Synchronous Method and Device for Laser Preheating and Laser Deposition of Wear-Resistant Layer on Turbine Blade Tip

Abstract

The present invention discloses a synchronous method and device for laser preheating and laser deposition of a wear-resistant layer on a turbine blade crown, which relates to the technical field of manufacturing components of an aero-engine. Among them, the synchronous method for laser preheating and laser deposition of the wear-resistant layer on the turbine blade crown includes a pretreatment step, a scanning path planning step, a parameter determination step, a synchronization step, a deposition step, and a control step, so that the laser preheating and laser deposition of the turbine blade crown workpiece are carried out synchronously. At the same time, it is ensured that during the deposition stage on the workpiece surface, the preheating temperature of the turbine blade crown workpiece is within the first target temperature range, and during the deposition stage on the surface to be deposited of the wear-resistant layer, the preheating temperature of the surface to be deposited of the wear-resistant layer is within the second target preheating temperature value range, realizing the synchronous preheating of the turbine blade crown workpiece and the surface to be deposited of the wear-resistant layer. Moreover, as the deposition process continues, the target preheating temperature can always be maintained, thereby effectively preventing the cracking of the wear-resistant layer on the turbine blade crown.

Description

Technical Field

[0001] The present invention belongs to the technical field of manufacturing of aero-engine components, and particularly relates to a synchronous method and device for laser preheating and laser deposition of a wear-resistant layer on a turbine blade crown. Background Art

[0002] At present, superalloys have excellent comprehensive high-temperature performance and excellent thermal fatigue characteristics, and have been widely used in manufacturing hot-end components such as turbine blades of aero-engines. However, during operation, severe wear occurs at the contact of the blade crowns of turbine blades, and the wear gradually develops and eventually easily leads to the overall failure of the turbine blades, seriously affecting the mechanical properties and safety of the engine. Therefore, preparing a wear-resistant layer on the surface of the turbine blade crown to improve its wear resistance is of great significance for extending the service life of the turbine blade. Since the heating or cooling rate during the laser deposition process can reach up to 107 K / s at most, the temperature gradient of the molten pool is high, the solidification speed is fast, and the generated thermal stress is high, so cracking is very likely to occur. In addition, the deposited material used for the wear-resistant layer has high hardness, high brittleness, and high crack sensitivity of the superalloy material. These factors all exacerbate the cracking of the surface laser-deposited wear-resistant layer of the superalloy turbine blade crown workpiece, seriously affecting the surface quality and mechanical properties of the wear-resistant layer.

[0003] In the prior art, for the cracking problem of the surface laser-deposited wear-resistant layer of the turbine blade crown workpiece, preheating the workpiece to be processed of the turbine blade crown before deposition can effectively reduce the possibility of cracking of the wear-resistant layer. The traditional preheating method mainly uses devices such as electric heating plates and vacuum furnaces to heat the substrate, but it has the following insurmountable disadvantages: the existing preheating method cannot achieve synchronous preheating of the turbine blade crown workpiece or the surface to be deposited with the wear-resistant layer, and it is difficult to always maintain the initial preheating temperature during the deposition process, nor can it perform real-time monitoring of the preheating temperature of the turbine blade crown workpiece and the surface to be deposited with the wear-resistant layer.

[0004] To solve the above deficiencies, it is necessary to study a synchronous method and device for laser preheating and laser deposition of a wear-resistant layer on a turbine blade crown. Summary of the Invention

[0005] The purpose of the present invention is to provide a synchronous method and device for laser preheating and laser deposition of a wear-resistant layer on a turbine blade crown, which solves the technical problems that the existing preheating method cannot achieve synchronous preheating of the turbine blade crown workpiece or the surface to be deposited with the wear-resistant layer, and it is difficult to always maintain the initial preheating temperature during the deposition process, nor can it perform real-time monitoring of the preheating temperature of the turbine blade crown workpiece and the surface to be deposited with the wear-resistant layer.

[0006] The first aspect of the present invention provides a synchronous method for laser preheating and laser deposition of a wear-resistant layer on a turbine blade crown, including a pretreatment step: pretreating the turbine blade crown workpiece and the wear-resistant layer material, adjusting the working angle of the infrared imager, and adjusting the laser preheating working head through a universal coupling; a scanning path planning step: starting the three-axis linkage numerical control machine tool control system to plan the scanning paths of the laser deposition working head and the laser preheating working head; a parameter determination step: determining the process parameters of the laser deposition working head and the laser preheating working head according to the properties of the turbine blade crown workpiece and the wear-resistant layer material; a synchronous step: according to the scanning path and the process parameters, making the laser preheating working head and the laser deposition working head move synchronously along the scanning path and emitting laser beams synchronously; a deposition step: through the control of the PLC controller, during the deposition stage on the workpiece surface, controlling the temperature of the turbine blade crown workpiece to rise to the first target preheating temperature; during the deposition stage on the surface to be deposited of the wear-resistant layer, controlling the temperature of the surface to be deposited of the wear-resistant layer to rise to the second target preheating temperature, thereby obtaining the wear-resistant layer of the turbine blade crown workpiece; a control step: real-time monitoring the preheating temperature of the turbine blade crown workpiece and the preheating temperature of the surface to be deposited of the wear-resistant layer through an infrared thermal imager, and controlling the preheating temperature of the turbine blade crown workpiece to be at the first target preheating temperature and controlling the preheating temperature of the surface to be deposited of the wear-resistant layer to be at the second target preheating temperature through the PLC controller.

[0007] Optionally, in the parameter determination step, according to the properties of the wear-resistant layer material, the process parameters of the laser deposition working head are determined through the PLC controller, the first target preheating temperature is obtained according to the dynamic recrystallization temperature of the turbine blade crown workpiece, the second target preheating temperature is obtained according to the dynamic recrystallization temperature of the wear-resistant layer material, and then the process parameters of the laser preheating working head are determined according to the first target preheating temperature and the second target preheating temperature.

[0008] Optionally, in the parameter determination step, a simultaneous model of energy density and temperature is set in the PLC controller, and the process parameters of the laser deposition working head and the laser preheating working head are calculated through the simultaneous model of energy density and temperature, where the simultaneous model of energy density and temperature is:

[0009] α(P / VDh)=C p dΔT

[0010] where α is the laser absorption rate of the turbine blade crown workpiece or the wear-resistant layer material, P is the laser power, V is the scanning speed, D is the spot diameter, h is the deposition layer thickness, C p is the specific heat capacity of the turbine blade crown workpiece or the wear-resistant layer material, d is the density of the turbine blade crown workpiece or the wear-resistant layer material, and ΔT is the temperature difference between the initial temperature and the dynamic recrystallization temperature of the turbine blade crown workpiece or the wear-resistant layer material.

[0011] Optionally, in the synchronization step, a three-axis linkage numerically controlled machine tool and a laser generator are used to synchronously move the laser preheating head and the laser deposition head along the scanning path, and the laser deposition head emits a laser beam with a spot diameter of d1, and the laser preheating head emits a laser beam with a spot diameter of wherein, the spot diameter is smaller than the spot diameter d1.

[0012] Optionally, in the control step, if the preheating temperature of the turbine blade crown workpiece is lower than the first target preheating temperature and the preheating temperature of the surface to be deposited with the wear-resistant layer is lower than the second target preheating temperature value range, the PLC controller transmits a temperature increase signal, or

[0013] if the preheating temperature of the turbine blade crown workpiece is higher than the first target preheating temperature and the preheating temperature of the surface to be deposited with the wear-resistant layer is higher than the second target preheating temperature value range, the PLC controller transmits a slow cooling signal, or

[0014] if the preheating temperature of the turbine blade crown workpiece is within the first target preheating temperature value range and the preheating temperature of the surface to be deposited with the wear-resistant layer is within the second target preheating temperature value range, the PLC controller transmits a control signal and continues to repeat the control step.

[0015] The second aspect of the present invention provides a synchronization device for laser preheating and laser deposition of a wear-resistant layer of a turbine blade crown, including: a three-axis linkage numerically controlled machine tool, including a bed body; a robotic arm, arranged on the side surface of the bed body and connected to the bed body; a fixing plate, arranged at the end of the robotic arm and connected to the robotic arm; a central hole, penetratingly arranged on the fixing plate; a universal coupling, arranged at the end of the fixing plate away from the robotic arm and connected to the fixing plate; a laser preheating head, arranged at the lower end of the universal coupling and connected to the universal coupling; a laser deposition head, passing through the fixing plate through the central hole and connected to the fixing plate.

[0016] Optionally, a laser generator is arranged on the first side surface of the bed body and is connected to both the laser deposition head and the laser preheating head.

[0017] Optionally, a workbench is arranged on the upper end surface of the bed body and is connected to the bed body; an infrared thermal imager is arranged on the upper end surface of the workbench and is connected to the workbench; a PLC controller is arranged on the side surface of the bed body and is connected to the infrared thermal imager.

[0018] Optionally, an annular slide rail is arranged on the upper end surface of the workbench and is connected to the workbench; a motor pulley car is arranged on the annular slide rail and is slidably connected to the annular slide rail; an air supply port is arranged on the side surface of the motor pulley car close to the fixing plate and is connected to the motor pulley car.

[0019] Optionally, the powder feeder and the argon gas cylinder integrated device is arranged on the second side of the bed body and connected to the laser deposition working head.

[0020] A synchronous method and device for laser preheating and laser deposition of a wear-resistant layer on a turbine blade crown provided by the present invention enables the synchronous progress of laser preheating and laser deposition of the turbine blade crown workpiece. Meanwhile, it ensures that during the deposition stage on the workpiece surface, the preheating temperature of the turbine blade crown workpiece is within the first target temperature range, and during the deposition stage on the surface to be deposited of the wear-resistant layer, the preheating temperature of the surface to be deposited of the wear-resistant layer is lower than the second target preheating temperature value range. It realizes the synchronous preheating of the turbine blade crown workpiece and the surface to be deposited of the wear-resistant layer, and can always maintain the preheating temperature as the deposition process continues. Moreover, it realizes the real-time online monitoring of the preheating temperature, thereby effectively preventing the cracking of the wear-resistant layer on the turbine blade crown. Description of the Drawings

[0021] By referring to the accompanying drawings and reading the following detailed description, the above and other objects, features, and advantages of the exemplary embodiments of the present invention will become easily understandable. In the drawings, several embodiments of the present invention are shown in an exemplary rather than restrictive manner, and the same or corresponding reference numerals represent the same or corresponding parts, where:

[0022] Figure 1 It is a schematic diagram of the operation process of the synchronous method for laser preheating and laser deposition of the wear-resistant layer on the turbine blade crown of the present invention;

[0023] Figure 2 It is a schematic diagram of the structure of the synchronous device for laser preheating and laser deposition of the wear-resistant layer on the turbine blade crown of the present invention;

[0024] Figure 3 It is a schematic diagram of the structure of the synchronous device for laser preheating and laser deposition of the wear-resistant layer on the turbine blade crown of the present invention from another angle;

[0025] Figure 4 It is a cross-sectional metallographic diagram of laser deposition of the wear-resistant layer on the turbine blade crown workpiece under the traditional vacuum furnace preheating method;

[0026] Figure 5 It is a cross-sectional metallographic diagram of laser deposition of the wear-resistant layer on the turbine blade crown workpiece under the laser synchronous preheating of the present invention.

[0027] Explanation of the Reference Numerals in the Drawings:

[0028] 1. Protection gas control system; 2. Three-axis linkage numerical control machine tool control system; 3. Integrated device of powder feeder and argon gas cylinder; 4. PLC controller; 5. Workbench; 6. Infrared thermal imager; 7. Ring-shaped slide rail; 8. Turbine blade crown workpiece; 9. Robot arm; 10. Fixed disk; 11. Laser deposition working head; 12. Universal coupling; 13. Laser preheating working head; 14. Air supply port; 15. Motor pulley car; 16. Pulley car control system; 17. Laser generator; 18. Laser generator control system; 19. Crack 1 generated by laser deposition of wear-resistant layer on turbine blade crown workpiece under traditional vacuum furnace preheating method; 20. Crack 2 generated by laser deposition of wear-resistant layer on turbine blade crown workpiece under traditional vacuum furnace preheating method. Specific implementation manners

[0029] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present disclosure can be more thoroughly understood and the scope of the present disclosure can be fully conveyed to those skilled in the art. Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art.

[0030] It should be noted that unless otherwise specified, the technical terms or scientific terms used in the present invention should have the ordinary meaning understood by those skilled in the art to which the present invention belongs. The terms "comprising", "including" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, the elements defined by the statement "including..." do not exclude the existence of additional identical elements in the process, method, article or device including the said elements.

[0031] This embodiment provides a synchronous method for laser preheating and laser deposition of a wear-resistant layer on a turbine blade crown. Pretreatment step: Pretreat the turbine blade crown workpiece 8 and the wear-resistant layer material, adjust the working angle of the infrared imager 6, and adjust the laser preheating head 13 through the universal coupling 12; Scanning path planning step: Start the three-axis linkage numerical control machine tool control system 2 to plan the scanning paths of the laser deposition head 11 and the laser preheating head 13; Parameter determination step: Determine the process parameters of the laser deposition head 11 and the laser preheating head 13 according to the properties of the turbine blade crown workpiece 8 and the wear-resistant layer material; Synchronization step: According to the scanning paths and process parameters, make the laser preheating head 13 and the laser deposition head 11 move synchronously along the scanning paths, and emit laser beams synchronously; Deposition step: Through the PLC controller 4, during the deposition stage on the workpiece surface, control the temperature of the turbine blade crown workpiece 8 to rise to the first target preheating temperature; during the deposition stage on the surface to be deposited of the wear-resistant layer, control the temperature of the surface to be deposited of the wear-resistant layer to rise to the second target preheating temperature, thereby obtaining the wear-resistant layer of the turbine blade crown workpiece 8; Control step: Real-time monitor the preheating temperature of the turbine blade crown workpiece 8 and the preheating temperature of the surface to be deposited of the wear-resistant layer through the infrared thermal imager, and control the preheating temperature of the turbine blade crown workpiece 8 to be at the first target preheating temperature and control the preheating temperature of the surface to be deposited of the wear-resistant layer to be at the second target preheating temperature through the PLC controller 4. The synchronous preheating of the turbine blade crown workpiece and the surface to be deposited of the wear-resistant layer is realized, and as the deposition process continues, the preheating temperature can always be maintained, and the real-time online monitoring of the preheating temperature is realized, thereby effectively preventing the cracking of the wear-resistant layer of the turbine blade crown.

[0032] Exemplarily, the pretreatment step: Pretreat the turbine blade crown workpiece 8 and the wear-resistant layer material, and adjust the working angles of the infrared imager 6 and the laser preheating head 13. Specifically, in the pretreatment step, first, grind the surface to be deposited of the turbine blade crown workpiece 8 to remove sharp edges and burrs until the metal luster is exposed. Then, polish the surface with cleaning agents such as alcohol and acetone to remove oil stains and impurities on the blade crown surface; obtain the surface to be deposited of the turbine blade crown; Secondly, place the turbine blade crown workpiece 8 on the workbench 5 and fix it, adjust the synchronous preheating device to directly above the surface to be deposited of the turbine blade crown workpiece 8, and use the universal coupling 12 to adjust the deviation angle between the laser preheating head 13 and the vertical direction of space; Fix the infrared thermal imager 6 on the workbench 5, and align the infrared thermal imager 6 with the turbine blade crown workpiece 8 or the surface to be deposited of the wear-resistant layer to realize the on-line real-time monitoring of the temperature of the turbine blade crown workpiece 8 or the surface to be deposited of the wear-resistant layer; Finally, send the dried wear-resistant layer material into the powder feeder and argon gas cylinder integrated device 3.

[0033] Exemplarily, during single-layer deposition, the infrared thermal imager 6 monitors the preheating temperature of the surface of the turbine blade crown workpiece 8 in real time. During multi-layer deposition, after the first layer deposition is completed, the infrared thermal imager 6 monitors the preheating temperature of the surface to be deposited with the wear-resistant layer in real time.

[0034] Exemplarily, a deviation angle β is set between the laser preheating head 13 and the vertical direction of the space. The deviation angle β is specifically based on the spot diameter d1 of the laser beam emitted by the laser deposition head 11, the spot diameter d2 of the laser beam emitted by the laser preheating head 13, the axial distance L between the laser preheating head 13 and the laser deposition head 11, and the distance H from the top of the laser preheating head 13 to the surface of the turbine blade crown workpiece 8: Considering the positional relationship of the above-mentioned working components, the included angle ;

[0035] In the above included angle β model: H is the distance from the top of the laser preheating head 13 to the surface of the turbine blade crown workpiece 8, d1 is the spot diameter of the laser beam emitted by the laser deposition head 11, d2 is the spot diameter of the laser beam emitted by the laser preheating head 13, and β is the deviation angle between the laser preheating head 13 and the vertical direction of the space.

[0036] By setting it in this way, the deviation angle β between the laser preheating head 13 and the vertical direction of the space is adjusted by the universal coupling 12, effectively avoiding the problem that when the laser beam vertically irradiates the turbine blade crown workpiece 8 or the surface to be deposited with the wear-resistant layer, too much laser reflection occurs, resulting in too little energy density of the laser beam absorbed by the turbine blade crown workpiece 8 or the wear-resistant layer material. Furthermore, the turbine blade crown workpiece 8 can quickly rise to the first target preheating temperature range (±10 °C), and the preheating temperature of the wear-resistant layer surface can quickly rise to the second target preheating temperature range (±10 °C), so that the turbine blade crown workpiece and the surface to be deposited with the wear-resistant layer can always maintain the preheating temperature.

[0037] In a possible embodiment, in the parameter determination step, according to the properties of the wear-resistant layer material, the process parameters of the laser deposition head 11 are determined by the PLC controller 4, the first target preheating temperature is obtained according to the dynamic recrystallization temperature of the turbine blade crown workpiece 8, the second target preheating temperature is obtained according to the dynamic recrystallization temperature of the wear-resistant layer material, and then the process parameters of the laser preheating head 13 are determined according to the first target preheating temperature and the second target preheating temperature.

[0038] Exemplarily, the process parameters of the laser deposition head 11 and the process parameters of the laser preheating head 13 in this embodiment are the laser power P1, the scanning speed V s , the powder feeding speed V g , and the spot diameter d1.

[0039] In a possible embodiment, in the parameter determination step, a simultaneous model of energy density and temperature is set in the PLC controller 4, and the process parameters of the laser deposition head 11 and the process parameters of the laser preheating head 13 are calculated through the simultaneous model of energy density and temperature. Among them, the simultaneous model of energy density and temperature is:

[0040] α(P / VDh)=C p dΔT

[0041] Where α is the laser absorption rate of the turbine blade crown workpiece or the wear-resistant layer material, P is the laser power, V is the scanning speed, D is the spot diameter, h is the deposition layer thickness, C p is the specific heat capacity of the turbine blade crown workpiece or the wear-resistant layer material, d is the density of the turbine blade crown workpiece or the wear-resistant layer material, and ΔT is the temperature difference between the initial temperature and the dynamic recrystallization temperature of the turbine blade crown workpiece or the wear-resistant layer material.

[0042] Exemplarily, in the parameter determination step, the simultaneous model of energy density and temperature built in the PLC controller 4 realizes precise control of the preheating temperature of the turbine blade crown workpiece 8 or the surface to be deposited of the wear-resistant layer by adjusting the process parameters of the laser preheating head 13, and takes the energy density required to heat the turbine blade crown workpiece 8 or the wear-resistant layer material to the corresponding dynamic recrystallization temperature as the determination standard for the output energy density of the laser preheating head 13.

[0043] Exemplarily, for the energy density model E m =ΔH m +ΔH f =C p d(T n -T0) in the thermodynamics theory, the following optimizations are carried out: ignoring the influence of the latent heat of phase change ΔH f , the energy density required to heat the turbine blade crown workpiece 8 or the wear-resistant layer material to the dynamic recrystallization temperature is E T =ΔH T =C p d(T n -T0), where E T is the energy density required to heat the turbine blade crown workpiece or the wear-resistant layer material to the dynamic recrystallization temperature, ΔH T is the joule heat required to heat the turbine blade crown workpiece or the wear-resistant layer material to the dynamic recrystallization temperature, C p is the specific heat capacity of the turbine blade crown workpiece or the wear-resistant layer material, d is the density of the turbine blade crown workpiece or the wear-resistant layer material, T nis the target preheating temperature (dynamic recrystallization temperature) of the turbine blade crown workpiece or the wear-resistant layer material. T0 is taken as the room temperature of 22°C. To fully consider the distribution of the laser energy density in the three-dimensional space and improve the accuracy of the correlation between the output energy density of the laser preheating head 13 and the preheating temperature of the surface of the turbine blade crown workpiece 8 or the wear-resistant layer to be deposited, the output laser energy density of the laser preheating head 13 is taken as the volumetric energy density E = P / VDh, where P is the laser power, V is the scanning speed, D is the spot diameter, and h is the deposition layer thickness.

[0044] Due to the refraction of the laser beam emitted onto the surface of the metal material, the energy density of the laser beam cannot be completely absorbed, and there is a laser absorption rate α of the metal material. Therefore, the energy density required to heat to the dynamic recrystallization temperature and the output energy density E of the laser preheating head have the following relationship: E T = αE, that is, α(P / VDh) = C p d(T n - T0). Therefore, in the parameter determination step, a simultaneous model of energy density and temperature is set in the PLC controller 4, specifically: α(P / VDh) = C p d(T n - T0). In this simultaneous model of energy density and temperature: when depositing the first layer, α is the laser absorption rate of the turbine blade crown workpiece material, C p is the specific heat capacity of the turbine blade crown workpiece material, d is taken as the density of the turbine blade crown workpiece material, T n is the first target preheating temperature (dynamic recrystallization temperature) of the turbine blade crown workpiece, and T0 is the room temperature of 22°C. After the deposition of the first layer is completed, during the subsequent deposition process, α is always the laser absorption rate of the wear-resistant layer material, C p is always the specific heat capacity of the wear-resistant layer material, d is the density of the turbine blade crown workpiece material, and T n is always the second target preheating temperature (the dynamic recrystallization temperature of this wear-resistant layer material) of the wear-resistant layer material, and T0 is taken as the room temperature of 22°C.

[0045] In a possible embodiment, in the synchronization step, using a three-axis linkage numerical control machine tool and a laser generator 17, the laser preheating head 13 and the laser deposition head 11 are moved synchronously along the scanning path, and the laser deposition head 11 emits a laser beam with a spot diameter of d1, and the laser preheating head 13 emits a laser beam with a spot diameter of where the spot diameter is smaller than the spot diameter d1.

[0046] Exemplarily, the laser generator 17 in this embodiment is an optical fiber laser generator 17, which is connected to the shutter through an output optical fiber, and the shutter is respectively connected to the laser preheating head 13 and the laser deposition head 11 through optical fibers. With this setting, two laser beams can be generated by the laser generator 17 connected with the shutter, and then transmitted to the laser preheating head 13 and the laser deposition head 11 respectively.

[0047] In a possible embodiment, in the control step, if the preheating temperature of the turbine blade crown workpiece 8 is lower than the first target preheating temperature and the preheating temperature of the surface to be deposited with the wear-resistant layer is lower than the second target preheating temperature value range, the PLC controller 4 transmits a heating signal. Or, if the preheating temperature of the turbine blade crown workpiece 8 is higher than the first target preheating temperature and the preheating temperature of the surface to be deposited with the wear-resistant layer is higher than the second target preheating temperature value range, the PLC controller 4 transmits a slow cooling signal. Or, if the preheating temperature of the turbine blade crown workpiece 8 is within the first target preheating temperature value range and the preheating temperature of the surface to be deposited with the wear-resistant layer is within the second target preheating temperature value range, the PLC controller 4 transmits a control signal and continues to repeat the control step.

[0048] Exemplarily, in the control step, the infrared thermal imager 6 monitors the preheating temperature of the turbine blade crown workpiece 8 or the surface to be deposited with the wear-resistant layer in real time and transmits it to the PLC controller 4 in real time. The process parameters are calculated by the PLC controller 4, and then it is judged whether the preheating temperature of the turbine blade crown workpiece 8 is within the first target temperature range and whether the preheating temperature of the surface to be deposited with the wear-resistant layer is within the second target preheating temperature value range. According to the judgment result, a heating signal, a slow cooling signal or a control signal is transmitted to the laser control system 18, the protective gas control system 1, the three-axis linkage numerical control machine tool control system 2, and the pulley car control system 16 to realize the automatic closed-loop control of the preheating temperature.

[0049] Exemplarily, if the influence of air convection on the turbine blade crown workpiece 8 is lower than the first target preheating temperature value range (less than 10 °C), or the preheating temperature of the surface to be deposited with the wear-resistant layer is affected by air convection and is lower than the second target preheating temperature value range (less than 10 °C), the PLC controller 4 transmits a heating signal to the three-axis linkage numerical control machine tool control system 2, the laser control system 18 and the protective gas control system 1, so that both the laser deposition head 11 and the laser preheating head 13 stop moving, stop coaxial powder feeding, prohibit the laser deposition head 11 from emitting light, and automatically compensate the output energy density of the laser preheating head 13. At this time, the scanning speed of the laser beam emitted by the laser preheating head 13 is still set to V in the simultaneous model of energy density and temperature. s, so as to quickly raise the turbine blade crown workpiece 8 to within the first target preheating temperature value range (±10 °C), or quickly raise the preheating temperature of the surface to be deposited with the wear-resistant layer to within the second target preheating temperature value range (±10 °C), so that the turbine blade crown workpiece and the surface to be deposited with the wear-resistant layer are preheated synchronously, and the preheating temperature can be maintained throughout the continuation of the deposition process.

[0050] Exemplarily, when the turbine blade crown workpiece 8 is higher than the first target preheating temperature value range (greater than 10 °C) due to the influence of laser deposition heat accumulation, or when the preheating temperature of the surface to be deposited with the wear-resistant layer is higher than the second target preheating temperature value range (greater than 10 °C) due to the influence of laser deposition heat accumulation, the PLC controller 4 transmits a slow cooling signal to the three-axis linkage numerical control machine tool control system 2, the laser control system 18, the protective gas control system 1 and the pulley car control system 16, so that both the laser deposition head 11 and the laser preheating head 13 stop moving, stop coaxial powder feeding, and at the same time prohibit the laser deposition head 11 and the laser preheating head 13 from emitting light, so that the gas supply port 14 conveys argon, and the motor pulley car 15 with an air outlet moves uniformly along the annular slide rail 7 to achieve uniform slow cooling and antioxidant protection of the turbine blade crown workpiece 8 or the surface to be deposited with the wear-resistant layer, so that the turbine blade crown workpiece 8 is uniformly reduced to within the first target preheating temperature value range (±10 °C), or the preheating temperature of the surface to be deposited with the wear-resistant layer is uniformly reduced to within the second target preheating temperature value range (±10 °C), so that the turbine blade crown workpiece and the surface to be deposited with the wear-resistant layer are preheated synchronously, and the preheating temperature can be maintained throughout the continuation of the deposition process.

[0051] Exemplarily, only when the PLC controller 4 determines that the turbine blade crown workpiece 8 is within the first target preheating temperature value range (±10 °C), or when the preheating temperature of the surface to be deposited with the wear-resistant layer is within the second target preheating temperature value range (±10 °C), the PLC controller 4 transmits a control signal to the three-axis linkage numerical control machine tool control system 2, the laser control system 18 and the protective gas control system 1, so that the laser deposition head 11 and the laser preheating head 13 continue to move synchronously and uniformly, allow coaxial powder feeding, the laser deposition head 11 and the laser preheating head 13 emit light normally, and the laser preheating and laser deposition manufacturing processes of the turbine blade crown wear-resistant layer continue, so that during the laser preheating and laser deposition manufacturing processes, the preheating temperature of the turbine blade crown workpiece 8 is always maintained within the first target preheating temperature T1 range (±10 °C), or the preheating temperature of the surface to be deposited with the wear-resistant layer is always maintained within the second target preheating temperature T2 range (±10 °C), maximizing the plasticity of the turbine blade crown workpiece 8 and the wear-resistant layer material, and reducing the temperature gradient and residual stress between the turbine blade crown workpiece 8 and the wear-resistant layer, and finally effectively suppressing the cracking phenomenon of the wear-resistant layer manufactured by laser deposition on the surface of the turbine blade crown.

[0052] Exemplarily, the infrared thermal imager 6 is connected to the signal input end of the PLC controller 4, and the signal output end of the PLC controller 4 is connected to the protective gas control system 1, the laser control system 18, and the pulley car control system 16; the motor pulley car 15 with an air supply port 14 is connected to the pulley car control system 16, and the air supply port 14 of the motor pulley car 15 and the protective gas control system 1 are connected to the powder feeder and argon gas cylinder integrated device; the annular slide rail 7 is horizontally placed on the workbench 5, and the motor pulley car 15 with an air outlet is connected to the annular slide rail 7 through a pulley; the above-mentioned various systems constitute the preheating temperature automatic closed-loop control system of this embodiment, which overcomes the problem that the existing preheating method cannot be integrated into the laser deposition manufacturing system to realize online temperature control preheating of the turbine blade crown workpiece 8 or the surface to be deposited with the wear-resistant layer, and the preheating temperature cannot be automatically closed-loop controlled, realizes online precise temperature control preheating and automatic closed-loop control of the preheating temperature, and finally effectively suppresses the cracking phenomenon of the wear-resistant layer of the turbine blade crown.

[0053] As Figure 2 and Figure 3 shown, this embodiment provides a synchronous device for laser preheating and laser deposition of a turbine blade crown wear-resistant layer, including: a three-axis linkage numerical control machine tool, including a machine body; a robotic arm 9, arranged on the side of the machine body and connected to the machine body; a fixed disk 10, arranged at the end of the robotic arm 9 and connected to the robotic arm 9; a central hole, penetratingly arranged in the fixed disk 10; a universal coupling 12, arranged at the end of the fixed disk 10 away from the robotic arm 9 and connected to the fixed disk 10; a laser preheating working head 13, arranged at the lower end of the universal coupling 12 and connected to the universal coupling 12; a laser deposition working head 11, passing through the fixed disk 10 through the central hole and connected to the fixed disk 10. Through the arrangement of the robotic arm 9, the fixed disk 10 and the central hole in this embodiment, the laser deposition working head 11 can be adjusted to directly above the turbine blade crown workpiece 8 through the robotic arm 9. At the same time, since the lower end of the universal coupling 12 is connected to the laser preheating working head 13, this setting enables the laser deposition working head 11 and the laser preheating working head 13 to move synchronously through the robotic arm 9, and enables the working angle of the laser preheating working head 13 to be adjustable. Furthermore, the robotic arm 9 of the three-axis linkage numerical control machine tool controls the fixed disk 10 to move at a constant speed, so that the laser preheating working head 13 and the laser deposition working head 11 connected to the fixed disk 10 move synchronously at a constant speed according to the planned scanning trajectory, realizing synchronous preheating of the turbine blade crown workpiece 8 and the surface to be deposited with the wear-resistant layer, and effectively preventing the cracking of the wear-resistant layer of the turbine blade crown.

[0054] Exemplarily, the universal coupling 12 is arranged at the end of the fixed disk 10 away from the robotic arm 9, as Figure 2As shown in the figure, the robotic arm 9 is arranged on the left side of the fixed disk 10 and fixedly connected to the fixed disk 10. The universal coupling 12 is arranged on the right side of the fixed disk 10 and fixedly connected to the fixed disk 10. With this arrangement, on the one hand, the laser deposition working head 11 and the laser preheating working head 13 fixed on the robotic arm 9 can move synchronously. On the other hand, the universal coupling 12 enables the working angle of the laser preheating working head 13 to be adjustable.

[0055] In a possible embodiment, as Figure 2 and Figure 3 shown, the laser generator 17 is arranged on the first side of the bed body and connected to the laser deposition working head 11 and the laser preheating working head 13.

[0056] Exemplarily, as Figure 2 and Figure 3 shown, the laser generator 17 is arranged on the right side of the bed body. The laser generator 17 is connected with a shutter and connected to the laser deposition working head 11 and the laser preheating working head 13 through optical fibers. Thus, the laser beam emitted from the laser generator 17 connected with the shutter is transmitted to the laser deposition working head 11 and the laser preheating working head 13 through the optical fibers.

[0057] In a possible embodiment, as Figure 2 and Figure 3 shown, the workbench 5 is arranged on the upper end surface of the bed body and connected to the bed body; the infrared thermal imager 6 is arranged on the upper end surface of the workbench 5 and connected to the workbench 5; the PLC controller 4 is arranged on the side surface of the bed body and connected to the infrared thermal imager 6.

[0058] Exemplarily, the workbench 5 is fixedly connected to the upper end surface of the bed body, and the infrared thermal imager 6 is connected to the PLC controller 4 through a wire, which is convenient for the PLC controller 4 to control the infrared thermal imager 6.

[0059] In a possible embodiment, as Figure 2 and Figure 3 shown, the annular slide rail 7 is arranged on the upper end surface of the workbench 5 and connected to the workbench 5; the motor pulley car 15 is arranged on the annular slide rail 7 and slidably connected to the annular slide rail 7; the air supply port 14 is arranged on the side surface of the motor pulley car 15 close to the fixed disk 10 and connected to the motor pulley car 15.

[0060] Exemplarily, the annular slide rail 7 is an elliptical annular slide rail 7, the turbine blade crown workpiece 8 is placed inside the elliptical area enclosed by the elliptical slide rail, and the motor pulley car 15 moves along the track direction of the elliptical slide rail, so that the motor pulley car 15 can slide around the turbine blade crown workpiece 8 along the elliptical slide rail. Since an air supply port 14 is provided on the motor pulley car 15, with this arrangement, when the laser preheating and laser deposition synchronization device in this embodiment is working, the air supply port 14 on the motor pulley car 15 supplies air to the turbine blade crown workpiece 8, thereby realizing antioxidant protection for the turbine blade crown workpiece 8.

[0061] In a possible embodiment, as Figure 2 and Figure 3 shown, the powder feeder and argon gas cylinder integrated device 3 is arranged on the second side of the bed body and is connected to the laser deposition working head 11.

[0062] Exemplarily, the powder feeder and argon gas cylinder integrated device 3 is arranged on the left side of the bed body, and through the gas transmission and powder feeding pipeline, the powder feeder and argon gas cylinder integrated device 3 is connected to the laser deposition working head 11, which is convenient for the laser deposition working head 11 to complete the coaxial powder feeding work while depositing the turbine blade crown workpiece 8 or the surface to be deposited with the wear-resistant layer.

[0063] Embodiment 1: In this embodiment, the alloy grade of the turbine blade crown workpiece 8 is IN939, and the alloy material grade of the material to be deposited on the wear-resistant layer is Stellite6. The specific method is as follows:

[0064] In the pretreatment step, the surface to be deposited and its side surface of the IN939 turbine blade crown are polished to remove sharp edges and burrs until the metal luster is exposed. Then, the surface is polished with cleaners such as alcohol and acetone to remove oil stains and impurities on the blade crown surface; the dried Stellite6 wear-resistant layer powder material is sent into the powder feeder and argon gas cylinder integrated device 3; the IN939 turbine blade crown workpiece 8 is placed on the workbench 5 and fixed, the synchronous preheating device is adjusted to be directly above the surface to be deposited of the IN939 turbine blade crown workpiece 8, and the deviation angle β between the laser preheating working head 13 and the vertical direction of space is adjusted to 40° by using the universal coupling 12; the infrared thermal imager 6 is fixed on the workbench 5. During the first-layer deposition, the lens of the infrared thermal imager 6 is aligned with the IN939 turbine blade crown workpiece 8; during multi-layer deposition, after the first-layer deposition is completed, the lens of the infrared thermal imager 6 is aligned with the surface to be deposited of the Stellite6 wear-resistant layer to realize on-line real-time monitoring of the temperature of the IN939 turbine blade crown workpiece 8 or the surface to be deposited of the Stellite6 wear-resistant layer.

[0065] In the scanning path planning step, the scanning paths of the two laser heads in the synchronous preheating device are planned through the three-axis linkage numerical control machine tool control system 2.

[0066] In the parameter determination step, the optimal laser deposition process parameter combination for laser-depositing the Stellite6 wear-resistant layer on the IN939 turbine blade crown workpiece 8 is input using the laser control system 18: laser power P1 = 600W, scanning speed V s = 5mm / s, powder feeding speed V g = 2.7g / min, spot diameter d1 = 2mm, to achieve good metallurgical bonding between the IN939 turbine blade crown workpiece 8 and the Stellite6 wear-resistant layer.

[0067] In the synchronization step, the dynamic recrystallization temperatures of the IN939 material of the turbine blade crown workpiece 8 and the Stellite6 material of the wear-resistant layer are used as the target preheating temperatures and input into the PLC controller 4, where: T1 is the dynamic recrystallization temperature of the material, is a coefficient (usually taken as 0.35 - 0.4), T m is the melting point temperature of the material; since the melting point temperatures of IN939 and Stellite6 are 1338°C and 1355°C respectively, considering that heat loss will reduce the preheating temperature, to reduce errors, the coefficient takes the maximum value of 0.4. Therefore, the dynamic recrystallization temperatures of the IN939 material of the turbine blade crown workpiece 8 and the Stellite6 material of the wear-resistant layer are 535.2°C and 542°C respectively; the PLC controller 4 passes through the built-in combined model of energy density and temperature: α(P / VDh)= C p d(T n - T0), automatically calculates the energy density required to heat the IN939 material of the turbine blade crown workpiece 8 or the Stellite6 material of the wear-resistant layer to the target preheating temperature, and converts the energy density into the process parameters (laser power P2, spot diameter d2, scanning speed V s ) of the laser preheating head 13 and transmits them to the laser control system 18, so that the laser beam emitted by the laser preheating head 13 can accurately raise the turbine blade crown workpiece 8 or the surface to be deposited of the wear-resistant layer to the dynamic recrystallization temperature (target preheating temperature); the specific heat capacities C p of IN939 and Stellite6 are 0.44J / g·C and 0.47 J / g·C respectively, the densities d are 8.18g / cm 3 and 8.21g / cm 3 respectively, and the temperature differences ΔT are 513.2°C and 520.0°C respectively; therefore, the energy density required to heat the IN939 material of the turbine blade crown workpiece 8 to the first target preheating temperature T1 is 1847.1J / cm 3 , or the energy density required to heat the Stellite6 material of the wear-resistant layer to the second target preheating temperature T2 is 2006.5J / cm 3; When depositing the first layer, C in the simultaneous model of energy density and temperature p dΔT is taken as 1847.1 J / cm 3 ; When depositing multiple layers, after the first layer deposition is completed, C in the simultaneous model of energy density and temperature p dΔT is taken as 2006.5 J / cm 3 ; Regarding the laser absorption rate α, since the polarization component of photons in the vertical direction is lost in the laser, only the parallel polarization component of the laser needs to be considered. According to the Fresnel model, the absorption rate of the metal material surface for the laser is , where: ρ is the resistivity of the metal material, ε is the laser wavelength. Since the difference in resistivity between IN939 and Stellite6 materials is at the order of 0.0000001 and the laser wavelengths are the same, the laser absorption rates of both IN939 and Stellite6 materials are taken as 0.6; since the thickness of the Stellite6 wear-resistant layer is 1.2 mm, through the calculation of the simultaneous model of energy density and temperature, it can be known that when depositing the first layer, the process parameters of the laser preheating head 13 are: laser power P = 75 W, scanning speed V s = 5 mm / s, spot diameter D = 4 mm. When depositing multiple layers, after the first layer deposition is completed, the process parameters of the laser preheating head 13 are: laser power P = 80 W, scanning speed V s = 5 mm / s, spot diameter D = 4 mm.

[0068] In the deposition step, the three-axis linkage numerical control machine tool and the laser generator 17 are turned on simultaneously, so that the laser preheating head 13 and the laser deposition head 11 move synchronously and uniformly. The laser deposition head 11 emits a laser beam with a spot diameter d1 of 2 mm, and simultaneously melts the surface of the IN939 turbine blade crown workpiece 8 and the Stellite6 wear-resistant layer powder material, and forms a Stellite6 wear-resistant layer with good metallurgical bonding on the surface of the IN939 turbine blade crown workpiece 8 to realize the laser deposition manufacturing process of the turbine blade crown wear-resistant layer. At the same time, the laser preheating head 13 emits a laser beam with an angle β of 40° deviating from the vertical direction of space and a spot diameter d2 of 4 mm to irradiate the surface of the IN939 turbine blade crown workpiece 8 or the surface of the Stellite6 wear-resistant layer to be deposited, quickly raising the preheating temperature of the turbine blade crown workpiece 8 to the first target preheating temperature T1, or the preheating temperature of the surface of the wear-resistant layer to be deposited to the second target preheating temperature T2, to realize the synchronous manufacturing process of laser preheating and laser deposition of the turbine blade crown wear-resistant layer.

[0069] In the control step, the infrared thermal imager 6 monitors the preheating temperature of the IN939 turbine blade crown workpiece 8 or the surface to be deposited with the Stellite6 wear-resistant layer in real time and transmits it to the PLC controller 4. The PLC controller 4 automatically determines whether the IN939 turbine blade crown workpiece 8 is within the range of the first target preheating temperature value T1 (±10°C), or whether the preheating temperature of the surface to be deposited with the Stellite6 wear-resistant layer is within the range of the second target preheating temperature value T2 (±10°C), and transmits different command signals to the laser control system 18, the protective gas control system 1, the three-axis linkage numerical control machine tool control system 2, and the pulley car control system 16 to achieve automatic closed-loop control of the preheating temperature. During the first-layer deposition, the range of the first target preheating temperature value T1 is 513.2°C - 10°C < T1 < 513.2°C + 10°C. During multi-layer deposition, after the end of the first-layer deposition, the range of the second target preheating temperature value T2 is 520.0°C - 10°C < T2 < 520.0°C + 10°C.

[0070] Exemplarily, if the IN939 turbine blade crown workpiece 8 is lower than the range of the first target preheating temperature value T1 (less than 10°C) due to air convection, or if the preheating temperature of the surface to be deposited with the Stellite6 wear-resistant layer is lower than the range of the second target preheating temperature value T2 (less than 10°C) due to air convection, the PLC controller 4 transmits a temperature increase signal to the three-axis linkage numerical control machine tool control system 2, the laser control system 18, and the protective gas control system 1, causing the laser deposition working head 11 and the laser preheating working head 13 to stop moving, stop coaxial powder feeding, prohibit the laser deposition working head 11 from emitting light, and automatically compensate the output energy density of the laser preheating working head 13 (the scanning speed of the laser beam emitted by the laser preheating working head 13 is still set to V s = 5 mm / s) to quickly increase the preheating temperature of the turbine blade crown workpiece 8 to within the range of the first target preheating temperature value T1 (±10°C), or quickly increase the preheating temperature of the surface to be deposited with the wear-resistant layer to within the range of the second target preheating temperature value T2 (±10°C). During the first-layer deposition, T 工件 < T1 - 10 takes T 工件 < 513.2°C - 10°C; during multi-layer deposition, after the end of the first-layer deposition, T 耐磨层 < T2 - 10 takes T 耐磨层 < 520.0°C - 10°C.

[0071] Exemplarily, when the turbine blade crown workpiece 8 is affected by laser deposition heat accumulation and is higher than the first target preheating temperature value T1 range (greater than 10 °C), or when the preheating temperature of the surface to be deposited with the wear-resistant layer is affected by laser deposition heat accumulation and is higher than the second target preheating temperature value T2 range (greater than 10 °C), the PLC controller 4 transmits a slow cooling signal to the three-axis linkage numerical control machine tool control system 2, the laser control system 18, the protective gas control system 1, and the pulley car control system 16, causing the laser deposition head 11 and the laser preheating head 13 to stop moving, stop coaxial powder feeding, and at the same time prohibit the laser deposition head 11 and the laser preheating head 13 from emitting light, enabling the gas supply port 14 to convey argon, and the motor pulley car 15 with the gas outlet to move uniformly along the annular slide rail 7 to perform uniform slow cooling and antioxidant protection on the turbine blade crown workpiece 8 or the surface to be deposited with the wear-resistant layer, so that the turbine blade crown workpiece 8 is uniformly reduced to within the first target preheating temperature value T1 range (±10 °C), or the preheating temperature of the surface to be deposited with the wear-resistant layer is uniformly reduced to within the second target preheating temperature value T2 range (±10 °C). During the first layer deposition, T 工件 >T1 + 10, take T 工件 >513.2 °C + 10 °C. During multi-layer deposition, after the first layer deposition is completed, T 耐磨层 >T2 + 10, take T 耐磨层 >520.0 °C + 10 °C.

[0072] Exemplarily, only when the PLC controller 4 determines that the preheating temperature of the turbine blade crown workpiece 8 is within the first target preheating temperature value T1 range (±10 °C), or when the preheating temperature of the surface to be deposited with the wear-resistant layer is within the second target preheating temperature value T2 range (±10 °C), the PLC controller 4 transmits an operation signal to the three-axis linkage numerical control machine tool control system 2, the laser control system 18, and the protective gas control system 1, causing the laser deposition head 11 and the laser preheating head 13 to continue to move synchronously and uniformly, allowing coaxial powder feeding, and the laser deposition head 11 and the laser preheating head 13 to emit light normally, and the manufacturing process of the synchronous method for laser preheating and laser deposition of the turbine blade crown wear-resistant layer continues, so as to ensure that the preheating temperature of the turbine blade crown workpiece 8 always remains within the first target preheating temperature T1 range (±10 °C) during the laser preheating and laser deposition manufacturing processes, or the preheating temperature of the surface to be deposited with the wear-resistant layer always remains within the second target preheating temperature T2 range (±10 °C), maximizing the plasticity of the turbine blade crown workpiece 8 and the wear-resistant layer material, and reducing the temperature gradient and residual stress between the turbine blade crown workpiece 8 and the wear-resistant layer, ultimately effectively suppressing the cracking phenomenon of the Stellite6 wear-resistant layer laser deposited on the surface of the IN939 single crystal alloy turbine blade crown.

[0073] This embodiment uses a laser synchronous preheating device to overcome the problem that the existing preheating method cannot achieve synchronous preheating of the turbine blade crown workpiece 8 or the surface to be deposited with the wear-resistant layer, and as the subsequent deposition process progresses, the effect of crack inhibition will decay with the progress of the subsequent deposition process, realizing precise selective area synchronous laser preheating of the turbine blade crown workpiece 8 and the surface to be deposited with the wear-resistant layer.

[0074] This embodiment uses an automatic closed-loop control system for preheating temperature to overcome the problem that the existing preheating method cannot be integrated into the laser deposition manufacturing system to achieve on-line temperature control preheating of the turbine blade crown workpiece 8 or the surface to be deposited with the wear-resistant layer, and the preheating temperature cannot be automatically controlled in a closed loop, realizing on-line precise temperature control preheating and automatic closed-loop control of the preheating temperature, and finally effectively inhibiting the cracking phenomenon of the wear-resistant layer of the turbine blade crown.

[0075] This embodiment uses a laser preheating device and an automatic closed-loop control system for preheating temperature, minimizing the temperature gradient and residual stress between the turbine blade crown workpiece 8 and the wear-resistant layer, and effectively inhibiting the cracking phenomenon of the wear-resistant layer of the turbine blade crown. As Figure 3 and Figure 4 shown, cracks will occur when using the traditional vacuum furnace preheating method, and the effect of crack inhibition is poor. By using the synchronous method and device of laser preheating and laser deposition in this embodiment, no cracks occur in both the wear-resistant layer and the turbine blade crown workpiece 8, and the surface quality is better than the former, and the effect of crack inhibition is better.

[0076] The device structure of this embodiment is simple and compact, easy to operate, meets the actual operation space requirements of the turbine blade crown workpiece 8, and can exert a good laser preheating anti-cracking effect, improving the problems and defects mentioned in the technical background.

[0077] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or substitutions, which should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A synchronous method for laser preheating and laser deposition of a wear-resistant layer on a turbine blade crown, characterized in that, include: Pretreatment step: pretreatment of turbine blade crown workpiece and wear-resistant layer material, adjustment of the working angle of the infrared imager, and adjustment of the laser preheating work head through the universal coupling; Scanning path planning step: planning the scanning paths of the laser deposition work head and the laser preheating work head through the three-axis linkage CNC machine tool; Parameter determination step: according to the properties of the turbine blade crown workpiece and the wear-resistant layer material, the process parameters of the laser deposition work head and the laser preheating work head are determined through the PLC controller; Synchronization step: according to the scanning path and process parameters, the laser preheating work head and the laser deposition work head are moved synchronously along the scanning path, and the laser beams are emitted synchronously; Deposition step: controlling the temperature of the turbine blade crown workpiece to rise to a first target preheating temperature during the deposition stage on the workpiece surface through a PLC controller; During the deposition stage of the wear-resistant layer on the surface to be deposited, the temperature of the wear-resistant layer on the surface to be deposited is controlled to rise to a second target preheating temperature, thereby obtaining a wear-resistant layer on the turbine blade shroud workpiece; Controlling step: monitoring the preheating temperature of the turbine blade crown workpiece and the preheating temperature of the surface to be deposited of the wear-resistant layer in real time by means of an infrared thermal imager, and controlling the preheating temperature of the turbine blade crown workpiece to be at a first target preheating temperature and the preheating temperature of the surface to be deposited of the wear-resistant layer to be at a second target preheating temperature by means of a PLC controller; In the parameter determination step, according to the properties of the wear-resistant layer material, the process parameters of the laser deposition work head are determined by the PLC controller, and the first target preheating temperature is obtained according to the dynamic recrystallization temperature of the turbine blade shroud workpiece, and the second target preheating temperature is obtained according to the dynamic recrystallization temperature of the wear-resistant layer material, and then the process parameters of the laser preheating work head are determined according to the first target preheating temperature and the second target preheating temperature; In the parameter determination step, a combined model of energy density and temperature is set in the PLC controller, and the process parameters of the laser deposition work head and the process parameters of the laser preheating work head are calculated by the combined model of energy density and temperature, wherein the combined model of energy density and temperature is: α(P / VDh) = C p dΔT Among them, α is the laser absorption rate of the turbine blade crown workpiece or the wear-resistant layer material, P is the laser power, V is the scanning speed, D is the spot diameter, h is the deposition layer thickness, C p is the specific heat capacity of the turbine blade crown workpiece or the wear-resistant layer material, d is the density of the turbine blade crown workpiece or the wear-resistant layer material, and ΔT is the temperature difference between the initial temperature and the dynamic recrystallization temperature of the turbine blade crown workpiece or the wear-resistant layer material.

2. The method for simultaneous laser preheating and laser deposition of a turbine blade shroud wear-resistant layer according to claim 1, characterized in that: In the synchronization step, a three-axis linkage CNC machine tool and a laser generator are used to make the laser preheating work head and the laser deposition work head move synchronously along the scanning path, and the laser deposition work head emits a laser beam with a spot diameter of d1, and the laser preheating work head emits a laser beam with a spot diameter of d2, wherein the spot diameter d2 is smaller than the spot diameter d1.

3. The synchronous method of laser preheating and laser deposition for the wear-resistant layer of the turbine blade crown according to claim 1, characterized in that, include: In the control step, if the preheating temperature of the turbine blade shroud workpiece is lower than the first target preheating temperature, and the preheating temperature of the surface to be deposited of the wear-resistant layer is lower than the second target preheating temperature value range, the PLC controller transmits a temperature increase signal, or, If the preheating temperature of the turbine blade crown workpiece is higher than the first target preheating temperature, and the preheating temperature of the surface to be deposited with the wear-resistant layer is higher than the second target preheating temperature value range, the PLC controller transmits a slow cooling signal, or, If the preheating temperature of the turbine blade crown workpiece is within the range of the first target preheating temperature value, and the preheating temperature of the surface of the wear-resistant layer to be deposited is within the range of the second target preheating temperature value, the PLC controller then transmits a control signal and continues to repeat the control steps.

4. A synchronous device for laser preheating and laser deposition of a wear-resistant layer on a turbine blade crown using the method as described in claim 1, characterized in that, Including: A three-axis linkage numerical control machine tool, including a bed body; A robotic arm, arranged on the side of the bed body and connected to the bed body; A fixed disk, arranged at the end of the robotic arm and connected to the robotic arm; A central hole, penetratingly arranged in the fixed disk; A universal coupling, arranged at the end of the fixed disk away from the robotic arm and connected to the fixed disk; A laser preheating working head, arranged at the lower end of the universal coupling and connected to the universal coupling; A laser deposition working head, passing through the fixed disk through the central hole and connected to the fixed disk; A workbench, arranged on the upper end surface of the bed body and connected to the bed body; An infrared thermal imager, arranged on the upper end surface of the workbench and connected to the workbench; A PLC controller, arranged on the side of the bed body and connected to the infrared thermal imager.

5. The synchronous device for laser preheating and laser deposition of the wear-resistant layer of the turbine blade crown according to claim 4, characterized in that, Also including: A laser generator, arranged on the first side of the bed body and connected to both the laser deposition working head and the laser preheating working head.

6. The synchronous device for laser preheating and laser deposition of the wear-resistant layer of the turbine blade crown according to claim 4, characterized in that, Also including: An annular slide rail, arranged on the upper end surface of the workbench and connected to the workbench; A motor pulley car, arranged on the annular slide rail and slidably connected to the annular slide rail; An air supply port, arranged on the side of the motor pulley car close to the fixed disk and connected to the motor pulley car.

7. The synchronous device for laser preheating and laser deposition of the wear-resistant layer of the turbine blade crown according to claim 4, characterized in that, Also including: A powder feeder and argon gas cylinder integrated device, arranged on the second side of the bed body and connected to the laser deposition working head.

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