Brazing material, component for brazing, and method of manufacturing them

Abstract

To provide a brazing material, a component for brazing, and methods of manufacturing them which enable joining components without problems which may be caused by a brazing material containing a binder, such as dripping, a production efficiency, and a load to a heater.SOLUTION: A brazing material is provided by fusing and solidifying brazing material powder.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a brazing material, a brazing component, and a method for producing the same. [Background technology]

[0002] Brazing has been used as a method for joining members made of ceramics or metals. For example, Patent Document 1 discloses a brazing material powder having a specific composition and particle size distribution.

[0003] When using a powdered brazing filler metal, since the brazing filler metal cannot be held (adhered) to the joint in its powder form, it is usually kneaded with a binder (organic substance), an organic solvent, etc. to form a paste, and then the paste brazing filler metal is applied to the joint by screen printing or the like, before brazing (joining) is performed, as in Patent Document 2. Patent Document 2 discloses a brazing composition having a brazing filler metal powder containing a specific metal and a specific binder composition, as a brazing composition excellent in application workability, adhesion, and storage stability. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-155460 A [Patent Document 2] JP 2014-184476 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, such paste-like brazing filler metals containing binders still have issues such as the possibility of dripping after application to the joint, and the need for a drying process after application, which affects production efficiency, leaving room for improvement. Furthermore, when the binder component in the paste is removed by heating, the evaporated binder component may adhere to the heating device and have adverse effects, which may cause wear on the device and require frequent cleaning. In addition, there is a problem that limitations are imposed on the brazing joint structure due to the application of paste. There is also a method of casting the brazing material to hold it in the joint without using a powder or paste brazing material, but this is not practical as it requires the cost of making the mold and the casting cost itself is high. An object of the present invention is to provide a brazing material and a brazing component capable of joining components together without causing problems that can occur with brazing materials containing binders, such as dripping, production efficiency, and load on a heating device, as well as a method for manufacturing the same. [Means for solving the problem]

[0006] As a result of intensive research, the present inventors have found that the above problems can be solved by a specific brazing material and a brazing member. In addition, they have found that such a brazing material and a brazing member can be manufactured by a specific manufacturing method, and have arrived at the present invention.

[0007] That is, the gist of the present invention is as follows. [1] A brazing filler metal consisting of a molten solid of brazing filler metal powder. [2] The brazing filler metal according to [1], wherein the brazing filler metal is at least one selected from the group consisting of Ni-based brazing filler metals, Ti-based brazing filler metals, and Fe-Cr-Ni-based brazing filler metals. [3] The brazing filler metal according to [1] or [2], wherein the brazing filler metal has a Vickers hardness of 400 HV or more. [4] The brazing filler metal according to any one of [1] to [3], wherein the brazing filler metal has pores therein. [5] The brazing filler metal according to any one of [1] to [4], wherein the brazing filler metal has a relative density of 25% or more and 99% or less. [6] The brazing filler metal according to any one of [1] to [5], wherein the brazing filler metal is in a rod-like shape. [7] A brazing member having a substrate, the substrate having a surface on which the brazing material according to any one of [1] to [6] is provided. [8] The brazing member according to [7], in which a portion of the brazing material is fused to the surface of the base material, and further the brazing material is additionally formed on the brazing material. [9] A method for manufacturing a brazing filler metal, comprising a step of forming a brazing filler metal consisting of a molten solid of a brazing filler metal powder by additive manufacturing.

[10] The method for producing a brazing filler metal according to [9], wherein the brazing filler metal is at least one selected from the group consisting of Ni-based brazing filler metal, Ti-based brazing filler metal, and Fe-Cr-Ni-based brazing filler metal.

[11] The method for producing a brazing filler metal according to [9] or

[10] , wherein the brazing filler metal has a Vickers hardness of 400 HV or more.

[12] The method for producing a brazing filler metal according to any one of [9] to

[11] , wherein the brazing filler metal has voids therein.

[13] The method for producing a brazing filler metal according to any one of [9] to

[12] , wherein the brazing filler metal has a relative density of 25% or more and 99% or less.

[14] The method for producing a brazing filler metal according to any one of [9] to

[13] , wherein the brazing filler metal has a rod-like shape.

[15] A method for manufacturing a brazing member having a brazing material on a substrate surface, the method comprising a step of forming a brazing material consisting of a molten solid of a brazing material powder on the substrate surface by additive manufacturing.

[16] The method for producing a brazing member according to

[15] , wherein the brazing filler metal is at least one selected from the group consisting of a Ni-based brazing filler metal, a Ti-based brazing filler metal, and an Fe-Cr-Ni-based brazing filler metal.

[17] The method for producing a brazing member according to

[15] or

[16] , wherein the brazing material has a Vickers hardness of 400 HV or more.

[18] The method for producing a brazing member according to any one of

[15] to

[17] , wherein the brazing filler metal has pores therein.

[19] The method for producing a brazing member according to any one of

[15] to

[18] , wherein the brazing filler metal has a relative density of 25% or more and 99% or less.

[20] The method for manufacturing a brazing member according to any one of

[15] to

[19] , wherein the additive manufacturing is a process for forming the brazing material on the surface of the base material by spraying a brazing material powder onto the surface of the base material and laser welding the brazing material.

[21] The method for manufacturing a brazing member according to any one of

[15] to

[19] , wherein the additive manufacturing is a process of forming the brazing material on the surface of the base material by arranging a brazing material powder on the surface of the base material and laser welding the brazing material. Effect of the Invention

[0008] According to the present invention, it is possible to provide a brazing material and a brazing component capable of joining components together without causing problems that can occur with a brazing material containing a binder, such as dripping, production efficiency, and load on a heating device, as well as a manufacturing method thereof. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The following describes in detail the embodiments of the present invention, but these descriptions are merely examples (representative examples) of the embodiments of the present invention, and the present invention is not limited to these contents as long as they do not depart from the gist of the present invention. In this specification, a numerical range expressed using "~" means a range including the numerical values ​​before and after "~" as the lower and upper limits, and "A~B" means A or more and B or less. means.

[0010] <Brazing material> A first embodiment of the present invention is a brazing filler metal made of a molten solid of a brazing filler metal powder. In this specification, the molten solidified brazing powder is a powder of brazing material that is melted by heating in part or in whole on the surface thereof, and then fused to each other, and then cooled to below the melting point and solidified. The brazing material according to this embodiment may have a sparse structure in which the brazing material powder is fused to each other only in part on the surface. The brazing material made of such a molten solidified material can maintain a certain shape because the powder is fused to each other, and can be easily held (adhered) to the joint without using an organic substance such as a binder. In addition, since it does not require processes such as manufacturing a mold, mixing and stirring the binder, a process of heating and removing the binder component, and a process of compacting the brazing material powder, it is highly productive, and can also be applied to brazing materials using metals that are difficult to compact and have low ductility. In other words, the brazing material according to this embodiment preferably does not contain a binder.

[0011] The raw material of the brazing material powder is not particularly limited, and metals, alloys, compounds, and mixtures used in known brazing materials can be used depending on the material of the members to be joined and the required performance such as corrosion resistance. For example, copper (Cu), nickel (Ni), silver (Ag), gold (Au), titanium (Ti), palladium (Pd) and their alloys, stainless steel, tantalum (Ta), niobium (Nb), and combinations thereof can be mentioned. In addition, the brazing material powder may contain additive components contained in known brazing materials such as phosphorus (P), boron (B), silicon (Si), and chromium (Cr), as well as unavoidable impurities.

[0012] More specifically, examples of raw materials for the brazing powder include the alloys listed below. Ni-based alloys include Ni-Cr-Fe-Si-B alloys (BNi-2), Ni-Cr-Fe-Si alloys (BNi-5), and Ni-Cr-P alloys (BNi-7) as specified in the Japanese Industrial Standards (JIS Z3265); Ag-based alloys include Ag-Cu-Zn-Cd alloys (BAg-1), Ag-Cu-Zn-Ni alloys (BAg-4), and Ag-Cu-Zn-Sn alloys (BAg-7) as specified in JIS Z3261; Ti-based alloys include Ti-Zr-Cu-Ni (BTi-3) as specified in American Welding Society (AWS) A5.8M / A5:2019; and Fe-Cr-Ni-based alloys include Iron Blaze (registered trademark) TB-2720 (trade name, manufactured by Tokyo Blaze Co., Ltd.).

[0013] Among the above, at least one selected from the group consisting of Ni-based alloys, Ti-based alloys, and Fe-Cr-Ni-based alloys is preferred, since these alloys have high hardness and low ductility and are difficult to provide in a form that does not contain organic substances such as binders using conventional techniques such as powder compaction. That is, the brazing material according to the present embodiment is preferably at least one selected from the group consisting of Ni-based brazing material, Ti-based brazing material, and Fe-Cr-Ni-based brazing material. Here, the Ni-based brazing material refers to a brazing material specified in JIS Z3265 and other brazing materials having a Ni content of 50 mass% or more, the Ti-based brazing material refers to a brazing material specified in AWS A5.8M / A5:2019 and other brazing materials having a Ti content of 25 mass% or more and a Ni content of less than 50 mass%, and the Fe-Cr-Ni-based brazing material refers to a brazing material containing Fe, Cr, and Ni, and having an Fe content of 27 mass% or more, a Ni content of less than 50 mass%, and a Ti content of less than 25 mass%.

[0014] The Vickers hardness of the brazing material is not particularly limited, but from the same viewpoint, it is preferably 400HV or more, more preferably 450HV or more, and particularly preferably 500HV or more. The upper limit of the Vickers hardness is not particularly limited, but is usually 1200HV or less. In order to set the Vickers hardness of the brazing material within the above range, a brazing material raw material having a composition that satisfies the above range may be used. The Vickers hardness is a value measured by a Vickers hardness test according to JIS Z2244:2009 on the surface of the brazing material bulk before powderization or on the surface of the brazing material after melting and solidifying.

[0015] The brazing powder can be produced by powdering the above-mentioned metals as raw materials by a known method such as atomization, rotating disk method, or pulverization method.

[0016] The brazing filler metal according to the present embodiment may have voids in the brazing filler metal. By having voids in the brazing filler metal, it is possible to avoid excessive heat input to the powder when melting the surface of the brazing filler metal powder or when brazing. The presence or absence of voids can be confirmed by a method such as observing the brazing filler metal surface with a microscope. The voids can be formed in the brazing material by, for example, manufacturing the brazing material according to the manufacturing method of the brazing material described later.

[0017] The presence or absence of voids in the brazing filler metal can also be confirmed from the value of the relative density of the brazing filler metal. When the brazing filler metal has pores, the lower limit of the relative density of the brazing filler metal is not particularly limited, but may be 25% or more, or 30% or more, and the upper limit of the relative density is not particularly limited, but may be 99% or less, 90% or less, or 80% or less. If the relative density is too low, the brazing material will have too many voids, resulting in insufficient joint strength, whereas if the relative density is too high, the brazing material will have too few voids, resulting in excessive heat input to the brazing material powder. The relative density of the brazing material can be adjusted by changing the supply amount and sweep speed during powder heating. The brazing material may be a dense material having no voids, that is, a relative density of 100%.

[0018] The relative density is the bulk density measured based on "JIS Z8807 Measurement method for density and specific gravity of solids" divided by the true density.

[0019] The shape of the brazing material according to this embodiment is not particularly limited, and examples thereof include a rod shape, a ring shape, a sheet shape, a wire shape, and the like. From the viewpoints of ease of handling and ease of cutting from the substrate, a rod shape is preferable. In addition, the size of the brazing material according to this embodiment is not particularly limited, but typically, if it is in a rod shape, it is about 3 to 50 cm long and about 0.5 to 10 mm thick, if it is in a ring shape, it is about 1 to 10 cm in diameter, and if it is in a sheet shape, it is about 1 cm × 1 cm to 20 cm × 100 cm.

[0020] The brazing filler metal according to this embodiment can be manufactured, for example, by a manufacturing method for a brazing filler metal according to a third embodiment described later.

[0021] <Brazing materials> A second embodiment of the present invention is a brazing component having a base material, the brazing component having a brazing material on the surface of the base material. The substrate and the brazing member are not particularly limited, and examples thereof include heat exchanger members having a stainless steel substrate. The preferred aspects of the brazing filler metal according to this embodiment are the same as those of the brazing filler metal according to the first embodiment described above.

[0022] A portion of the brazing material is fused to the surface of the substrate, and additional brazing material is formed on the brazing material. It is preferable that the brazing material is partially fused to the surface of the substrate, so that the brazing material is held (adhered) to the surface of the substrate, the members can be appropriately joined, and the subsequent additional formation can be stably performed. By additionally forming the brazing material on the brazing material fused to the surface of the substrate, a sufficient amount of brazing material for joining the members can be secured on the substrate without dripping.

[0023] The brazing member according to this embodiment can be manufactured, for example, by placing the brazing material according to the first embodiment on a predetermined joint on a substrate, heating the substrate and the brazing material to melt the brazing material surface, and then cooling and solidifying. When the brazing material has a rod-like or ring-like shape, for example, after a part of the brazing material is fused and solidified on the substrate surface, an unnecessary part on the upper part of the brazing material may be cut and removed. It can also be manufactured by a manufacturing method according to a fourth embodiment described later.

[0024] <Method of manufacturing brazing material and brazing member> A third embodiment of the present invention is a method for manufacturing a brazing material, comprising a step of forming a brazing material made of a molten solid of a brazing material powder by additive manufacturing. A fourth embodiment of the present invention is a method for manufacturing a brazing member having a brazing material on a substrate surface, comprising a step of forming a brazing material made of a molten solid of a metal compound powder on the substrate surface by additive manufacturing.

[0025] Additive manufacturing is defined by ISO and ASTM (American Society for Testing and Materials) standards as a technology for creating parts from 3D shape data by attaching materials, and is sometimes called 3D printing, etc. Technologies known as additive manufacturing and cladding are also included in additive manufacturing.

[0026] The additive manufacturing is preferably a process of forming the brazing material on the substrate surface by spraying a brazing material powder onto the substrate surface and laser welding the brazing material. It is also preferable that the additive manufacturing is a process of forming the brazing material on the surface of the substrate by placing a brazing material powder on the surface of the substrate and laser welding the brazing material.

[0027] An example of a specific procedure for forming a brazing filler metal made of a molten solid of a brazing filler metal powder by additive manufacturing is as follows, but is not limited to this. First, the brazing powder, which is the raw material for the brazing material, is thinly spread on a plate-shaped substrate such as stainless steel, and the surface is irradiated and scanned with a laser beam or an electron beam to selectively melt and solidify (weld) the required areas, thereby bonding the brazing powder to the substrate. This allows the subsequent lamination to be performed stably. The substrate may be preheated in order to quickly bond the brazing powder to the substrate. Next, new brazing material powder is supplied onto the brazing material powder that is in close contact with the base material, and the brazing material powder is layered by repeatedly irradiating and scanning with a laser light or electron beam, which serves as a heat source, to form a brazing material having a rod-like or ring-like shape. From the viewpoint of manufacturing efficiency, the brazing material powder may be sprayed and melted and solidified (welded) by laser light irradiation or arc discharge, etc., and this may be scanned continuously to form planar layers, which are then stacked to form the brazing material. After forming the brazing filler metal of the desired thickness (height) on the substrate, the joint with the substrate can be broken or cut using a wire-cut electric discharge machine or the like to obtain a brazing filler metal consisting of a molten solidified product of the brazing filler metal powder. In addition, the adhesion between the brazing powder and the base material, or between the brazing powders themselves, does not need to be achieved by completely melting the entire brazing powder; it is sufficient if only a portion of the surface is adhered to the extent that the brazing powder does not move.

[0028] When manufacturing a brazing component having a brazing material on the surface of the substrate, the substrate in the above procedure is used as the substrate of the brazing component, and a desired amount of brazing material is formed directly on the portion to be brazed using the same procedure. The substrate is not limited to a plate-shaped substrate, and may be, for example, a rod-shaped substrate depending on the members to be brazed.

[0029] By manufacturing brazing filler metal and brazing components using the above-mentioned method, the process of applying and drying a paste-like brazing filler metal is not required, so there is no problem with dripping, and the workability and manufacturing efficiency are excellent.

[0030] Furthermore, by producing the brazing material and brazing components by the above-mentioned method, the brazing material itself functions as a self-alignment jig during brazing, and there is an advantage in that the amount of brazing material applied can be easily controlled.

[0031] The preferred embodiment of the brazing material powder as the raw material is the same as that in the first embodiment.

[0032] When spraying the brazing material powder, a heat source such as a laser beam may be irradiated perpendicularly to the substrate and the brazing material powder may be supplied obliquely from the side, or the brazing material powder may be sprayed perpendicularly to the substrate and the heat source such as a laser beam may be irradiated obliquely from the side.

[0033] The injection supply speed of the brazing powder is not particularly limited, but is usually 0.5 to 25 g / min, preferably 1 to 20 g / min, and more preferably 1.5 to 15 g / min. The heat source for melting the surface of the brazing powder is not particularly limited, but from the viewpoint of increasing the processing speed and preventing the surface oxidation of the brazing powder, a laser beam capable of rapid and localized heating with a high energy density is preferred.

[0034] The conditions for irradiating the laser light are not particularly limited, but the output is usually 10 to 1500W, preferably 20 to 1400W, and more preferably 40 to 1200W. The number of times of irradiation with the laser light and the scanning speed are not particularly limited, and may be appropriately adjusted depending on the amount and shape of the brazing material to be laminated. EXAMPLES

[0035] The present invention will be described in more detail below with reference to specific examples, although the present invention is not limited thereto.

[0036] In Examples 1 to 3, the following raw materials were used as the brazing powder. Raw materials used: Ni wax (Tokyo Blaze Co., Ltd., product number TB-905X) Chemical composition: Ni61 mass%, Cr29 mass%, Si4 mass%, P6 mass% Solidus: 980℃ Liquidus line: 1040℃ Specific gravity: 7.7g / cm 3 Hardness: 780HV

[0037] The relative density of the brazing material was calculated from the value obtained by dividing the bulk density measured based on "JIS Z8807 Method for measuring density and specific gravity of solids" by the true density.

[0038] Example 1 A high-precision laser cladding device (manufactured by Muratani Machinery Works, device name: ALPION) was used to spray and supply brazing material powder at 8 g / min onto a stainless steel plate substrate at room temperature, while irradiating the substrate with laser light at an output of 60 W. This process was repeated 1,200 times to form a rod-shaped brazing material 5 cm high and 3 mm wide on the substrate. The joint with the substrate was then cut off, and the brazing material was removed. The brazing filler metal obtained was a molten solid in which the surfaces of the brazing filler metal powder were partially fused, had voids, and had a relative density of 90%.

[0039] Example 2 The brazing material powder was sprayed at 2 g / min in the circumferential direction on the surface of a stainless steel rod substrate at room temperature using the same device as in Example 1, while the laser light was irradiated at an output of 100 W. This step was repeated twice to form a brazing material in the shape of a rib having a height of 0.2 cm on the substrate. The obtained brazing material was a molten solid in which a portion of the surface of the brazing material powder was fused, had voids, and had a relative density of 50%.

[0040] Example 3 1 g of brazing powder was placed on the surface of a stainless steel plate at room temperature, and the powder thickness was leveled by applying pressure from above with a stainless steel plate. The brazing powder was then irradiated with a 50 W laser beam at a scanning speed of 10 mm / s using a laser brazing device having a semiconductor laser light source as described in JP 2019-063852 A, and the process was repeated 10 times to form a 0.1 mm thick, 10 mm square sheet brazing material on the substrate. The brazing material obtained was a molten solid in which part of the surface of the brazing powder was fused, had voids, and had a relative density of 40%.

[0041] By brazing (joining) components together using the brazing material or brazing components obtained as described above, it is possible to join the components together without using a binder.

Claims

1. A brazing filler metal consisting of a molten solid of brazing filler metal powder.

2. The brazing filler metal is at least one selected from the group consisting of Ni-based brazing filler metal, Ti-based brazing filler metal, and Fe-Cr-Ni-based brazing filler metal; The brazing material according to claim 1.

3. The Vickers hardness of the brazing material is 400 HV or more. The brazing material according to claim 1.

4. The brazing material has voids therein. The brazing material according to claim 1.

5. The relative density of the brazing material is 25% or more and 99% or less. The brazing material according to claim 4.

6. The brazing material is in a rod shape. The brazing material according to claim 1.

7. A brazing member having a substrate, the substrate having the brazing material according to any one of claims 1 to 6 on a surface thereof.

8. The brazing member according to claim 7 , wherein a part of the brazing material is fused to the surface of the base material, and further the brazing material is additionally formed on the brazing material.

9. A method for producing a brazing material, comprising the steps of:

1. A method for manufacturing a brazing filler metal, comprising: forming a brazing filler metal by additive manufacturing, the brazing filler metal comprising a molten solid of a brazing filler metal powder.

10. The brazing filler metal is at least one selected from the group consisting of Ni-based brazing filler metal, Ti-based brazing filler metal, and Fe-Cr-Ni-based brazing filler metal; A method for producing the brazing material according to claim 9.

11. The Vickers hardness of the brazing material is 400 HV or more. A method for producing the brazing material according to claim 9.

12. The brazing material has voids therein. A method for producing the brazing material according to claim 9.

13. The relative density of the brazing material is 25% or more and 99% or less. A method for producing the brazing material according to claim 12.

14. The brazing material is in a rod shape. A method for producing the brazing material according to claim 9.

15. A method for producing a brazing member having a brazing material on a substrate surface, comprising: A brazing material comprising a molten solid of a brazing material powder is formed on the surface of the substrate by additive manufacturing. A method for manufacturing a brazing member.

16. The brazing filler metal is at least one selected from the group consisting of Ni-based brazing filler metal, Ti-based brazing filler metal, and Fe-Cr-Ni-based brazing filler metal; The method for producing a brazing member according to claim 15.

17. The Vickers hardness of the brazing material is 400 HV or more. The method for producing a brazing member according to claim 15.

18. The brazing material has voids therein. The method for producing a brazing member according to claim 15.

19. The relative density of the brazing material is 25% or more and 99% or less. The method for producing a brazing member according to claim 18.

20. The additive manufacturing is a process of forming the brazing material on the substrate surface by spraying a brazing material powder onto the substrate surface and laser welding the brazing material; The method for manufacturing a brazing member according to any one of claims 15 to 19.

21. The additive manufacturing step is a step of forming the brazing material on the substrate surface by disposing a brazing material powder on the substrate surface and laser welding the brazing material to the substrate surface. The method for manufacturing a brazing member according to any one of claims 15 to 19.