Optical fiber laser shock peening apparatus and method of use

Abstract

The application provides a kind of optical fiber conduction laser shock peening processing device and its using method, including optical fiber and arc surface total reflection mirror;Optical fiber is used to output laser;Arc surface total reflection mirror is set on the light path of laser, for focusing and outputting from side, side is placed in water environment;Wherein, arc surface total reflection mirror can focus laser on hole inner wall, and laser shock peening is carried out on hole inner wall.The application utilizes green laser with wavelength of 532 nanometers to transmit in water flow for laser shock peening, and the working area to laser reflection area is all in water environment or glass environment, not in contact with air, reduces the influence of shock wave and water splashed by constraint layer on arc surface total reflection mirror, and can realize laser shock peening on small aperture hole in narrow space.

Description

Technical Field

[0001] This invention relates to the field of laser shock peening, and more specifically, to a fiber-optic laser shock peening processing apparatus and its method of use. Background Technology

[0002] Laser shock peening typically uses a lens to transmit the laser beam. After transmission via fiber optics, a collimating lens at the output end obtains parallel light, and a focusing lens can then be used to achieve conventional laser shock peening. However, fiber lasers transmit very low energy, requiring a very small focal point, with laser shock peening almost at the focal point. During laser shock peening, water is used as a confinement layer. The laser strikes the confinement layer, generating a shock wave that causes water splashing. When the peening location is close to a reflector, water splashing can cause water to adhere to the reflective surface. When performing laser shock peening on internal holes or concealed surfaces, space constraints mean that if the laser peening location is too close to the reflector, the powerful laser beam and the impact of the shock wave can easily damage the reflector. Summary of the Invention

[0003] (a) Technical problems to be solved The technical problem to be solved by the present invention is that the existing technology is difficult to achieve laser reflection and focusing in a narrow space, and the shock wave and splashed water can easily damage the reflector.

[0004] (II) Technical Solution To achieve the above objectives, the technical solution adopted by the present invention is as follows: This invention provides a fiber-optic laser shock peening processing apparatus, comprising an optical fiber and a curved total reflection mirror; the optical fiber is used to output a laser, wherein the laser is a green laser with a wavelength of 532 nanometers; the curved total reflection mirror is disposed in the optical path of the laser and is used to focus the laser and output it from the side, wherein the side is placed in an aqueous environment; wherein the curved total reflection mirror can focus the laser onto the inner wall of a hole, thereby performing laser shock peening on the inner wall of the hole.

[0005] Preferably, the device further includes a cylindrical housing, with the optical fiber and the arc-shaped total reflection mirror placed inside the cylindrical housing, and the optical fiber arranged along the axial direction of the cylindrical housing.

[0006] Preferably, it also includes a rotary motor, the output end of which is connected to the cylindrical housing.

[0007] Preferably, the cylindrical shell has a first end and a second end, the optical fiber is disposed at the first end, the arc-shaped total reflection mirror is disposed at the second end, the second end has a notch, the arc-shaped total reflection mirror focuses the laser and outputs it from the notch, the first end is used to connect to a water source, the water source is input from the first end and flows out from the notch.

[0008] Preferably, the arc-shaped total reflection mirror includes an optical glass substrate, the third end of which is cylindrical, and the fourth end of which has an arc-shaped total reflection surface, and the laser beam is emitted from the third end to the fourth end.

[0009] Preferably, the arc-shaped total reflection mirror includes a cylindrical metal substrate with an arc-shaped total reflection surface, and the laser is incident on the arc-shaped total reflection surface along the axial direction of the cylindrical metal substrate.

[0010] Preferably, the cylindrical metal substrate is made of copper, and the arc-shaped total reflective surface is plated with silver or gold.

[0011] Preferably, the arc-shaped total reflection mirror is a spherical mirror, and the center of the spherical mirror coincides with the focal point of the laser.

[0012] The present invention also provides a method of using the fiber-optic laser shock peening processing device, comprising the following steps: Place the arc-shaped total reflection mirror near the hole to be processed; The laser is output from the optical fiber, and the arc-shaped total reflection mirror focuses the laser through the water environment and outputs it from the side to act on the inner wall of the hole to be processed. The arc-shaped total reflection mirror is driven to rotate in order to achieve laser shock strengthening of the circumferential inner wall of the hole to be processed.

[0013] (III) Beneficial Effects The above-described technical solution of the present invention has at least the following advantages: This invention utilizes a 532 nm green laser transmitted through flowing water for laser shock peening. The entire working area and laser reflection area are within an aqueous or glass environment, without contact with air, reducing the impact of shock waves and water sputtering from the confinement layer on the curved total internal reflection mirror. The curved total internal reflection mirror achieves laser reflection and focusing, with the focused laser at a certain angle to the normal of the working surface, enabling laser shock peening of small-diameter holes within a confined space. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the structure of the fiber-optic laser shock peening processing device provided in an embodiment of the present invention.

[0016] Figure 2 This is a schematic diagram of the arc-shaped total reflection mirror provided in Embodiment 1 of the present invention.

[0017] Figure 3 This is a schematic diagram of the arc-shaped total reflection mirror provided in Embodiment 2 of the present invention.

[0018] Figure 4 This is a schematic diagram of the arc-shaped total reflection mirror provided in Embodiment 3 of the present invention.

[0019] Figure 5 This is a schematic diagram illustrating the implementation principle of the fiber-optic laser shock peening processing device provided in Embodiment 3 of the present invention.

[0020] Figure 6 This is a photograph of the curved surface total reflection mirror provided in Embodiment 3 of the present invention.

[0021] The labels for the attached figures are as follows: 1. Optical fiber; 2. Curved total reflection mirror; 3. Aquatic environment; 4. Cylindrical shell; 5. Rotary motor; 21. Optical glass substrate; 22. Curved total reflection surface; 23. Cylindrical metal substrate; 41. First end; 42. Second end; 211. Third end; 212. Fourth end; 421. Notch. Detailed Implementation

[0022] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0023] It should be noted that when a component is referred to as "fixed to" or "set on" another component, it can be located directly on or indirectly on the other component. When a component is referred to as "connected to" another component, it can be directly or indirectly connected to the other component.

[0024] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate that the device or element must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0025] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating relative importance or the number of technical features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. The specific implementation of this invention will be described in more detail below with reference to specific embodiments: Example 1 like Figure 1 and Figure 2 As shown, this embodiment of the invention provides a fiber-optic laser shock peening processing device, including an optical fiber 1, an arc-shaped total reflection mirror 2, a cylindrical housing 4, and a rotary motor 5. The optical fiber 1 is used to output laser light. The arc-shaped total reflection mirror 2 is disposed in the optical path of the laser light, used to focus the laser light and output it from the side, which is placed in a water environment 3. The arc-shaped total reflection mirror 2 can focus the laser light onto the inner wall of the hole, performing laser shock peening on the inner wall of the hole. The optical fiber 1 and the arc-shaped total reflection mirror 2 are placed inside the cylindrical housing 4, with the optical fiber arranged along the axial direction of the cylindrical housing 4. The output end of the rotary motor 5 is connected to the cylindrical housing 4. Specifically, the laser light is a green laser with a wavelength of 532 nanometers. The curved total internal reflection mirror 2 is preferably an ellipsoidal mirror. In this embodiment, a 532 nm wavelength green laser is transmitted in water flow for laser shock enhancement. The entire working area and the laser reflection area are in a water environment or a glass environment, without contact with air. An ellipsoidal mirror is used for reflection and focusing. The focused laser is tilted at a certain angle to the normal of the working surface. The curved total internal reflection mirror 2 is used to directly focus the laser output from the optical fiber. The curved total internal reflection mirror 2, which has high reflectivity to green light, is used. The purpose of this invention is to achieve laser reflection and focusing in a narrow space and reduce the impact of shock waves and splashed water on the curved total internal reflection mirror 2.

[0026] Furthermore, the cylindrical shell 4 has a first end 41 and a second end 42. The optical fiber 1 is disposed at the first end 41, and the arc-shaped total reflection mirror 2 is disposed at the second end 42. The second end 42 has a notch 421. The arc-shaped total reflection mirror 2 focuses the laser and outputs it from the notch 421. The first end 41 is used to connect to a water source. The water source enters from the first end 41 and flows out from the notch 421.

[0027] Furthermore, the curved-surface total internal reflection mirror 2 includes an optical glass substrate 21, the third end 211 of which is cylindrical, and the fourth end 212 of which has a curved-surface total internal reflection surface 22. Laser light is emitted from the third end 211 to the fourth end 212. The curved-surface total internal reflection mirror 2 is cylindrical... Furthermore, the curved surface total reflection mirror 2 includes an optical glass substrate 21 as the base, with its top surface processed into an elliptical spherical surface of revolution (i.e., a curved surface total reflection surface 22). The laser output from the optical fiber 1 enters from the bottom of the cylindrical optical glass substrate 21, undergoes total reflection on the curved surface total reflection surface 22, is focused by the curved surface total reflection surface 22, and is output from the side. The light-emitting surface is the water environment 3. Since the refractive indices of glass and water are similar, the laser transmission angle on this surface does not change much.

[0028] Furthermore, the curved total internal reflection mirror 2 is a spherical mirror, with the center of the sphere coinciding with the focal point of the laser. This design further reduces the directional change of the laser at the glass / water interface.

[0029] Example 2 like Figure 1 and Figure 3 As shown, based on Embodiment 1, the difference between this embodiment and Embodiment 1 is that: In this embodiment, the arc-shaped total reflection mirror 2 includes a cylindrical metal substrate 23, which has an arc-shaped total reflection surface 22. The laser beam is incident on the arc-shaped total reflection surface 22 along the axial direction of the cylindrical metal substrate 23.

[0030] Furthermore, the cylindrical metal substrate 22 is made of copper, and the arc-shaped total reflective surface 22 is plated with silver or gold. Specifically, the arc-shaped total reflection mirror 2 uses a cylindrical copper substrate (cylindrical metal substrate 22) as the base, and its top surface is processed into an ellipsoid (arc-shaped total reflection surface 22). The ellipsoid is rotated around the major axis formed by the two foci of the ellipse as the center of rotation. The ellipse on the plane is rotated around the center of rotation to form a rotating surface for high-precision milling of the cylindrical metal substrate. The surface roughness is better than Ra 20nm. The surface is plated with silver or gold. The laser output from the optical fiber enters from the axis of the cylindrical metal substrate 22. When designing the optical fiber installation and fixing device, it is necessary to ensure that the optical fiber passes through the focal position. Generally, the optical fiber outlet is placed at the focal position, but it cannot be guaranteed that the fiber outlet is equivalent to the center point of the point light source. Therefore, a small range of adjustment is required. The adjustment range can be adjusted back and forth according to the diameter of the optical fiber. The laser is totally reflected on the arc-shaped total reflection surface 22, focused by the total reflection surface and output from the side. The entire optical fiber 1 and the arc-shaped total reflection mirror 2 are water-intake from the first end 41 through the water nozzle and water-outtake from the notch 421, or the whole is immersed in water.

[0031] Example 3 like Figure 4 , Figure 5 and Figure 6As shown, in this embodiment, based on Embodiment 2, the specific dimensions of the curved surface total reflection mirror 2 are as follows: the major axis of the ellipsoid that fits with the curved surface total reflection mirror 2 is 63.6 mm, the minor axis is 21.2 mm, the ratio of the major axis to the minor axis is 3:1, the major axis forms a 45-degree angle with the central axis of the curved surface total reflection mirror 2, one focal point is on the central axis of the curved surface total reflection mirror 2, and the other focal point is 9.5 mm away from the central axis of the curved surface total reflection mirror 2. This fiber-optic laser shock peening processing device can achieve laser shock peening of an inner hole with a diameter of 20 mm. By reducing the length of the major axis, the focal length can be further reduced, and laser shock peening of an inner hole with a diameter of 10 mm can be achieved.

[0032] The present invention also provides a method of using an optical fiber-guided laser shock peening processing device, comprising the following steps: Place the curved total reflection mirror 2 near the hole to be processed; A 1.5mm core diameter optical fiber is used to transmit a high-intensity pulsed laser in the range of 100mJ / 10ns. The center of the fiber end face is installed on the focal point of the elliptical spherical transmitting mirror and can be precisely adjusted within a range of 1.5mm. The size of the spot at the focal point is tested, and the position with the smallest spot and the largest brightness, which forms the strongest impact sound, is the optimal fixed position of the optical fiber. The arc-shaped total reflection mirror 2 focuses the laser through the water environment and outputs it from the side to act on the inner wall of the hole to be processed. The curved total reflection mirror 2 is driven to rotate to achieve laser shock strengthening of the circumferential inner wall of the hole to be processed.

[0033] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A fiber-optic laser shock peening processing apparatus, characterized in that, include: Optical fiber, used to output laser light, which is a green laser with a wavelength of 532 nanometers; An arc-shaped total internal reflection mirror, which is an ellipsoidal mirror, is placed in the optical path of the laser to focus the laser and output it from the side, which is placed in an aqueous environment; A cylindrical shell is provided, in which the optical fiber and the arc-shaped total reflection mirror are placed. The optical fiber is arranged along the axial direction of the cylindrical shell. The cylindrical shell has a first end and a second end. The optical fiber is located at the first end, and the arc-shaped total reflection mirror is located at the second end. The second end has an opening. The arc-shaped total reflection mirror focuses the laser and outputs it from the opening. The first end is used to connect to a water source. The water source enters from the first end and flows out from the opening. In this system, a 532 nm wavelength green laser is transmitted through water flow for laser shock enhancement. The entire working area and the laser reflection area are in an aquatic environment, without contact with air. The curved total reflection mirror can focus the laser onto the inner wall of the hole. The focused laser is tilted at a certain angle to the normal of the working surface, thus performing laser shock enhancement on the inner wall of the hole. The ellipsoid that is attached to the curved total reflection mirror has a major axis of 63.6 mm and a minor axis of 21.2 mm, with a major-to-minor axis ratio of 3:

1. The major axis is at a 45-degree angle to the central axis of the curved total reflection mirror. One focal point is on the central axis of the curved total reflection mirror, and the other focal point is 9.5 mm away from the central axis of the curved total reflection mirror.

2. The fiber-optic laser shock peening processing apparatus as described in claim 1, characterized in that, It also includes a rotary motor, the output end of which is connected to the cylindrical housing.

3. The fiber-optic laser shock peening processing apparatus as described in claim 1, characterized in that, The arc-shaped total reflection mirror includes an optical glass substrate, the third end of which is cylindrical, and the fourth end of which has an arc-shaped total reflection surface. The laser beam is emitted from the third end to the fourth end.

4. The fiber-optic laser shock peening processing apparatus as described in claim 1, characterized in that, The arc-shaped total reflection mirror includes a cylindrical metal substrate with an arc-shaped total reflection surface. The laser is incident on the arc-shaped total reflection surface along the axial direction of the cylindrical metal substrate.

5. The fiber-optic laser shock peening processing apparatus as described in claim 4, characterized in that, The cylindrical metal substrate is made of copper, and the arc-shaped total reflective surface is plated with silver or gold.

6. A method of using the fiber-optic laser shock peening processing apparatus as described in any one of claims 1-5, characterized in that, Includes the following steps: Place the arc-shaped total reflection mirror near the hole to be processed; The laser is output from the optical fiber, and the arc-shaped total reflection mirror focuses the laser through the water environment and outputs it from the side to act on the inner wall of the hole to be processed. The arc-shaped total reflection mirror is driven to rotate in order to achieve laser shock strengthening of the circumferential inner wall of the hole to be processed.

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