Electron beam welding method for a porous metal material, welded piece

Abstract

The present application relates to the technical field of welding, in particular to a kind of electron beam welding method of porous metal material and welded piece;The method comprises: the welding end face of the porous metal material to be welded is processed into vertical plane, and the workpiece to be welded is obtained;Two the workpiece to be welded is fixed together using welding tooling, to form I-shaped groove between two vertical planes;Multiple powder laying-spot welding treatment is carried out in the I-shaped groove, and the welded piece is obtained;Wherein, the powder laying-spot welding treatment includes: laying metal powder in the I-shaped groove, and using pulse electron beam to continuously spot weld the metal powder, to form porous weld. By using the method of the present application, the problems of pore blockage, pore structure damage and welded joint collapse in the welding process of porous metal material are solved.

Description

Technical Field

[0001] This invention relates to the field of welding technology, and more specifically, to an electron beam welding method for porous metal materials and a welded component. Background Technology

[0002] Porous materials refer to materials containing a certain number of closed or interconnected pores that form a network structure. Porous metallic materials combine the structural characteristics of metals with the functional characteristics of pores, thus possessing advantages such as good machinability, strong shape stability, excellent heat transfer and dissipation capabilities, low specific gravity, and large specific surface area, making them widely used in various fields. However, porous metallic materials are difficult to manufacture, making it challenging to produce large or complex parts, requiring welding techniques to connect different components. Furthermore, porous metallic parts inevitably suffer wear, cracks, and other damage during service. To avoid complete material failure, advanced repair techniques are needed to repair damaged areas while preserving their original performance, thereby extending the material's service life. This process also requires welding connections.

[0003] However, the special morphology and physicochemical properties of porous metal materials place high demands on the welding methods used. For example, traditional fusion welding of porous materials can lead to joint collapse, brazing can cause the filler metal to penetrate into the base material on both sides and block the pores, and solid-phase bonding can damage the pore structure. Summary of the Invention

[0004] The technical problem solved by this invention is at least one of the following problems: during the welding process of porous metal materials, problems such as pore blockage, pore structure damage and weld joint collapse are prone to occur.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0006] An electron beam welding method for porous metallic materials includes:

[0007] Step S1: Machin the welding end face of the porous metal material to be welded into a vertical plane to obtain the workpiece to be welded;

[0008] Step S2: Fix the two workpieces to be welded together using welding fixtures to form an I-shaped bevel between the two vertical planes;

[0009] Step S3: Perform multiple powder-laying and spot welding processes in the I-shaped bevel to obtain a welded part; wherein, the powder-laying and spot welding process includes: laying metal powder in the I-shaped bevel, and continuously spot welding the metal powder with a pulsed electron beam to form a porous weld.

[0010] Optionally, the accelerating voltage of the pulsed electron beam is 50-120kV, the welding beam current is 3-10mA, and the welding speed is 2-5m / s.

[0011] Optionally, in step S3, the step of laying metal powder in the I-shaped bevel includes spreading the metal powder evenly in the I-shaped bevel and scraping off the excess metal powder in the I-shaped bevel with a scraper.

[0012] Optionally, the scraper is made of rubber or plastic.

[0013] Optionally, in step S1, the welding end face of the porous metal material to be welded is processed into a vertical plane using a slow wire cutting process.

[0014] Optionally, in step S1, during the process of machining the welding end face of the porous metal material to be welded into a vertical plane, the pore blockage or pore damage that occurs in the porous metal material to be welded during the machining process is repaired by chemical corrosion or electrochemical corrosion methods.

[0015] Optionally, the metal powder has the same composition as the porous metal material to be welded.

[0016] Optionally, the porous metal material to be welded is a nickel-based high-temperature alloy.

[0017] Optionally, it also includes: step S4, cleaning the weld bead to remove excess metal powder.

[0018] The present invention also provides a weldable component, which is manufactured by the electron beam welding method for porous metal materials as described above.

[0019] Compared with existing technologies, the electron beam welding method for porous metal materials provided by this invention is based on fusion welding. Utilizing the advantages of high precision and controllable input energy of scanning electron beams, it facilitates control over weld size and solidification rate, preventing weld metal from collapsing and filling pores, thus avoiding joint collapse caused by pore filling. Furthermore, the welding method employing metal powder deposition and continuous spot welding with pulsed electron beams allows for the connection of porous metal materials while maintaining the porous morphology of the weld joint. This welding method does not require external force applied to the workpiece during the welding process, thus preventing pore damage and the penetration of filler metal into the base material on both sides, which could block pores. In addition, the welding method of this invention fully leverages the advantages of electron beam welding, such as minimal welding deformation, minimal vacuum environment contamination, and stable welding quality, thereby significantly improving the welding quality of porous metal materials. Attached Figure Description

[0020] Figure 1This is a schematic flowchart of the electron beam welding method for porous metal materials in an embodiment of the present invention;

[0021] Figure 2 This is a schematic diagram of the structure of two workpieces to be welded after being fixed together using welding fixtures in an embodiment of the present invention;

[0022] Figure 3 A schematic diagram illustrating the use of a scraper to remove excess metal powder from an "I"-shaped bevel in an embodiment of the present invention;

[0023] Figure 4 This is a schematic diagram illustrating the continuous spot welding of the metal powder using a pulsed electron beam in an embodiment of the invention.

[0024] Explanation of reference numerals in the attached figures:

[0025] 1. Positioning component; 2. Workpiece to be welded; 201. Vertical plane; 3. Metal powder; 4. Scraper; 5. Pulsed electron beam. Detailed Implementation

[0026] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0027] It should be noted that, unless otherwise specified, the features in the embodiments of this invention can be combined with each other. The terms "comprising," "including," "containing," and "having" are non-limiting, meaning that other steps and other components that do not affect the results can be added. The above terms cover the terms "composed of" and "substantially composed of." Unless otherwise specified, the materials, equipment, and reagents are commercially available.

[0028] Traditional fusion welding of porous metal materials is prone to the molten weld metal flowing downwards, filling the pores and causing the joint to collapse. During brazing, the filler metal flows into the pores due to gravity and capillary action, causing the pores at the brazed joint to be completely blocked. Solid-state bonding usually requires the application of external force to connect the materials, but this process is usually accompanied by the breakage and reconnection of the joint interface, which will damage the pore structure of porous metal materials.

[0029] In response to the above problems, such as Figure 1 As shown, this embodiment of the invention provides an electron beam welding method for porous metal materials, comprising:

[0030] Step S1: The welding end face of the porous metal material to be welded is processed into a vertical plane 201 to obtain the workpiece 2 to be welded;

[0031] Step S2: Fix the two workpieces 2 to be welded together using welding fixtures to form an I-shaped bevel between the two vertical planes 201;

[0032] Step S3: Perform multiple powder laying-spot welding processes in the I-shaped groove until the weld height in the I-shaped groove is slightly higher than the groove depth to obtain a welded part. Among them, the powder laying-spot welding process includes: laying metal powder 3 in the I-shaped groove, and using a pulsed electron beam 5 to continuously perform spot welding on the metal powder to form a porous weld;

[0033] Step S4: Clean the weld bead to remove the excess metal powder.

[0034] Step S5: Cut off the excess part of the welded part. It should be noted that the excess part refers to the part that exceeds the dimensional specifications of the welded part.

[0035] Compared with the prior art, the electron beam welding method for porous metal materials provided by the present invention is based on fusion welding. By utilizing the advantages of high precision and controllable input energy of the scanning electron beam, it is convenient to control the weld size and the weld solidification speed, so that the weld metal will not collapse and fill the pores, and there will be no joint collapse caused by filling the pores. At the same time, in the present invention, the welding method of laying metal powder and continuous spot welding with a pulsed electron beam can realize the connection of porous metal materials on the premise of ensuring the porous morphology at the welding position. The welding method of the present invention does not require external force to be applied to the workpiece to be welded during the welding process, so there will be no situation of pore damage, nor will there be a situation where the filler metal penetrates into the base metals on both sides and blocks the pores. In addition, the welding method of the present invention also gives full play to the advantages of small welding deformation, small vacuum environmental pollution and stable welding quality of electron beam welding, thereby greatly improving the welding quality of porous metal materials.

[0036] Exemplarily, in the embodiment of the present invention, after the two workpieces to be welded are fixed together using a welding fixture in step S2, the structure is as Figure 2 shown. The welding fixture includes a plurality of positioning members 1. Each workpiece to be welded 2 is fixed by three positioning members 1 distributed in a "product" shape. An I-shaped groove is formed between the vertical planes 201 of the two workpieces to be welded 2. In some embodiments of the present invention, the acceleration voltage of the pulsed electron beam 5 is 50-120 kV, the welding beam current is 3-10 mA, and the welding speed is 2-5 m / s.

[0037] In some embodiments of the present invention, in step S3, laying the metal powder 3 in the I-shaped groove includes spreading the metal powder 3 flat in the I-shaped groove, and using a scraper 4 to scrape off the excess metal powder in the "I"-shaped groove. Preferably, the scraper 4 is made of rubber or plastic to avoid damage to the workpiece to be welded 2 by the scraper 4. Figure 3 It is a schematic diagram of using the scraper 4 to scrape off the excess metal powder in the "I"-shaped groove. Figure 4This is a schematic diagram of continuous spot welding of the metal powder using a pulsed electron beam.

[0038] During the continuous spot welding of the metal powder using pulsed electron beam 5, the continuous spot welding at the interface of the "I" shaped groove base material should utilize the deflection function of the electron beam to make the angle between the direction of the electron beam and the normal direction of the "I" shaped groove interface less than 90°, that is, the electron beam obliquely passes through the metal powder and the groove interface base material, so that the interface of the base material melts and forms a metallurgical bond with the molten powder.

[0039] In some embodiments of the present invention, in step S1, the process of machining the welding end face of the porous metal material to be welded into a vertical plane 201 is carried out by slow wire cutting. Surface processing of porous metal materials is prone to causing pore blockage. Using slow wire cutting to process the welding end face can effectively avoid the above situation, thus ensuring that the pores at the welding end face are open.

[0040] In some embodiments of the present invention, in step S1, during the process of processing the welding end face of the porous metal material to be welded into a vertical plane 201, the pore blockage or pore damage that occurs in the porous metal material to be welded during the processing is repaired by chemical corrosion (e.g., pickling) or electrochemical corrosion methods.

[0041] In some embodiments of the present invention, the metal powder has the same composition as the porous metal material to be welded. Exemplarily, the porous metal material to be welded is a nickel-based high-temperature alloy, such as Inconel 718, Inconel 625, etc.

[0042] The present invention also provides a weldable component, which is manufactured by the electron beam welding method for porous metal materials as described above.

[0043] It should be noted that in this invention, the width of the I-shaped bevel is related to the beam deflection angle achievable by the electron beam welding machine and the thickness of the workpieces to be welded. The minimum width of the I-shaped bevel should be such that, under electron beam deflection, the bottom of the bevel of one side of the workpiece to be joined melts, and the electron beam is not blocked by the upper edge of the bevel of the other side of the workpiece to be welded. The electron beam power at the interface of the base material during continuous spot welding should be different from the area inside the bevel containing only metal powder. That is, the area from the bevel interface to the center of the bevel should be divided into a power gradient zone and a power stability zone. Whether the power increases or decreases between the bevel interface and the power stability zone depends on the properties of the base material and the metal powder. It should also be noted that the width of the I-shaped bevel is the distance between the two workpieces to be welded.

[0044] Furthermore, it should be noted that although the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. An electron beam welding method for porous metallic materials, characterized in that, include: Step S1: The welding end face of the porous metal material to be welded is processed into a vertical plane (201) to obtain the workpiece to be welded (2); wherein, in step S1, the welding end face of the porous metal material to be welded is processed into a vertical plane (201) by slow wire cutting. Step S2: Fix the two workpieces (2) to be welded together using welding fixtures to form an I-shaped bevel between the two vertical planes (201); Step S3: Perform multiple powder-spot welding processes in the I-shaped bevel to obtain a welded part; wherein, the powder-spot welding process includes: laying metal powder (3) in the I-shaped bevel, and continuously spot welding the metal powder with a pulsed electron beam (5) to form a porous weld.

2. The electron beam welding method for porous metallic materials according to claim 1, characterized in that, In step S3, the accelerating voltage of the pulsed electron beam (5) is 50-120kV, the welding beam current is 3-10mA, and the welding speed is 2-5m / s.

3. The electron beam welding method for porous metallic materials according to claim 1, characterized in that, In step S3, the step of laying metal powder (3) in the I-shaped bevel includes spreading the metal powder (3) evenly in the I-shaped bevel and scraping off the excess metal powder in the I-shaped bevel with a scraper (4).

4. The electron beam welding method for porous metal materials according to claim 3, characterized in that, The scraper (4) is made of rubber or plastic.

5. The electron beam welding method for porous metallic materials according to claim 1, characterized in that, In step S1, during the process of processing the welding end face of the porous metal material to be welded into a vertical plane (201), the pore blockage or pore damage that occurs in the porous metal material to be welded during the processing is repaired by chemical corrosion or electrochemical corrosion methods.

6. The electron beam welding method for porous metallic materials according to claim 1, characterized in that, The metal powder (3) has the same composition as the porous metal material to be welded.

7. The electron beam welding method for porous metallic materials according to claim 1, characterized in that, The porous metal material to be welded is a nickel-based high-temperature alloy.

8. The electron beam welding method for porous metallic materials according to claim 1, characterized in that, It also includes: step S4, cleaning the weld bead to remove excess metal powder.

9. A welded component, characterized in that, It is prepared by electron beam welding of porous metal materials as described in any one of claims 1-8.

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