Preparation method for improving surface performance of high-damping MnCu alloy

Abstract

The invention discloses a preparation method for improving the surface performance of a high-damping MnCu alloy, and relates to the technical field of surface treatment of metal alloys. According to the preparation method, a laser cladding technology is adopted for preparing a FeCoCrNiMn high-entropy alloy coating on the surface of a high-damping MnCu alloy matrix; and then a high-current pulsed electron beam technology is adopted for conducting surface alloying and element homogenization treatment on the FeCoCrNiMn high-entropy alloy coating obtained after laser cladding, so that the surface abrasion resistance of the MnCu alloy is improved, and meanwhile the high damping characteristic of the MnCu alloy is guaranteed.

Description

Technical Field

[0001] This application relates to the field of surface treatment technology for metal alloys, and in particular to a method for preparing high-damping MnCu alloys with improved surface properties. Background Technology

[0002] High-damping MnCu alloys are widely used in precision instruments, aerospace, and automotive manufacturing due to their excellent vibration damping performance. However, MnCu alloys have poor mechanical properties, making it difficult to meet the service performance requirements in complex environments. They are prone to severe wear and even failure when operating under harsh conditions such as high temperature and high pressure.

[0003] Laser cladding technology refers to a process in which a selected coating material is placed on the surface of a substrate, and then irradiated with a laser to melt both the coating material and a thin layer on the substrate surface simultaneously. This melted material then rapidly solidifies, forming a surface coating with extremely low dilution and a metallurgical bond to the substrate material, thus significantly improving the wear resistance of the substrate surface. Laser cladding technology has significant application potential and a broad prospect due to its advantages of low cost, short cycle time, high cleanliness, and minimal deformation. However, laser cladding technology still faces some serious technical challenges, such as surface roughness and cracking.

[0004] High-damping MnCu alloys require manganese-rich microregions to ensure their high damping characteristics. These microregions can be formed through the segregation of Mn elements. Due to the high thermal energy of laser cladding technology, the substrate area near the cladding layer cools slowly, making it prone to atomic diffusion. This reduces the number of manganese-rich microregions and lowers the damping characteristics of high-damping MnCu alloys. Summary of the Invention

[0005] In view of this, this application provides a method for preparing a high-damping MnCu alloy with improved surface properties. The method involves preparing a FeCoCrNiMn high-entropy alloy coating on the surface of a high-damping MnCu alloy substrate using laser cladding technology, and then performing surface alloying and element homogenization treatment on the laser-clad FeCoCrNiMn high-entropy alloy coating using high-current pulsed electron beam technology. This improves the surface wear resistance of the MnCu alloy while ensuring its high damping characteristics.

[0006] The specific technical solution adopted is as follows: A method for preparing high-damping MnCu alloy with improved surface properties includes the following steps: S1. FeCoCrNiMn high-entropy alloy powder is clad onto the surface of a high-damping MnCu alloy substrate using laser cladding technology to obtain a high-entropy alloy coating; the high-entropy alloy coating is an FeCoCrNiMn coating with a thickness of 0.3mm~0.6mm; S2. The high-entropy alloy coating is subjected to high-current pulsed electron beam irradiation alloying treatment.

[0007] Preferably, in step S1, FeCoCrNiMn high-entropy alloy powder with an equiatomic ratio is used as the cladding material.

[0008] More preferably, the FeCoCrNiMn high-entropy alloy powder is a spherical powder of elemental Fe, Co, Cr, Ni, and Mn with a particle size of 45~150 μm and a purity of greater than or equal to 99.9%.

[0009] Preferably, the laser cladding process parameters are as follows: laser power of 1000~2000W, scanning speed of 10~20mm / s, spot diameter of 4mm, overlap rate of 40~60%, powder feeding rate under the influence of carrier gas of 200~400mg / s, and protective gas argon flow rate of 10~20L / min; the argon pressure is 0.5~1MPa.

[0010] Preferably, the process parameters for the high-current pulsed electron beam irradiation are: electron beam energy of 27 eV and energy density of 4~6 J / cm³. 2 The pulse width is 1.5 μs, the target distance is 150 mm to 200 mm, and the vacuum degree P ≤ 5 × 10⁻⁵. -3 Pa, irradiation times are 20 to 40 times.

[0011] Preferably, before laser cladding the high-damping MnCu alloy substrate, the substrate surface is ground, polished, cleaned, and preheated. The preheating treatment can reduce coating cracking caused by stress due to the difference in thermal expansion between the substrate and the coating material.

[0012] Preferably, in order to ensure the flowability of the high-entropy alloy powder, the process also includes cleaning and drying the FeCoCrNiMn high-entropy alloy powder.

[0013] Preferably, before irradiating the high-entropy alloy coating with a high-current pulsed electron beam, the high-entropy alloy coating is polished to remove abrasive and oil stains from the coating surface, thereby obtaining a smooth surface.

[0014] Effective effects: 1) A high-entropy FeCoCrNiMn alloy coating was prepared on the surface of a high-damping MnCu alloy substrate using laser cladding technology. Then, the surface alloying and element homogenization treatment of the laser-clad FeCoCrNiMn high-entropy alloy coating was carried out using high-current pulsed electron beam technology, thereby improving the surface wear resistance of the high-damping MnCu alloy and ensuring the high damping characteristics of the high-damping MnCu alloy.

[0015] 2) The hardness of traditional cast MnCu alloy is only 150~170HV, while the surface hardness of MnCu alloy coated with high-entropy FeCoCrNiMn alloy by laser cladding is 220HV. The hardness of MnCu alloy coated with high-entropy FeCoCrNiMn alloy by laser cladding and then irradiated with high-current pulsed electron beam is 243HV. Attached Figure Description

[0016] Figure 1 These are surface hardness diagrams for Example 1, Comparative Example 1, and Comparative Example 2.

[0017] Figure 2 These are surface friction and wear curves for Example 1, Comparative Example 1, and Comparative Example 2.

[0018] Figure 3 These are three-dimensional surface topographic images of Example 2 and Comparative Example 3. Detailed Implementation

[0019] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described in this application are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0020] Example 1 This embodiment proposes a method for preparing high-damping MnCu alloy with improved surface properties, comprising the following steps: (1) Grind and polish the surface of the high-damping alloy (MnCu alloy) substrate, and use acetone for ultrasonic cleaning to remove oil stains. Then, place the manganese copper high-damping alloy (MnCu alloy) in a muffle furnace and preheat it to 400°C. Under the condition of ensuring that no phase transformation occurs, reduce the coating cracking caused by stress due to the thermal expansion difference between the substrate and the coating material.

[0021] (2) The FeCoCrNiMn high-entropy alloy powder was cleaned in acetone under ultrasonic treatment to remove surface impurities and grease. Then, the high-entropy alloy powder was dried in a vacuum drying oven at 80℃~100℃ for 3h and kept for 12h to obtain powder with better flowability.

[0022] (3) Using laser cladding technology, the above FeCoCrNiMn powder is fed into the powder tank. The laser cladding process parameters are set as follows: laser power (P) is 1000w, scanning speed (V) is 10mm / s, spot diameter is 4mm, overlap rate is 50%, and powder feeding rate under the influence of carrier gas is 200mg / s.

[0023] (4) The prepared FeCoCrNiMn high-entropy alloy coating is polished to remove the surface oxide layer and unmelted particles, and then ultrasonically cleaned with acetone to obtain a clean FeCoCrNiMn high-entropy alloy coating.

[0024] (5) Next, the prepared laser cladding coating was irradiated using high-current pulsed electron beam technology. The process parameters for high-current pulsed electron beam irradiation were: electron beam energy of 27 eV and energy density of 4 J / cm³. 2 The pulse width is 1.5 μs, the target distance is 200 mm, and the vacuum degree P ≤ 5 × 10⁻⁶. -3 Pa, irradiation times 20 times.

[0025] (6) After cleaning the prepared FeCoCrNiMn high-entropy alloy coating in acetone under ultrasonic waves, a high-damping MnCu alloy can be obtained.

[0026] Comparative Example 1 The surface of the high-damping alloy (MnCu alloy) substrate was ground and polished, and then ultrasonically cleaned with acetone to remove oil stains.

[0027] Comparative Example 2 A surface treatment method for high-damping MnCu alloys includes the following steps: (1) Grind and polish the surface of the high damping alloy (MnCu alloy) substrate and use acetone for ultrasonic cleaning to remove oil stains. Then, place the manganese copper damping alloy in a muffle furnace and preheat it to 400°C. Under the condition of ensuring that no phase transformation occurs, reduce the coating cracking caused by stress due to the thermal expansion difference between the substrate and the coating material.

[0028] (2) The FeCoCrNiMn high-entropy alloy powder was cleaned in acetone under ultrasonic treatment to remove surface impurities and grease. Then, the high-entropy alloy powder was dried in a vacuum drying oven at 80℃~100℃ for 3h and kept for 12h to obtain powder with better flowability.

[0029] (3) Using laser cladding technology, the above FeCoCrNiMn powder is fed into the powder tank. The laser cladding process parameters are set as follows: laser power (P) is 1000w, scanning speed (V) is 10mm / s, spot diameter is 4mm, overlap rate is 50%, and powder feeding rate under the influence of carrier gas is 200mg / s.

[0030] (4) Polish the prepared laser cladding coating to remove the surface oxide layer and unmelted particles, and then use acetone for ultrasonic cleaning to obtain a clean coating.

[0031] Test method: 1) Vickers hardness test The Vickers hardness test adopts the national standard GB / T4340 Vickers hardness test for metallic materials.

[0032] 2) Friction performance test A disc-type friction and wear testing machine was used, with a maximum test force of 200 N. Due to the low hardness of the alloy, to ensure that the friction balls did not damage the sample surface, the test force was set to 10 N, and the friction duration was 800 s. Measurements were repeated three times in different areas of each group of samples, and the average value was selected. The wear rate of the sample was defined as:

[0033] Where: W is the wear rate (m 3 / N·m); v is the wear volume (mm). 3 f is the load (N); l is the total wear distance. The width and depth of the wear marks on the worn surface of the specimen after the friction and wear test were measured using a laser confocal microscope.

[0034] The coefficient of friction of the sample is defined as:

[0035] In the formula: μ is the coefficient of friction; m is the frictional torque (N·m); f is the load (N); and r is the sliding radius (mm).

[0036] 2) Damping characteristic test The test was conducted according to GB / T18258-2000 "Test Method for Damping Performance of Damping Materials", and the loss factor tanδ was used to represent it. The larger the loss factor, the better the damping effect of the alloy.

[0037] Figure 1 The surface hardness diagrams for Example 1, Comparative Example 1, and Comparative Example 2 show that the surface hardness of the FeCoCrNiMn high-entropy alloy coating after laser cladding is 220 HV, which is much greater than the surface hardness of the MnCu alloy substrate. Subsequent high-current pulsed electron beam experiments were performed on the coating with the same laser cladding experimental parameters, and the surface hardness was 243 HV. This indicates that the surface hardness of the alloy is improved after laser cladding, and the surface hardness is significantly improved after high-current pulsed electron beam treatment.

[0038] Figure 2 The surface friction coefficient diagrams for Examples 1, 1 (Comparative Example), and 2 show that the friction coefficient of the coating after laser cladding is approximately 0.25, while the friction coefficient of the original substrate is approximately 0.55. Subsequent high-current pulsed electron beam experiments were conducted on the coatings with the same laser cladding experimental parameters for 20 cycles, resulting in a significant reduction in friction coefficient to approximately 0.16. This indicates that the wear resistance of the alloy is improved after laser cladding, and the wear resistance of the alloy is significantly enhanced after high-current pulsed electron beam treatment.

[0039] The MnCu alloy used in this application has a loss factor of 0.018 at 60℃ (generally, a loss factor greater than 0.01 is considered to have good damping characteristics). After processing with laser cladding and high-current pulsed electron beam, the cladding layer was cut off by wire cutting, and its loss factor was tested to be 0.015 at 60℃, maintaining good damping characteristics.

[0040] Example 2 This embodiment proposes a method for preparing high-damping MnCu alloy with improved surface properties, comprising the following steps: (1) Grind and polish the surface of the high-damping alloy (MnCu alloy) substrate, and use acetone for ultrasonic cleaning to remove oil stains. Then, place the high-damping alloy (MnCu alloy) in a muffle furnace and preheat it to 400°C. Under the condition of ensuring that no phase transformation occurs, reduce the coating cracking caused by stress due to the thermal expansion difference between the substrate and the coating material.

[0041] (2) The FeCoCrNiMn powder was cleaned in acetone under ultrasonic treatment to remove surface impurities and grease. Then, the FeCoCrNiMn powder was dried in a vacuum drying oven at 80℃~100℃ for 3h and kept for 12h to obtain a powder with better flowability.

[0042] (3) Using laser cladding technology, the above FeCoCrNiMn powder is fed into the powder tank. The laser cladding process parameters are set as follows: laser power (P) is 1500w, scanning speed (V) is 12mm / s, spot diameter is 4mm, overlap rate is 50%, and the powder feeding amount under the influence of the carrier gas is 300mg / s.

[0043] (4) Polish the prepared laser cladding coating to remove the surface oxide layer and unmelted particles, and then use acetone for ultrasonic cleaning to obtain a clean coating.

[0044] (5) Next, the prepared laser cladding coating was irradiated using high-current pulsed electron beam technology. The process parameters for high-current pulsed electron beam irradiation were: electron beam energy of 27 eV and energy density of 6 J / cm³. 2 The pulse width is 1.5 μs, the target distance is 150 mm, and the vacuum degree P ≤ 5 × 10⁻⁶. -3 Pa, irradiation times: 25.

[0045] (6) After cleaning the prepared coating in acetone under ultrasonic waves, a high-damping MnCu alloy can be obtained.

[0046] Comparative Example 3 (1) Grind and polish the surface of the high-damping alloy (MnCu alloy) substrate, and use acetone for ultrasonic cleaning to remove oil stains. Then, place the high-damping alloy (MnCu alloy) in a muffle furnace and preheat it to 400°C. Under the condition of ensuring that no phase transformation occurs, reduce the coating cracking caused by stress due to the thermal expansion difference between the substrate and the coating material.

[0047] (2) The FeCoCrNiMn powder was cleaned in acetone under ultrasonic treatment to remove surface impurities and grease. Then, the FeCoCrNiMn powder was dried in a vacuum drying oven at 80℃~100℃ for 3h and kept for 12h to obtain a powder with better flowability.

[0048] (3) Using laser cladding technology, the above FeCoCrNiMn powder is fed into the powder tank. The laser cladding process parameters are set as follows: laser power (P) is 1500w, scanning speed (V) is 12mm / s, spot diameter is 4mm, overlap rate is 50%, and the powder feeding amount under the influence of the carrier gas is 300mg / s.

[0049] (4) The prepared laser cladding coating is polished to remove the surface oxide layer and unfinished particles, and then ultrasonically cleaned with acetone to obtain a clean coating.

[0050] (5) Next, the prepared laser cladding coating was irradiated using high-current pulsed electron beam technology. The process parameters for high-current pulsed electron beam irradiation were: electron beam energy of 27 eV and energy density of 6 J / cm³. 2 The pulse width is 1.5 μs, the target distance is 150 mm, and the vacuum degree P ≤ 5 × 10⁻⁶. -3 Pa, irradiation times: 30.

[0051] (6) After cleaning the prepared coating in acetone under ultrasonic waves, a high-damping MnCu alloy can be obtained.

[0052] Figure 3 Examples 2 and 3 (Comparative Example 3) show three-dimensional morphology images. Using the same laser cladding experimental parameters but with different numbers of high-current pulsed electron beam (HCP) experiments, the results indicate that the deep blue pits are molten pits caused by HCP irradiation. As the number of irradiations increases to 30, the number and depth of the deep blue pits decrease, while the surface smoothness of the sample increases. This is because after multiple HCP irradiations, the surface molten pits fuse together through repeated remelting, and impurities are removed along with the eruption of the molten pits, resulting in a decrease in molten pit density, an increase in surface smoothness, and a denser alloy on the material surface.

[0053] The high-damping MnCu alloy described in this application has a Mn mass content of more than 70%, including but not limited to M2052 manganese copper alloy.

Claims

1. A method for preparing high-damping MnCu alloy with improved surface properties, characterized in that: Includes the following steps: S1. FeCoCrNiMn high-entropy alloy powder is clad onto the surface of a high-damping MnCu alloy substrate using laser cladding technology to obtain a high-entropy alloy coating; the high-entropy alloy coating is an FeCoCrNiMn coating with a thickness of 0.3mm~0.6mm; S2. The high-entropy alloy coating is subjected to high-current pulsed electron beam irradiation alloying treatment.

2. The preparation method for improving the surface properties of high-damping MnCu alloy according to claim 1, characterized in that: In step S1, FeCoCrNiMn high-entropy alloy powder with an equiatomic ratio is used as the cladding material.

3. The preparation method for improving the surface properties of high-damping MnCu alloy according to claim 2, characterized in that: The FeCoCrNiMn high-entropy alloy powder is a spherical powder of elemental Fe, Co, Cr, Ni, and Mn with a particle size of 45~150 μm and a purity of ≥99.9%.

4. The preparation method for improving the surface properties of high-damping MnCu alloy according to claim 1, characterized in that: The laser cladding process parameters are as follows: laser power of 1000~2000w, scanning speed of 10~20mm / s, spot diameter of 4mm, overlap rate of 40~60%, powder feeding rate under the influence of carrier gas of 200~400mg / s, protective gas argon flow rate of 10~20L / min; and argon pressure of 0.5~1Mpa.

5. The preparation method for improving the surface properties of high-damping MnCu alloy according to claim 1, characterized in that: The process parameters for the high-current pulsed electron beam irradiation are: electron beam energy of 27 eV and energy density of 4~6 J / cm³. 2 The pulse width is 1.5 μs, the target distance is 150 mm to 200 mm, and the vacuum degree P ≤ 5 × 10⁻⁵. -3 Pa, irradiation times are 20 to 40 times.

6. The preparation method for improving the surface properties of high-damping MnCu alloy according to claim 1, characterized in that: Before laser cladding the high-damping MnCu alloy substrate, the substrate surface is ground, polished, cleaned, and preheated. The preheating treatment can reduce coating cracking caused by stress due to the difference in thermal expansion between the substrate and the coating material.

7. The preparation method for improving the surface properties of high-damping MnCu alloy according to claim 1, characterized in that: Before laser cladding, the FeCoCrNiMn high-entropy alloy powder is cleaned and dried.

8. The preparation method for improving the surface properties of high-damping MnCu alloy according to claim 1, characterized in that: Before subjecting the high-entropy alloy coating to high-current pulsed electron beam irradiation, the coating is first polished to remove abrasive and oil stains from the surface, resulting in a smooth surface.

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