Directional energy deposition processing coupled coherent gradient polarization sensing coaxial measurement system and method

Abstract

The invention provides a system and method for coupling directional energy deposition processing with coherent gradient polarization sensing coaxial measurement, and the system comprises a laser processing assembly which uses a processing laser beam to position a processing area of the surface of a to-be-measured processing and manufacturing sample, and carries out the directional deposition of powder in the processing area; collimated laser beams emitted by the laser shaping assembly are emitted to a processing area on the surface of a to-be-measured processing and manufacturing sample, and reflected laser beams reflected by the processing area are reflected to the polarization measurement assembly; the polarization measurement assembly enables the reflected laser beams to form diffraction spots; the image collecting and processing system is used for collecting diffraction spots and forming interference images, and meanwhile coherent gradient polarization sensing measurement and post-processing calculation are carried out on the interference images. Real-time accurate synchronous measurement of the deformation field of the directional energy deposition manufacturing area can be accurately and effectively realized, the principle is simple and easy to implement, and the system is convenient to popularize and apply.

Description

Technical Field

[0001] The present application relates to the field of on-site real-time manufacturing technologies such as semiconductor devices and laser directed energy deposition manufacturing, and in particular to a system and method for directed energy deposition processing coupled with coherent gradient polarization sensing coaxial measurement. Background Art

[0002] Coherent gradient sensor is a full-field interference type gradient coherent optical measurement method based on dual grating common optical path shearing interference technology. The measurement principle of the reflective coherent gradient sensor is that the object wave enters the dual grating system to generate interference. Through the phase analysis of the interference fringe field before deformation (zero fringe field) and after deformation, the full-field off-plane displacement gradient data of the object surface can be solved. In particular, the coherent gradient polarization sensor based on the polarization grating and polarization phase shift principle has been widely used in the field of macro and micro measurement of various materials and structures with its full-field, real-time, high-precision and high-sensitivity measurement advantages.

[0003] However, in the field of on-site real-time manufacturing and processing technology such as semiconductor devices and directed energy deposition, in-situ real-time monitoring of deformation in and around the manufacturing area is particularly critical, which can effectively reflect or invert the deformation field state of the manufacturing area. Therefore, a new coaxial real-time measurement technology for the deformation field of directed energy deposition manufacturing is urgently needed. Compared with other off-axis measurements or other regional measurements, coaxial measurement can directly monitor the manufacturing and processing area in situ, so it usually has higher calculation and inversion accuracy, and the results and conclusions obtained are relatively more reliable. In the optical measurement related technologies of directed energy deposition coaxial monitoring, there are currently related relatively mature application processing methods, including direct coaxial visual sensing technology, spectral-based analysis methods, etc. However, these methods generally solve displacement, and because they are usually incoherent visual test methods, the resolution and accuracy of the obtained deformation fields such as strain fields and deformation gradient fields are generally not high compared with coherent optical methods, and the prospects for high-precision real-time measurement applications in the industry are currently limited. The in-situ monitoring accuracy of high-precision coherent gradient polarization sensing measurement technology is high, but there is currently no relevant coaxial monitoring configuration designed. Therefore, how to develop a high-precision coaxial real-time deformation field measurement device and technology based on high-precision coherent gradient polarization sensing measurement technology that matches laser directional energy deposition manufacturing equipment and field environment is a technical problem that technical personnel in this field urgently need to solve. Summary of the invention

[0004] The present application aims to solve at least one of the technical problems in the related art to a certain extent. The present application proposes a system and method for directional energy deposition processing coupled with coherent gradient polarization sensing coaxial measurement, which can accurately and effectively realize real-time and accurate measurement of the deformation field of the manufacturing area of ​​the directional energy deposition manufacturing object, and the measurement principle is simple, which further expands the scope and application scenarios of the coherent gradient polarization sensor.

[0005] To achieve the above-mentioned purpose, the present application proposes a system for directional energy deposition processing coupled with coherent gradient polarization sensing coaxial measurement, comprising: A laser processing assembly, which uses a processing laser beam to locate a processing area on the surface of the sample to be processed and manufactured, and directionally deposits powder in the processing area on the surface of the sample to be processed and manufactured; A laser shaping component, wherein the collimated laser beam emitted by the laser shaping component is first incident on the laser processing component through the prism component, and then is incident on the processing area of ​​the surface of the processed sample to be measured through the laser processing component. The reflected laser beam reflected by the processing area of ​​the surface of the processed sample to be measured is initially in a collimated state, and is first incident on the prism component through the laser processing component, and then is reflected by the prism component to the polarization measurement component; the processing laser beam is coaxial with the collimated laser beam incident on the surface of the processed sample to be measured by the laser processing component; The polarization measurement component comprises a polarizer, a polarization transmission grating group and a filter lens which are sequentially arranged along the optical path direction of the reflected laser beam; the polarization transmission grating group comprises a front polarization transmission grating and a rear polarization transmission grating, the reflected laser beam is diffracted on the front polarization transmission grating, the diffracted beam passing through the front polarization transmission grating is diffracted again on the rear polarization transmission grating, and the diffracted beam is converged into a diffraction spot through the filter lens; and An image acquisition and processing system is arranged downstream of the filter lens along the optical path direction of the reflected laser beam; it is used to acquire the diffraction spots and form an interference image, and at the same time perform coherent gradient polarization sensing measurement and post-processing calculation on the interference image.

[0006] In some embodiments, the laser processing assembly includes a laser cladding head connected to an observation port by a side, a dichroic mirror and a processing laser; wherein the processing laser is used to generate the processing laser beam and transmit it through the dichroic mirror to the surface of the sample to be tested for positioning the processing area; the laser cladding head is used to deposit powder to the processing area positioned by the processing laser beam; the collimated laser beam is emitted through the observation port and the dichroic mirror to the surface of the sample to be tested.

[0007] In some embodiments, the dichroic mirror is a long-wave pass dichroic mirror so that the infrared band beam of the processing laser beam is transmitted and focused on the processing area of ​​the surface of the sample to be processed, and the dichroic mirror is used to reflect the collimated laser beam and the reflected laser beam.

[0008] In some embodiments, the laser shaping assembly includes a laser that provides the collimated laser beam, and a beam expanding convex lens and a collimating convex lens that are sequentially arranged along the optical path direction of the collimated laser beam; The beam expanding convex lens and the collimating convex lens are both plano-convex lenses and are both arranged on a slider; the slider is adapted to a slide rail extending along the optical path direction of the collimated laser beam.

[0009] In some embodiments, the prism assembly includes a beam splitter and a plane reflector; the collimated laser beam emitted by the laser shaping assembly is incident on the surface of the sample to be measured through the beam splitter and the dichroic mirror; the reflected laser beam is turned from the reflective surfaces of the beam splitter and the dichroic mirror to the plane reflector and then remains horizontally incident on the polarization measurement assembly.

[0010] In some embodiments, the reflective surfaces of the beam splitter prism and the dichroic mirror each include two right-angle optical quartz glass prisms, and the inclined surfaces of the two right-angle optical quartz glass prisms are bonded and coated with a semi-transparent and semi-reflective film or a dichroic film to form the transmission and reflection surfaces.

[0011] In some embodiments, the polarizer is a linear polarizer made of a dichroic material to convert the reflected laser beam of natural light into linearly polarized light.

[0012] In some embodiments, the front polarization transmission grating and the rear polarization transmission grating are both transmissive Ronchi square wave diffraction gratings made of liquid crystal polymer; the duty cycle of the transmissive Ronchi square wave diffraction grating is 1:1.

[0013] In some embodiments, the image acquisition and processing system includes a digital industrial polarization camera integrated with an aperture stop and a computer image post-processing system.

[0014] In some embodiments, all components other than the computer image post-processing system and the laser processing assembly are integrated onto the bottom plate base by a support assembly.

[0015] According to a second aspect, the present application proposes a method for coaxial measurement of directed energy deposition processing coupled with coherent gradient polarization sensing, using the system described in any of the above embodiments, comprising the following steps: Building the system described in any of the above embodiments; According to the characteristics of the processing area of ​​the surface of the sample to be measured, the laser shaping component is adjusted, and the laser shaping component emits a collimated laser beam and is incident on the surface of the sample to be measured through the prism component and the laser processing component; the reflected laser beam reflected by the surface of the sample to be measured is initially in a collimated state; at the same time, the clamping state of the polarization measurement component is adjusted so that the grating lines of the front polarization transmission grating and the rear polarization transmission grating are parallel to each other; The laser processing component emits a processing laser beam to locate a processing area on the surface of the sample to be processed and to deposit powder in a directional manner in the processing area; The image acquisition and processing system acquires the diffraction spots and forms an interference image, and simultaneously performs coherent gradient polarization sensing measurement and post-processing calculation on the interference image.

[0016] In some embodiments, the surface roughness of the surface of the manufactured sample to be tested after polishing is less than or equal to 0.02 μm.

[0017] In some embodiments, the polarization directions of the target surface superpixels of the digital industrial polarization camera are 0°, 45°, 90°, and 135° from left to right and from top to bottom in a clockwise direction, respectively.

[0018] Compared with the prior art, this application has the following advantages: This application uses laser processing components to separate light of different wavelengths and realize the simultaneous realization of laser directional energy deposition manufacturing processing and in-situ measurement; the polarization state of the interference light beam is adjusted by the polarization measurement component and image acquisition and processing system of the coherent gradient polarization sensing technology to obtain the spatial phase shift deformation field results in real time. The principle is simple and the operation is convenient. It solves the technical problem of high-precision real-time synchronous intuitive measurement of the processing and manufacturing area at the processing and manufacturing site, and expands the application scope of related technologies. In addition, this application is applicable to the processing and manufacturing of various optical surfaces that can reflect mirrors and real-time coaxial measurement of deformation, realizing the requirements of efficient, non-destructive, easy-to-operate in-situ real-time high-precision information sensing in the process of optical surface industrial processing and manufacturing, and has a wide range of applications.

[0019] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which: Figure 1 It is a schematic diagram of the structure of a system for directional energy deposition processing coupled with coherent gradient polarization sensing coaxial measurement in one embodiment of the present application; Figure 2This is an optical path diagram of a system for directional energy deposition processing coupled with coherent gradient polarization sensing coaxial measurement in one embodiment of the present application; Figure 3 is a schematic diagram of the polarization direction of a target surface superpixel of a digital industrial polarization camera in one embodiment of the present application; In the figure, 0, bottom plate base; 1, single longitudinal mode laser; 101, laser support; 2, beam expander convex lens; 201, beam expander frame; 202, beam expander support; 203, first slider; 204, first slide rail; 3, collimator convex lens; 301, collimator frame; 302, collimator support; 303, second slider; 4, beam splitter prism; 401, beam splitter prism support; 5, laser cladding head; 501, dichroic mirror; 502, processing laser; 6, sample to be processed and manufactured; 601, six-degree-of-freedom processing platform; 7, plane reflector; 701, plane reflector support; 8, polarizer; 801, polarizer Device frame; 802, polarizer support; 9, front liquid crystal polarization Ronchi transmission grating; 901, front grating clamping frame; 902, front grating support; 10, rear liquid crystal polarization Ronchi transmission grating; 1001, rear grating clamping frame; 1002, rear grating support; 11, filter lens; 1101, filter lens frame; 1102, filter lens support; 1103, connecting plate; 12, pixelated polarization camera; 1201, camera support; 1202, one-dimensional pitch stage; 1203, aperture stop; 1204, third slider; 1205, second slide rail; 13, computer image post-processing system. DETAILED DESCRIPTION

[0021] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be construed as limiting the present application. On the contrary, the embodiments of the present application include all changes, modifications and equivalents that fall within the spirit and connotation of the appended claims.

[0022] To achieve the above-mentioned objectives, the first aspect of the present application proposes a system for directional energy deposition processing coupled with coherent gradient polarization sensing coaxial measurement, including a laser processing component, a laser shaping component, a polarization measurement component and an image acquisition and processing system; wherein the laser processing component uses a processing laser beam to locate a processing area on the surface of a sample 6 to be processed and manufactured to be tested, and directionally deposits powder in the processing area on the surface of the sample 6 to be processed and manufactured to be tested.

[0023] The laser processing assembly includes a laser cladding head 5 connected to the observation port on the side, a dichroic mirror 501 and a processing laser 502; the processing laser 502 is used to generate a processing laser beam, which is a near-infrared processing laser beam, and its infrared band beam can pass through the dichroic mirror 501 and transmit to the surface of the processed and manufactured sample 6 to be tested to locate the processing area; the dichroic mirror 501 is a long-wave pass dichroic mirror 501, so that the infrared band beam of the processing laser beam is transmitted and focused on the surface of the processed and manufactured sample 6 to be tested to achieve processing area positioning; the laser cladding head 5 includes a powder delivery pipe (not marked), a protective gas pipe (not marked) and a condensing water pipe (not marked), etc. The laser cladding head 5 can deposit powder to the processing area located by the processing laser beam, so as to achieve quantitative deposition in the processing area determined on the surface of the processed and manufactured sample 6 to complete the processing.

[0024] The collimated laser beam emitted by the laser shaping component is first incident on the laser processing component through the prism component, and then emitted to the processing area on the surface of the processed sample 6 to be tested through the laser processing component. The reflected laser beam reflected by the processing area on the surface of the processed sample 6 to be tested is initially in a collimated state. The reflected laser beam is first incident on the prism component through the laser processing component, and then reflected to the polarization measurement component through the prism component; the processing laser beam is coaxial with the collimated laser beam emitted by the laser processing component to the surface of the processed sample 6 to be tested.

[0025] The laser shaping assembly includes a laser for providing a collimated laser beam, and a beam expanding convex lens 2 and a collimating convex lens 3 arranged in sequence along the optical path of the collimated laser beam. Figure 1 The front-to-back direction in the image is consistent, where the front-to-back direction and the optical axis z are as follows: Figure 1 As shown in the marking. In this embodiment, the laser can be a single longitudinal mode laser 1, which provides a monochromatic laser with a laser wavelength of 532 nm, and the monochromatic laser matches each optical element in this system. The collimated laser beam emitted by the laser is directed toward the negative direction of the z-axis as the optical path direction of the collimated laser beam, that is, the laser emits the collimated laser beam from back to front.

[0026] For example, the beam expander convex lens 2 and the collimator convex lens 3 are both plano-convex lenses, and the materials of the beam expander convex lens 2 and the collimator convex lens 3 can be both optical glass K9. In this embodiment, after the laser emits a collimated laser beam, the collimated laser beam passes through the beam expander convex lens 2 and the collimator convex lens 3 in sequence along the optical path of the collimated laser beam and reaches the prism assembly, and then passes through the side connection observation port of the laser cladding head 5 and is reflected to the surface of the processed and manufactured sample 6 to be tested through the dichroic mirror 501, wherein the reflected laser beam after the collimated laser beam is reflected by the processing area on the surface of the processed and manufactured sample 6 to be tested is initially in a collimated state, but after the directional energy deposition processing is performed on the surface of the processed and manufactured sample 6 to be tested, the reflected laser beam after the processing area on the surface of the processed and manufactured sample 6 to be tested is deformed, so that the reflected laser beam then reaches the prism assembly through the dichroic mirror 501, and is reflected to the polarization measurement assembly through the prism assembly; in addition, the processing laser beam is coaxial with the collimated laser beam emitted by the laser processing assembly to the surface of the processed and manufactured sample 6 to be tested.

[0027] In this embodiment, the reflected laser beam reflected from the surface of the processed sample 6 to be tested is reflected to the polarization measurement component through the prism component. At this time, the propagation direction of the reflected laser beam is from front to back, which is opposite to the direction of the initial collimated laser beam. Therefore, the prism component changes the extension direction of the collimated laser beam. It should be explained that in order to ensure that the reflected laser beam after the collimated laser beam is reflected from the surface of the processed sample 6 to be tested is initially in a collimated state, the surface of the processed sample 6 to be tested needs to be precisely polished, and the surface roughness after polishing is not greater than 0.02 m, to achieve specular reflection.

[0028] The polarization measurement component includes a polarizer 8, a polarization transmission grating group and a filter lens 11 which are arranged in sequence along the optical path direction of the reflected laser beam; the polarization transmission grating group includes a front polarization transmission grating and a rear polarization transmission grating, the reflected laser beam is diffracted on the front polarization transmission grating, the diffracted beam passing through the front polarization transmission grating is diffracted again on the rear polarization transmission grating, and the diffracted beam is converged into a diffraction spot through the filter lens 11.

[0029] The polarization measurement component includes a polarizer 8, a transmission grating group and a filter lens 11 arranged in sequence along the optical path direction of the reflected laser beam; the reflected laser beam is transmitted to the polarizer 8 and converted into linearly polarized light for transmission, wherein the polarizer 8 is a linear polarizer made of a dichroic material to convert the reflected laser beam of natural light into linearly polarized light.

[0030] The transmission grating group includes a front liquid crystal polarization Ronchi transmission grating 9 and a rear liquid crystal polarization Ronchi transmission grating 10. The linearly polarized light beam is diffracted on the front polarization transmission grating, and the diffracted circularly polarized light beam passing through the front polarization transmission grating is diffracted again on the rear polarization transmission grating to form a circularly polarized light beam in an orthogonal direction, which is converged into a diffraction spot through the filter lens 11 and interfered with by the pixelated polarization camera 12 for imaging; the material of the example filter lens 11 is optical glass K9.

[0031] The front polarization transmission grating and the rear polarization transmission grating of the example are both Ronchi square wave diffraction gratings made of liquid crystal polymer, with a duty cycle of 1:1; for example, the front polarization transmission grating is the front liquid crystal polarization Ronchi transmission grating 9, and the linearly polarized light passing through the front liquid crystal polarization Ronchi transmission grating 9 is incident perpendicular to the grating plane (that is, the incident angle passing through the grating is 0 degrees). The linearly polarized light is diffracted on the front polarization transmission grating to form two circularly polarized light beams in orthogonal directions, and the diffracted circularly polarized light beams then reach the rear polarization transmission grating; the rear polarization transmission grating can be the rear liquid crystal polarization Ronchi transmission grating 10, and the diffracted circularly polarized light beams reach the rear liquid crystal polarization Ronchi transmission grating 10 and undergo a second diffraction, each forming a circularly polarized light beam in an orthogonal direction, and after passing through the rear liquid crystal polarization Ronchi transmission grating 10, they can directly reach the filter lens 11 to be converged into a diffraction spot and enter the pixelated polarization camera 12 of the image acquisition and processing system to generate an interference pattern, wherein the light path diagram of the system is as shown in FIG. Figure 2 shown.

[0032] The image acquisition and processing system is arranged downstream of the filter lens 11 along the optical path direction of the reflected laser beam, and is used to collect diffraction spots and form interference images, and at the same time perform coherent gradient polarization sensing measurement and post-processing calculation on the interference images.

[0033] In this embodiment, along the optical path direction of the laser reflected light beam, the image acquisition and processing system is arranged downstream of the filter lens 11 along the optical path direction of the laser reflected light beam, so as to collect the laser image diffraction spot, and perform coherent gradient polarization sensing measurement and post-processing calculation. The image acquisition and processing system includes a digital industrial polarization camera integrated with an aperture diaphragm 1203 and an integrated computer image post-processing system 13, wherein the computer image post-processing system 13 can process the image of the digital industrial polarization camera. The digital industrial polarization camera is a pixelated polarization camera 12, that is, the lens of the pixelated polarization camera 12 of the present application is integrated with an aperture diaphragm 1203; the diffraction spot enters the pixelated polarization camera 12 integrated with the aperture diaphragm 1203 and interferes in front of the target to form an interference image, and the collected interference image information is sent to the computer image post-processing system 13 for further calculation and post-processing.

[0034] The present application utilizes a laser shaping component, the collimated laser beam emitted by the laser shaping component is incident on the laser cladding head 5 of the manufacturing and processing component through the beam splitter prism 4, and further reflected to the optical surface of the object to be measured through the dichroic mirror 501 inside the laser cladding head 5; the manufacturing and processing laser is transmitted to the surface of the manufacturing and processing area on the top of the object to be measured through the dichroic mirror 501, so as to realize coaxial manufacturing and measurement. The laser reflection beam in the visible light band reflected by the optical surface of the object to be measured is in a nearly collimated state, and is reflected back to the prism component through the dichroic mirror 501 inside the laser cladding head 5, and further reflected to the polarization measurement component; the polarization measurement component converges the beam result of the laser reflection beam into a diffraction spot and generates interference; the image acquisition and processing system is set to collect the laser image diffraction spot downstream of the filter lens 11 along the optical path direction of the laser reflection beam, and performs polarization phase shift to perform coherent gradient polarization sensing measurement and post-processing calculation. The present application can accurately and effectively realize the real-time, accurate and synchronous measurement of the deformation field in the directional energy deposition manufacturing area, the principle is simple and easy to implement, and the system is easy to promote and apply.

[0035] The present application utilizes the characteristics of the dichroic mirror 501 to separate light of different wavelength bands and realize the simultaneous realization of laser directional energy deposition manufacturing processing and in-situ measurement; the polarization state of the interference light beam is adjusted by the polarization measurement component and image acquisition and processing system of the coherent gradient polarization sensing technology to obtain the spatial phase shift deformation field result in real time. The principle is simple and the operation is convenient. It solves the technical problem of high-precision real-time synchronous and intuitive measurement in the processing and manufacturing area of ​​the processing and manufacturing site, and expands the application scope of the relevant technology; and the present application is suitable for the processing and manufacturing of various optical surfaces that can reflect mirrors and real-time coaxial measurement of deformation, realizing the requirements of efficient, non-destructive, easy-to-operate in-situ real-time high-precision information sensing in processes such as industrial processing and manufacturing of optical surfaces, and has a wide range of applications.

[0036] In some embodiments, the prism assembly includes a beam splitter prism 4 and a plane reflector 7; the collimated laser beam emitted by the laser shaping assembly is incident on the surface of the processed sample 6 to be measured through the beam splitter prism 4 and the dichroic mirror 501; the reflected laser beam is turned from the reflecting surface of the beam splitter prism 4 and the dichroic mirror 501 to the plane reflector 7 and then kept horizontally incident on the polarization measurement assembly.

[0037] In the front-to-back direction, the beam splitter prism 4 is arranged between the collimating convex lens 3 and the laser cladding head 5. The beam splitter prism 4 includes two right-angle optical quartz glass prisms, and the inclined surfaces of the two right-angle optical quartz glass prisms are bonded and coated with a semi-transparent and semi-reflective film or a two-way beam splitting film to form a reflective surface. In other words, the inclined surfaces of the two right-angle optical quartz glass prisms are bonded as follows: Figure 1As shown, the laser light passing through the collimating convex lens 3 passes through the beam splitter prism 4 and reaches the side observation window of the laser cladding head 5, and the dichroic mirror 501 inside it is a long-wave dichroic mirror. The dichroic mirror 501 includes two right-angle optical quartz glass prisms, and the inclined surfaces of the two right-angle optical quartz glass prisms are attached and coated with a dichroic film to form a reflecting surface. Therefore, the dichroic mirror 501 can reflect the reflected collimated laser beam in the visible light band, and the laser reflected beam reflected by the optical surface of the object to be measured is sent to the beam splitter prism 4; and the near-infrared band light beam processed and manufactured at the same time will be transmitted through the dichroic mirror 501 and focused on the target surface manufacturing area to realize coaxial manufacturing and measurement.

[0038] Therefore, the reflection surface of the beam splitter 4 transmits the collimated laser beam to the dichroic mirror 501, and the dichroic mirror 501 reflects the collimated laser beam onto the optical surface of the object to be measured and reflects the reflected light back to the beam splitter 4; the beam splitter 4 reflects the laser reflected beam onto the plane reflector 7; the plane reflector 7 is parallel to the reflection surface of the beam splitter 4 to turn the reflected laser beam so that the optical path direction of the reflected laser beam is consistent with the horizontal direction. Therefore, compared with the related art, the present application adds a laser cladding head 5 and an internal dichroic mirror 501, and the laser reflected beam becomes a diffraction spot and enters the pixelated polarization camera 12 of the integrated aperture diaphragm 1203 to perform interference imaging and collection on the diffraction spot. The collected information is connected and sent to the computer image post-processing system 13 for further calculation and post-processing, so as to realize the full-field real-time measurement of the deformation and temperature of the optical surface of the top manufacturing area of ​​the processed and manufactured sample 6 to be measured. It has a simple structure and a concise principle, and does not need to change the original coherent gradient polarization sensing measurement system optical path arrangement, is easy to operate, and has a low economic cost for transformation.

[0039] In some embodiments, the beam expanding convex lens 2 and the collimating convex lens 3 are both arranged on different sliders; there are multiple sliders and they are adapted to the slide rails extending along the optical path direction of the collimated laser beam, and the extension direction of the slide rails is the same as the optical path direction of the collimated laser beam. In this embodiment, the beam expanding convex lens 2 and the collimating convex lens 3 are respectively arranged on the sliders, and the position of the beam expanding convex lens 2 and the collimating convex lens 3 can be adjusted by moving the sliders on the slide rails. For example, considering that it is necessary to translate the beam expanding convex lens 2 and the collimating convex lens 3 according to the test requirements in order to modulate the laser emitted by the single longitudinal mode laser 1, a first slide rail 204 is arranged along the front-to-back direction, and a first slider 203 and a second slider 303 are arranged on the first slide rail 204 in sequence, the beam expanding convex lens 2 is arranged on the first slider 203; the collimating convex lens 3 is arranged on the second slider 303; when it is necessary to modulate the laser according to the test requirements, the beam expanding convex lens 2 and the collimating convex lens 3 are translated accordingly by the first slider 203 and the second slider 303, and it is ensured that the centers of the beam expanding convex lens 2 and the collimating convex lens 3 are at the same horizontal height.

[0040] In some embodiments, all components except the computer image post-processing system 13, the laser cladding head 5, the dichroic mirror 501, the processing laser 502, the test specimen 6, and the six-degree-of-freedom processing platform 601 are integrated onto the bottom plate base 0 by the support assembly.

[0041] In some embodiments, the system also includes a support assembly and a fixing member; the support assembly includes multiple supports, and all components except the laser cladding head 5, the dichroic mirror 501, the processing laser 502, the powder feeding pipe, the protective gas pipe, the condensation water pipe, and the test sample 6 are integrated on the bottom plate base 0 through the support assembly and the fixing member, wherein the test sample 6 is arranged on a six-degree-of-freedom processing platform 601.

[0042] For example, the laser shaping assembly includes a laser support 101 disposed on the bottom plate base 0, on which a single longitudinal mode laser 1 for providing a laser light source is fixedly disposed; a beam expander convex lens 2 and a collimator convex lens 3 are connected at the same horizontal plane height along the optical path through a first slide rail 204. A beam splitter prism support 401 for fixing and placing a beam splitter prism 4 is disposed on the bottom plate base 0. After the beam splitter prism support 401 raises the horizontal height of the beam splitter prism 4, it is ensured that the laser modulated by the laser shaping assembly can completely pass through the beam splitter prism 4. In some schemes, in order to fix the beam expander convex lens 2 and the collimator convex lens 3, a beam expander support 202 is disposed on the first slider 203, and the beam expander convex lens 2 is fixedly disposed on the beam expander frame 201 at the top of the beam expander support 202, and a collimator support 302 is disposed on the second slider 303, and the collimator convex lens 3 is fixedly disposed on the collimator frame 301 at the top of the collimator support 302.

[0043] For another example, the bottom plate base 0 is provided with a front grating support 902 and a rear grating support 1002 for fixing the front liquid crystal polarization Ronchi transmission grating 9 and the rear liquid crystal polarization Ronchi transmission grating 10, respectively. The front grating support 902 is fixedly provided with a front grating clamping frame 901 for clamping the front liquid crystal polarization Ronchi transmission grating 9, and the rear grating support 1002 is provided with a rear grating clamping frame 1001 for clamping the rear liquid crystal polarization Ronchi transmission grating 10. The polarizer 8 is fixed on the polarizer support 802 via a polarizer frame 801. The light on the surface of the specimen can reach the filter lens 11 after being diffracted twice by the front liquid crystal polarization Ronchi transmission grating 9 and the rear liquid crystal polarization Ronchi transmission grating 10, and converges into a diffraction spot and enters the image acquisition and processing system containing the pixelated polarization camera 12.

[0044] In addition, a connecting plate 1103 is provided on the bottom plate base 0, a filter lens support 1102 for fixing the filter lens 11 is fixedly provided on the connecting plate 1103, a filter lens frame 1101 installed on the top thereof is used to install the filter lens 11, a second slide rail 1205 is fixedly provided on the connecting plate 1103, a one-dimensional pitching platform 1202 is slidably connected to the second slide rail 1205 through a third slider 1204, a camera support 1201 is fixedly provided on the one-dimensional pitching platform 1202, and the camera support 1201 is fixedly connected to the pixelated polarization camera 12 of the integrated aperture diaphragm 1203. The laser cladding head 5 is particularly fixedly placed, the dichroic mirror 501 is fixed in the internal area of ​​the laser cladding head 5 and is highly consistent with the beam splitter prism 4; the processing laser 502 is coaxial with the incident laser beam emitted from the outlet of the laser cladding head 5; the powder feeding pipe, the protective gas pipe and the condensed water pipe surround the lower part of the laser cladding head 5.

[0045] It should be noted that the wavelength limit of each optical element and the surface to be measured in the system should be matched with the monochromatic laser light source emitted by the single longitudinal mode laser 1, and the laser support 101, the beam expander support 202, the first slider 203, the first slide rail 204, the collimator support 302, the second slider 303, the beam splitter prism support 401, the plane reflector support 701, the front grating clamping frame 901, the rear grating clamping frame 1001, the connecting plate 1103, the camera support 1201, and the one-dimensional pitch table 1202 are all made of 304 stainless steel, and the surfaces of the first slider 203, the first slide rail 204, the second slider 303, the front grating clamping frame 901, the rear grating clamping frame 1001, the connecting plate 1103, the one-dimensional pitch table 1202, the third slider 1204, and the second slide rail 1205 are all subjected to black oxidation treatment.

[0046] According to a second aspect, the present application proposes a method for coaxial measurement of directed energy deposition processing coupled with coherent gradient polarization sensing, and the measurement is performed using the system in any of the above embodiments, comprising the following steps: S1: Building a system in any of the above embodiments; S2: adjusting the laser shaping assembly according to the characteristics of the processing area on the surface of the processed sample 6 to be measured, the laser shaping assembly emits a collimated laser beam and is incident on the surface of the processed sample 6 to be measured through the prism assembly and the laser processing assembly; the reflected laser beam reflected by the surface of the processed sample 6 to be measured is initially in a collimated state; at the same time, adjusting the clamping state of the polarization measurement assembly so that the grating lines of the front polarization transmission grating and the rear polarization transmission grating are parallel to each other; S3: The laser processing component emits a processing laser beam to locate the processing area on the surface of the test specimen 6 to be processed and deposits powder in a directional manner in the processing area; S4: The image acquisition and processing system acquires the diffraction spots and forms an interference image, and performs coherent gradient polarization sensing measurement and post-processing calculation on the interference image.

[0047] Among them, build Figure 1 The system shown in the figure includes a bottom plate base 0, on which a laser shaping assembly is arranged; wherein the beam splitter prism 4 can reflect the laser reflected beam of the optical surface of the top processing and manufacturing area of ​​the to-be-tested processing and manufacturing sample 6 reflected by the long-wave pass dichroic mirror to the plane reflector 7, wherein the roughness of the optical surface to be tested is not greater than 0.02 μm; the plane reflector 7 turns the reflected laser beam to the polarizer 8; along the front-back direction, a transmission grating group is arranged behind the polarizer 8, and a filter lens 11 is arranged behind the transmission grating group; corresponding to the direction of the optical path, a pixelated polarization camera 12 is arranged behind the filter lens 11 to realize spatial phase shift and image acquisition. wherein the polarizer 8 converts the laser reflected beam of natural light into linearly polarized light; the transmission grating group includes a front polarization transmission grating and a rear polarization transmission grating; the front polarization transmission grating and the rear polarization transmission grating are both transmission-type liquid crystal polymer diffraction gratings with a line density of 20 lines / mm.

[0048] After building the system for directional energy deposition processing coupled with coherent gradient polarization sensing coaxial measurement, adjust the positions of the beam expanding convex lens 2, the collimating convex lens 3, the beam splitting prism 4 and the dichroic mirror 501 on the optical axis and the pitch angle and position of the six-degree-of-freedom processing platform 601 according to the characteristics of the optical surface of the processing area of ​​the test sample 6 to be tested, so that the initial light beam after reflection from the surface of the test sample 6 is in a collimated state; the six-degree-of-freedom processing platform 601 is a processing platform set up to facilitate manufacturing processing in environments such as laser directional energy deposition.

[0049] Adjust the clamping state of the rear polarization transmission grating and the rear polarization transmission grating so that the grating lines in two directions of the two gratings are parallel to each other, and the target surface of the digital industrial polarization camera is orthogonal to the extension direction of the collimated laser beam; open the pixelated polarization camera 12 with the integrated aperture diaphragm 1203 to start collecting data, and further measure and post-process the deformation gradient field and temperature field through the computer image post-processing system 13; the polarization directions of the super-pixels on the target surface of the digital industrial polarization camera are 0°, 45°, 90°, and 135° from left to right and from top to bottom in a clockwise direction, respectively. The results are as follows: Figure 3 shown.

[0050] It should be noted that, in the description of this application, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of this application, unless otherwise specified, the meaning of "plurality" is two or more.

[0051] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code that includes one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0052] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0053] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A system for directed energy deposition processing coupled with coherent gradient polarization sensing coaxial measurement, characterized in that: include A laser processing assembly, which uses a processing laser beam to locate a processing area on the surface of the sample to be processed and manufactured, and directionally deposits powder in the processing area on the surface of the sample to be processed and manufactured; A laser shaping component, wherein the collimated laser beam emitted by the laser shaping component is first incident on the laser processing component through the prism component, and then is incident on the processing area of ​​the surface of the processed sample to be measured through the laser processing component. The reflected laser beam reflected by the processing area of ​​the surface of the processed sample to be measured is initially in a collimated state, and is first incident on the prism component through the laser processing component, and then is reflected by the prism component to the polarization measurement component; the processing laser beam is coaxial with the collimated laser beam incident on the surface of the processed sample to be measured by the laser processing component; The polarization measurement component comprises a polarizer, a polarization transmission grating group and a filter lens which are sequentially arranged along the optical path direction of the reflected laser beam; the polarization transmission grating group comprises a front polarization transmission grating and a rear polarization transmission grating, the reflected laser beam is diffracted on the front polarization transmission grating, the diffracted beam passing through the front polarization transmission grating is diffracted again on the rear polarization transmission grating, and the diffracted beam is converged into a diffraction spot through the filter lens; as well as An image acquisition and processing system is arranged downstream of the filter lens along the optical path direction of the reflected laser beam; it is used to acquire the diffraction spots and form an interference image, and at the same time perform coherent gradient polarization sensing measurement and post-processing calculation on the interference image.

2. The system according to claim 1, characterized in that The laser processing assembly includes a laser cladding head connected to an observation port by a side, a dichroic mirror and a processing laser; wherein the processing laser is used to generate the processing laser beam and transmit it through the dichroic mirror to the surface of the to-be-tested processed and manufactured sample to locate the processing area; the laser cladding head is used to deposit powder to the processing area located by the processing laser beam; the collimated laser beam is projected to the surface of the to-be-tested processed and manufactured sample through the observation port and the dichroic mirror.

3. The system according to claim 2, characterized in that The dichroic mirror is a long-wave pass dichroic mirror, so that the infrared band beam of the processing laser beam is transmitted and focused on the processing area of ​​the surface of the sample to be tested, and the dichroic mirror is used to reflect the collimated laser beam and the reflected laser beam.

4. The system according to claim 2, characterized in that The laser shaping assembly comprises a laser for providing the collimated laser beam, and a beam expanding convex lens and a collimating convex lens sequentially arranged along the optical path direction of the collimated laser beam; The beam expanding convex lens and the collimating convex lens are both plano-convex lenses and are both arranged on a slider; the slider is adapted to a slide rail extending along the optical path direction of the collimated laser beam.

5. The system according to any one of claims 2 to 4, characterized in that: The prism assembly includes a beam splitter and a plane reflector; the collimated laser beam emitted by the laser shaping assembly is incident on the surface of the sample to be measured through the beam splitter and the dichroic mirror; the reflected laser beam is turned from the reflective surfaces of the beam splitter and the dichroic mirror to the plane reflector and then remains horizontally incident on the polarization measurement assembly.

6. The system according to claim 5, characterized in that The reflective surfaces of the beam splitter prism and the dichroic mirror each include two right-angle optical quartz glass prisms, and the inclined surfaces of the two right-angle optical quartz glass prisms are bonded and coated with a semi-transparent and semi-reflective film or a dichroic film to form a transmission and reflection surface.

7. The system according to claim 1, characterized in that The polarizer is a linear polarizer made of a dichroic material to convert the reflected laser beam of natural light into linear polarized light.

8. The system according to claim 1, characterized in that The front polarization transmission grating and the rear polarization transmission grating are both transmission-type Ronchi square-wave diffraction gratings made of liquid crystal polymer; the duty ratio of the transmission-type Ronchi square-wave diffraction grating is 1:

1.

9. The system according to claim 1, characterized in that The image acquisition and processing system comprises a digital industrial polarization camera integrated with an aperture stop and a computer image post-processing system.

10. The system according to claim 9, characterized in that All components other than the computer image post-processing system and the laser processing assembly are integrated onto the bottom plate base by the support assembly.

11. A method for directional energy deposition processing coupled with coherent gradient polarization sensing coaxial measurement, characterized in that: Using the system described in any one of claims 1-10, comprising the following steps: Constructing a system as described in any one of claims 1 to 10; According to the characteristics of the processing area of ​​the surface of the sample to be measured, the laser shaping component is adjusted, and the laser shaping component emits a collimated laser beam and is incident on the surface of the sample to be measured through the prism component and the laser processing component; the reflected laser beam reflected by the surface of the sample to be measured is initially in a collimated state; at the same time, the clamping state of the polarization measurement component is adjusted so that the grating lines of the front polarization transmission grating and the rear polarization transmission grating are parallel to each other; The laser processing component emits a processing laser beam to locate a processing area on the surface of the sample to be processed and to deposit powder in a directional manner in the processing area; The image acquisition and processing system acquires the diffraction spots and forms an interference image, and simultaneously performs coherent gradient polarization sensing measurement and post-processing calculation on the interference image.

12. The method according to claim 11, characterized in that The surface roughness of the surface of the manufactured sample to be tested after polishing is less than or equal to 0.02 μm.

13. The method according to claim 11, characterized in that The polarization directions of the target surface superpixels of the digital industrial polarization camera are 0°, 45°, 90°, and 135° from left to right and from top to bottom in a clockwise direction.

Images