Nickel-aluminum bronze cladding layer in-situ heat treatment method based on electron beam surface treatment

Abstract

The invention discloses an in-situ heat treatment method of a nickel-aluminum bronze cladding layer based on electron beam surface treatment, and belongs to the technical field of high-energy beam heat treatment. The problems that according to an existing heat treatment method for the cladding layer on the surface of the nickel-aluminum bronze part, oxidation of base metal alloy is aggravated, and a large amount of energy is consumed are solved. According to the method, the nickel-aluminum bronze cladding layer or the repairing layer is subjected to in-situ heat treatment based on the electron beam surface treatment technology, the beta'phase of the nickel-aluminum bronze cladding layer can be completely eliminated, the cladding layer has the excellent mechanical property and corrosion property, meanwhile, the influence on base metal is reduced or completely avoided, alloy oxidation cannot be caused, and energy is saved. Test results show that the yield strength of the cladding layer subjected to in-situ heat treatment is 511.19 + / -6.053 MPa, the tensile strength is 816.43 + / -12.328 MPa, and the hardness is 238.14 + / -3.33 HV < 0.5 >.

Description

Technical Field

[0001] The invention relates to an in-situ heat treatment method for a nickel-aluminum bronze cladding layer based on electron beam surface treatment, and belongs to the technical field of high-energy beam heat treatment. Background Art

[0002] Nickel-aluminum bronze is a copper alloy primarily alloyed with nickel, iron, and aluminum. Its phases include α, κ, and β' phases. The β' phase, a martensitic structure, is highly brittle and detrimental to the alloy's corrosion resistance, typically requiring a 6-hour heat treatment at 675°C to completely eliminate it.

[0003] To improve the surface properties of nickel-aluminum bronze components, a common method is to create a nickel-aluminum bronze alloy cladding layer on their surface. Cladding refines the grain structure, thereby improving the surface hardness, wear resistance, and corrosion resistance of the components. Furthermore, surface damage to nickel-aluminum bronze components is often repaired using technologies such as cladding, electrospark deposition, laser directed energy deposition, arc additive manufacturing, and electron beam fuse deposition. These cladding and repair methods typically result in rapid solidification of the material, forming a β' phase in the alloy. The presence of the β' phase can affect the mechanical properties and corrosion resistance of the cladding layer, limiting the full realization of its excellent performance.

[0004] The traditional solution is to heat treat the clad components to improve the material's structure and performance. However, this method may not only change the original structure of the parent material, resulting in performance degradation, but also aggravate the oxidation of the alloy. The overall heat treatment process usually consumes a lot of energy. Summary of the Invention

[0005] In order to solve the problems of aggravated oxidation of the base alloy and large energy consumption in the existing heat treatment method for the surface cladding layer of nickel-aluminum bronze parts, the present invention provides an in-situ heat treatment method for the nickel-aluminum bronze cladding layer based on electron beam surface treatment.

[0006] The technical solution of the present invention:

[0007] One of the objects of the present invention is to provide an in-situ heat treatment method for a nickel-aluminum bronze cladding layer, the method comprising the following steps:

[0008] (1) Prepare a cladding layer on nickel-aluminum bronze alloy, leaving a processing allowance;

[0009] (2) Using electron beam in-situ heat treatment to treat the cladding layer;

[0010] (3) After the in-situ treatment is completed, cool to room temperature and remove the processing allowance.

[0011] Further defined, the nickel-aluminum bronze alloy in (1) is C95800 nickel-aluminum bronze sheet, and the material of the cladding layer or repair layer is SCu6328 (CuAl9Ni5Fe3Mn2) nickel-aluminum bronze alloy.

[0012] Even further defined, in (1), the method of surfacing, electric spark deposition, laser directed energy deposition, arc additive manufacturing and electron beam wire deposition is used to prepare the cladding layer.

[0013] Even further defined, in (1), the electron beam wire deposition method is used to prepare the cladding layer.

[0014] Further defined, the process parameters for preparing the cladding layer in (1) are: the vacuum degree of the vacuum chamber is 7×10 -2 Pa, the acceleration voltage U is 50 - 70 kV, the focusing current I f is 1000 - 1050 mA, the wire feeding speed V feed is 2 - 3 m / min, the printing speed V print is 500 - 700 mm / min, the beam current density I b is 50 - 60 mA.

[0015] Even further defined, the process parameters for preparing the cladding layer in (1) are: the vacuum degree of the vacuum chamber is 7×10 -2 Pa, the acceleration voltage U is 60 kV, the focusing current I f is 1030 mA, the wire feeding speed V feed is 2.4 m / min, the printing speed V print is 600 mm / min, the beam current density I b is 55 mA.

[0016] Further defined, the process parameters of the electron beam in-situ heat treatment of the cladding layer in (2) are: the vacuum degree of the vacuum chamber is 7×10 -2 Pa, the acceleration voltage U is 50 - 70 kV, the focusing current I f is 1050 - 1100 mA, the beam current density I b is 30 - 40 mA, the scanning speed V is 500 - 700 mm / min, the electron beam oscillates in a ring, the ring diameter is 3 - 5 mm, the oscillation frequency is 300 Hz, and it scans back and forth 3 - 6 times.

[0017] Even further defined, the process parameters of the electron beam in-situ heat treatment of the cladding layer in (2) are: the vacuum degree of the vacuum chamber is 7×10 -2 Pa, the acceleration voltage U is 60 kV, the focusing current I f is 1080 mA, the beam current density I bThe current is 35 mA, the scanning speed V is 600 mm / min, the electron beam oscillates in a ring, the ring diameter is 4 mm, the oscillation frequency is 300 Hz, and the scanning is repeated 5 times.

[0018] The second object of the present invention is to provide an application of the in-situ heat treatment method for the above nickel-aluminum bronze cladding layer, specifically for improving the surface properties of nickel-aluminum bronze parts.

[0019] Furthermore, the yield strength of the nickel-aluminum bronze cladding layer treated by the in-situ heat treatment method for the nickel-aluminum bronze cladding layer is 511.19 ± 6.053 MPa, the tensile strength is 816.43 ± 12.328 MPa, and the hardness is 238.14 ± 3.33 HV 0.5 .

[0020] Advantages of the present invention:

[0021] Based on the electron beam surface treatment technology, the present invention conducts in-situ heat treatment on the nickel-aluminum bronze cladding layer or repair layer, which can completely eliminate the β' phase in the nickel-aluminum bronze cladding layer, making the cladding layer have excellent mechanical properties and corrosion resistance. At the same time, it reduces or completely avoids the influence on the base material, does not cause oxidation of the alloy, and saves energy. The test results show that the yield strength of the cladding layer after in-situ heat treatment is 511.19 ± 6.053 MPa, which is about 10.1% higher than that before treatment; the tensile strength is 816.43 ± 12.328 MPa, which is about 7.1% higher than that before treatment; the hardness is 238.14 ± 3.33 HV 0.5 , which is about 8.2% higher than that before treatment. Description of the drawings

[0022] Figure 1 It is the microscopic tissue morphology diagram of the nickel-aluminum bronze cladding layer prepared in the example and Comparative Example 1;

[0023] Figure 2 It is the tensile property stress-strain curve of the nickel-aluminum bronze cladding layer prepared in the example and Comparative Example 1;

[0024] Figure 3 It is the hardness comparison diagram of the nickel-aluminum bronze cladding layer prepared in the example and Comparative Example 1;

[0025] Figure 4 It is the microscopic tissue morphology of the nickel-aluminum bronze cladding layer prepared in Comparative Examples 2-1 to 2-5;

[0026] Figure 5 It is the hardness comparison diagram of the nickel-aluminum bronze cladding layer prepared in the example and Comparative Examples 2-1 to 2-5. Specific embodiments

[0027] To make the above objects, features, and advantages of the present invention more apparent and understandable, the following describes the specific embodiments of the present invention in detail in conjunction with the embodiments of the specification.

[0028] In the following description, many specific details are set forth in order to provide a thorough understanding of the present invention. However, the present invention may be practiced in other ways different from those described herein. Those skilled in the art can make similar generalizations without departing from the spirit of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0029] Secondly, the so-called "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The appearances of "in one embodiment" in different places in this specification do not all refer to the same embodiment, nor are they separate or alternative embodiments that are mutually exclusive of other embodiments.

[0030] The experimental methods used in the following embodiments are all conventional methods unless otherwise specified. The materials, reagents, methods, and instruments used, unless otherwise specified, are all conventional materials, reagents, methods, and instruments in this field, and those skilled in the art can obtain them through commercial channels.

[0031] In the following embodiments and comparative examples, the manufacturing of specific components is not corresponding. Therefore, the final dimensions of the components are not restored for the cladding layer, and only surface cleaning is performed, which does not affect the performance of the cladding layer.

[0032] If the manufacturing of specific components is involved in the cladding process, ensure that the deposition of the alloy layer is completed according to the design requirements, and leave enough machining allowance for subsequent processing steps. This allowance should ensure that unnecessary parts can be removed in subsequent processes while ensuring the quality and performance of the cladding layer.

[0033] Embodiment

[0034] (1) Using a C95800 nickel-aluminum bronze plate with dimensions of 150 mm × 80 mm × 12 mm as the substrate, clamp the substrate with a flat and clean surface on the motion system in the vacuum chamber of the electron beam wire deposition equipment.

[0035] (2) Use an SCu6328 (CuAl9Ni5Fe3Mn2) nickel-aluminum bronze alloy wire with a diameter of 1.6 mm to prepare the cladding layer, and install the clean and dry wire on the wire feeding mechanism of the electron beam wire deposition equipment;

[0036] (3) Start the electron beam wire deposition equipment and wait until the vacuum degree of the vacuum chamber of the electron beam wire deposition equipment reaches the usage requirement (7×10 -2 Pa). Prepare the nickel-aluminum bronze cladding layer with the following process parameters: the acceleration voltage U is 60 kV, and the focusing current I fis 1030 mA, wire feeding speed V feed is 2.4 m / min, printing speed V print is 600 mm / min, beam current density Ib is 55 mA.

[0037] (4) Set the automatic program to control the electron beam to scan and heat-treat the surface of the cladding layer by the operating system, and set the following processing parameters: acceleration voltage U = 60 kV, focusing current I f is 1080 mA, beam current density I b is 35 mA, scanning speed V is 600 mm / min. The electron beam oscillates in a ring, the ring diameter is 4 mm, and the oscillation frequency is 300 Hz. Scan 5 times in a cycle.

[0038] (5) Take out the prepared nickel-aluminum bronze cladding layer and clean the surface.

[0039] Comparative Example 1

[0040] The difference between this comparative example and the example is that step (4) is not carried out, and the remaining process steps and parameter settings are the same as those in the example.

[0041] Comparative Example 2-1

[0042] The difference between this comparative example and the example is that in step (4), the beam current density I b is 25 mA and scanned 5 times, and the remaining process steps and parameter settings are the same as those in the example.

[0043] Comparative Example 2-2

[0044] The difference between this comparative example and the example is that in step (4), the beam current density I b is 25 mA and scanned 10 times, and the remaining process steps and parameter settings are the same as those in the example.

[0045] Comparative Example 2-3

[0046] The difference between this comparative example and the example is that in step (4), the beam current density I b is 35 mA and scanned 2 times, and the remaining process steps and parameter settings are the same as those in the example.

[0047] Comparative Example 2-4

[0048] The difference between this comparative example and the example is that in step (4), the beam current density I b is 35 mA and scanned 8 times, and the remaining process steps and parameter settings are the same as those in the example.

[0049] Comparative Example 2-5

[0050] The difference between this comparative example and the example is that in step (4), the beam current density Ib is 45 mA, and it is scanned twice. The remaining process steps and parameter settings are the same as those in the embodiment.

[0051] Analyze the microstructure morphology and mechanical properties of the nickel-aluminum bronze alloy cladding layers obtained in the examples and comparative examples.

[0052] (1) The microstructure morphologies of the nickel-aluminum bronze cladding layers prepared in the examples and Comparative Example 1 are as Figure 1 shown. It can be seen from the figure that the nickel-aluminum bronze cladding layer obtained in the example is composed of α phase and κ phase, without β' phase, and fine κ phase particles are dispersed in the α phase matrix. The nickel-aluminum bronze cladding layer obtained in Comparative Example 1 contains more β' phase. The cyclic scanning in the example effectively promotes the decomposition of β' phase into α and κ phases, and makes the supersaturated alloying elements precipitate to form fine and dense κ phase particles. The microstructure of the example is beneficial to obtaining high strength and high hardness.

[0053] (2) The tensile stress-strain curves of the nickel-aluminum bronze cladding layers prepared in the examples and Comparative Example 1 are as Figure 2 shown. It can be seen from the figure that the yield strength of the example is 512 MPa and the tensile strength is 817 MPa. The yield strength of Comparative Example 1 is 464 MPa and the tensile strength is 762 MPa. By comparison, it can be known that the nickel-aluminum bronze cladding layer obtained in the example has higher strength.

[0054] (3) The hardness comparison of the nickel-aluminum bronze cladding layers prepared in the examples and Comparative Example 1 is as Figure 3 shown. It can be seen from the figure that the hardness of the example is 238 HV 0.5 , and the hardness of the comparative example is 220 HV 0.5 . By comparison, it can be known that the alloy obtained in the example has higher hardness.

[0055] In summary, the comparison between the example and Comparative Example 1 shows that the content of the present invention can effectively improve the performance of the cladding layer. The yield strength is increased by about 10.1%; the tensile strength is increased by about 7.1%; the hardness is increased by about 8.2%.

[0056] (4) The microstructure morphologies of the nickel-aluminum bronze cladding layers prepared in Comparative Examples 2-1 to 2-5 are as Figure 4 shown, where (a) to (e) correspond to Comparative Examples 2-1 to 2-5 in sequence. It can be seen from the figure that the nickel-aluminum bronze cladding layer obtained in Comparative Example 2-1 contains more β' phase, which is similar to Comparative Example 1. That is, the beam current density I bis 25 mA, and scanning 5 times cannot or does not significantly change the microstructure of the cladding layer. In the nickel-aluminum bronze cladding layer obtained in Comparative Example 2-2, the β' phase decomposes into α and κ phases, but fine and dense κ-phase particles are not precipitated. In the nickel-aluminum bronze cladding layer obtained in Comparative Example 2-3, the β' phase decomposes into α and κ phases, and κ-phase particles are precipitated, but the κ-phase particles are not as dense as those in the Examples. In the nickel-aluminum bronze cladding layer obtained in Comparative Example 2-4, the κ phase aggregates and grows to form larger particles. In Comparative Example 2-5, due to the excessive beam current density during cyclic scanning, more remelting occurs during the in-situ heat treatment of the prepared cladding layer, and the melting depth is about 2.1 mm. The microstructure of Comparative Example 2-5 is shown in Figure (e). Due to the remelting of the cladding layer, its microstructure is similar to that of the Examples, but the size of the microstructure is relatively coarser. Excessive remelting of the cladding layer will result in a larger machining allowance, which is not conducive to restoring the final dimensions of the parts. Excessive remelting will also result in a large amount of heat input, consuming energy while affecting the microstructure and properties of the part base material. Therefore, the beam current density of 45 mA used in Comparative Example 2-5 cannot be used for in-situ heat treatment. Compared with the cladding layers in Comparative Examples 2-1 to 2-5, the microstructure of the Examples is more conducive to obtaining high strength and high hardness.

[0057] (5) The hardness comparison of the nickel-aluminum bronze cladding layers prepared in the Examples and Comparative Examples 2-1 to 2-5 is as Figure 5 shown. It can be seen from the figure that the hardness of the Examples is 238.14 ± 3.33 HV 0.5 , the hardness of Comparative Example 2-1 is 217.28 ± 1.23 HV 0.5 , the hardness of Comparative Example 2-2 is 213.64 ± 2.79 HV 0.5 , the hardness of Comparative Example 2-3 is 229.33 ± 1.56 HV 0.5 , the hardness of Comparative Example 2-4 is 223.61 ± 2.36 HV 0.5 , the hardness of Comparative Example 2-5 is 192.46 ± 2.84 HV 0.5 . By comparison, it can be known that the alloy obtained in the Examples has higher hardness.

[0058] The above are only the preferred embodiments of the present invention. In view of the fact that those skilled in the art to which the present invention pertains can make appropriate changes and modifications to the above-mentioned embodiments, therefore, the present invention is not limited to the specific embodiments described above, and some modifications and changes to the present invention should also fall within the protection scope of the claims of the present invention.

Claims

1. An in-situ heat treatment method for a nickel-aluminum bronze cladding layer, characterized in that, Including: (1) Prepare a cladding layer on a nickel-aluminum bronze alloy, leaving a machining allowance; (2) Perform in-situ heat treatment on the cladding layer using an electron beam; (3) After the in-situ treatment is completed, cool to room temperature and remove the machining allowance.

2. The method according to claim 1, characterized in that, (1) The nickel-aluminum bronze alloy in (1) is a C95800 nickel-aluminum bronze plate, and the material of the cladding layer or repair layer is an SCu6328 nickel-aluminum bronze alloy.

3. The method according to claim 2, characterized in that, (1) Use methods such as surfacing, electro-spark deposition, laser direct energy deposition, arc additive manufacturing, and electron beam wire deposition to prepare the cladding layer.

4. The method according to claim 3, wherein (1) Use the electron beam wire deposition method to prepare the cladding layer.

5. The method according to claim 4, wherein The process parameters for preparing the cladding layer are as follows: the vacuum degree of the vacuum chamber is 7×10 -2 Pa, the acceleration voltage U is 50 - 70 kV, and the focusing current I f is 1000 - 1050 mA, the wire feeding speed V feed is 2 - 3 m / min, the printing speed V print is 500 - 700 mm / min, and the beam current density I b is 50 - 60 mA.

6. The method according to claim 5, characterized in that The process parameters for preparing the cladding layer are as follows: the vacuum degree of the vacuum chamber is 7×10 -2 Pa, the acceleration voltage U is 60 kV, and the focusing current I f is 1030 mA, the wire feeding speed V feed is 2.4 m / min, the printing speed V print is 600 mm / min, and the beam current density I b is 55 mA.

7. The method according to claim 1, characterized in that, (2) The process parameters of the electron beam in-situ heat treatment cladding layer are as follows: the vacuum degree of the vacuum chamber is 7×10 -2 Pa, the acceleration voltage U is 50 - 70 kV, the focusing current I f is 1050 - 1100 mA, the beam current density I b is 30 - 40 mA, the scanning speed V is 500 - 700 mm / min, the electron beam oscillates circularly, the circular diameter is 3 - 5 mm, the oscillation frequency is 300 Hz, and it scans 3 - 6 times in a cycle.

8. The method according to claim 7, characterized in that, (2) The process parameters of the electron beam in-situ heat treatment cladding layer are as follows: the vacuum degree of the vacuum chamber is 7×10 -2 Pa, the acceleration voltage U is 60 kV, and the focusing current I f is 1080 mA, the beam current density I b is 35 mA, the scanning speed V is 600 mm / min, the electron beam oscillates in a ring, the ring diameter is 4 mm, the oscillation frequency is 300 Hz, and it scans back and forth 5 times.

9. Use of the in-situ heat treatment method for the nickel-aluminum bronze cladding layer according to any one of claims 1 to 8, characterized in that, For improving the surface properties of nickel-aluminum bronze components.

10. The nickel-aluminum bronze cladding layer after being treated by the in-situ heat treatment method of the nickel-aluminum bronze cladding layer described in any one of claims 1 to 8, characterized in that, Yield strength 511.19 ± 6.053 MPa, tensile strength 816.43 ± 12.328 MPa, hardness 238.14 ± 3.33 HV 0.5 .

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