A method and auxiliary device for laser shock strengthening of corner edges

Abstract

This invention relates to a laser shock peening method for corner edges, comprising: processing an auxiliary device with the same outer contour as the corner according to the corner's digital model; selecting an absorption layer application step based on the length of the corner area to be strengthened, wherein the application step includes: first applying the absorption layer to the corner surface; placing the processed auxiliary device on the component corresponding to the corner, aligning the outer contour of the auxiliary device with the outer contour of the corner; and applying a clamping force to the auxiliary device; or, placing the processed auxiliary device on the component, aligning the outer contour of the auxiliary device with the outer contour of the corner; applying a clamping force to the auxiliary device; applying the absorption layer to the corner surface; spraying deionized water onto the outer surface of the absorption layer to form a deionized water constraint layer; and emitting a laser pulse toward the deionized water constraint layer to complete the strengthening of one corner position. The purpose is to solve the problem of strengthening the corner edges of components.

Description

Technical Field

[0001] This invention belongs to the field of advanced laser processing and laser application technology, and particularly relates to a method and auxiliary device for laser shock strengthening of corner edges. Background Technology

[0002] Laser shock peening (laser shot peening) technology utilizes nanosecond-level high-intensity pulsed laser light that penetrates a laser-transparent confinement medium. The laser is absorbed by an absorption layer on the metal surface, generating high-temperature, high-pressure plasma. This induces a strong shock wave, causing plastic deformation in the metal material and generating residual compressive stress on the surface and near the surface, thereby improving the fatigue performance of the metal structure. The specific process principle is as follows: A high-power-density (GW / cm²) short-pulse (ns) laser beam emitted from a laser passes through a transparent confinement layer and irradiates the energy-absorbing layer coated (or affixed) on the surface of the metal material. This vaporizes and ionizes the laser, forming a high-temperature, high-pressure plasma. The plasma continues to absorb energy, explodes, and induces a high-pressure shock wave. Under the confinement of the confinement layer, a strong shock wave propagates into the material. Because the peak pressure of the shock wave reaches the order of 10⁹ Pa, far exceeding the dynamic yield strength of the material, macroscopic plastic deformation occurs, inducing residual compressive stress on the material surface, thus improving the fatigue resistance of the component. It is widely used in aerospace and other fields.

[0003] Compared to traditional strengthening processes, laser shock peening is a non-contact process where the beam can reach any surface, offering high flexibility and the ability to strengthen complex curved surfaces such as holes, grooves, slots, teeth, and corners. It is particularly advantageous for strengthening corners and arc surfaces. However, when strengthening the edges of open, curved corner surfaces, two problems arise: first, the deionized water constraint layer required for the strengthening process cannot be placed at the corner edge due to the lack of support, thus affecting the strengthening effect; second, during corner strengthening, the shearing effect generated by the strong shock wave at the corner edge can easily damage the absorption layer, leading to ablation and affecting the strengthening effect. Summary of the Invention

[0004] This invention addresses the above-mentioned problems by proposing a laser shock peening method and auxiliary device for strengthening corner edges, with the aim of solving the problem of strengthening corner edges of components.

[0005] To achieve the above objectives, the present invention provides a method for laser shock strengthening of corner edges, comprising the following steps:

[0006] Based on the rotation angle model of the component, an auxiliary device with the same rotation angle outer contour as the component is manufactured;

[0007] Based on the length of the corner area to be strengthened of the component, a bonding step is selected to apply an absorbent layer to the surface of the corner area to be strengthened. The bonding step includes: bonding method one, firstly applying an absorbent layer to the surface of the corner to be strengthened, then placing the processed auxiliary device on the component corresponding to the corner to be strengthened, aligning the outer contour of the auxiliary device with the outer contour of the corner to be strengthened, and finally applying a pressing force to the auxiliary device; or bonding method two, firstly placing the processed auxiliary device on the component, aligning the outer contour of the auxiliary device with the outer contour of the corner to be strengthened of the component, then applying a pressing force to the auxiliary device, and finally applying an absorbent layer to the surface of the corner to be strengthened of the component.

[0008] After completing the above-mentioned bonding steps, deionized water is sprayed onto the outer surface of the absorbent layer to form a deionized water constraint layer.

[0009] A laser pulse is emitted toward the deionized water confinement layer to complete the reinforcement of a corner position to be reinforced.

[0010] Furthermore, before performing the bonding step, the corner surfaces of the component to be reinforced and the auxiliary devices are wiped clean with alcohol or acetone.

[0011] Furthermore, the absorbent layer applied to the corner surface to be reinforced is an adhesive tape with a certain degree of elasticity.

[0012] Furthermore, the tape is aluminum foil tape or PVC black tape.

[0013] Furthermore, in the first step of the application method, the length of the corner area to be reinforced does not exceed 30mm; in the second step of the application method, the length of the corner area to be reinforced exceeds 30mm.

[0014] Furthermore, in the first step of the application method, the height of the absorbent layer exceeds the edge of the corner to be reinforced by 3mm to 5mm. The excess part is folded and flattened along the edge using a special tool, so that the surface of the flattened absorbent layer is free of bubbles, wrinkles and bulges.

[0015] Furthermore, in the steps of the first and second application methods, an arc-shaped clamp is used to press the auxiliary device and the component together; wherein, the equivalent relationship between the pitch of the arc-shaped clamp and the clamping force is determined in advance using a pressure sensor, and the pitch of the arc-shaped clamp is adjusted according to the equivalent relationship to control the clamping force.

[0016] Furthermore, in the second application method, a special tool is used to flatten the applied absorbent layer so that the absorbent layer is tightly adhered to the surface of the corner to be reinforced and the surface of the auxiliary device, and the surface of the absorbent layer is free of obvious joint marks, bubbles, wrinkles and bulges.

[0017] Furthermore, in the application step, the clamping force applied to the auxiliary device satisfy:

[0018] ;

[0019] Wherein, As is the contact area of ​​the auxiliary device. The yield strength of the component material.

[0020] Furthermore, after completing the reinforcement of a corner position to be reinforced, the auxiliary device is removed, the absorbent layer is peeled off, and the reinforced corner surface is cleaned with alcohol or acetone.

[0021] To achieve the above objectives, the present invention provides an auxiliary device for a laser shock strengthening method for corner edges.

[0022] The above-mentioned technical solution of the present invention has the following advantages: by designing and processing an auxiliary device that is completely consistent with the outer contour of the corner to be strengthened and has a certain height, the auxiliary device is pressed tightly against the edge of the corner to be strengthened, so that the deionized water constraint layer is supported at the corner edge; at the same time, the absorption layer application process and method are adjusted and optimized in a targeted manner, so as to achieve non-destructive strengthening of the corner edge. Attached Figure Description

[0023] Figure 1 This is a three-dimensional structural diagram of the component with convex rounded corners disclosed in this invention.

[0024] Figure 2 This is a three-dimensional structural diagram of the component with concave rounded corners disclosed in this invention.

[0025] Figure 3 This is a schematic diagram of the structure of the three rounded corner edges disclosed in this invention.

[0026] Figure 4 This is a schematic diagram of an auxiliary device and component that are not attached, as disclosed in this invention.

[0027] Figure 5 This is a schematic diagram of the structure of an auxiliary device and a component fitting together, as disclosed in this invention.

[0028] Figure 6 This is a schematic diagram of a laser shock reinforcement structure for corner edges disclosed in this invention.

[0029] Figure 7 This is a schematic diagram of the structure before the absorption layer is applied, as disclosed in this invention.

[0030] In the figure: 1. Component; 1-1. Convex rounded corner; 1-2. Concave rounded corner; 1-1a. Convex rounded corner to be strengthened; 1-2a. Concave rounded corner to be strengthened; 2. Auxiliary device; 3. Absorption layer; 4. Deionized water confinement layer; 5. Pulsed laser. Detailed Implementation

[0031] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0032] In the description of the present invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended only to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0033] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0034] To address the problem of strengthening the corner edges of components, this invention provides a laser shock peening method for corner edges. For example... Figure 1 and Figure 2 As shown, the corners of the component 1 to be strengthened include two types: convex rounded corner 1-1 and concave rounded corner 1-2; wherein, convex rounded corner 1-1 has a convex rounded corner surface 1-1a to be strengthened, and concave rounded corner 1-2 has a concave rounded corner surface 1-2a to be strengthened. Figure 3 As shown, the edges of a rounded solid can be divided into three types: rounded corners (A), chamfered corners (B), and right corners (C).

[0035] The following describes a corner edge laser shock strengthening method based on this embodiment, illustrating the technical solution. Figures 4-7 The method includes:

[0036] Step S100: Based on the rotation angle model of the component, process an auxiliary device that is identical to the outer contour of the component's rotation angle.

[0037] S200: Based on the length of the corner area to be strengthened of the component, select a step for applying an absorbent layer to the surface of the corner area to be strengthened, wherein the application step includes: application method one, such as... Figure 4 First, an absorbent layer is applied to the surface of the corner to be strengthened. Then, the processed auxiliary device is placed on the component corresponding to the corner to be strengthened, aligning the outer contour of the auxiliary device with the outer contour of the corner to be strengthened. Finally, a clamping force is applied to the auxiliary device; or, a second application method is used, such as... Figure 5 First, the processed auxiliary device is placed on the component, so that the outer contour of the auxiliary device is aligned with the outer contour of the corner of the component to be strengthened. Then, a clamping force is applied to the auxiliary device. Finally, an absorbent layer is attached to the surface of the corner of the component to be strengthened.

[0038] Step S300: After completing the above-mentioned bonding steps, deionized water is sprayed onto the outer surface of the absorbent layer to form a deionized water constraint layer.

[0039] Step S400: Emit a laser pulse toward the deionized water confinement layer to complete the reinforcement of a corner position to be reinforced.

[0040] The methods of the above embodiments will be described in detail below with specific examples.

[0041] Based on the corner model of component 1, an aluminum alloy auxiliary device 2 with a height of 20mm to 40mm and an outer contour identical to the arc surface is machined. The surface roughness of the working contour of the auxiliary device 2 is Ra1.6 to Ra3.2. As in step S100, the lower chamfer of the auxiliary device 2 is the same as the chamfer of the edge of the corner body to be strengthened, as shown in the schematic diagram. Figure 4 and Figure 5 As shown.

[0042] Wipe the arc surface to be reinforced and the aluminum alloy auxiliary device 2 clean with alcohol or acetone; apply an aluminum foil tape or PVC black tape (3M 427 / 425 aluminum foil tape is recommended) with a thickness of 80-150μm to the arc surface to be reinforced as the absorbent layer 3. The absorbent layer 3 is a tape with a certain degree of extensibility. The material used for the absorbent layer 3 is not limited to this in this embodiment.

[0043] The absorbent layer 3 can be applied to the corner edge to be reinforced in two ways: application method one and application method two. Application method one is: applying absorbent layer + auxiliary device + pressing force + reinforcement. Application method two is: auxiliary device + pressing force + applying absorbent layer + reinforcement.

[0044] The application steps for Method 1 are as follows: When the length of the arc surface does not exceed 30mm, the steps of "applying absorbent layer + auxiliary device + pressing force + reinforcement" are adopted: First, apply absorbent layer 3 to the surface of the corner to be reinforced, ensuring that absorbent layer 3 is tightly adhered to the corner surface. The height of absorbent layer 3 should exceed the corner edge by 3mm to 5mm. Use a special tool to fold and flatten the excess portion 3-1 along the edge. The surface of the flattened tape should be free of bubbles, wrinkles, and bulges. Place the auxiliary device 2, which has been prepared in the above steps, on the component 1 of the corner to be reinforced, aligning the arc surface of the corner to be reinforced with the arc surface of the auxiliary device 2. Figure 4 As shown. The auxiliary device 2 and component 1 are pressed together by a bow-shaped clamp. The equivalent relationship between the pitch of the bow-shaped clamp and the clamping force is determined in advance by a pressure sensor. The pitch of the bow-shaped clamp is adjusted according to the equivalent relationship to control the clamping force, thereby applying a suitable clamping force to improve the strengthening quality of subsequent laser shock.

[0045] Application steps for Method Two: When the length of the arc surface exceeds 30mm, the following steps are used: "Auxiliary device + clamping force + application of absorbent layer + reinforcement": First, place the auxiliary device 2, prepared in the above steps, on the component 1 at the corner to be reinforced, aligning the arc surface of the corner to be reinforced with the arc surface of the auxiliary device 2. Use a bow-shaped clamp or pressure block to press the auxiliary device 2 firmly against the component 1. Apply the absorbent layer 3 tightly to the arc surface to be reinforced and the arc surface of the auxiliary device 2. Use a special tool to flatten the absorbent layer 3, ensuring that the absorbent layer 3 is tightly bonded to the surface to be reinforced (including the arc surface of the auxiliary device 2). There should be no obvious joint marks between the arc surface to be reinforced and the arc surface of the auxiliary device 2 on the surface of the absorbent layer 3, and the surface of the absorbent layer 3 should be free of bubbles, wrinkles, and bulges.

[0046] It is worth noting that, in the above-mentioned application step, the clamping force applied to the auxiliary device 2 It should meet the following requirements: Where As is the contact area of ​​the auxiliary device. The yield strength of the component material.

[0047] After completing the above-described application steps, deionized water is sprayed onto the arc surface to be strengthened, forming a 1-2 mm thick deionized water film as the deionized water constraint layer 4. The laser shock peening equipment is then activated and a pulsed laser 5 is emitted. In this embodiment, the auxiliary device 2, through clamping force, makes close contact with the corner edge to be strengthened, thus supporting the deionized water constraint layer 4 at the corner edge. After strengthening is complete, the auxiliary device 2 is removed, the absorbent layer 3 is peeled off, and the strengthened surface is cleaned with alcohol or acetone.

[0048] The corner edge laser shock strengthening method and auxiliary device 2 of the above embodiments can achieve non-destructive strengthening of corner edges, and ensure the integrity of the absorption layer during corner edge strengthening, thus ensuring the strengthening effect of corner edges.

[0049] This embodiment achieves non-flattened laser shock strengthening of component 1 and absorption layer 3 (using aluminum foil tape) on the concave corner arc surface of titanium alloy, as shown in the figure below. The steps are as follows:

[0050] Aluminum alloy auxiliary device 2, which is 20mm to 40mm high and has an outer contour that is the same as the arc surface, is machined according to the corner digital model. The surface roughness of the working contour surface of the auxiliary device 2 is Ra3.2.

[0051] Wipe the component 1 and the aluminum alloy auxiliary device 2, which are to be reinforced, clean with alcohol or acetone;

[0052] Place the auxiliary device 2 on the corner component 1 to be strengthened, aligning the arc surface of the corner to be strengthened with the arc surface of the auxiliary device 2, and use a bow-shaped clamp to press the auxiliary device 2 and component 1 together. (The pressing force is not specified in the original text.) =100kN (As=0.1) Apply aluminum foil tape tightly to the arc surface to be reinforced and the arc surface of the auxiliary device, as shown in the figure below;

[0053] Laser impact strengthening is performed on the curved surface to be strengthened after the coating is applied;

[0054] After the reinforcement is complete, remove auxiliary device 2, peel off the aluminum foil tape, and clean the reinforced surface with alcohol or acetone.

[0055] To address the problem of strengthening the corner edges of components, this invention also provides an auxiliary device for a laser shock strengthening method for corner edges.

[0056] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for laser shock strengthening of corner edges, characterized in that, The following steps are involved: Based on the rotation angle model of the component, an auxiliary device with the same rotation angle outer contour as the component is manufactured; Based on the length of the corner area to be strengthened of the component, a step of applying an absorbent layer to the surface of the corner area to be strengthened is selected. The application step includes: Method 1: First, apply the absorbent layer to the surface of the corner to be strengthened, then place the processed auxiliary device on the component corresponding to the corner to be strengthened, aligning the outer contour of the auxiliary device with the outer contour of the corner to be strengthened, and finally apply a clamping force to the auxiliary device; or Method 2: First, place the processed auxiliary device on the component, aligning the outer contour of the auxiliary device with the outer contour of the corner to be strengthened, then apply a clamping force to the auxiliary device, and finally apply the absorbent layer to the surface of the corner to be strengthened of the component; The clamping force F0 applied to the auxiliary device satisfies: 1MPa×As≤F0<(0.5-0.7)×σs×As, where As is the contact area of ​​the auxiliary device, and σs is the yield strength of the component material; After completing the above-mentioned bonding steps, deionized water is sprayed onto the outer surface of the absorbent layer to form a deionized water constraint layer. A laser pulse is emitted toward the deionized water confinement layer to complete the reinforcement of a corner position to be reinforced.

2. The laser shock peening method for corner edges as described in claim 1, characterized in that, Before performing the bonding step, the corner surfaces of the component to be reinforced and the auxiliary devices are wiped clean with alcohol or acetone.

3. The laser shock peening method for corner edges as described in claim 1, characterized in that, The absorbent layer applied to the corner surface to be reinforced is an adhesive tape with a certain degree of elasticity.

4. The laser shock peening method for corner edges as described in claim 1, characterized in that, In step one of the application methods, the length of the corner area to be reinforced does not exceed 30mm; in step two of the application methods, the length of the corner area to be reinforced exceeds 30mm.

5. The laser shock peening method for corner edges as described in claim 1, characterized in that, In the first step of the application method, the height of the absorbent layer exceeds the edge of the corner to be reinforced by 3mm to 5mm. The excess part is folded over and flattened along the edge with a special tool so that the surface of the absorbent layer after flattening is free of bubbles, wrinkles and bulges.

6. The laser shock peening method for corner edges as described in claim 1, characterized in that, In the steps of the first and second application methods, the auxiliary device and the component are pressed together using a bow-shaped clamp; wherein, the equivalent relationship between the pitch of the bow-shaped clamp and the clamping force is determined in advance using a pressure sensor, and the clamping force is controlled by adjusting the pitch of the bow-shaped clamp according to the equivalent relationship.

7. The laser shock peening method for corner edges as described in claim 1, characterized in that, In the second step of the application method, a special tool is used to flatten the applied absorbent layer so that the absorbent layer is tightly attached to the surface of the corner to be reinforced and the surface of the auxiliary device, and the surface of the absorbent layer is free of obvious joint marks, bubbles, wrinkles and bulges.

8. The laser shock peening method for corner edges as described in claim 1, characterized in that, After completing the reinforcement of a corner position, the process also includes removing the auxiliary device, peeling off the absorbent layer, and cleaning the reinforced corner surface with alcohol or acetone.

9. An auxiliary device, characterized in that, The auxiliary device is used in the corner edge laser shock strengthening method according to any one of claims 1-8.

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