A Laser Welding Method and Equipment for an Aeroengine Component

Abstract

The present invention relates to the field of laser welding technology, and discloses a laser welding method and device for an aero-engine component, including: detecting a welding area to generate geometric morphology data of the area, where the geometric morphology data includes the size, curvature and surface state of the welding area; emitting a preheating beam, adjusting the focal diameter of the preheating beam according to the geometric morphology data to form a preheating area, preheating the welding area, controlling the power and irradiation time of the preheating beam through real-time feedback, starting a welding beam to form a welding area, and performing welding within the preheating area. During the welding process, a heat preservation beam is synchronously emitted to form a heat preservation area around the welding area, and the heat map information during the welding process is monitored in real time. This laser welding method and device for an aero-engine component can make the temperature distribution in the welding area uniform and control the temperature gradient of the material during the welding process, avoid generating large thermal stresses, and improve the welding quality.

Description

Technical Field

[0001] The present invention relates to the technical field of laser welding, and particularly relates to a laser welding method and device for an aeroengine component. Background Art

[0002] An aeroengine is the core power device of modern aircraft, and its performance directly affects the safety, reliability and economy of the aircraft. As an important part of the aeroengine, the combustion chamber shell bears extremely high temperature and pressure, and is required to have excellent heat resistance, strength and oxidation resistance. To meet this series of stringent requirements, the combustion chamber shell is usually made of high-temperature alloys (such as nickel-based alloys) or titanium alloys and other materials. The welding process of these materials requires extremely high precision and stability. During the welding process, controlling the welding quality and preventing welding defects are the keys to ensuring the performance and life of the combustion chamber shell. Any welding defect will seriously affect the overall performance and safety of the engine.

[0003] Currently, the laser welding method for aeroengine components directly uses a laser beam to weld in the area to be welded, and completes the welding process by setting fixed welding parameters (such as welding power, welding speed, etc.). In order to avoid thermal stress and deformation generated during the welding process, relatively low welding power and slow welding speed are usually adopted in the prior art, which is likely to affect the welding efficiency. Moreover, the prior art has insufficient control over thermal stress, which is likely to result in uneven temperature distribution in the welding area and a large temperature gradient of the material during the welding process, easily generating large thermal stress and causing deformation and cracking of the material, thus affecting the welding quality. Summary of the Invention

[0004] The purpose of the present invention is to provide a laser welding method and device for an aeroengine component, so as to make the temperature distribution in the welding area uniform and control the temperature gradient of the material during the welding process, avoid generating large thermal stress, and improve the welding quality.

[0005] To achieve the above purpose, the present invention is realized through the following technical solutions:

[0006] Design a laser welding method for an aeroengine component, including:

[0007] S100. Detect the area to be welded to generate geometric shape data of the area, and the geometric shape data includes the size, curvature and surface state of the welding area;

[0008] S200. Emit a preheating beam, adjust the focus diameter of the preheating beam according to the geometric shape data to form a preheating area, preheat the area to be welded, and control the power and irradiation time of the preheating beam through real-time feedback;

[0009] S300. Start the welding beam to form a welding area and perform welding within the preheating area. During the welding process, synchronously emit a heat preservation beam to form a heat preservation area around the welding area, and real-time monitor the heat map information during the welding process. Dynamically adjust the power and position range of the heat preservation beam according to the heat map information.

[0010] S400. After welding is completed, perform non-destructive testing on the weld seam to obtain the test results. Optimize the collaborative mode and power configuration of the preheating, welding, and heat preservation beams according to the test results.

[0011] Optionally, the S100 specifically includes:

[0012] S110. Clean the area to be welded, removing the oxide layer, oil stains, and other impurities on the surface.

[0013] S120. Use a three-dimensional laser scanner to scan the cleaned area to be welded, collect three-dimensional point cloud data, and adjust the relative position between the scanner and the area to be welded during the scanning process to ensure that the entire area to be welded is covered by the scanning.

[0014] S130. Preprocess the collected three-dimensional point cloud data, remove noise and redundant points, generate a three-dimensional geometric model of the area to be welded, extract the geometric features of the area to be welded, where the geometric features include dimensions, curvature, and surface condition, obtain geometric morphology data, verify the extracted geometric morphology data, and import the verified geometric morphology data into the welding control system.

[0015] Optionally, the 130 specifically includes:

[0016] S131. Process the collected three-dimensional point cloud data using a filtering algorithm to remove noise and redundant points, and generate a three-dimensional geometric model of the area to be welded through three-dimensional modeling.

[0017] S132. Obtain the dimensions of the area to be welded by calculating the external boundaries of the geometric model in each direction, obtain the surface condition of the area to be welded by collecting the surface height data of the area to be welded and calculating the average value of the surface height data of the area to be welded using statistical methods, determine a fitting neighborhood within the neighborhood of each point of the three-dimensional geometric model, and fit the three-dimensional point cloud data within the fitting neighborhood by the least squares method.

[0018] S133. Fit a local surface to obtain the fitted local surface, calculate the principal curvature of the point through the fitted local surface to obtain the curvature, and integrate to obtain the geometric morphology data.

[0019] S134. Compare and verify the geometric morphology data with a preset standard model, perform error analysis, obtain that the geometric morphology data is within the error range, and import the verified geometric morphology data into the welding control system.

[0020] Optionally, the S200 specifically includes:

[0021] S210. Start the preheating beam emission device to emit a preheating beam, preliminarily calibrate the power and irradiation time of the preheating beam, set the focus diameter of different parts of the area to be welded according to the curvature information in the extracted geometric morphology data, set a relatively small focus diameter for the area to be welded with a larger surface curvature, and set a relatively large focus diameter for the area to be welded with a smaller curvature. Irradiate the preheating beam onto the area to be welded to form a preheating area;

[0022] S220. Start the temperature monitoring system to monitor the temperature change of the area to be welded in real time, obtain temperature distribution data, feedback and adjust the power and focus diameter of the preheating beam according to the temperature distribution data, and optimize the focus diameter according to the temperature distribution data;

[0023] S230. Through the feedback control system, confirm the effect after adjusting the focus diameter and power of the preheating beam, so that the preheating area stably and evenly covers the area to be welded, and the temperature should be evenly distributed within a predetermined area.

[0024] Optionally, the S300 specifically includes:

[0025] S310. Emit a welding beam, set the power of the welding beam, set the focus diameter of the welding beam according to the geometric morphology data, and irradiate the welding beam onto the preheating area to form a welding area;

[0026] S320. Synchronously emit a heat preservation beam while emitting the welding beam, set the power, distribution shape and position range of the heat preservation beam according to the geometric morphology data, and form a heat preservation area around the welding area;

[0027] S330. Through the heat map monitoring system, collect data of the welding area, heat preservation area and materials around the heat preservation area in real time during the welding process to obtain heat map information;

[0028] S340. According to the heat map information, dynamically adjust the power and position range of the heat preservation beam through the welding control system.

[0029] Optionally, the distribution shape of the heat preservation beam includes a multi-segment annular beam or a longitudinal strip beam or a dot matrix beam;

[0030] The distribution shape of the heat preservation beam is selected according to the geometric morphology data, and the selected distribution shape is used as the preliminary mode of the light source module.

[0031] Optionally, the S340 specifically includes:

[0032] S341. When the distribution shape of the heat preservation light beam is set as a dot matrix light beam;

[0033] S342. According to the heat map information, for the area with a relatively fast temperature change, increase the density of the dot matrix light beams of the heat preservation light beam and reduce the distance between the dot matrix light beams; for the area with a relatively slow temperature change, reduce the density of the dot matrix light beams and increase the distance between the dot matrix light beams;

[0034] S343. Increase the power of the dot matrix light beams in the area with a lower temperature and reduce the power of the dot matrix light beams in the area with a higher temperature.

[0035] Optionally, the S330 specifically includes:

[0036] S331. Start the heat map monitoring system, which includes an infrared thermal imager and a temperature sensor, and collect data of the welding area, the heat preservation area, and the materials around the heat preservation area in real time;

[0037] S332. Integrate the temperature data collected by the temperature sensor and the image data captured by the infrared thermal imager to generate heat map information and display the temperature distribution.

[0038] Optionally, the heat map information includes the temperature values of the welding area, the heat preservation area, and the materials around them during the welding process, the dividing line of the temperature area, and the change rate over time, which is used to judge the uniformity of the temperature distribution and whether there is a large temperature gradient.

[0039] An aircraft engine component laser welding device, adopting the aircraft engine component laser welding method as described above, includes:

[0040] A detection component, used to scan the area to be welded and generate geometric morphology data of the area;

[0041] A welding component, which includes a welding mechanism and a heat preservation mechanism. The welding mechanism is used to emit a preheating light beam and a welding light beam, and the heat preservation mechanism is used to emit a heat preservation light beam;

[0042] A temperature monitoring mechanism, used to collect temperature data of the area to be welded and the surrounding materials during the welding process in real time to generate heat map information.

[0043] The present invention provides an aircraft engine component laser welding method and device, which have the following beneficial effects:

[0044] The laser welding method and equipment for the aero-engine component ensure a full understanding of the welding area before welding through geometric morphology data detection, so as to provide accurate parameters for subsequent preheating and welding (i.e., the focal diameter for adjusting preheating and welding), avoiding welding defects caused by uneven surface states of materials. The area to be welded is preheated by a preheating beam, and the power and focal diameter of the beam are adjusted using a real-time feedback mechanism to ensure the uniformity of preheating. This not only helps reduce the thermal stress at the initial stage of welding but also prevents material deformation caused by excessive temperature gradients in the welding area. During the welding process, a heat preservation beam is emitted simultaneously and the heat map information is monitored in real time, and the power and position range of the heat preservation beam are dynamically adjusted to ensure uniform temperature distribution around the welding area, effectively reducing material cracking and deformation around the welding area caused by thermal stress during welding, improving the overall quality and reliability of welding. After welding is completed, the weld quality is evaluated by non-destructive testing methods. After obtaining the test results, the collaborative mode and power configuration of the preheating, welding, and heat preservation beams are optimized to further improve the welding quality, consistency, and reliability, thus providing the final performance. Description of the Drawings

[0045] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0046] The structures, proportions, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those familiar with this technology to understand and read, and are not used to limit the conditions under which the present invention can be implemented. Therefore, they do not have a substantial technical meaning. Any modification of the structure, change in the proportional relationship, or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope that can be covered by the technical content disclosed in the present invention.

[0047] Figure 1 It is one of the flow schematic diagrams of the laser welding method for the aero-engine component in Embodiment 1. Detailed Embodiments

[0048] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope protected by the present invention.

[0049] Please refer to Figure 1, the present invention provides a technical solution: a laser welding method for an aero-engine component, comprising:

[0050] S100. Detect the area to be welded to generate geometric morphology data of the area. The geometric morphology data includes the size, curvature, and surface state of the welding area. At the initial stage of laser welding of the aero-engine component, detect the area to be welded and generate the geometric morphology data of this area to obtain detailed information on the size, curvature, and surface state of the welding area. The accurate measurement of the size helps to determine the amount of material required for welding and the action range of the beam. The detection of the curvature obtains the shape characteristics of the welding area, while the surface state, such as surface roughness, flatness, etc., will affect the absorption and reflection of the welding beam and affect the welding effect. Through the geometric morphology data, the physical characteristics of the area to be welded can be grasped, providing data support for subsequent preheating and welding operations;

[0051] S200. Emit a preheating beam. According to the geometric morphology data, adjust the focal diameter of the preheating beam to form a preheating area and preheat the area to be welded. Through real-time feedback control of the power and irradiation time of the preheating beam, emit the preheating beam according to the generated geometric morphology data and adjust its focal diameter to form a uniform preheating area. During the irradiation of the preheating beam, monitor and adjust the power and irradiation time of the beam through a real-time feedback control system to make the preheating beam adapt to the geometric characteristics of the welding area. Through real-time adjustment, ensure the uniform energy distribution of the preheating beam, avoid local overheating or overcooling, thereby reducing thermal stress and material deformation, and providing thermodynamic conditions for the welding process;

[0052] S300. Start the welding beam to form a welding area and perform welding within the preheating area. Among them, during the welding process, synchronously emit a heat preservation beam to form a heat preservation area around the welding area, and real-time monitor the heat map information during the welding process. Dynamically adjust the power and position range of the heat preservation beam according to the heat map information. During the welding process, in order to ensure the welding quality and reduce thermal stress, synchronously emit a heat preservation beam during the welding process to form a heat preservation area around the welding area. Dynamically adjust the power and position range of the heat preservation beam by real-time monitoring the heat map information during the welding process to ensure uniform temperature distribution, avoid local overheating or too fast cooling, and avoid large temperature gradients;

[0053] After the S400 welding is completed, perform non-destructive testing on the weld seam to obtain the test results. According to the test results, optimize the collaborative mode and power configuration of the preheating, welding, and heat preservation beams. The non-destructive testing method can include ultrasonic testing or X-ray testing to ensure the integrity and quality of the weld seam. Analyze the defects and problems in the weld seam based on the test results, and optimize and adjust the collaborative mode and power configuration of the preheating, welding, and heat preservation beams. Through feedback and optimization, continuously improve to ensure the stability and reliability of the welding quality and improve the welding efficiency and effect.

[0054] S100 specifically includes:

[0055] S110. Clean the area to be welded, remove the oxide layer, oil stains, and other impurities on the surface. Clean the area to be welded to avoid surface contaminants from affecting the welding quality. Contaminants in the area to be welded can cause unstable weld seams and welding defects. Clean the welding area by using cleaning agents and mechanical methods (such as brushes, sandpaper, or chemical solvents) to make the surface of the area to be welded smooth and clean, providing a good foundation for scanning and welding operations.

[0056] S120. Use a three-dimensional laser scanner to scan the cleaned area to be welded and collect three-dimensional point cloud data. Adjust the relative position of the scanner and the area to be welded during the scanning process to ensure that the entire area to be welded is covered. During the three-dimensional laser scanning process, continuously adjust the relative position of the scanner and the area to be welded to ensure that all areas are completely covered without omission, ensuring that the collected data accurately reflects the actual shape and surface characteristics of the welding area. These data are used for subsequent geometric feature extraction and analysis.

[0057] S130. Preprocess the collected three-dimensional point cloud data, remove noise and redundant points, generate a three-dimensional geometric model of the area to be welded, extract the geometric features of the area to be welded. The geometric features include dimensions (such as length, width, thickness), curvature (such as radius of curvature), and surface condition (such as surface roughness), to obtain geometric morphology data. Verify the extracted geometric morphology data, and import the verified geometric morphology data into the welding control system to provide a reference position for preheating and welding. First, preprocess the collected three-dimensional point cloud data, use filtering algorithms (such as Gaussian filtering, statistical filtering, etc.) to remove noise and redundant points to ensure the cleanliness and accuracy of the data. Then, generate a three-dimensional geometric model of the area to be welded through surface reconstruction and triangulation technology. Next, extract the geometric features of the welding area, including dimensions (such as length, width, thickness), curvature (such as radius of curvature), and surface condition (such as surface roughness). These geometric morphology data will be verified. Through comparison with the standard model and error analysis, ensure the accuracy of the data. Finally, import the verified geometric morphology data into the welding control system to provide a reference position for preheating and welding, ensuring precise control of the welding process and high-quality output.

[0058] 130 specifically includes:

[0059] S131. Process the collected three-dimensional point cloud data using a filtering algorithm, remove noise and redundant points, and generate a three-dimensional geometric model of the area to be welded through three-dimensional modeling. Through denoising, abnormal points and redundant points in the data can be eliminated, improving the data quality. Subsequently, use three-dimensional modeling technology to convert the processed point cloud data into a three-dimensional geometric model, accurately reflecting the true shape of the area to be welded, providing a basis for subsequent geometric feature extraction.

[0060] S132. Obtain the dimensions (i.e., length, width, thickness) of the area to be welded by calculating the external boundaries of the geometric model in each direction. By collecting the surface height data of the area to be welded and using statistical methods to calculate the average value of the surface height data of the area to be welded, obtain the surface condition (i.e., surface roughness) of the area to be welded. Determine a fitting neighborhood within the neighborhood of each point in the three-dimensional geometric model, and fit the three-dimensional point cloud data within the fitting neighborhood by the least squares method.

[0061] S133. Fit a local surface to obtain the fitted local surface, calculate the principal curvature of the points through the fitted local surface to obtain the curvature (i.e., radius of curvature), and integrate to obtain the geometric morphology data.

[0062] S134. Compare the geometric shape data with a preset standard model, conduct error analysis, and obtain that the geometric shape data is within the error range. Import the verified geometric shape data into the welding control system to provide a reference position for preheating and welding. By comparison, determine whether the geometric shape data is within the allowable error range to ensure the reliability of the data. Through error analysis, outliers in the data can be discovered and corrected to ensure the accuracy of the data. Import the verified geometric shape data into the welding control system to provide a reference position for the preheating and welding processes. The welding control system uses this data to optimize the welding path, power configuration, and other parameters, improving the accuracy and quality of the welding process.

[0063] S200 specifically includes:

[0064] S210. Start the preheating beam emission device to emit a preheating beam, initially calibrate the power and irradiation time of the preheating beam. According to the curvature information in the extracted geometric shape data, set the focal diameters of different parts of the area to be welded. Set a relatively small focal diameter for the area to be welded with a larger surface curvature, and set a relatively large focal diameter for the area to be welded with a smaller curvature. Irradiate the preheating beam onto the area to be welded to form a preheating area. First, start the preheating beam emission device to emit an initial preheating beam towards the area to be welded. To ensure the accuracy of the preheating process, first initially calibrate the power and irradiation time of the preheating beam so that the beam can evenly cover the area to be welded and achieve the required initial preheating effect. According to the curvature information in the geometric shape data extracted in the previous step, set the focal diameters of different parts of the area to be welded. For areas with a larger surface curvature, select a relatively small focal diameter to ensure that the beam energy is highly concentrated and improve the local heating efficiency; for areas with a smaller surface curvature, set a larger focal diameter to evenly distribute the beam energy and avoid local overheating. Finally, irradiate the adjusted preheating beam onto the area to be welded to form a preheating area to prepare for the subsequent welding process.

[0065] S220. Start the temperature monitoring system to continuously monitor the temperature changes in the area to be welded and obtain temperature distribution data. Adjust the power and focal diameter of the preheating beam according to the feedback of the temperature distribution data. Optimize the focal diameter according to the temperature distribution data. The temperature monitoring system obtains the temperature distribution data of the area to be welded through an infrared thermal imager or other sensors, accurately records the temperatures of different points in the area, and adjusts the power and focal diameter of the preheating beam according to the real-time feedback of the temperature distribution data. For areas with a lower temperature, increase the power of the preheating beam or adjust the focal diameter to concentrate more heat; for areas with a higher temperature, appropriately reduce the beam power or increase the focal diameter to avoid local overheating. Through this dynamic adjustment, ensure that the temperature distribution in the area to be welded is uniform, avoid local temperatures being too high or too low, thereby improving the preheating effect and welding quality.

[0066] S230. Through the feedback control system, confirm the effects after adjusting the focus diameter and power of the preheating beam, so that the preheating area stably and uniformly covers the area to be welded. The temperature should be evenly distributed within the predetermined area. According to the temperature distribution data collected and analyzed in real time for the area to be welded, ensure that the preheating area stably and uniformly covers the entire area to be welded. At this stage, the temperature in the preheating area is evenly distributed within the predetermined area, avoiding local overheating or overcooling phenomena to prevent welding defects (such as cold cracks, hot cracks, etc.). Once the temperature distribution reaches the expectation and it is confirmed that the preheating area has achieved the required stability and uniformity, perform the final adjustment. At this time, precisely adjust the power and focus diameter of the preheating beam to ensure the smooth progress of the subsequent welding process and provide appropriate temperature conditions for welding, thereby improving the welding quality.

[0067] S300 specifically includes:

[0068] S310. Emit the welding beam, set the power of the welding beam, and set the focus diameter of the welding beam according to the geometric morphology data. Irradiate the welding beam onto the preheating area to form a welding area. Setting the power of the welding beam ensures that there is sufficient energy to melt and fuse the engine component materials together. Too low power may result in insecure welding, while too high power may damage the components. It is also crucial to set the focus diameter of the welding beam based on the geometric morphology data of the components. Different geometric shapes and sizes require appropriate focus diameters to ensure that the welding beam can accurately act on the target area. Then irradiate the welding beam onto the preheating area, which has been pre-treated to facilitate the smooth progress of the welding process, thereby forming a welding area. This step lays the foundation for subsequent welding and heat preservation operations. Appropriate welding parameter settings can improve the welding quality, reduce welding defects, and ensure the performance and safety of aeroengine components;

[0069] S320. Synchronously emit the heat preservation beam while emitting the welding beam. Set the power, distribution shape, and position range of the heat preservation beam according to the geometric morphology data to form a heat preservation area around the welding area. The heat preservation beam forms a heat preservation area around the welding area. On the one hand, it can prevent the welding area from cooling rapidly after welding because rapid cooling will generate large internal stresses in the welded part, which may lead to defects such as cracks and affect the service life and reliability of aeroengine components. On the other hand, appropriate heat preservation can make the material microstructure in the welding area more uniform, improve the strength and toughness of the welded joint, and ensure that the components can still operate stably under complex working conditions. By precisely setting the distribution shape and position range of the heat preservation beam, accurate heat preservation control can be carried out for different welding situations, effectively improving the heat preservation effect;

[0070] S330. Through the heat map monitoring system, data of the welding area, the heat preservation area, and the materials around the heat preservation area are collected in real time during the welding process to obtain heat map information. By collecting the data of the welding area, the heat preservation area, and the materials around the heat preservation area, heat map information can be obtained. These information can intuitively reflect the temperature distribution in each area during the welding process. The temperature distribution provides a data basis for subsequent welding quality control and can timely detect the situation of possible local overheating or underheating during the welding process;

[0071] S340. According to the heat map information, the power and position range of the heat preservation beam are dynamically adjusted through the welding control system. After obtaining the detailed heat map information, the welding control system can dynamically adjust the power and position range of the heat preservation beam according to the actual temperature distribution. In terms of power adjustment, when it is detected that the temperature of a certain part of the welding area is too low, appropriately increasing the power of the heat preservation beam can increase the heat input in this area and avoid welding defects caused by insufficient temperature. On the contrary, if the temperature of a certain part is too high, reducing the power can prevent material damage caused by overheating. In terms of position range adjustment, according to the situation shown in the heat map, the heat preservation beam is accurately moved to the area that needs heat preservation, which can ensure that the entire welding area and the surrounding materials are in a suitable temperature environment. This dynamic adjustment can further optimize the temperature field during the welding process, make the temperature in the welding area more uniform, thereby improving the welding quality, reducing welding deformation and internal stress, enhancing the overall performance and reliability of the aeroengine components, and meeting the usage requirements of the aeroengine under extreme working conditions such as high temperature and high pressure.

[0072] In this embodiment, as a preferred solution, the distribution shape of the heat preservation beam includes a multi-segment ring-shaped beam, a longitudinal strip-shaped beam, or a dot matrix-shaped beam;

[0073] The distribution shape of the heat preservation beam is selected according to the geometric morphology data, and the selected distribution shape is used as the preliminary mode of the light source module;

[0074] A gradient heat preservation field is formed by multi-segment ring superposition, which can accurately match complex curved surface structures (such as the root surface of a turbine blade, a special-shaped flange interface, or the connection section between a conical combustion chamber outer shell and a turbine), realizing circumferential uniform heat dissipation. For example, when welding a disk assembly with a changing curvature, the ring distribution can effectively suppress local heat accumulation caused by geometric mutations and avoid circumferential stress concentration. Or during the welding of the combustion chamber outer shell, circumferential uniform heat compensation can be realized, suppressing the "fish tail" defect caused by the temperature difference between the starting and ending points of welding. The heat field generated by the multi-segment ring-shaped beam can guide the solidification direction of the molten pool to be consistent with the main stress direction of the combustion chamber (such as the circumferential weld at the turbine end), making the columnar crystals arranged tangentially, which can improve the high-temperature creep resistance of the welded part of the combustion chamber outer shell, and a continuous heat barrier can be formed at the edge of the multi-segment ring-shaped beam, reducing the turbulence of the shielding gas;

[0075] During the welding process of the longitudinal seam of the combustion chamber cylinder (i.e., the straight weld of the afterburner) or the planar structure with stiffeners (i.e., the welding of the outer shell cooling rib plates), the longitudinal strip-shaped light beam forms a gradient heat preservation field. The length direction of the longitudinal strip-shaped light beam is parallel to the welding direction, which can synchronously compensate for the longitudinal shrinkage stress. When there are fluctuations in the assembly gap (i.e., the gap changes between 0.1 - 0.3 mm), the strip width can be dynamically expanded to 1.5 - 3 mm. The gap is filled by the edge heat flow to avoid lack of fusion defects, and the longitudinal strip-shaped light beam can form a width gradient transition zone;

[0076] During the welding process of the gradient heat preservation field formed by the dot-shaped light beam in the ultra-thin combustion chamber wall plate (i.e., the superalloy with a thickness of 0.3 - 0.8 mm) or the interface bonding area formed by the connection of multiple materials (i.e., the ceramic matrix composite and the superalloy), taking the ultra-thin combustion chamber wall plate (i.e., the alloy with a thickness of 0.3 - 0.8 mm) as an example, when the spacing of the dot-shaped light beam is 0.2 - 0.5 mm, the heat input density decreases, which can prevent the thin wall from burning through and is suitable for the welding of the 0.3 mm-class combustion chamber tail nozzle. Taking the interface bonding area formed by the connection of multiple materials (i.e., the ceramic matrix composite and the superalloy) as an example, the gap of the dot-shaped light beam can provide a release path for the residual stress and can reduce the welding crack rate of the ceramic matrix composite outer shell;

[0077] During the light beam selection process, for the curved surface / ring-shaped structure (i.e., the circumferential weld of the flame tube or the connection section between the conical combustion chamber outer shell and the turbine), multi-segment ring-shaped light beams are preferentially selected. For dissimilar materials / thin walls (i.e., the connection between titanium alloy and ceramic), dot-shaped light beams are selected. For long straight welds / stiffeners (i.e., the longitudinal seam of the cylinder), longitudinal strip-shaped light beams are used. Taking the welding of the conical combustion chamber as an example, the straight edge section of the cone uses longitudinal strip-shaped light beams, and the curved edge section is switched to multi-segment ring-shaped light beams. The light beams can be quickly switched and used in combination. Combining the heat map information, when local overheating is detected, the ring-shaped light beam is switched to the dot-shaped light beam to form a "shape-power" double closed-loop control.

[0078] S340 specifically includes:

[0079] S341. When the distribution shape of the heat preservation light beam is set as the dot-shaped light beam, the dot-shaped light beam will be distributed in the form of multiple points instead of continuous light beam irradiation, which can more precisely control the heat distribution and avoid heat concentration at a certain point, resulting in local overheating or overcooling. Through the dot-shaped distribution, higher flexibility can be provided for the temperature adjustment of each point and the heat distribution in the heat preservation area can be made more uniform, which helps to maintain the stability and uniformity of the temperature during the welding process;

[0080] S342. According to the heat map information, for areas with rapid temperature changes, increase the density of the dot-matrix beams of the thermal insulation beams and reduce the spacing between the dot beams. For areas with slow temperature changes, reduce the density of the dot-matrix beams and increase the spacing of the dot-matrix beams. When the temperature changes rapidly in certain areas during the welding process, more heat input is required to quickly restore temperature uniformity. Therefore, increase the density of the dot-matrix beams and reduce the spacing between points, so that more beams can irradiate this area, thereby accelerating its temperature rise. For areas with slow temperature changes, the heat is already relatively uniform. Reducing the density of the thermal insulation beams and increasing the point spacing can avoid overheating. This dynamic adjustment can optimize the heat distribution according to the thermal changes in different areas, ensuring temperature stability during the welding process;

[0081] S343. Increase the power of the dot-matrix beams in the areas with lower temperatures and reduce the power of the dot-cross beams in the areas with higher temperatures. For the areas with lower temperatures, increase the power of the dot-matrix beams to provide more heat to raise the temperature of this area, making the temperature of the entire welding area more uniform. For the areas with higher temperatures, reduce the power output of the dot-matrix beams to avoid overheating and prevent welding defects such as excessive melting or excessive metal expansion. This method of dynamically adjusting the beam power according to temperature changes can ensure that the entire welding area is within the ideal temperature range, thereby improving the welding quality and reducing the occurrence of adverse effects;

[0082] In the welding of the combustion chamber outer casing of an aeroengine, the dot-matrix beams discretize the energy input and decompose the continuous thermal field into multiple independently controllable micro-regions (i.e., the dot-matrix beams are distributed in a dot matrix with a spacing of 0.2 - 0.5 mm). It is applicable to thin-walled (i.e., 0.3 mm-class combustion chamber wall panels) and interface bonding regions formed by connecting multiple materials (i.e., ceramic matrix composites and superalloys). The dot-matrix thermal insulation beams can reduce the heat input density per unit area and avoid burning through ultra-thin components. According to the heat map information, for areas with rapid temperature changes, the dot matrix density is increased from the conventional 20 points / cm² to 50 points / cm², and the spacing is reduced from 0.5 mm to 0.2 mm. The high-density dot matrix coverage suppresses sudden temperature changes, reducing the width of the heat-affected zone from 1.5 mm to 0.8 mm. For areas with slow temperature changes, the density is reduced to 10 points / cm², and the spacing is increased to 1.0 mm to reduce redundant heat input and avoid grain coarsening of materials caused by heat diffusion;

[0083] When adjusting the power of the dot matrix beam, that is, when a low-temperature region with ΔT≥80°C is detected, such as the interface bonding region formed by connecting multiple materials (i.e., ceramic matrix composite and superalloy), the dot matrix power is increased from 500W to 800W to promote the formation of the diffusion layer through local thermal compensation and inhibit the generation of brittle intermetallic compounds. When an overheating region with ΔT≤ -50°C is detected (such as around the center of the molten pool), the power is reduced from 800W to 300W, and a "thermal barrier" is formed by combining with the reduction of the dot matrix density.

[0084] S330 specifically includes:

[0085] S331. Start the heat map monitoring system. The heat map monitoring system includes an infrared thermal imager and a temperature sensor, which collect data of the welding area, the heat preservation area, and the materials around the heat preservation area in real time. Through the collaborative work of the infrared thermal imager and the distributed optical fiber temperature sensor, a three-dimensional thermal field reconstruction of the welding area is carried out. The infrared thermal imager captures the surface radiation heat distribution at a sampling rate of 1000Hz. The synchronous optical fiber sensor is located on the back of the weld to obtain the internal temperature gradient. An infrared filter with a wavelength of 1.5μm is used to shield the welding plasma interference and reduce the temperature measurement error during welding. At this time, in the application of nickel-based single crystal alloy welding, data of 8 axial temperature measurement points are collected simultaneously with the welding system to construct a heat conduction model in the thickness direction and accurately predict the grain growth trend in the heat affected zone;

[0086] S332. Integrate the temperature data collected by the temperature sensor and the image data captured by the infrared thermal imager to generate heat map information and display the temperature distribution. Align the infrared image and the optical fiber temperature data at the sub-pixel level to establish a temperature field model in a three-dimensional coordinate system. At the same time, when the temperature gradient exceeds the critical value (for example, ΔT>300°C / mm during titanium alloy welding), an early warning is automatically triggered and the potential crack area is marked.

[0087] The heat map information includes the temperature values of the welding area, the heat preservation area, and the materials around them during the welding process, the dividing line of the temperature area, and the change rate over time, which is used to judge the uniformity of the temperature distribution and whether there is a large temperature gradient. Optical fiber sensors are arranged in the welding area to obtain the temperature values of key points (such as the center of the molten pool and the boundary of the heat affected zone) at a sampling frequency of 0.1 second, and cooperate with the infrared thermal imager to scan to generate a temperature gradient image and capture the dynamic change of the dividing line of the temperature area;

[0088] Based on the obtained temperature field model, combined with the heat flux inversion calculation, based on the finite element heat conduction equation, the heat flux density distribution is inversely deduced through the grid nodes to predict the molten pool expansion trend in advance.

[0089] A laser welding device for an aeroengine component adopts the above-mentioned laser welding method for an aeroengine component, including:

[0090] A detection component for scanning the area to be welded and generating geometric morphology data of the area;

[0091] A welding component, the welding component includes a welding mechanism and a heat preservation mechanism, the welding mechanism is used to emit a preheating beam and a welding beam, and the heat preservation mechanism is used to emit a heat preservation beam;

[0092] A temperature monitoring mechanism for real-time collecting temperature data of the area to be welded and surrounding materials during the welding process to generate heat map information.

[0093] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A laser welding method for aircraft engine components, characterized in that: include: S100, inspecting the area to be welded and generating geometric shape data of the area, wherein the geometric shape data includes the size, curvature and surface state of the welding area; S200, emitting a preheating beam, adjusting the focal diameter of the preheating beam according to the geometric shape data, forming a preheating area, preheating the area to be welded, and controlling the power and irradiation time of the preheating beam through real-time feedback; S300, starting a welding beam to form a welding area, so that welding is performed in the preheating area, wherein during the welding process, a heat preservation beam is synchronously emitted to form a heat preservation area around the welding area, and heat map information during the welding process is monitored in real time, and the power and position range of the heat preservation beam are dynamically adjusted according to the heat map information; S400, after the welding is completed, the weld is subjected to nondestructive testing to obtain the test results, and the coordination mode and power configuration of the preheating, welding and insulation beams are optimized according to the test results; The S200 specifically includes: S210, starting the preheating beam emitting device to emit the preheating beam, preliminarily calibrating the power and irradiation time of the preheating beam, setting the focal diameters of different parts of the area to be welded according to the curvature information in the extracted geometric morphology data, setting a relatively small focal diameter for the area to be welded with a larger surface curvature, and setting a relatively large focal diameter for the area to be welded with a smaller curvature, irradiating the preheating beam to the area to be welded, and forming a preheating area; S220, start the temperature monitoring system, monitor the temperature change of the area to be welded in real time, obtain temperature distribution data, adjust the power and focus diameter of the preheating beam according to the temperature distribution data feedback, and optimize the focus diameter according to the temperature distribution data; S230, confirming the effect of adjusting the focal diameter and power of the preheating beam through a feedback control system, so that the preheating area stably and evenly covers the area to be welded, and the temperature should be evenly distributed in the predetermined area; The S300 specifically includes: S310, emitting a welding beam, setting the power of the welding beam, setting the focal diameter of the welding beam according to the geometric shape data, irradiating the welding beam to the preheating area, and forming a welding area; S320, emitting a heat preservation beam synchronously with the emitting welding beam, setting the power, distribution shape and position range of the heat preservation beam according to the geometric shape data, and forming a heat preservation area around the welding area; S330, using a heat map monitoring system, collecting data of the welding area, the insulation area, and materials around the insulation area in real time during the welding process to obtain heat map information; S340, dynamically adjusting the power and position range of the heat preservation beam through the welding control system according to the heat map information; The distribution shape of the heat preservation light beam includes a multi-segment ring-shaped light beam or a longitudinal strip-shaped light beam or a dot-shaped light beam; The distribution shape of the heat preservation light beam is selected according to the geometric shape data, and the selected distribution shape is used as the preliminary mode of the light source module.

2. The method for laser welding of aircraft engine components according to claim 1, characterized in that: The S100 specifically includes: S110, clean the area to be welded and remove the oxide layer, oil stains and other impurities on the surface; S120, using a 3D laser scanner to scan the cleaned area to be welded, collecting 3D point cloud data, and adjusting the relative position between the scanner and the area to be welded during the scanning process to ensure that the scanning covers the entire area to be welded; S130, preprocessing the collected three-dimensional point cloud data, removing noise and redundant points, generating a three-dimensional geometric model of the area to be welded, extracting geometric features of the area to be welded, the geometric features including size, curvature and surface state, obtaining geometric morphology data, verifying the extracted geometric morphology data, and importing the verified geometric morphology data into a welding control system.

3. The method for laser welding of aircraft engine components according to claim 2, characterized in that: The S130 specifically includes: S131, using a filtering algorithm to process the collected three-dimensional point cloud data, removing noise and redundant points, and generating a three-dimensional geometric model of the area to be welded through three-dimensional modeling; S132, obtaining the size of the area to be welded by calculating the outer boundaries of the geometric model in all directions, obtaining the surface state of the area to be welded by collecting surface height data of the area to be welded and calculating the average value of the surface height data of the area to be welded by using a statistical method, determining a fitting neighborhood in the neighborhood of each point of the three-dimensional geometric model, and fitting the three-dimensional point cloud data in the fitting neighborhood by using a least squares method; S133, fitting a local surface to obtain a fitted local surface, calculating the principal curvature of the point through the fitted local surface to obtain the curvature, and obtaining geometric shape data through integration; S134, comparing and verifying the geometric shape data with a preset standard model, performing error analysis, obtaining that the geometric shape data is within an error range, and importing the verified geometric shape data into a welding control system.

4. The method for laser welding of aircraft engine components according to claim 1, characterized in that: The S340 specifically includes: S341, when the distribution shape of the heat preservation light beam is set to a lattice light beam; S342. According to the heat map information, for areas where the temperature changes rapidly, the density of the dot-shaped beams of the heat preservation beams is increased, and the spacing between the dot-shaped beams is reduced; for areas where the temperature changes slowly, the density of the dot-shaped beams is reduced, and the spacing between the dot-shaped beams is increased; S343. Increase the dot-matrix beam power in the lower temperature area and reduce the dot-matrix cross beam power in the higher temperature area.

5. The method for laser welding of aircraft engine components according to claim 1, characterized in that: The S330 specifically includes: S331, start a heat map monitoring system, wherein the heat map monitoring system includes an infrared thermal imager and a temperature sensor, and collects data of the welding area, the insulation area, and the materials around the insulation area in real time; S332. Integrate the temperature data collected by the temperature sensor and the image data captured by the infrared thermal imager to generate heat map information to display the temperature distribution.

6. The method for laser welding of aircraft engine components according to claim 1, characterized in that: The heat map information includes the temperature values ​​of the welding area, the insulation area and the surrounding materials during the welding process, the boundary lines of the temperature areas and the rate of change over time, which is used to determine the uniformity of the temperature distribution and whether there is a large temperature gradient.

7. A laser welding device for aircraft engine components, characterized in that: The method for laser welding of aircraft engine components according to any one of claims 1 to 6 comprises: A detection component is used to scan the area to be welded and generate geometric shape data of the area; A welding assembly, the welding assembly comprising a welding mechanism and a heat preservation mechanism, the welding mechanism is used to emit a preheating beam and a welding beam, and the heat preservation mechanism is used to emit a heat preservation beam; The temperature monitoring mechanism is used to collect temperature data of the area to be welded and the surrounding materials during the welding process in real time to generate heat map information.

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