A device and method for strengthening aero-engine blades with pulsed magnetic fields

Abstract

This application provides a device for strengthening aero-engine blades with a pulsed magnetic field. The device includes: a magnet collector disposed in a discharge circuit for amplifying the current in the discharge circuit; an aero-engine blade disposed in the middle of the magnet collector; an insulating layer disposed between the magnet collector and the aero-engine blade; the insulating layer serves to prevent current conduction between the magnet collector and the aero-engine blade; and a carbon fiber composite material clamping sleeve disposed around the magnet collector. This application also provides a method for strengthening aero-engine blades with a pulsed magnetic field. This invention addresses the irregular shape and curved surface characteristics of aero-engine blades by employing a magnet collector that conforms to the shape on both sides and is closely fitted to the blade to be strengthened, utilizing the near-source effect of a pulsed magnetic field to strengthen its surface.

Description

Technical Field

[0001] This application belongs to the field of surface strengthening technology of metallic materials, specifically relating to a device and method for strengthening aero-engine blades with a pulsed magnetic field. Background Technology

[0002] As a key core component of aero-engines, blades play an important role in improving the overall performance of the engine. Therefore, research on surface strengthening technology for aero-engine blades is particularly important.

[0003] Traditional surface treatment methods, such as laser shock, ion implantation, and shot peening, have achieved the goal of enhancing the surface performance of engine blades. However, some technologies may weaken other properties while improving certain blade properties. Other technologies still have certain inherent limitations due to process reasons, resulting in micro-deformation of the blade surface.

[0004] In addition, the irregular shape of engine blades makes it easy for many surface modification technologies to produce uneven processing during implementation.

[0005] Pulsed magnetic field technology, as a high-energy-density electromagnetic process, is an emerging method for material preparation or modification. It is achieved through the instantaneous discharge of high voltage and large capacitance in a discharge circuit. The material being processed in the circuit is affected by the excitation current, and its surface can also generate a strong induced current, i.e., the skin effect.

[0006] According to the formula for calculating skin depth As can be seen from (ω angular frequency; μ permeability; σ electrical conductivity), the electrical conductivity of a material is a key parameter affecting the enhancement effect of the pulsed magnetic field. However, materials commonly used in aero-engines, such as titanium alloys, have very low electrical conductivity, 5.85 × 10⁻⁶ at room temperature. 5 S / m, which is only 1 / 100 of the conductivity of copper, and the same problem exists in materials such as titanium-aluminum alloys and high-temperature alloys.

[0007] This results in the induced current being unable to be concentrated on the material surface when the pulsed magnetic field is applied to such materials, or even distributed throughout the entire material. The material cannot form a pressure difference under the influence of the magnetic field force, and therefore cannot achieve the strengthening effect. Summary of the Invention

[0008] To address the aforementioned technical problems, in a first aspect, this application provides a device for strengthening aero-engine blades with a pulsed magnetic field, the device comprising:

[0009] A magnet collector device is installed in the discharge circuit to amplify the current in the discharge circuit. A gap should be left between the magnet collector device and the discharge circuit.

[0010] An aero-engine blade is positioned in the middle of the magnet collector, wherein the aero-engine blade should be in close contact with the magnet collector;

[0011] An insulating layer is disposed between the magnet collector and the aero-engine blade; the insulating layer has the function of preventing current conduction in the magnet collector and the aero-engine blade;

[0012] A carbon fiber composite material clamping barrel is disposed around the magnet collector; wherein, the carbon fiber composite material clamping barrel is the same length as the magnet collector and is tightly fitted around the magnet collector; the carbon fiber composite material clamping barrel has the function of restricting the movement of the magnet collector and providing insulation.

[0013] Preferably, the magnet collector comprises:

[0014] Episode 1: Porcelain;

[0015] The second magnet collector is symmetrically arranged in the discharge circuit with the first magnet collector; wherein the aero-engine blade is arranged between the first magnet collector and the second magnet collector and is in close contact with the first magnet collector and the second magnet collector.

[0016] Preferably, the first magnet collector has a semi-circular structure, with the outer side having the same shape as the solenoid in the discharge circuit and the inner side having the same shape as one side of the blade to be strengthened.

[0017] Preferably, the second magnetizer has a semi-circular structure, with the outer side having the same shape as the solenoid in the discharge circuit and the inner side having the same shape as the other side of the blade to be strengthened.

[0018] Preferably, the insulating layer is disposed between the first magnet collector, the second magnet collector and the aero-engine blade, and has the function of preventing current from flowing between the magnet collector and the aero-engine blade.

[0019] Preferably, the carbon fiber composite material hoop is tightly fitted around the magnet collector, which has the function of restricting the movement of the magnet collector and providing insulation.

[0020] Preferably, the device further includes:

[0021] Pulse magnetic field generator

[0022] The pulsed magnetic field generator will form a discharge circuit, and the discharge current in the discharge circuit should be a high-frequency and high-energy current, so that the induced current formed on the surface of the aero-engine blade is more concentrated, which is more conducive to the realization of the surface strengthening effect of the aero-engine blade.

[0023] Secondly, this application also provides a method for strengthening aero-engine blades with a pulsed magnetic field, the method comprising:

[0024] Insert the engine blade to be strengthened into the middle of the yellow wax paper and embed it in the central recess of the magnet.

[0025] The assembly of the parts is completed by merging the first and second sets of magnetic components and then putting a carbon fiber composite material hoop on the outer layer.

[0026] Connect the conductive rod leading out of the solenoid to the discharge terminal of the high-voltage pulse power supply, and tighten the connection with bolts;

[0027] Charge the capacitor to 10kV, then turn on the high-voltage discharge switch to discharge the circuit, thus completing one impulse process.

[0028] This application has the following beneficial technical effects:

[0029] This invention addresses the unique shape and curved surface characteristics of aero-engine blades by employing a magnetic collector that conforms to the shape of both sides and fits closely to the blade to be strengthened. It utilizes the near-source effect of pulsed magnetic field to strengthen the surface of the blade, solving the problem that aero-engine blade materials have low electrical conductivity and are difficult to strengthen with pulsed magnetic field, and making the strengthening effect of aero-engine blades more uniform. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the overall circuit provided in an embodiment of the present invention;

[0031] Figure 2 A cross-sectional view of the device provided in an embodiment of the present invention;

[0032] Figure 3 This is a schematic diagram of the device structure provided in an embodiment of the present invention;

[0033] Figure 4 This is a comparison chart of Vickers hardness results when the preferred embodiment of the present invention is applied to TC4 material;

[0034] Wherein: 1-magnet collector; 2-insulating layer; 3-blade; 4-hoop barrel. Detailed Implementation

[0035] This invention discloses a method and apparatus for strengthening aero-engine blades using pulsed magnetic fields. Addressing the irregular and curved surface characteristics of aero-engine blades, a magnetic collector with both sides conforming to the shape of the blade to be strengthened is employed. The surface is strengthened using the near-source effect of the pulsed magnetic field. The method includes: a magnetic field concentrating fixture, i.e., the magnetic collector, is configured within a pulsed magnetic field generator; the part of the engine blade to be strengthened is placed at the center of the magnetic collector, wherein the shape of the center of the magnetic collector is consistent with the shape of the blade and is closely fitted; an insulating layer is placed between the magnetic collector and the blade to prevent current conduction; and a carbon fiber composite material clamp is used for external restraint. When the circuit discharges, an induced current is generated on the surface of the magnetic collector in the circuit, which is also the excitation current of the blade to be strengthened. The blade at the center of the magnetic collector also generates a strong induced current due to the near-source effect. The reverse current generated between the magnetic collector and the blade surface can create a magnetic pressure of up to GPa, acting on the surface of the blade to be strengthened. Through the above method and apparatus, the surface strengthening of irregularly shaped and curved aero-engine blades using pulsed magnetic fields is achieved.

[0036] Please see Figure 1-4 This invention proposes a method and apparatus for strengthening aero-engine blades with pulsed magnetic fields. The method is based on the pulsed magnetic field near-source effect. When the part to be strengthened is closely attached to the excitation current generating device, it can play a very strong magnetic field force amplification role, i.e., the pulsed magnetic field near-source effect. When the distance between the two surfaces is close enough, the magnetic field force amplification effect can compensate for the disadvantage of the low conductivity of the material leading to the non-concentrated distribution of induced current.

[0037] In this embodiment of the application, the apparatus includes:

[0038] A magnet collector device is installed in the discharge circuit to amplify the current in the discharge circuit. A gap should be left between the magnet collector device and the discharge circuit.

[0039] An aero-engine blade is positioned in the middle of the magnet collector, wherein the aero-engine blade should be in close contact with the magnet collector.

[0040] An insulating layer is disposed between the magnet collector and the aero-engine blade; the insulating layer has the function of preventing current conduction in the magnet collector and the aero-engine blade;

[0041] A carbon fiber composite material clamping barrel is disposed around the magnet collector; wherein, the carbon fiber composite material clamping barrel is the same length as the magnet collector and is tightly fitted around the magnet collector; the carbon fiber composite material clamping barrel has the function of restricting the movement of the magnet collector and providing insulation.

[0042] The magnet collector includes:

[0043] Episode 1: Porcelain;

[0044] The second magnet collector is symmetrically arranged in the discharge circuit with the first magnet collector; wherein the aero-engine blade is arranged between the first magnet collector and the second magnet collector and is in close contact with the first magnet collector and the second magnet collector.

[0045] The first magnet collector has a semi-circular structure, with its outer side having the same shape as the solenoid in the discharge circuit and its inner side having the same shape as one side of the blade to be strengthened; the second magnet collector has a semi-circular structure, with its outer side having the same shape as the solenoid in the discharge circuit and its inner side having the same shape as the other side of the blade to be strengthened.

[0046] The insulating layer should be as thin as possible while maintaining good insulation performance. The insulating layer is disposed between the first magnet collector, the second magnet collector, and the aero-engine blade, and serves to prevent current conduction between the magnet collector and the aero-engine blade.

[0047] The carbon fiber composite material clamping barrel should be as thin as possible. The carbon fiber composite material clamping barrel is tightly fitted around the magnet collector, serving to restrict the magnet collector's movement and provide insulation.

[0048] The device further includes:

[0049] Pulse magnetic field generator

[0050] The pulsed magnetic field generator will form a discharge circuit, and the discharge current in the discharge circuit should be a high-frequency and high-energy current, so that the induced current formed on the surface of the aero-engine blade is more concentrated, which is more conducive to the realization of the surface strengthening effect of the aero-engine blade.

[0051] The present invention has the following technical effects:

[0052] This invention addresses the unique shape and curved surface characteristics of aero-engine blades by employing a magnetic collector that conforms to the shape of both sides and fits closely to the blade to be strengthened. It utilizes the near-source effect of pulsed magnetic field to strengthen the surface of the blade, solving the problem that aero-engine blade materials have low electrical conductivity and are difficult to strengthen with pulsed magnetic field, and making the strengthening effect of aero-engine blades more uniform.

[0053] In other embodiments of this application, in conjunction with the appendix Figure 1-4 This invention provides a method and apparatus for strengthening aero-engine blades using a pulsed magnetic field. The method employs a high-voltage, large-capacitance magnetic field generator and a magnet collector to perform surface strengthening treatment on the aero-engine blades. The apparatus mainly consists of upper and lower magnet collectors and an insulating layer, as detailed below. Figure 2 As shown.

[0054] Please see Figure 1-3 One specific implementation of this invention is as follows:

[0055] 1. Tooling preparation

[0056] A solenoid is made by winding 30 turns of 3mm*5mm flat copper wire, with an inner diameter of 90mm and a length of 150mm. Magnetizers 1-1 and 1-2 are made of copper, 150mm long and 80mm in outer diameter. Inside, a frustum with an upper base radius of 10mm, a lower base radius of 35mm, and a height of 60mm is hollowed out at both the top and bottom. The shape of the hollowed-out core of the magnetizer matches the shape of the blade to be strengthened. Two layers of 0.02mm thick yellow wax paper are laid between the upper and lower magnetizers as an insulating layer. The magnetizers are wrapped with a 150mm long, 80mm inner diameter, and 3mm thick carbon fiber composite material hoop.

[0057] 2. Implementation Steps

[0058] (1) Insert the engine blade to be strengthened into the middle of the yellow wax paper and embed it in the central recess of the magnet;

[0059] (2) Combine the upper and lower magnetic components and put a carbon fiber composite material hoop on the outer layer to complete the parts assembly work;

[0060] (3) Connect the conductive rod leading out of the solenoid to the discharge terminal of the high voltage pulse power supply, and tighten the connection with bolts;

[0061] (4) Charge the capacitor to 10kV, then turn on the high voltage discharge switch to discharge the circuit to complete one impulse process;

[0062] (5) The impact voltage and number of impacts can be adjusted according to actual needs.

[0063] (6) Figure 4 The Vickers hardness test results of TC4 titanium alloy samples before and after impact with a pulsed magnetic field using this method and apparatus show that the maximum hardness of the sample after 20 impacts increased by 7.5% compared with the original hardness, confirming the effectiveness of this method and apparatus.

[0064] This invention discloses a method and apparatus for strengthening aero-engine blades with pulsed magnetic fields. In view of the irregular shape and curved surface of aero-engine blades, a magnetic collector with both sides conforming to the shape and closely attached to the blade to be strengthened is used to strengthen the surface by utilizing the near-source effect of pulsed magnetic fields.

[0065] Specifically, this includes: configuring a magnetic field concentration tool, namely a magnetic collector, inside the pulse magnetic field generator; placing the part of the engine blade to be strengthened at the center of the magnetic collector; the shape of the center position of the magnetic collector is consistent with the shape of the blade and fits tightly; placing an insulating layer between the magnetic collector and the blade to prevent current conduction; and wrapping the outside with a carbon fiber composite material hoop for restraint.

[0066] When the circuit discharges, an induced current is generated on the surface of the magnet collector in the circuit, which is also the excitation current of the blade to be strengthened. The blade at the center of the magnet collector, affected by the proximity effect, also generates a strong induced current on its surface. The reverse current generated between the magnet collector and the blade surface can create a magnetic pressure of up to GPa, acting on the surface of the blade to be strengthened. Through the above method and device, the surface strengthening of irregularly shaped and curved aero-engine blades using pulsed magnetic fields is achieved.

[0067] The magnet collectors in the circuit can be made of brass or other highly conductive materials. This method is based on the near-source effect of pulsed magnetic fields, with the magnetic field enhancement parts at the center of the magnet collectors on both sides closely attached to the surface of the blade to be strengthened.

[0068] This method is based on the near-source effect of pulsed magnetic fields, with the shape of the magnetic field enhancement region at the center of the magnet collectors on both sides varying according to the shape of the blade to be strengthened. An insulating layer is placed between the magnet collector and the blade to prevent current conduction. The blade to be strengthened can be made of low-conductivity materials such as titanium alloy, titanium-aluminum alloy, or high-temperature alloy. The carbon fiber composite hoop is the same length as the magnet collector and is tightly fitted around the magnet collector.

Claims

1. A device for strengthening aero-engine blades with a pulsed magnetic field, characterized in that, The device includes: A magnet collector device is installed in the discharge circuit to amplify the current in the discharge circuit. A gap should be left between the magnet collector device and the discharge circuit. An aero-engine blade is positioned in the middle of the magnet collector, wherein the aero-engine blade should be in close contact with the magnet collector; An insulating layer is disposed between the magnet collector and the aero-engine blade; the insulating layer has the function of preventing current conduction in the magnet collector and the aero-engine blade; A carbon fiber composite material clamping barrel is disposed around the magnet collector; wherein, the carbon fiber composite material clamping barrel is the same length as the magnet collector and is tightly fitted around the magnet collector; the carbon fiber composite material clamping barrel has the function of restricting the movement of the magnet collector and providing insulation; The magnet collector includes: Episode 1: Porcelain; The second magnetic collector is symmetrically arranged in the discharge circuit with the first magnetic collector; wherein the aero-engine blade is arranged between the first magnetic collector and the second magnetic collector and is in close contact with the first magnetic collector and the second magnetic collector; The first magnet collector has a semi-circular structure, with the outer side having the same shape as the solenoid in the discharge circuit and the inner side having the same shape as one side of the blade to be strengthened; the second magnet collector has a semi-circular structure, with the outer side having the same shape as the solenoid in the discharge circuit and the inner side having the same shape as the other side of the blade to be strengthened.

2. The apparatus according to claim 1, characterized in that, The insulating layer is disposed between the first magnet collector, the second magnet collector and the aero-engine blade, and has the function of preventing current from flowing between the magnet collector and the aero-engine blade.

3. The apparatus according to claim 1, characterized in that, The device further includes: Pulse magnetic field generator The pulsed magnetic field generator will form a discharge circuit, and the discharge current in the discharge circuit should be a high-frequency and high-energy current, so that the induced current formed on the surface of the aero-engine blade is more concentrated, which is more conducive to the realization of the surface strengthening effect of the aero-engine blade.

4. A method for strengthening aero-engine blades with a pulsed magnetic field, characterized in that, The method is applied to the apparatus as described in any one of claims 1-3, and the method comprises: Insert the engine blade to be strengthened into the middle of the yellow wax paper and embed it in the central recess of the magnet. The assembly of the parts is completed by merging the first and second sets of magnetic components and then covering the outer layer with a carbon fiber composite material hoop. Connect the conductive rod leading out of the solenoid to the discharge terminal of the high-voltage pulse power supply, and tighten the connection with bolts; Charge the capacitor to 10kV, then turn on the high-voltage discharge switch to discharge the circuit, thus completing one impulse process.

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