Blade type precision casting directional solidification control method

Abstract

The invention relates to the field of manufacturing industry, and discloses a blade type precision casting directional solidification control method which comprises the following steps: preparing: selecting a seed crystal material according to an alloy system of a casting, pretreating the seed crystal material, designing the shape and size of the seed crystal material according to the design requirement of the casting, and processing to obtain a seed crystal material; then, a position mark is preset on a blade casting wax mold, the machined seed crystal material is placed at the preset position of the wax mold through a positioning device and fixed, and a machined part is obtained; and regulation and control: diffraction signals generated in the directional solidification process of the machined part are analyzed to obtain crystal orientation. Seed crystals are selected according to a casting alloy system, laser processing is carried out, preparation is carried out through real-time parameter regulation and control, the seed crystals are fixed through optical positioning and low-temperature glue, a good crystal growth starting end is established, X-ray diffraction online detection is carried out, a deep learning algorithm and an intelligent control strategy are applied, and crystal orientation is regulated and controlled through a magnetic field device.

Description

Technical Field

[0001] The present invention relates to the technical field of manufacturing, and specifically to a method for controlling the directional solidification of precision castings of blade type. Background Art

[0002] In modern manufacturing, precision casting technology is crucial for the production of high-performance components. With the rapid development of industries such as aerospace and energy power, the performance requirements for key components are constantly increasing. Precision castings of blade type, as key components of core equipment such as aero-engines and gas turbines, their quality directly affects the overall performance, reliability, and service life of the equipment. In these fields, extremely stringent requirements are imposed on aspects such as the high-temperature strength, fatigue resistance, and corrosion resistance of the blades, which has promoted the continuous innovation and development of precision casting technology.

[0003] In the traditional directional solidification process of precision castings of blade type, the preparation of seed crystals mostly relies on machining, which is difficult to accurately meet the specific requirements of the casting alloy system, resulting in poor dimensional and shape accuracy of the produced precision castings of blade type. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the present invention provides a method for controlling the directional solidification of precision castings of blade type, which solves the problem of poor dimensional and shape accuracy of precision castings of blade type produced by the traditional directional solidification process of precision castings of blade type.

[0005] To achieve the above objectives, the present invention is realized through the following technical solutions: A method for controlling the directional solidification of precision castings of blade type, including the following steps:

[0006] S1. Preparation: Select a seed crystal material according to the alloy system of the casting, and perform pretreatment on it. Then, design the shape and size of the seed crystal material according to the design requirements of the casting, and perform machining. Then, mark a preset position on the wax mold of the blade casting, and place the machined seed crystal material at the preset position of the wax mold through a positioning device and fix it to obtain a processed part;

[0007] S2. Regulation: Analyze the diffraction signals generated during the directional solidification of the processed part to obtain the crystal orientation, and dynamically adjust the magnetic field parameters through a magnetic field generating device in combination with a control algorithm and an adaptive control strategy to regulate the crystal orientation;

[0008] S3. Coordination: While regulating the crystal orientation, use an adaptive control algorithm to dynamically adjust the process parameters according to the temperature feedback, and adjust the cooling parameters to obtain a wax mold blank with the seed crystal crystal orientation completed;

[0009] S4. Control: Remove impurities from the raw materials of the casting through a refining process, and then pour them into the wax mold blank, and complete the directional solidification by controlling the magnetic field parameters, process parameters, and cooling parameters.

[0010] Preferably, the pretreatment in S1 includes cleaning in an organic solvent such as acetone with ultrasonic waves of 40 - 60 kHz for 15 - 20 minutes, and then drying at 10 -3 -10 -4 Pa in a vacuum environment and at a temperature of 100 - 120°C for 2 - 3 hours. The processing is carried out by adjusting the laser parameters of the laser processing equipment according to the characteristics of the seed crystal material. The positioning device includes an optical positioning device, and the fixing is carried out using a low-temperature curing adhesive.

[0011] Preferably, S2 specifically includes the following steps

[0012] S201. Install an X-ray generator and a detector on the directional solidification equipment and debug them. Place the workpiece in the directional solidification device, and collect the diffraction signals generated by the workpiece during the directional solidification process through a data acquisition card;

[0013] S202. Analyze the collected diffraction signals using an algorithm based on deep learning to obtain the angular value of the crystal orientation and the orientation deviation range;

[0014] S203. According to the angular value of the crystal orientation and the orientation deviation range, dynamically adjust the magnetic field parameters through the magnetic field generating device according to the deviation angle, in combination with a control algorithm and an adaptive control strategy;

[0015] S204. At the same time, use non-contact detection technology to monitor the change of the crystal orientation in real time and regulate the crystal orientation.

[0016] Preferably, in S201, the debugging is to adjust the tube voltage, tube current of the X-ray generator, and the integration time of the detector according to the material and thickness of the casting. In S202, the analysis is to use a hybrid model algorithm of a convolutional neural network - recurrent neural network based on deep learning to extract features and classify the collected diffraction signals, and calculate the angular value of the crystal orientation and the orientation deviation range through the weights and thresholds obtained from model training. In S203, the control algorithm includes a proportional - integral - derivative control algorithm, and the adaptive control strategy includes a fuzzy adaptive control strategy. The magnetic field parameters include magnetic field strength and magnetic field direction.

[0017] Preferably, S3 specifically includes the following steps

[0018] S301. While regulating the crystal orientation, use a thermocouple to monitor the temperature of the seed crystal material in real time;

[0019] S302. Adopt an adaptive control algorithm to dynamically adjust the process parameters related to the early stage of crystal growth according to the temperature feedback;

[0020] S303. Select a cooling technique according to the size and complexity of the casting, and use an infrared thermal imager to monitor the temperature distribution on the surface of the seed material in real time;

[0021] S304. Adjust the cooling parameters according to the temperature distribution, perform pre-cooling control, and obtain a wax mold blank with the crystal orientation of the seed crystal completed.

[0022] Preferably, the process parameters in S302 include the preheating temperature, the heating rate, and the crystal pulling rate. The cooling techniques in S303 include composite air and water cooling and liquid metal cooling. The cooling parameters in S304 include the air cooling wind speed, the water flow rate of the water cooling jacket, the temperature and flow rate of the cooling bath.

[0023] Preferably, step S4 specifically includes the following steps

[0024] S401. Select raw materials according to the requirements of precision castings of blade type, remove impurities through a refining process, and introduce argon gas for protection during the melting process to obtain molten metal;

[0025] S402. Adopt a bottom-pouring casting method, seal the casting environment, maintain a slightly positive pressure state, and pour the molten metal into the wax mold blank;

[0026] S403. Complete the directional solidification process of the casting by controlling the magnetic field parameters, process parameters, cooling parameters, and casting parameters.

[0027] Preferably, the refining process in S401 includes vacuum melting, electroslag remelting, and argon oxygen decarburization. The flow rate of the argon gas is 5-10 L / min. The casting parameters in S403 include the casting temperature, the casting speed, the filling time, and the gate size.

[0028] The present invention provides a method for controlling the directional solidification of precision castings of blade type. It has the following beneficial effects:

[0029] 1. By selecting a seed crystal according to the alloy system of the casting, preparing it through laser processing and real-time parameter adjustment, fixing the seed crystal with optical positioning and low-temperature glue, laying a good foundation for crystal growth, detecting online by X-ray diffraction, using a deep learning algorithm and an intelligent control strategy, and adjusting the crystal orientation by a magnetic field device. At the same time, using a thermocouple and an infrared thermal imager in cooperation with an adaptive algorithm to accurately adjust the temperature field-related processes and cooling parameters, the present invention realizes the overall control of the directional solidification process, and solves the problem of poor dimensional and shape accuracy of precision castings of blade type made by the traditional directional solidification process of precision castings of blade type.

[0030] 2. The present invention constructs an on-line detection based on X-ray diffraction, cooperates with a deep learning algorithm and an intelligent control strategy, monitors in real time and precisely regulates the crystal orientation, corrects the crystal orientation deviation during the solidification process, reduces the scrap rate of castings, and ensures that the crystal orientation of the final casting meets the high-quality standard.

[0031] 3. The present invention dynamically adjusts the process parameters and cooling parameters through an adaptive control algorithm, realizes precise control of the temperature field, maintains an ideal temperature gradient, is conducive to the directional growth of crystals, reduces the generation of internal defects. At the same time, through the refining process and gas control technology, impurities are removed and gas mixing is reduced, further improving the internal quality and mechanical properties of the casting, and extending the service life of precision castings such as blades.

[0032] 4. The present invention realizes process connection from the preparation and placement of the seed crystal, to the detection and regulation of the crystal orientation, and then to the temperature field control and pouring. Through real-time on-line detection of the crystal orientation and a fast-response magnetic field regulation mechanism, crystal orientation problems can be discovered and solved in time during the solidification process of the casting, avoiding a large amount of rework caused by problems found in later detection, saving production time. The rapid adjustment of the adaptive control algorithm for process parameters and cooling parameters ensures the efficient progress of the entire directional solidification process and increases the output of castings per unit time. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a flowchart of the method for controlling the directional solidification of precision castings of blades proposed by the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] The technical solutions of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0035] Please refer to the attached Figure 1 , the embodiment of the present invention provides a method for controlling the directional solidification of precision castings of blades, including the following steps:

[0036] S1. Preparation: Select a seed crystal material according to the alloy system of the casting, and perform pretreatment on it. Then, design the shape and size of the seed crystal material according to the design requirements of the casting, and perform processing. Then, mark a preset position on the wax mold of the blade casting, and place the processed seed crystal material at the preset position of the wax mold through a positioning device and fix it to obtain a processed part; the pretreatment in S1 includes cleaning with 40 - 60 kHz ultrasonic waves in organic solvents such as acetone for 15 - 20 minutes, and then placing it at 10 -3 -10 -4Dry for 2 - 3 hours in a Pa vacuum environment at a temperature of 100 - 120°C, and process it by adjusting the laser parameters of the laser processing equipment according to the characteristics of the seed crystal material. The positioning device includes an optical positioning device, and it is fixed by using a low-temperature curing adhesive.

[0037] Specifically, select the seed crystal material according to the alloy system of the precision castings of blade type. Different alloy systems have specific requirements for the characteristics of the seed crystal material. For example, for the blade castings of nickel-based superalloy system, it is necessary to select a nickel-based alloy with high purity (usually the purity is higher than 99.9%) and a specific crystal orientation as the seed crystal material to ensure that the subsequent castings can obtain an ideal crystal structure and performance.

[0038] Pretreat the selected seed crystal material. Clean it in an organic solvent such as acetone with 40 - 60 kHz ultrasonic waves for 15 - 20 minutes. Utilizing the cavitation effect of ultrasonic waves can effectively remove the oil stains, impurities, oxide layers, etc. on the surface of the seed crystal material. After cleaning, place the seed crystal material in a -3 -10 -4 Pa vacuum environment and dry it at a temperature of 100 - 120°C for 2 - 3 hours. Drying in a vacuum environment can prevent the seed crystal material from adsorbing moisture and impurities in the air again during the drying process, ensure the cleanliness of its surface, and provide a good foundation for subsequent processing and use.

[0039] Next, according to the design requirements of the casting, use computer-aided design (CAD) software to precisely design the shape and size of the seed crystal material. After the design is completed, use a laser processing equipment to process the seed crystal material. During the processing, according to the characteristics of the seed crystal material, such as hardness, melting point, etc., precisely adjust the laser parameters of the laser processing equipment. Taking the nickel-based alloy seed crystal material as an example, during cutting, the laser power is usually set at 10 - 20 W, the pulse frequency is 50 - 100 kHz, and the scanning speed is 5 - 10 mm / s; while during fine processing such as drilling, the power is adjusted to 5 - 8 W, the frequency is increased to 100 - 150 kHz, and the speed is reduced to 1 - 3 mm / s. At the same time, use a high-speed camera and image processing algorithm to monitor the heat affected zone, molten pool morphology, etc. in real time, and dynamically adjust the laser parameters to ensure the stability and processing accuracy of the processing process, and avoid defects such as cracks and deformation of the seed crystal material caused by improper laser parameters.

[0040] In the wax mold making stage of the blade casting, a preset position identifier is set on the wax mold. This identifier is used to accurately locate the placement position of the seed crystal material. The positioning device uses an optical positioning device, specifically a visual recognition system, whose working principle is based on an industrial camera, lens, light source, and image processing software. With the assistance of the light source, the industrial camera captures images of the wax mold and the seed crystal material. The image processing software analyzes the images using advanced algorithms such as template matching to accurately identify the preset position marks on the wax mold and the characteristics of the seed crystal. Then, by calculating the position deviation between the two, the deviation information is transmitted to the mechanical execution mechanism to control devices such as robotic arms to accurately place the seed crystal at the preset position. During the placement process, an angle sensor is used to continuously monitor the orientation of the seed crystal to ensure that the orientation error is controlled within a very small range. After the placement is completed, a low-temperature curing adhesive is used to fix the seed crystal to ensure that the seed crystal remains stable during subsequent processes, thus obtaining the workpiece.

[0041] S2. Regulation: Analyze the diffraction signals generated during the directional solidification process of the workpiece to obtain the crystal orientation, and dynamically adjust the magnetic field parameters through a magnetic field generating device in combination with a control algorithm and an adaptive control strategy to regulate the crystal orientation; S2 specifically includes the following steps

[0042] S201. Install an X-ray generator and a detector on the directional solidification equipment and debug them. Place the workpiece into the directional solidification device, and collect the diffraction signals generated by the workpiece during the directional solidification process through a data acquisition card;

[0043] S202. Analyze the collected diffraction signals using an algorithm based on deep learning to obtain the angular value of the crystal orientation and the orientation deviation range;

[0044] S203. According to the angular value of the crystal orientation and the orientation deviation range, dynamically adjust the magnetic field parameters through the magnetic field generating device according to the deviation angle in combination with the control algorithm and the adaptive control strategy;

[0045] S204. At the same time, use non-contact detection technology to continuously monitor the change of the crystal orientation and regulate the crystal orientation.

[0046] In S201, the debugging is to debug the tube voltage, tube current of the X-ray generator, and the integration time of the detector according to the material and thickness of the casting. In S202, the analysis is to use a hybrid model algorithm of convolutional neural network-recurrent neural network based on deep learning to extract features and classify the collected diffraction signals, and calculate the angular value of the crystal orientation and the orientation deviation range through the weights and thresholds obtained from model training. In S203, the control algorithm includes a proportional-integral-differential control algorithm, and the adaptive control strategy includes a fuzzy adaptive control strategy. The magnetic field parameters include magnetic field strength and magnetic field direction.

[0047] Specifically, an X-ray generator with high stability and a detector with high sensitivity and high resolution are selected. The X-ray generator should have tube voltage and tube current parameters that can be adjusted within a wide range to meet the detection requirements of castings with different materials and thicknesses. The detector should be capable of rapid response and accurately capturing weak diffraction signals. During installation, finite element analysis software is used to simulate the propagation path of X-rays inside the equipment to determine the optimal installation positions of the X-ray generator and the detector, ensuring that the X-ray beam can irradiate the key detection parts of the workpiece vertically or approximately vertically, while the detector can effectively receive the X-rays diffracted. The debugging process is crucial. It is necessary to adjust the tube voltage, tube current of the X-ray generator, and the integration time of the detector according to the material and thickness of the casting. For castings of different materials, such as nickel-based superalloys, cobalt-based alloys, etc., their absorption and scattering characteristics of X-rays are different. Taking nickel-based superalloys as an example, when the thickness of the casting is 5-10 mm, the tube voltage is usually set at 35-45 kV, the tube current is 20-30 mA, and the detector integration time is 0.5-1 second. If the casting material is cobalt-based alloy and the thickness is 8-12 mm, the tube voltage needs to be appropriately increased to 40-50 kV, the tube current is adjusted to 25-35 mA, and the integration time is extended to 1-1.5 seconds. During the debugging process, through repeated testing of standard samples, the position and angle of the detector are continuously optimized, and at the same time, combined with indicators such as signal strength and clarity, the tube voltage, tube current, and integration time are finely adjusted to ensure that clear and accurate diffraction signals can be collected. After debugging, the workpiece is placed in the directional solidification device, and the diffraction signals generated by the workpiece during the directional solidification process are collected through a data acquisition card. The data acquisition card has the ability to collect data at high speed and transmit data accurately, and can collect 5-10 diffraction signals per second to ensure real-time acquisition of crystal orientation information.

[0048] The collected diffraction signals are analyzed using a hybrid model algorithm of a convolutional neural network-recurrent neural network (CNN-RNN) based on deep learning. The convolutional neural network (CNN) is good at feature extraction of data such as images and can effectively extract the spatial features in the diffraction signals. The recurrent neural network (RNN) has good processing ability for time series data and can process the change characteristics of diffraction signals over time. By combining the two, this hybrid model algorithm can process the diffraction signals more comprehensively and accurately. During the model training stage, a large amount of diffraction pattern data with known crystal orientations is used to train the model. By continuously adjusting the weights and thresholds of the model, the model can accurately extract features and classify the collected diffraction signals, and finally calculate the angular value and orientation deviation range of the crystal orientation.

[0049] According to the angular value of the crystal orientation and the orientation deviation range, the magnetic field generating device dynamically adjusts the magnetic field parameters according to the deviation angle, combining a control algorithm and an adaptive control strategy. The control algorithm adopts the proportional-integral-derivative (PID) control algorithm, which calculates the weighted sum of the current crystal orientation deviation (proportional term), the integral of the deviation over time (integral term), and the rate of change of the deviation (differential term) to obtain the value of the magnetic field parameters that need to be adjusted. The adaptive control strategy adopts the fuzzy adaptive control strategy, which dynamically adjusts the parameters of the PID control algorithm according to the fuzzy information such as the magnitude and change trend of the real-time monitored crystal orientation deviation. When the crystal orientation deviation is large and changes rapidly, the proportional coefficient is appropriately increased to accelerate the adjustment speed of the magnetic field parameters; when the crystal orientation gradually approaches the ideal value, the integral coefficient is decreased to avoid overaccumulation of the integral term leading to overshoot. The magnetic field parameters include the magnetic field strength and the magnetic field direction. By precisely adjusting these parameters, effective control of the crystal orientation is achieved. At the same time, the X-ray diffraction non-contact detection technology is used to monitor the change of the crystal orientation in real time, forming a closed-loop control, continuously optimizing the magnetic field control effect, and ensuring that the crystal orientation meets the expectations.

[0050] S3. Collaboration: While regulating the crystal orientation, an adaptive control algorithm is used to dynamically adjust the process parameters according to the temperature feedback and adjust the cooling parameters to obtain a wax mold blank with the crystal orientation of the seed crystal completed; S3 specifically includes the following steps

[0051] S301. While regulating the crystal orientation, use a thermocouple to monitor the temperature of the seed crystal material in real time;

[0052] S302. Adopt an adaptive control algorithm to dynamically adjust the process parameters related to the early stage of crystal growth according to the temperature feedback;

[0053] S303. According to the size and complexity of the casting, select a cooling technique, and use an infrared thermal imager to monitor the temperature distribution on the surface of the seed crystal material in real time;

[0054] S304. Adjust the cooling parameters according to the temperature distribution, perform pre-cooling regulation, and obtain a wax mold blank with the crystal orientation of the seed crystal completed.

[0055] The process parameters in S302 include the preheating temperature, the heating rate, and the crystal pulling rate. The cooling techniques in S303 include the combined cooling of air cooling and water cooling and the liquid metal cooling. The cooling parameters in S304 include the air cooling wind speed, the water flow speed of the water cooling jacket, the temperature and flow rate of the cooling bath.

[0056] Specifically, while regulating the crystal orientation, the temperature of the seed material is monitored in real time using a thermocouple. A thermocouple is a temperature sensor based on the thermoelectric effect that can quickly and accurately measure the temperature change of the seed material. The thermocouple is arranged at key positions around the seed material to ensure comprehensive and accurate acquisition of the temperature information of the seed material.

[0057] An adaptive control algorithm is adopted to dynamically adjust the process parameters related to the early stage of crystal growth according to the temperature feedback. The process parameters include preheating temperature, heating rate, crystal pulling rate, etc. For example, for nickel-based superalloy blade castings, the preheating temperature of the mold shell usually needs to reach 1000 - 1100 °C, and the heating rate is controlled at 5 - 10 °C / min. During the crystal growth process, if the thermocouple monitors that the temperature of the seed material is too high or too low, the adaptive control algorithm will automatically adjust these process parameters according to the preset control rules. When the temperature is too high, the crystal pulling rate is appropriately reduced and the crystal growth time is extended to allow sufficient heat dissipation; when the temperature is too low, the heating rate is appropriately increased to accelerate the heating speed of the mold shell and provide a suitable temperature environment for crystal growth.

[0058] According to the size and complexity of the casting, a cooling technique is selected. For small blade castings, an air-cooling and water-cooling composite cooling technique is used. Air-cooling removes heat through the airflow generated by equipment such as fans, and water-cooling absorbs heat by setting up a water-cooling jacket outside the mold shell and using circulating water. A thermal imager is used to monitor the temperature distribution on the surface of the seed material in real time. The thermal imager can present the temperature distribution in a visual way. By analyzing the temperature distribution image, the cooling parameters are adjusted in a timely manner. For example, when it is found that the temperature of a certain area on the surface of the seed material is too high, the air-cooling wind speed or the water flow rate of the water-cooling jacket corresponding to this area is appropriately increased. For large and complex blade castings, a liquid metal cooling technique is introduced. The mold shell is immersed in a low-melting-point liquid metal (such as a tin-bismuth alloy) cooling bath, and by controlling the temperature and flow rate of the cooling bath, precise regulation of the temperature field of the casting is achieved. The cooling parameters are adjusted according to the temperature distribution for pre-cooling regulation to ensure that the seed material grows in a suitable temperature field environment and obtain a wax mold blank with the crystal orientation of the seed completed.

[0059] S4. Control: Remove impurities from the raw material of the casting through a refining process, and then pour it into the wax mold blank, and complete directional solidification by controlling the magnetic field parameters, process parameters, and cooling parameters; S4 specifically includes the following steps

[0060] S401. According to the requirements of precision castings of blades, select the raw material, remove impurities through a refining process, and introduce argon for protection during the melting process to obtain the molten metal;

[0061] S402. Adopt a bottom-pouring casting method, seal the casting environment, maintain a slightly positive pressure state, and pour the molten metal into the wax mold blank;

[0062] S403. By controlling the magnetic field parameters, process parameters, cooling parameters and pouring parameters, the directional solidification process of the casting is completed.

[0063] The refining process in S401 includes vacuum melting, electroslag remelting, argon oxygen decarburization method, and the flow rate of argon is 5-10 L / min. The pouring parameters in S403 include pouring temperature, pouring speed, filling time, and gate size.

[0064] Specifically, according to the requirements of precision castings of blades, suitable raw materials are selected. The selection of raw materials needs to comprehensively consider factors such as alloy system, purity requirements, and cost. Impurities are removed through the refining process, which includes vacuum melting, electroslag remelting, and argon oxygen decarburization method. During the vacuum melting process, the raw materials are placed in a vacuum environment of 10 -3 -10 -4 Pa for melting. By using high temperature, impurities are volatilized and removed, and at the same time, it prevents gases such as oxygen and nitrogen in the air from reacting with the metal. During electroslag remelting, the coarse metal electrode is remelted and refined in the high-temperature liquid slag, and impurities are further removed through the metallurgical reaction of the slag to improve the purity and uniformity of the metal. The argon oxygen decarburization (AOD) method is mainly used to remove impurities such as carbon and sulfur in the metal. During the melting process, a mixed gas of argon and oxygen is introduced into the molten metal, and the impurities are converted into gases and discharged through the oxidation reaction. During the entire melting process, argon is introduced for protection, and the flow rate of argon is 5-10 L / min, effectively isolating the air and preventing the metal from oxidizing to obtain pure molten metal.

[0065] Adopt the bottom-pouring method, seal the pouring environment, maintain a slightly positive pressure state, and pour the molten metal into the wax mold blank. The bottom-pouring method can make the molten metal enter the mold shell smoothly, reduce the splashing and oxidation of the molten metal, and is conducive to obtaining high-quality castings. The sealed pouring environment and slightly positive pressure state can prevent external air from entering the mold shell and avoid defects such as porosity in the casting.

[0066] By controlling the magnetic field parameters, process parameters, cooling parameters, and pouring parameters, the directional solidification process of the casting is completed. During the pouring process, according to the material and structure of the casting, parameters such as pouring temperature, pouring speed, filling time, and gate size are precisely controlled. For nickel-based superalloy blades, the pouring temperature is usually controlled within 1550 - 1600 °C. Within this temperature range, the molten metal has good fluidity and can fully fill all parts of the mold shell; the pouring speed and filling time need to be adjusted according to the complexity of the mold shell and the characteristics of the molten metal to ensure that the molten metal can uniformly and quickly fill the mold shell, avoiding defects such as cold shut and incomplete filling; the design of the gate size needs to consider the flow rate and pressure of the molten metal to ensure the stability of the molten metal during pouring. At the same time, continuously control the magnetic field parameters, adjust the magnetic field strength and direction, and promote the growth of crystals along the predetermined direction; according to the actual situation during the solidification process of the casting, dynamically adjust process parameters such as the crystal pulling rate, as well as cooling parameters such as the air-cooling wind speed, water-cooling jacket water flow rate, temperature and flow rate of the cooling bath, etc., to ensure that the casting completes directional solidification under precisely controlled conditions and obtains high-quality precision castings of blade type.

[0067] 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 method for controlling directional solidification of precision castings of blades, characterized in that: The following steps are involved: S1. Preparation: Select seed crystal materials according to the alloy system of the casting and pre-treat them, then design the shape and size of the seed crystal materials according to the design requirements of the casting, and process them, then preset position marks on the wax mold of the blade casting, place the processed seed crystal materials at the preset position of the wax mold through a positioning device and fix them to obtain a processed part; S2. Control: Analyze the diffraction signal generated by the workpiece during the directional solidification process to obtain the crystal orientation, and dynamically adjust the magnetic field parameters through the magnetic field generating device combined with the control algorithm and adaptive control strategy to control the crystal orientation; S3, Collaboration: While regulating the crystal orientation, an adaptive control algorithm is used to dynamically adjust the process parameters according to temperature feedback, and the cooling parameters are adjusted to obtain a wax mold blank with a seed crystal orientation completed; S4. Control: The raw materials of the casting are subjected to a refining process to remove impurities, and then poured into a wax mold blank, and directional solidification is achieved by controlling magnetic field parameters, process parameters, and cooling parameters.

2. The method for controlling directional solidification of precision castings of blades according to claim 1, characterized in that: The pretreatment in S1 includes cleaning in an organic solvent such as acetone with 40-60kHz ultrasonic waves for 15-20 minutes and then placing the mixture in a 10 -3 -10 -4 The method comprises drying the seed crystal in a Pa vacuum environment at a temperature of 100-120°C for 2-3 hours, wherein the processing is performed by adjusting the laser parameters of the laser processing equipment according to the properties of the seed crystal material, the positioning device comprises an optical positioning device, and the fixing is performed by fixing with a low-temperature curing adhesive.

3. The method for controlling directional solidification of precision castings of blades according to claim 1, characterized in that: The S2 specifically includes the following steps S201, installing an X-ray generator and a detector on the directional solidification equipment and debugging them, placing the workpiece into the directional solidification device, and collecting the diffraction signal generated by the workpiece during the directional solidification process through a data acquisition card; S202, analyzing the collected diffraction signals using a deep learning-based algorithm to obtain an angle value and an orientation deviation range of the crystal orientation; S203, dynamically adjusting magnetic field parameters according to the angle value of crystal orientation and the orientation deviation range by using a magnetic field generating device according to the deviation angle in combination with a control algorithm and an adaptive control strategy; S204. At the same time, non-contact detection technology is used to monitor the change of crystal orientation in real time and adjust the crystal orientation.

4. The method for controlling directional solidification of blade-type precision castings according to claim 3, characterized in that: The debugging in S201 is to adjust the X-ray generator tube voltage, tube current, and detector integration time according to the casting material and thickness. The analysis in S202 is to use a convolutional neural network-recurrent neural network hybrid model algorithm based on deep learning to extract and classify the collected diffraction signals, and calculate the angle value and orientation deviation range of the crystal orientation through the weights and thresholds obtained through model training. The control algorithm in S203 includes a proportional-integral-differential control algorithm, the adaptive control strategy includes a fuzzy adaptive control strategy, and the magnetic field parameters include magnetic field strength and magnetic field direction.

5. The method for controlling directional solidification of precision castings of blades according to claim 1, characterized in that: S3 specifically includes the following steps S301, while adjusting the crystal orientation, using a thermocouple to monitor the temperature of the seed crystal material in real time; S302, using an adaptive control algorithm to dynamically adjust process parameters related to the early stage of crystal growth according to temperature feedback; S303, selecting cooling technology according to the size and complexity of the casting, and using a thermal imager to monitor the temperature distribution on the surface of the seed crystal material in real time; S304, adjusting cooling parameters according to temperature distribution, performing pre-cooling control, and obtaining a wax mold blank with a seed crystal orientation completed.

6. The method for controlling directional solidification of precision castings of blades according to claim 1, characterized in that: The process parameters in S302 include preheating temperature, heating rate, and crystal pulling rate. The cooling technology in S303 includes air cooling and water cooling composite cooling, and liquid metal cooling. The cooling parameters in S304 include air cooling wind speed, water flow rate of the water cooling jacket, and temperature and flow rate of the cooling bath.

7. The method for controlling directional solidification of precision castings of blades according to claim 1, characterized in that: The S4 specifically includes the following steps S401. Select raw materials according to the requirements of precision castings of blades, remove impurities through refining process, and introduce argon gas protection during smelting to obtain molten metal; S402, using a bottom pouring method, sealing the pouring environment, maintaining a slightly positive pressure state, and pouring the molten metal into the wax mold blank; S403, completing the directional solidification process of the casting by controlling the magnetic field parameters, process parameters, cooling parameters and pouring parameters.

8. The method for controlling directional solidification of precision castings of blades according to claim 7, characterized in that: The refining process in S401 includes vacuum melting, electroslag remelting, and argon oxygen decarburization. The flow rate of the argon gas is 5-10 L / min. The pouring parameters in S403 include pouring temperature, pouring speed, filling time, and gate size.

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