Selective laser melting forming splicing equipment and splicing method

Abstract

The invention belongs to the technical field of additive manufacturing, and discloses selective laser melting forming splicing equipment and a splicing method. The selective laser melting forming splicing equipment comprises a forming cabin, a powder supporting platform, a laser generator, laser scanning equipment and a central control system. The powder supporting platform is arranged in the forming cabin; the laser generator is arranged in the forming cabin and located above the powder supporting platform. The laser scanning equipment is slidably arranged on the inner side wall of the forming cabin through a translation mechanism; the central control system can obtain actual contour data, compare the actual contour data with theoretical contour data of the theoretical model, determine actual size data and displacement data of the workpiece, modify the scaling of the theoretical model according to the actual size data and displacement data of the workpiece, and move the position of the theoretical model. And the theoretical contour and the actual contour coincide. The selective laser melting forming splicing method uses selective laser melting forming splicing equipment. According to the invention, the splicing efficiency and the splicing quality can be effectively improved.

Description

Technical Field

[0001] This invention relates to the field of additive manufacturing technology, and in particular to a laser selective melting forming continuation equipment and continuation method. Background Technology

[0002] Selective Laser Melting (SLM) is a process that uses a laser generator to produce a laser beam. This beam is then collimated and expanded by a collimator and beam expander to reduce its divergence before entering a galvanometer. The galvanometer system, controlled by the workpiece's three-dimensional model, sintersects the workpiece on a powder support platform. Each sintering layer is created by dividing the three-dimensional model into layers of 40μm-100μm thickness, with powder layered and sintered sequentially. The number of sintering layers typically ranges from several thousand to tens of thousands. During sintering, warping often occurs due to model structure issues, support design problems, or unsuitable printing parameters. In such cases, it is usually necessary to open the workpiece chamber and polish it before continuing printing. During the opening process, due to the solidification and shrinkage characteristics of the metal material itself, combined with the vibration of the parts caused by grinding and other processes, the formed solid parts are prone to deviate from the original model. After the printing is continued, there will be certain joint marks. The deviation of the joint is between 0.3mm and 0.8mm. The joint marks cannot be manually ground, and the abnormality is eventually detected, resulting in scrap.

[0003] Currently, laser selective melting equipment primarily uses manual rejoining. There are three main rejoining methods: First, direct rejoining after a long pause by opening the forming chamber; second, rejoining after surface grinding of the workpiece after opening the chamber; and third, rejoining after the part has separated from the substrate, cutting off the defective portion, and re-entering the forming chamber for printing rejoining. The first method is less difficult, and the rejoining marks are generally acceptable. The second and third methods are more challenging. Due to the solidification shrinkage characteristics of metal materials, opening the chamber can cause model position shifts, especially after wire cutting the defective section. When re-entering the forming chamber, the model position is often misaligned. These types of parts are often of extremely high value, resulting in significant scrap costs. Existing rejoining technologies have low precision and cannot meet high-precision rejoining requirements.

[0004] Therefore, there is an urgent need for a laser selective melting forming and splicing equipment and method to solve the above-mentioned technical problems. Summary of the Invention

[0005] The purpose of this invention is to provide a laser selective melting forming continuation equipment and method, which aims to solve the problem of low continuation accuracy in the prior art. This laser selective melting forming continuation equipment and method can effectively improve continuation efficiency and continuation quality.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] A laser selective melting forming continuation device includes:

[0008] Forming chamber;

[0009] A powder support platform is disposed inside the forming chamber, and the powder support platform is used to support the powder to be sintered;

[0010] A laser generator is disposed above the forming chamber. The laser generator is used to emit a laser beam, which is used to sinter the powder.

[0011] A laser scanning device is slidably mounted on the inner wall of the forming chamber via a translation mechanism. The laser scanning device is used to scan the sintered layer and the workpiece and obtain the actual contour data of the sintered layer and the workpiece.

[0012] The central control system is electrically connected to both the laser scanning device and the translation mechanism. The central control system can control the movement of the translation mechanism, acquire the actual contour data, determine the actual size data of the workpiece, compare the actual contour data with the theoretical contour data of the theoretical model, determine the displacement data, modify the scaling ratio of the theoretical model according to the actual size data and the displacement data, and move the position of the theoretical model so that the theoretical contour and the actual contour coincide.

[0013] In some possible implementations, the laser selective melting forming continuation equipment further includes a dust removal structure, which includes a blowing assembly and a suction assembly. The blowing assembly is disposed on one outer side wall of the forming chamber, and the suction assembly is disposed on the other outer side wall of the forming chamber. The blowing assembly and the suction assembly are disposed opposite to each other and are both in communication with the forming chamber.

[0014] In some possible implementations, the blowing assembly includes an interconnected blowing pipe and a blower. The blowing pipe includes a main blowing pipe and two branch blowing pipes. The forming chamber has two blowing ports, one of which is located near the top of the forming chamber and the other is located near the bottom of the forming chamber. One end of each of the two branch blowing pipes is connected to the main blowing pipe, and the other end of each branch blowing pipe is connected to the two blowing ports respectively.

[0015] In some possible implementations, the suction assembly includes a suction pipe and a suction device that are interconnected, with a filter element disposed inside the suction device, the end of the suction pipe away from the suction device communicating with the suction port of the forming chamber, and the suction port being disposed near the bottom end of the forming chamber.

[0016] In some possible implementations, the translation mechanism includes a drive unit mounted on the forming chamber, a slide rail disposed on the forming chamber, and a slide groove disposed on the laser scanning device. The laser scanning device is drivenly connected to the output end of the drive unit, and the drive unit is electrically connected to the central control system.

[0017] A laser selective melting forming continuation method, using laser selective melting forming continuation equipment as described in any of the above embodiments, the laser selective melting forming continuation method comprising the following steps:

[0018] S1. Provide a defective workpiece, and after cutting off the defect, place the workpiece into the forming chamber, with the top surface of the workpiece flush with the top surface of the powder supported on the powder support platform.

[0019] S2, sintering positioning grid;

[0020] S3. The central control system controls the translation mechanism to move, so that the laser scanning device slides along the inner wall of the forming chamber, and the laser scanning device scans the positioning grid and the top surface contour of the workpiece to obtain the actual contour data.

[0021] S4. The central control system acquires the actual contour data, compares the actual contour data with the theoretical contour data of the theoretical model, determines the adjustment data, and modifies the theoretical model according to the adjustment data so that the theoretical contour and the actual contour coincide.

[0022] In some possible implementations, when sintering the positioning grid, the laser power of the laser generator is 140W-220W, the scanning speed of the laser generator is 1000mm / s-1500mm / s, and the thickness of the powder layer is 60μm-100μm.

[0023] In some possible implementations, step S4 includes:

[0024] S41. The central control system acquires the actual contour data, determines the actual size data of the workpiece, compares the actual contour data with the theoretical contour data of the theoretical model, determines the area scaling ratio, and the central control system performs scaling processing on the theoretical contour data according to the area scaling ratio.

[0025] S42. Compare the actual contour data with the scaled theoretical contour data to determine the displacement data, and move the position of the theoretical model according to the displacement data so that the theoretical contour and the actual contour coincide.

[0026] In some possible implementations, in step S3, the laser power of the laser scanning device when scanning the positioning grid and the top surface contour of the workpiece is 13mW-17mW, the laser wavelength is 600nm-700nm, the dot pitch is 0.005mm-0.015mm, and the scanning speed v < 500,000 dots / second.

[0027] In some possible implementations, in step S3, when the laser scanning device scans the positioning grid and the top surface contour of the workpiece, the movement accuracy of the laser scanning device is ±1μm.

[0028] The beneficial effects of this invention are:

[0029] The laser selective melting forming and splicing equipment provided by this invention includes a laser scanning device that is slidably mounted on the inner wall of the forming chamber via a translation mechanism. The laser scanning device is used to scan the sintered layer and the workpiece and obtain their actual contour data. The laser scanning device can quickly and accurately scan and position the sintered layer and the workpiece, which can effectively improve splicing efficiency and quality.

[0030] This invention also provides a laser selective melting forming continuation method. Using the aforementioned laser selective melting forming continuation equipment, when acquiring actual contour data, the central control system can flexibly control the translation mechanism's movement, allowing the laser scanning device to slide smoothly along the inner wall of the forming chamber. The laser scanning device scans the positioning grid and the top surface contour of the workpiece to obtain actual contour data. The laser scanning device can quickly and accurately scan and position the positioning grid and the top surface contour of the workpiece to obtain high-precision contour data. The central control system compares the actual contour data with the theoretical contour data of the theoretical model, determines the adjustment data, and modifies the theoretical model according to the adjustment data, so that the theoretical contour and the actual contour coincide, which can effectively improve the continuation efficiency and continuation quality. The width of the continuation mark can be controlled below 0.3mm. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the structure of the laser selective melting forming continuation equipment provided in an embodiment of the present invention;

[0032] Figure 2 This is a flowchart of the laser selective melting forming continuation method provided in the embodiments of the present invention.

[0033] In the picture:

[0034] 100. Forming chamber; 110. Air outlet; 120. Air suction outlet; 200. Powder support platform; 300. Laser generator; 400. Laser scanning equipment; 500. Central control system; 611. Air blowing pipe; 6111. Branch air blowing pipe; 6112. Main air blowing pipe; 621. Air suction pipe; 700. Translation mechanism; 800. Scanning galvanometer; 900. Flat mirror; 1000. Scraper; 1100. Positioning grid;

[0035] 10. Workpiece. Detailed Implementation

[0036] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0037] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0038] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0039] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0040] like Figure 1As shown, this embodiment provides a laser selective melting forming continuation equipment, including a forming chamber 100, a powder support platform 200, a laser generator 300, a laser scanning device 400, and a central control system 500. The powder support platform 200 is disposed within the forming chamber 100 and is used to support the powder to be sintered. The laser generator 300 is disposed within the forming chamber 100 and above the powder support platform 200, and is used to emit a laser beam for sintering the powder. The laser scanning device 400 is slidably disposed on the inner wall of the forming chamber 100 via a translation mechanism 700, and is used to scan the sintered layer (such as the positioning grid 1100) and the workpiece 10 to obtain the sintered layer. The actual contour data of workpiece 10; the laser scanning device 400 and the translation mechanism 700 are both electrically connected to the central control system 500. The central control system 500 can control the movement of the translation mechanism 700, acquire the actual contour data, determine the actual size data of workpiece 10, compare the actual contour data with the theoretical contour data of the theoretical model, determine the displacement data, modify the scaling ratio of the theoretical model according to the actual size data and displacement data, and move the position of the theoretical model so that the theoretical contour and the actual contour coincide.

[0041] The laser selective melting forming and splicing equipment provided in this embodiment includes a laser scanning device 400, which is slidably mounted on the inner wall of the forming chamber 100 via a translation mechanism 700. The laser scanning device 400 is used to scan the sintered layer and the workpiece 10 and obtain their actual contour data. The laser scanning device 400 can quickly and accurately scan and position the sintered layer and the workpiece 10, effectively improving splicing efficiency and quality.

[0042] Optionally, the laser selective melting forming continuation equipment also includes a scanning galvanometer 800 and a flat mirror 900. The scanning galvanometer 800 is disposed on top of the forming chamber 100, and the flat mirror 900 is disposed between the scanning galvanometer 800 and the laser generator 300. The laser beam emitted by the laser generator 300 passes sequentially through the scanning galvanometer 800 and the flat mirror 900 before entering the forming chamber 100 to sinter the powder. The scanning galvanometer 800 can perform planar offset processing on the laser beam, and the flat mirror 900 is used to protect the scanning galvanometer 800. See, for example... Figure 1 In this embodiment, the laser generator 300 employs a dual-laser design, serving as the energy output terminal and capable of emitting two laser beams to perform additive manufacturing on two workpieces 10. Correspondingly, two scanning galvanometers 800 and two planar mirrors 900 are provided, with each of the two scanning galvanometers 800 corresponding to one of the two laser beams, and each of the two planar mirrors 900 corresponding to one of the two scanning galvanometers 800. In other embodiments, the type and number of laser generators 300 can also be configured as needed.

[0043] See also Figure 1 The laser selective melting forming continuation equipment also includes a dust removal structure, which comprises a blowing assembly and a suction assembly. The blowing assembly is located on one outer wall of the forming chamber 100, and the suction assembly is located on the other outer wall of the forming chamber 100. The blowing assembly and the suction assembly are arranged opposite to each other and are both connected to the forming chamber 100. The blowing assembly is used to blow air into the forming chamber 100 to blow away the smoke and slag powder generated during laser sintering. The suction assembly is used to suck the blown smoke and slag powder out of the forming chamber 100 to prevent the smoke and slag powder from adhering to the surface of the flat mirror 900 and damaging the flat mirror 900.

[0044] Optionally, the blowing assembly includes interconnected blowing pipes 611 and blowers. The blowing pipes 611 include a main blowing pipe 6112 and two branch blowing pipes 6111. The forming chamber 100 has two blowing ports 110, one of which is located near the top of the forming chamber 100, and the other is located near the bottom of the forming chamber 100. One end of each of the two branch blowing pipes 6111 is connected to the main blowing pipe 6112, and the other end of each branch blowing pipe 6111 is connected to the two blowing ports 110 respectively. By providing two blowing ports 110, the upper blowing port 110 is used to press down the smoke and dust in the upper space of the forming chamber 100 to prevent the smoke and dust from floating and contaminating the flat mirror 900; the lower blowing port 110 is used to blow away the smoke and dust in the lower space of the forming chamber 100, thereby improving dust removal efficiency.

[0045] Optionally, the suction assembly includes a suction pipe 621 and a suction device that are interconnected. A filter element is installed inside the suction device. The end of the suction pipe 621 away from the suction device is connected to the suction port 120 of the forming chamber 100. The suction port 120 is located near the bottom of the forming chamber 100. The suction device absorbs smoke and dust from the space below the forming chamber 100 and filters the extracted smoke and dust.

[0046] Preferably, both the air outlet 110 and the air inlet 120 are designed in a mesh shape. The mesh-shaped air outlets make the airflow more evenly distributed, avoiding local airflow that is too strong or too weak; the mesh-shaped air outlets can act as a barrier to prevent foreign objects from entering the forming chamber 100; the mesh-shaped air outlets have a stable and durable structure with strong resistance to deformation; the mesh-shaped air outlets have neat lines and a simple appearance.

[0047] Optionally, the laser selective melting forming continuation equipment also includes a scraper 1000, which is slidably mounted within the forming chamber 100. The scraper 1000 is used to spread powder on the forming surface of the workpiece 10, ensuring that the thickness of each powder layer is consistent, providing a stable powder layer for the subsequent laser melting process; during the powder spreading process, the scraper 1000 can apply a certain pressure to the powder, compacting it, thereby providing a denser powder layer, reducing voids between powder particles, and improving the density and mechanical properties of the workpiece 10.

[0048] In this embodiment, the translation mechanism 700 includes a drive component mounted on the forming chamber 100, a slide rail disposed on the forming chamber 100, and a slide groove disposed on the laser scanning device 400. The laser scanning device 400 is drive-connected to the output end of the drive component, and the drive component is electrically connected to the central control system 500. The combination of the slide rail and the slide groove can effectively improve the sliding stability of the laser scanning device 400 and prevent movement deviation. During the sliding process of the laser scanning device 400, there is surface contact between the laser scanning device 400 and the slide rail, which can evenly distribute the weight of the laser scanning device 400 on the slide rail and improve the load-bearing capacity of the slide rail. Optionally, the slide rail can be detachably installed in the forming chamber 100 to facilitate adjustment of the installation position of the slide rail.

[0049] like Figure 2 As shown, this embodiment also provides a laser selective melting forming continuation method. Using the above-mentioned laser selective melting forming continuation equipment, the laser selective melting forming continuation method includes the following steps:

[0050] S1. Provide a defective workpiece 10, and after cutting off the defect, place the workpiece 10 into the forming chamber 100, with the top surface of the workpiece 10 flush with the top surface of the powder supported on the powder support platform 200.

[0051] S2, sintering positioning grid 1100;

[0052] S3. The central control system 500 controls the translation mechanism 700 to move, so that the laser scanning device 400 slides along the inner wall of the forming chamber 100. The laser scanning device 400 scans the positioning grid 1100 and the top surface contour of the workpiece 10 to obtain the actual contour data.

[0053] S4. The central control system 500 acquires the actual contour data, compares the actual contour data with the theoretical contour data of the theoretical model, determines the adjustment data, and modifies the theoretical model according to the adjustment data so that the theoretical contour and the actual contour coincide.

[0054] The laser selective melting forming continuation method provided in this embodiment uses the aforementioned laser selective melting forming continuation equipment. When acquiring actual contour data, the central control system 500 can flexibly control the movement of the translation mechanism 700, allowing the laser scanning device 400 to slide smoothly along the inner wall of the forming chamber 100. The laser scanning device 400 scans the positioning grid 1100 and the top surface contour of the workpiece 10 to obtain actual contour data. The laser scanning device 400 can quickly and accurately scan and position the positioning grid 1100 and the top surface contour of the workpiece 10 to obtain high-precision contour data. The central control system 500 compares the actual contour data with the theoretical contour data of the theoretical model, determines the adjustment data, and modifies the theoretical model according to the adjustment data, so that the theoretical contour and the actual contour coincide, which can effectively improve the continuation efficiency and continuation quality. The width of the continuation mark can be controlled to be below 0.3mm.

[0055] It should be noted that during the sintering of the positioning grid 1100, the scraper 1000 is required to spread the powder, which flattens the powder and exposes the top surface contour of the workpiece 10. Whether the workpiece 10 is removed and placed back into the forming chamber 100 for further joining, the position of the positioning grid 1100 in the forming chamber 100 and the theoretical model remains fixed. Using the positioning grid 1100 as the positioning reference, the laser scanning device 400 acquires and outputs the scanned image to the central control system 500 during sintering. The central control system 500 can directly measure the position of the current workpiece 10's solid feature joining surface relative to the positioning grid 1100, and then compare it with the position of the workpiece 10's feature joining surface relative to the positioning grid 1100 in the theoretical model. This allows for precise determination of the positional offset, moving the X and Y axes of the theoretical model to ensure that the theoretical and actual contours coincide with high accuracy. Among them, the theoretical contour data of the theoretical model refers to the model constructed by the central control system 500 based on the size parameters of the workpiece 10. The theoretical model also includes the theoretical positioning grid 1100.

[0056] Optionally, when sintering the positioning grid 1100, the laser power of the laser generator 300 is 140W-220W, and the scanning speed of the laser generator 300 is 1000mm / s-1500mm / s; the thickness of the powder layer is 60μm-100μm. By using low energy density sintering process parameters, it is ensured that the sintered lines can be clearly identified by the laser scanning device 400, preventing warping.

[0057] Optionally, in step S3, the laser power of the laser scanning device 400 when scanning the positioning grid 1100 and the top surface contour of the workpiece 10 is 13mW-17mW, the laser wavelength is 600nm-700nm, the point spacing is 0.005mm-0.015mm, and the scanning speed v < 500,000 points / second. If the laser power is too high, the highly reflective surface will be overexposed, leading to errors in the calculation of the sampling point position; if the laser power is too low, the number of photons reflected from the surface of the workpiece 10 and the surface of the positioning grid 1100 will be small, making them susceptible to interference from ambient light and reducing data accuracy. If the point spacing is too large, the point cloud density will be insufficient and unable to reflect the true contour; if the point spacing is too small, the sampling areas of adjacent points will overlap, generating redundant points and increasing data processing time. If the scanning speed is too fast, the scanning head of the laser scanning device 400 will not be able to accurately stop at the preset position due to inertia, causing the position of adjacent sampling points to shift; if the scanning speed is too slow, the scanning rate will be too low. For example, the laser power can be set to 15mW, the laser wavelength to 650nm, and the dot pitch to 0.01mm.

[0058] Optionally, in step S3, when the laser scanning device 400 scans the positioning grid 1100 and the top surface contour of the workpiece 10, the movement accuracy of the laser scanning device 400 is ±1μm to ensure the scanning accuracy of the laser scanning device 400.

[0059] Optionally, the distance between the bottom surface of the translation mechanism 700 and the top surface of the powder is 10cm-14cm, and the moving step size of the laser scanning device 400 is ≤0.05mm / step. This configuration ensures that the laser scanning device 400 acquires all contour data during the forming process of the workpiece 10 and ensures high scanning accuracy. For example, the distance between the bottom surface of the translation mechanism 700 and the top surface of the powder can be any value among 10cm, 12cm, 14cm, or 10cm-14cm.

[0060] In this embodiment, step S4 includes:

[0061] S41. The central control system 500 acquires the actual contour data, determines the actual size data of the workpiece 10, and compares the actual contour data with the theoretical contour data of the theoretical model (i.e., the theoretical size data of the workpiece 10) to determine the area scaling ratio. The central control system 500 then performs scaling processing on the theoretical contour data according to the area scaling ratio.

[0062] S42. Compare the actual contour data with the scaled theoretical contour data to determine the displacement data, and move the position of the theoretical model according to the displacement data so that the theoretical contour and the actual contour coincide.

[0063] By determining the area scaling ratio, the theoretical contour data is scaled to correct and calibrate the theoretical model, compensating for dimensional shrinkage caused by cooling after powder forming, and improving the positional accuracy of subsequent positioning. It is conceivable that in other embodiments, the actual contour data can first be compared with the theoretical contour data of the theoretical model to determine the displacement data. Based on the displacement data, the position of the theoretical model is moved so that the centers of the theoretical and actual contours coincide. Then, the actual contour data is compared with the theoretical contour data of the theoretical model (i.e., the theoretical dimensions of workpiece 10) to determine the area scaling ratio. Based on the area scaling ratio, the theoretical contour data is scaled to make the theoretical and actual contours coincide.

[0064] Preferably, if the overlap rate between the theoretical profile and the actual profile is low, steps S2-S4 need to be repeated.

[0065] Taking a workpiece 10 with an outline size of 600mm × 600mm and an original scaling ratio of 1.0025 as an example, the laser selective melting forming continuation method includes:

[0066] S1. Cut off the cracked part of the workpiece 10, reinstall it into the forming chamber 100, fill the forming chamber 100 with protective gas, and after the oxygen content reaches the control requirements, run the scraper 1000 to spread powder. The scraper 1000 scrapes the powder flat to expose the outline of the workpiece 10.

[0067] S2, sintering positioning grid 1100;

[0068] S3, the central control system 500 controls the translation mechanism 700 to move, and the laser scanning device 400 scans the positioning grid 1100 and the top surface contour of the workpiece 10 to obtain the actual contour data. The contour size of the scanned workpiece 10 is 599.45mm×599.78mm.

[0069] S4. The central control system 500 acquires the actual contour data, resets the scaling ratio to 1.001, compares the actual contour data with the scaled theoretical contour data, determines the displacement data, the X-axis offset is 1.3mm, the Y-axis offset is 1.0mm, and moves the position of the theoretical model so that the theoretical contour and the actual contour coincide.

[0070] To verify the actual splicing effect, after step S4, powder can be re-spread on the top surface of workpiece 10, and scraper 1000 can scrape the powder flat to expose the outline of workpiece 10. The positioning grid 1100 is sintered, and laser scanning equipment 400 scans the positioning grid 1100 and the top surface outline of workpiece 10 to obtain the actual outline data. The outline size of workpiece 10 is 600.05mm × 600.38mm. Then, the displacement data is determined, with X-axis offset of 0.25mm and Y-axis offset of 0.25mm. The width of the actual splicing mark is measured to be 0.25mm, which further improves the splicing accuracy.

[0071] Taking a workpiece 10 with an outline size of 350mm × 350mm and an original scaling ratio of 1.0033 as an example, the laser selective melting forming continuation method includes:

[0072] S1. Open the chamber, grind the warped area of ​​the workpiece 10 flat, close the chamber, fill the forming chamber 100 with protective gas, and after the oxygen content reaches the control requirements, run the scraper 1000 to spread powder. The scraper 1000 scrapes the powder flat, revealing the outline of the workpiece 10.

[0073] S2, sintering positioning grid 1100;

[0074] S3, the central control system 500 controls the translation mechanism 700 to move, and the laser scanning device 400 scans the positioning grid 1100 and the top surface contour of the workpiece 10 to obtain the actual contour data. The contour size of the scanned workpiece 10 is 349.23mm×349.36mm.

[0075] S4. The central control system 500 acquires the actual contour data, resets the scaling ratio to 1.0025, compares the actual contour data with the scaled theoretical contour data, determines the displacement data, the X-axis offset is 0.9mm, the Y-axis offset is 1.2mm, and moves the position of the theoretical model so that the theoretical contour and the actual contour coincide.

[0076] To verify the actual splicing effect, after step S4, powder can be re-spread on the top surface of workpiece 10, and scraper 1000 can scrape the powder flat to expose the outline of workpiece 10. The positioning grid 1100 is sintered, and laser scanning equipment 400 scans the positioning grid 1100 and the top surface outline of workpiece 10 to obtain the actual outline data. The outline size of workpiece 10 is 350.1mm × 350.23mm. Then, the displacement data is determined, the X-axis offset is 0.13mm, the Y-axis offset is 0.13mm, and the width of the actual splicing mark is measured to be 0.13mm, which further improves the splicing accuracy.

[0077] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A laser selective melting forming and splicing device, characterized in that, include: Forming chamber (100); A powder support platform (200) is disposed inside the forming chamber (100), and the powder support platform (200) is used to support the powder to be sintered; A laser generator (300) is disposed above the forming chamber (100). The laser generator (300) is used to emit a laser beam, which is used to sinter the powder. A laser scanning device (400) is slidably disposed on the inner wall of the forming chamber (100) via a translation mechanism (700). The laser scanning device (400) is used to scan the sintered layer and the workpiece (10) and obtain the actual contour data of the sintered layer and the workpiece (10). The central control system (500), the laser scanning device (400), and the translation mechanism (700) are all electrically connected to the central control system (500). The central control system (500) can control the movement of the translation mechanism (700). The central control system (500) can acquire the actual contour data, determine the actual size data of the workpiece (10), compare the actual contour data with the theoretical contour data of the theoretical model, determine the displacement data, modify the scaling ratio of the theoretical model according to the actual size data and the displacement data, and move the position of the theoretical model so that the theoretical contour and the actual contour coincide.

2. The laser selective melting forming and splicing equipment according to claim 1, characterized in that, The laser selective melting forming continuation equipment also includes a dust removal structure, which includes a blowing component and a suction component. The blowing component is disposed on one outer side wall of the forming chamber (100), and the suction component is disposed on the other outer side wall of the forming chamber (100). The blowing component and the suction component are disposed opposite to each other and are both connected to the forming chamber (100).

3. The laser selective melting forming and splicing equipment according to claim 2, characterized in that, The blowing assembly includes an interconnected blowing pipe (611) and a blower. The blowing pipe (611) includes a main blowing pipe (6112) and two branch blowing pipes (6111). The forming chamber (100) has two blowing ports (110), one of which is located near the top of the forming chamber (100) and the other is located near the bottom of the forming chamber (100). One end of each of the two branch blowing pipes (6111) is connected to the main blowing pipe (6112), and the other end of each branch blowing pipe (6111) is connected to the two blowing ports (110).

4. The laser selective melting forming and splicing equipment according to claim 3, characterized in that, The suction assembly includes a suction pipe (621) and a suction device that are interconnected. A filter element is installed inside the suction device. The end of the suction pipe (621) away from the suction device is connected to the suction port (120) of the forming chamber (100). The suction port (120) is located near the bottom end of the forming chamber (100).

5. The laser selective melting forming and splicing equipment according to claim 1, characterized in that, The translation mechanism (700) includes a drive component installed in the forming chamber (100), a slide rail disposed in the forming chamber (100), and a slide groove disposed in the laser scanning device (400). The laser scanning device (400) is connected to the output end of the drive component, and the drive component is electrically connected to the central control system (500).

6. A laser selective melting forming continuation method, characterized in that, Using the laser selective melting forming and rejoining equipment as described in any one of claims 1-5, the laser selective melting forming and rejoining method includes the following steps: S1. Provide a defective workpiece (10), and after cutting off the defect, place the workpiece (10) into the forming chamber (100), with the top surface of the workpiece (10) flush with the top surface of the powder supported on the powder support platform (200). S2, sintering positioning grid (1100); S3. The central control system (500) controls the translation mechanism (700) to move, so that the laser scanning device (400) slides along the inner wall of the forming chamber (100), and the laser scanning device (400) scans the positioning grid (1100) and the top surface contour of the workpiece (10) to obtain the actual contour data. S4. The central control system (500) acquires the actual contour data, compares the actual contour data with the theoretical contour data of the theoretical model, determines the adjustment data, and modifies the theoretical model according to the adjustment data so that the theoretical contour and the actual contour coincide.

7. The laser selective melting forming continuation method according to claim 6, characterized in that, When sintering the positioning grid (1100), the laser power of the laser generator (300) is 140W-220W, the scanning speed of the laser generator (300) is 1000mm / s-1500mm / s, and the thickness of the powder layer is 60μm-100μm.

8. The laser selective melting forming continuation method according to claim 6, characterized in that, Step S4 includes: S41. The central control system (500) acquires the actual contour data, determines the actual size data of the workpiece (10), compares the actual contour data with the theoretical contour data of the theoretical model, determines the area scaling ratio, and the central control system (500) performs scaling processing on the theoretical contour data according to the area scaling ratio. S42. Compare the actual contour data with the scaled theoretical contour data to determine the displacement data, and move the position of the theoretical model according to the displacement data so that the theoretical contour and the actual contour coincide.

9. The laser selective melting forming continuation method according to claim 6, characterized in that, In step S3, the laser scanning device (400) scans the positioning grid (1100) and the top surface contour of the workpiece (10) with a laser power of 13mW-17mW, a laser wavelength of 600nm-700nm, a dot pitch of 0.005mm-0.015mm, and a scanning speed v < 500,000 dots / second.

10. The laser selective melting forming continuation method according to claim 6, characterized in that, In step S3, when the laser scanning device (400) scans the positioning grid (1100) and the top surface contour of the workpiece (10), the moving accuracy of the laser scanning device (400) is ±1μm.

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