tool including any one of Ir-based alloy, Ni-based alloy, Co-based alloy, cemented carbide, tool steel, and ceramic. Examples of Ir-based alloys include Ir-Re, Ir-Re-Zr, Ir-Hf, and Ir-Zr, examples of Ni-based alloys include Ni-Ir and Ni-Ir-Al-W, Ni-Al-V, and examples of Co-based alloys include Co-Cr, Co-Mo, Co-W, Co-Cr-Ru, and Co-Al-W. Examples of the ceramics include PCBN and Ti-C, Ti-N, Si-N. Examples of the cemented carbide include W-C, W-Re, W-C-Co, and W-C-Ni. Examples of the tool steel include SK, SKD, SKH, and SKs. In the present embodiment, a rubbing tool without a probe is used as the rubbing tool. The friction tool without the probe has, for example, the shape shown in fig. 1 to 4. Here, the rubbing tool 5 has a rod shape, and the tip portion thereof does not have a probe pin for friction stir bonding. The tip portion may have the shapes shown in fig. 1 (flat shape) and fig. 2 (curved shape), but is preferably a rough surface having a plurality of irregularities. The shape of fig. 3 in which the spiral notch is formed and the shape of fig. 4 in which the contact surface has numerous protrusions are considered as examples, although depending on the operation of the friction tool. By forming the shape of fig. 3, the material causing the plastic flow can be gathered on the shaft of the friction tool, and the plastic flow can be promoted. Further, the shape of fig. 4 also reduces the pressing force of the friction tool.

(step 2)

Step 2 will be described with reference to fig. 5. The metal base material 1 has a 1 st region 2a and a 2 nd region 2 b. The 1 st region 2a is, for example, a portion after fusion welding. The 2 nd region 2b is a portion other than the portion subjected to fusion welding, that is, a normal portion of the base material which does not need to be repaired or modified. In step 2, the friction tool 5 without a probe is pressed against the surface of the 1 st region 2a while rotating the friction tool 5 by the motor 7, and the surface of the 1 st region 2a is pressed while generating frictional heat, thereby repairing defects and/or modifying discontinuous portions of the tissue. In the present embodiment, either one of the two modes is included, that is, the friction tool 5 is rotated first and then pressed against the surface of the 1 st region 2a, or the friction tool 5 is pressed against the surface of the 1 st region 2a in a non-rotated state and then the friction tool 5 is started to rotate. Fig. 5 shows a mode (line construction) in which the friction tool 5 is moved in the direction 8 along the 1 st region 2a while being rotated. The plastic flow is generated by the rotation action of the friction tool 5, and then the solidification is performed. As shown in fig. 5, in the present embodiment, the width of the solidified portion (solidified portion after plastic region formation) 6 where plastic flow has occurred substantially coincides with the diameter of the tool.

By changing the insertion direction, the working direction, and the moving direction of the friction tool 5 with respect to the metal base material 1, various works can be performed. Here, the insertion direction refers to a pressing direction of the friction tool 5 against the base material, the application direction refers to a direction in which the friction tool 5 moves in a state of being in contact with and/or pressed against the base material, and the movement direction refers to a direction in which the friction tool 5 moves in a state of not being pressed.

Fig. 6 shows a method of spot construction. As shown in fig. 6, in the 2 nd step, the friction tool 5 is pressed until the portion pressed against by the friction tool 5 is plastically deformed. The insertion direction a of the friction tool 5 is the depth direction with respect to the base material, and the working direction B is likewise the depth direction. The moving direction C of the friction tool 5 is a direction in which the friction tool 5 is separated from the base material after the application. In this way, spot construction is performed in substantially the same size as the tip end portion of the friction tool 5. If the amount of movement in the working direction B, i.e., the depth direction, of the friction tool 5 is increased, the pressing is enhanced, and the depth of the solidified portion 6 where the plastic flow has occurred becomes large.

Fig. 7 shows a method of line construction. As shown in fig. 7, in the 2 nd step, the relative movement between the friction tool 5 and the metal base material 1 is in the in-plane direction of the base material only. The rubbing tool 5 is moved away from the end of the metal base material 1 in the in-plane direction in advance, and is set at a position where it can be pressed effectively when the rubbing tool 5 contacts the surface of the metal base material 1, so that the rubbing tool 5 is moved only in the in-plane direction. As the friction tool 5 moves, the portion pressed against by the friction tool 5 is plastically deformed. The insertion direction a, the application direction B, and the movement direction C of the friction tool 5 are all in-plane directions with respect to the base material. In this way, a line construction having substantially the same width as the tip end portion of the friction tool 5 is performed from one end of the base material to the other end. By setting the friction tool 5 at a position where the metal-based base material 1 can be pressed more efficiently (making the position where it is located deeper), the pressing is enhanced, and the depth of the solidified portion 6 where plastic flow has occurred is increased. By repeating the line construction in parallel, a wider range of construction can be achieved, and for example, the entire surface of the base material can be repaired and/or modified.

As shown in fig. 7, by inclining the friction tool 5 by θ ° with respect to the metal base material 1 such that the tip of the friction tool 5 precedes the application direction, the friction tool 5 can be moved in the in-plane direction while the base material is pressed by the friction tool 5 more smoothly. θ is preferably 1 to 45 °, and more preferably 1 to 5 °.

Fig. 8 shows a method of line construction. As shown in fig. 8, in the 2 nd step, the relative movement between the friction tool 5 and the metal base material 1 is the in-plane direction of the base material and the direction obtained by combining the depth direction of the base material and the in-plane direction of the base material. Since the friction tool 5 is tilted by θ ° and moved in the direction of the rotation axis of the tool, the insertion direction a of the friction tool 5 has vector components in both the depth direction and the in-plane direction. Since the insertion direction a has a vector component in the depth direction, the friction tool 5 can press the metal base material 1. The friction tool 5 is movable in the in-plane direction while maintaining the pressed state. That is, the working direction B is an in-plane direction. Then, the rubbing tool 5 is moved in the opposite direction to the insertion direction a, and the rubbing tool 5 is separated from the base material. That is, the moving direction C has vectors in both the depth direction and the in-plane direction. In this way, a part of the surface of the base material is subjected to line construction having substantially the same width as the tip end portion of the friction tool 5. By repeating the line construction side by side, construction with a wider range can be achieved.

Fig. 9 shows a method of line construction. Fig. 9 is a modification of fig. 8. As shown in fig. 9, in the 2 nd step, the relative movement between the friction tool 5 and the metal base material 1 is in the in-plane direction of the base material and in the depth direction of the base material. Since the friction tool 5 is tilted by θ ° and moved vertically downward, the insertion direction a of the friction tool 5 has a vector component only in the depth direction. Since the insertion direction a has a vector component in the depth direction, the friction tool 5 can press the metal base material 1. The friction tool 5 is movable in the in-plane direction while maintaining the pressed state. That is, the working direction B is an in-plane direction. Then, the rubbing tool 5 is moved vertically upward, and the rubbing tool 5 is separated from the base material. That is, the moving direction C has a vector component in the depth direction. In this way, a part of the surface of the base material is subjected to line construction having substantially the same width as the tip end portion of the friction tool 5. By repeating the line construction side by side, construction with a wider range can be achieved.

Fig. 10 shows a method of multiple point construction. Fig. 10 is a modification of fig. 6. As shown in fig. 10, in the 2 nd step, the friction tool 5 is pressed until the portion pressed against by the friction tool 5 is plastically deformed. The insertion direction a of the friction tool 5 is the depth direction with respect to the base material, and the working direction B is also the depth direction. Further, with respect to the moving direction C of the friction tool 5, after pressing against the friction tool 5, it is moved toward the original direction, that is, vertically upward. In this way, spot construction is performed in substantially the same size as the tip end portion of the friction tool 5. Subsequently, the rubbing tool 5 is moved in the in-plane direction of the base material, and then spot application is performed in the same manner. The solidified portion 6 where plastic flow has occurred becomes an aggregate of a plurality of point constructions. By changing the amount of movement in the depth direction of the application direction B of the friction tool 5 in accordance with each point of application, the depth of the solidified portion 6 where plastic flow has occurred can also be changed for each point of application.

Fig. 11 shows a method of multiple point construction. Fig. 11 is a modification of fig. 10. As shown in fig. 11, in the 2 nd step, the friction tool 5 is pressed until the portion pressed against by the friction tool 5 is plastically deformed. Specifically, the insertion direction a and the application direction B of the friction tool 5 are directions obtained by combining the depth direction of the base material and the in-plane direction of the base material. Since the friction tool 5 is tilted by θ ° and moved in the direction of the tool rotation axis, the insertion direction a and the working direction B of the friction tool 5 have vector components in both the depth direction and the in-plane direction. Since the insertion direction a and the application direction B have vector components in the depth direction, the friction tool 5 can press the metal base material 1. After the friction tool 5 is pressed against, the friction tool 5 is moved in the original direction as the moving direction C of the friction tool 5, and the friction tool 5 is separated from the base material. The moving direction C has a vector component of a direction combining the depth direction of the base material and the in-plane direction of the base material. In this way, spot construction is performed in substantially the same size as the tip end portion of the friction tool 5. Next, the moving direction C of the rubbing tool 5 is shifted to the in-plane direction of the base material, and then spot application is performed in the same manner. The solidified portion 6 where plastic flow has occurred becomes an aggregate of a plurality of point constructions. By changing the vector component in the depth direction of the application direction B of the friction tool 5 in accordance with each point application, the depth of the solidified portion 6 where plastic flow has occurred can also be changed for each point application.

Fig. 12 shows a method of line construction for base materials having non-uniform thicknesses. As shown in fig. 12, in the 2 nd step, the relative movement of the friction tool 5 and the metal base material 1 is a direction in which the depth direction of the base material and the in-plane direction of the base material are combined. Since the friction tool 5 is tilted by θ ° and moved in the direction of the rotation axis of the tool, the insertion direction a of the friction tool 5 has vector components in both the depth direction and the in-plane direction. Since the insertion direction a has a vector component in the depth direction, the friction tool 5 can press the metal base material 1. The friction tool 5 is moved along the surface of the base material while being kept pressed. That is, the application direction B is a direction in which the depth direction of the base material and the in-plane direction of the base material are combined. At this time, the vector component in the depth direction of the base material is adjusted so that the positional relationship between the distal end portion of the friction tool 5 and the surface of the metal base material 1 is fixed. Then, the friction tool 5 is moved in the opposite direction to the insertion direction a. That is, the moving direction C has vector components in both the depth direction and the in-plane direction. In this way, a part of the surface of the base material is subjected to line construction having substantially the same width as the tip end portion of the friction tool 5. By repeating the line construction side by side, construction with a wider range can be achieved. Further, the construction can be performed more smoothly by synchronizing θ so that the angle formed by the inclination of the axis of the friction tool 5 and the surface of the metal base material 1 is constant during the construction.

In the present embodiment, it is preferable to further include the following step (step 3): at least a part of the 1 st region of the metal-based substrate before the repair and/or modification is provided with or deposited with a material having the same composition as the metal-based substrate. In the present embodiment, since the metal-based base material is pressed by the friction tool, the thickness of the base material becomes thin after the repair or modification. Therefore, the 3 rd step can prevent the thickness of the base material from being reduced.

Fig. 13 shows a method of line construction for the deposited base material. As shown in fig. 13, in the 2 nd step, the relative movement of the friction tool 5 and the metal base material 1 is a direction in which the depth direction of the base material and the in-plane direction of the base material are combined. Since the friction tool 5 is tilted by θ ° and moved in the direction of the rotation axis of the tool, the insertion direction a of the friction tool 5 has vector components in both the depth direction and the in-plane direction. Since the insertion direction a has a vector component in the depth direction, the friction tool 5 can press the buildup layer 3 on the metal base material 1. In this case, the vector component in the depth direction of the base material is adjusted so as to finally become the original base material thickness. The friction tool 5 is moved in the in-plane direction of the base material while being kept pressed. That is, the application direction B is the in-plane direction of the base material. Then, the friction tool 5 is moved in the opposite direction to the insertion direction a. That is, the moving direction C has vector components in both the depth direction and the in-plane direction. In this way, a part of the surface of the base material is subjected to line work having substantially the same width as the front end portion of the friction tool 5, and the base material is processed to return to the original thickness. In the method of fig. 13, the pressing to the original base thickness is not required to be performed 1 time, but the pressing may be performed a plurality of times for the same portion to restore the original base thickness. Further, by repeating the line construction in parallel, a wider range of construction can be achieved.

As shown in fig. 8, 9, 11, 12, and 13, as in fig. 7, by inclining the friction tool 5 by θ ° with respect to the metal base material 1, plastic flow can be generated in the depth direction, and the construction can be performed more smoothly.

In the structure manufactured by the method of the present embodiment, casting defects existing in the repaired portion or the modified portion, defects due to fusion bonding, and discontinuous portions of the structure are reduced by the effect of repair and/or modification. Thus, the starting point of breakage is reduced, and the mechanical properties equivalent to those of the base material are ensured. For example, if a structure used in a high-temperature and high-pressure environment is produced by fusion welding and a fusion-bonded joint is repaired or modified by a probe-less tool, the joint of the latter structure exhibits excellent mechanical properties. In other words, the structural body has high reliability. Specifically, in the present embodiment, the tensile strength of the base material including the repaired and/or modified 1 st region is 60 to 200%, preferably 80 to 150%, of the tensile strength of the base material including only the 2 nd region.

Further, since the probe-less jig is used for repairing and/or reforming, the end hole does not remain after the application, and the contamination of impurities by the probe-less jig can be suppressed to within 1mm from the surface of the repaired portion and/or the reformed portion. That is, the foreign matter by the rubbing tool is not mixed into the surface of the repaired and/or modified portion to a depth exceeding 1 mm. Even if there is no impurity contamination by the probe tool, since the impurity is present at a shallow position from the surface of the repaired portion or the modified portion, the impurity is easily removed by cutting or polishing of the outer surface, and the adverse effect on the product manufactured using the structure can be reduced.

In the present embodiment, the following step (step 4) may be further included: before repairing and/or modifying the metal base material, at least a part of the 1 st region is melted. In the present embodiment, the 1 st region of the metal base material before repair and/or modification may have a portion welded from the front surface to the back surface. This structure has an advantage that the mechanical properties of the repaired portion or the modified portion are ensured by the repairing and/or modifying step using the probe-less tool, and therefore, at least a part of the 1 st region can be melted or fusion-bonded before the repairing and/or modifying. Therefore, the melting condition and atmosphere, the accuracy of the butt joint of the joint portion, and the size and amount of the internal defect, which must be controlled at the time of manufacturing the structure, can be alleviated. Therefore, the apparatus can be simplified, and the product can be stably supplied.

In the present embodiment, it is preferable to use a heat source other than frictional heat as an auxiliary before or during the repair and/or modification. The heat source other than the frictional heat is, for example, heating by a burner or heating by energization heat generation. The depth of the solidified portion where plastic flow has occurred can be increased.

In the present embodiment, the portion of the metal base material from the surface to the maximum depth of 20mm can be repaired and/or modified. When the metal base material has a thickness exceeding 20mm, the portion of the metal base material from the surface to the maximum depth of 20mm can be repaired and/or modified. When the metal-based base material has a thickness of 20mm or less, the entire thickness direction of the metal-based base material or a portion of the metal-based base material having a thickness thinner than the thickness of the base material from the surface can be repaired and/or modified. When the method of the present embodiment is applied to both sides of a metal-based substrate, the substrate can be repaired or modified to a thickness of 40 mm.

In the present embodiment, when the metal base material includes any one of Cu, Ag, Au, a Cu-based alloy, an Ag-based alloy, and an Au-based alloy, and the friction tool includes any one of an Ir-based alloy, a Ni-based alloy, a Co-based alloy, a cemented carbide, a tool steel, and ceramics, particularly excellent repair and modification can be performed.

In the present embodiment, when the metal base material includes Pt or a Pt-based alloy, and the friction tool includes any one of an Ir-based alloy, a cemented carbide, and a ceramic, particularly favorable repair and modification can be performed.