A method for forming a high-strength high-hardness silicon carbide aluminum alloy at low temperature

Abstract

The application relates to the field of manufacturing forming, and discloses a low-temperature forming method for ultra-low-plasticity high-strength high-hardness silicon carbide aluminum alloy, which comprises the following steps: selecting forming materials according to requirements, and constructing a blank body through additive manufacturing; rough machining of the blank body is carried out through a low-temperature machining device to obtain a rough blank; secondary forming of the rough blank is carried out through an ultrasonic vibration device and an ultrasonic-assisted low-temperature machining device to obtain a workpiece; heat isostatic pressing treatment is carried out on the workpiece through a heat isostatic pressing device to obtain a treated piece; and the treated piece is subjected to electric spark machining through an electric spark machining machine tool to obtain a finished piece. Through the low-temperature forming and ultrasonic-assisted technologies, the material deformation resistance is significantly reduced; in the low-temperature forging and rolling process, the temperature and deformation parameters are controlled, so that the material can be plastically deformed under relatively low pressure; and the ultrasonic assistance further improves the material fluidity and reduces the required forming pressure.

Description

Technical Field

[0001] This invention relates to the field of manufacturing and forming technology, specifically to a low-temperature forming method for ultra-low plasticity, high strength, and high hardness silicon carbide aluminum alloys. Background Technology

[0002] In modern manufacturing, with the rapid development of aerospace, automotive, and electronic equipment industries, the requirements for the performance and precision of components are becoming increasingly stringent. Advances in materials science have led to the continuous emergence of new materials, among which ultra-low plasticity, high strength, and high hardness materials, due to their unique performance advantages, have shown enormous application potential in numerous fields. These materials can withstand higher loads, possess better wear resistance and corrosion resistance, and help achieve lightweight product design, improving product reliability and service life.

[0003] Currently, the molding of ultra-low plasticity, high strength, and high hardness materials typically employs high temperature and high pressure to induce plastic deformation. Applying immense pressure through large forging equipment in a high-temperature environment requires ultra-large tonnage forging equipment to overcome the deformation resistance of these materials. This not only results in exorbitant equipment procurement costs, often reaching tens of millions of yuan or more, but also necessitates a large footprint and demanding requirements for factory infrastructure, increasing construction costs and hindering the widespread adoption of the technology. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a low-temperature forming method for ultra-low plasticity, high-strength, and high-hardness silicon carbide aluminum alloys. This method solves the problem that traditional forming methods for ultra-low plasticity, high-strength, and high-hardness materials require extra-large tonnage forging equipment to overcome the deformation resistance of these materials, which hinders the widespread adoption of the technology.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a method for low-temperature forming of ultra-low plasticity, high-strength, and high-hardness silicon carbide aluminum alloy, comprising the following steps:

[0006] S1. Select molding materials according to requirements and construct blanks from them through additive manufacturing;

[0007] S2. The billet is roughed by medium-low temperature forming using medium-low temperature processing equipment to obtain a rough billet;

[0008] S3. The blank is subjected to secondary forming by ultrasonic-assisted low-temperature processing equipment using ultrasonic vibration equipment to obtain the workpiece;

[0009] S4. The workpiece is subjected to hot isostatic pressing treatment using a hot isostatic pressing equipment to obtain the treated part;

[0010] S5. Perform electrical discharge machining on the workpiece using an electrical discharge machining machine to obtain a finished part;

[0011] S6. The surface of the finished part is treated by physical vapor deposition equipment or laser surface alloying equipment to obtain forgings, and a collaborative optimization model is established based on various parameters.

[0012] Preferably, the forming material in S1 includes silicon carbide aluminum alloy material, and the additive manufacturing of the preform specifically includes the following steps:

[0013] S101. Design a product model according to requirements, and use gas atomization method to prepare the molding material into powder;

[0014] S102. Using plasma treatment technology, active groups are introduced on the powder surface to perform surface modification treatment on the powder;

[0015] S103. A selective laser melting device equipped with a fiber laser is used to construct the blank in a closed forming cavity filled with argon gas. An adaptive scanning strategy is applied according to the structural complexity of different parts of the model, and the scanning path adopts a partitioned alternating scanning method to construct the blank.

[0016] Preferably, the power of the fiber laser is 400-1000W, the oxygen content of the sealed forming cavity is controlled below 0.1%, the laser scanning speed of the laser melting equipment is 800-1200mm / s, and the layer thickness is 0.02-0.05mm.

[0017] Preferably, the low-temperature forming roughing process in S2 includes low-temperature forging and low-temperature rolling. The low-temperature forging has a forging temperature of 400-700℃, a deformation of 10%-20 mm per pass, and a forging pressure of 50-200 MPa. The low-temperature rolling has a rolling temperature of 400-700℃, a reduction of 0.5-2 mm per pass, and a rolling force of 30-150 kN.

[0018] Preferably, in S3, the ultrasonic generator of the ultrasonic vibration device has an output frequency of 20-40kHz, a power of 50-1500W, a surface vibration amplitude of 0.01-0.1mm, and the mold temperature of the low-temperature processing device is 240-260℃.

[0019] Preferably, the heating rate of the hot isostatic pressing equipment in S4 is 1-10℃ / min, the pressure is 50-200MPa, and the vacuum degree is 10. -3 -10 -4 Pa.

[0020] Preferably, in S5, the pulse power supply output voltage of the electrical discharge machining tool is 60-120V, the pulse width is 1-50μs, the pulse interval is 5-100μs, and deionized water is used as the working fluid with a working fluid temperature of 20-30℃.

[0021] Preferably, in the physical vapor deposition equipment in S6, the argon flow rate is 20-50 sccm, the nitrogen flow rate is 5-20 sccm, the substrate bias voltage is -50 to -200V, the deposition temperature is 200-500℃, the deposition time is 2-4h, and the coating thickness is 1-5μm. The laser surface alloying equipment has a laser power of 1-5kW, a scanning speed of 5-20mm / s, a spot diameter of 0.5-2mm, and an instantaneous melting depth of 0.1-0.5mm on the workpiece surface.

[0022] Preferably, the step S6 of establishing a collaborative optimization model based on various parameters includes the following steps:

[0023] S601, take the parameters of additive manufacturing, the parameters of medium and low temperature forming rough machining, the parameters of secondary forming, the parameters of hot isostatic pressing, the parameters of electrical discharge machining, and the parameters of surface treatment as variables.

[0024] S602. Construct an objective function based on the properties of the forming material and the quality indicators of the forging;

[0025] S603. Using an intelligent optimization algorithm, a model is constructed based on variables and an objective function, and the model is solved. Through iterative calculation, the optimized parameters are obtained.

[0026] Preferably, the performance in S602 includes strength, hardness, plasticity, and fatigue life; the quality indicators include dimensional accuracy, surface roughness, and internal defect rate; and the intelligent optimization algorithm in S603 includes genetic algorithm, particle swarm optimization algorithm, and simulated annealing algorithm.

[0027] This invention provides a method for low-temperature forming of ultra-low plasticity, high-strength, and high-hardness silicon carbide aluminum alloys. It offers the following advantages:

[0028] 1. This invention significantly reduces the material's deformation resistance by combining medium-low temperature forming with ultrasonic assistance and other technologies. During medium-low temperature forging and rolling, temperature and deformation parameters are controlled so that the material can undergo plastic deformation under relatively low pressure. Ultrasonic assistance further improves the material's fluidity and reduces the pressure required for forming. Therefore, there is no need for extra-large tonnage equipment, which reduces equipment procurement and maintenance costs, improves the economy and flexibility of production, and promotes the widespread adoption of the technology.

[0029] 2. This invention precisely constructs the blank through additive manufacturing, refines the material grains through medium-low temperature forming roughing, improves the material density and uniformity, effectively eliminates internal porosity and shrinkage defects through hot isostatic pressing, improves the mechanical properties of the material, achieves high-precision surface processing through electrical discharge machining with low surface roughness, and endows the product with excellent surface properties through physical vapor deposition and laser surface alloying. By combining the effects of various processes, the final thin-walled, thin-webbed, high-ribbed, and other complex forgings have high quality and high precision, meeting the needs of high-end applications.

[0030] 3. This invention reduces material waste by additive manufacturing to stack materials on demand; during medium and low temperature molding and subsequent processing, it precisely controls process parameters to reduce scrap rate; by establishing a collaborative optimization model to optimize the combination of process parameters, it improves production efficiency, shortens the production cycle, further reduces overall production costs, and enhances product market competitiveness.

[0031] 4. This invention combines low-temperature forming with ultrasonic-assisted technology. During low-temperature forging and rolling, temperature and deformation parameters are controlled. Ultrasonic vibration reduces the friction coefficient between the material and the die, promotes atomic diffusion, and improves material flowability. This achieves maximum forming performance while minimizing material deformation resistance. Additive manufacturing allows for on-demand material stacking, reducing waste. Precise control of parameters in subsequent processes reduces scrap rates. In addition, the advantage of forming under low loads allows for high-quality forming of large, precision, and complex-shaped forgings with relatively low equipment tonnage, significantly improving material utilization. Attached Figure Description

[0032] Figure 1 This is a flowchart of a low-temperature forming method for ultra-low plasticity, high strength, and high hardness silicon carbide aluminum alloys proposed in this invention. Detailed Implementation

[0033] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] Please see the appendix Figure 1 This invention provides a method for low-temperature forming of ultra-low plasticity, high-strength, and high-hardness silicon carbide aluminum alloy, comprising the following steps:

[0035] S1. Select the molding material according to the requirements and construct the blank through additive manufacturing; the molding material in S1 includes silicon carbide aluminum alloy material, and the additive manufacturing of the blank specifically includes the following steps:

[0036] S101. Design a product model according to requirements, and use gas atomization method to prepare the molding material into powder;

[0037] S102. Using plasma treatment technology, active groups are introduced on the powder surface to perform surface modification treatment on the powder;

[0038] S103. A selective laser melting device equipped with a fiber laser is used to construct the blank in a closed forming cavity filled with argon gas. An adaptive scanning strategy is applied according to the structural complexity of different parts of the model, and the scanning path adopts a partitioned alternating scanning method to construct the blank.

[0039] The power of the fiber laser is 400-1000W, the oxygen content in the sealed forming cavity is controlled below 0.1%, the laser scanning speed of the laser melting equipment is 800-1200mm / s, and the layer thickness is 0.02-0.05mm.

[0040] Specifically, using 3D modeling software, a product model is precisely designed based on the product's specific functions and structural requirements. The model must not only reflect the product's external shape but also provide detailed design for any complex internal structures, such as crystal lattice structures and porous structures. After completing the model design, powder is prepared using a gas atomization method. This method involves spraying molten silicon carbide aluminum alloy with high-pressure gas to break it into fine droplets, which are then rapidly cooled and solidified to form powder. The powder has a uniform particle size, which meets the requirements of subsequent additive manufacturing.

[0041] By employing plasma treatment technology to modify the surface of powders, the plasma treatment equipment generates high-energy plasma containing a large number of ions, electrons, and active free radicals. When the powder is in the plasma environment, these active particles chemically react with the powder surface, introducing active groups. This surface modification effectively enhances the bonding force of the powder in subsequent molding processes, improves the quality of the molded parts, and increases the physical adsorption between powder particles, allowing the powder to fuse better during selective laser melting and reducing the generation of internal defects.

[0042] The model was constructed using a selective laser melting (SLM) device equipped with a fiber laser. The forming chamber of the device is a sealed structure. Before forming, argon gas is introduced into the chamber, and the oxygen content is monitored in real time using an oxygen content sensor to ensure that the oxygen content is controlled below 0.1%. This is because silicon carbide aluminum alloy powder reacts readily with oxygen under high-temperature laser conditions, leading to a decline in material properties. Strict control of the oxygen content can effectively prevent oxidation. The power of the fiber laser is set between 400-1000W, which provides sufficient energy to rapidly melt and solidify the powder. The laser scanning speed is maintained at 800-1200mm / s, and the layer thickness is controlled at 0.02-0.05mm. During the scanning process, an adaptive scanning strategy is applied according to the structural complexity of different parts of the model. For complex structures and thin-walled areas, the scanning speed is appropriately reduced and the energy input is increased to ensure sufficient powder melting and forming quality. For simpler structures, the normal scanning speed is used to improve forming efficiency. The scanning path employs a partitioned, alternating scanning method, which effectively reduces the accumulation of thermal stress and prevents deformation or cracking of the billet due to excessive thermal stress. Through layer-by-layer deposition, a billet with a complex shape is ultimately constructed. After the billet is formed, its internal structure is non-destructively inspected using industrial CT with an accuracy of up to 0.1 mm, ensuring the absence of obvious internal defects. Simultaneously, electron backscatter diffraction (EBSD) technology is used to analyze the microstructure of the billet, detecting grain orientation and size distribution, providing a basis for adjusting subsequent process parameters.

[0043] S2. The billet is roughed by medium-low temperature forming using medium-low temperature processing equipment to obtain a rough billet. The medium-low temperature forming roughing in S2 includes medium-low temperature forging and medium-low temperature rolling. The forging temperature of medium-low temperature forging is 400-700℃, the deformation per pass is 10%-20, and the forging pressure is 50-200MPa. The rolling temperature of medium-low temperature rolling is 400-700℃, the reduction per pass is 0.5-2mm, and the rolling force is 30-150kN.

[0044] Specifically, after the billet is constructed, it enters the medium-low temperature forming rough machining stage, which includes two methods: medium-low temperature forging and medium-low temperature rolling. The appropriate processing method is selected according to the shape and performance requirements of the product.

[0045] For medium- and low-temperature forging, a hydraulic forging machine is used. The forging temperature is controlled between 400-700℃ according to the characteristics of silicon carbide aluminum alloy. Within this temperature range, the plasticity of the material is improved to a certain extent, while maintaining high strength and hardness. Before forging, the die is preheated and a special high-temperature lubricant is applied. Die preheating can reduce the temperature difference between the billet and the die and reduce thermal stress, while the high-temperature lubricant can significantly reduce the coefficient of friction, making the billet easier to flow and deform during the forging process. The forging process employs a multi-pass forging technique, with each pass controlling the deformation to 10%-20%. Through multiple forging passes, the material's microstructure can be gradually altered, making it denser, while preventing cracking due to excessive deformation in a single pass. The forging pressure ranges from 50-200 MPa, and a pressure sensor monitors the forging pressure in real time to ensure it remains stable within the set range. After forging, a hardness tester is used to test the hardness of the billet, ensuring the hardness value meets the expected range. A metallographic microscope is used to observe the material's microstructure, ensuring its uniformity. Furthermore, a thermal simulation testing machine is used to simulate the forging process, analyzing the dynamic recrystallization behavior of the material under different forging process parameters, providing theoretical support for optimizing the actual forging process.

[0046] For medium- and low-temperature rolling, two- or four-high mills are used, with the rolling temperature controlled between 400-700℃. The rolls are preheated before rolling, and rolling lubricant is applied. Preheating the rolls reduces thermal shock between the rolls and the billet, while the rolling lubricant reduces friction during rolling, improving rolling quality. The rolling process employs multi-pass rolling, with each pass reducing the thickness by 0.5-2mm. By controlling the reduction, the thickness and properties of the sheet can be precisely adjusted. The rolling force ranges from 30-150kN, and a rolling force sensor monitors the rolling force to ensure stability. After rolling, the thickness tolerance of the sheet is checked and controlled within ±0.1mm. Simultaneously, the mechanical properties of the sheet are tested to ensure it meets the performance requirements of the rough-machined parts. An online sheet shape detection system monitors the sheet shape in real time, and by adjusting parameters such as roll crown and rolling force distribution, the sheet shape is precisely controlled to ensure flatness.

[0047] S3. The workpiece is obtained by secondary forming of the rough blank using an ultrasonic vibration device and an ultrasonic-assisted low-temperature processing device. The ultrasonic generator output frequency of the ultrasonic vibration device in S3 is 20-40kHz, the power is 50-1500W, the amplitude of the mold surface is 0.01-0.1mm, and the mold temperature of the low-temperature processing device is 240-260℃.

[0048] Specifically, after the rough blank is processed, ultrasonic vibration equipment is used to carry out ultrasonic-assisted low-temperature secondary molding. The ultrasonic vibration equipment mainly consists of an ultrasonic generator, a transducer, and an amplitude transformer. The ultrasonic generator outputs a high-frequency electrical signal with a frequency of 20-40kHz and a power of 50-1500W. The transducer converts the electrical signal into mechanical vibration, and the amplitude transformer further amplifies the vibration amplitude, so that the mold surface generates an amplitude of 0.01-0.1mm.

[0049] During the secondary molding process, ultrasonic vibration continuously acts on the contact surface between the mold and the blank. On one hand, ultrasonic vibration can significantly reduce the coefficient of friction between the material and the mold. Experimental tests show that the coefficient of friction can be reduced by 30%-50%. Real-time monitoring of frictional changes using a friction sensor allows the material to fill the mold cavity more smoothly during medium- and low-temperature molding, reducing molding pressure and mold wear. On the other hand, the high-frequency vibration of ultrasound promotes atomic diffusion and dislocation movement within the material. In medium- and low-temperature environments, the activity of material atoms is relatively low, and ultrasonic vibration provides additional energy, accelerating the atomic diffusion process and improving material flowability. This results in more uniform filling within the mold cavity. When manufacturing parts with complex internal cavity structures, ultrasonic assistance ensures that the material fully fills every corner of the cavity, reducing molding defects. The mold temperature of the low-temperature processing equipment is controlled at 240-260℃. The mold temperature is monitored in real time by a temperature sensor and precisely regulated by a cooling system or heating device. Within this temperature range, combined with ultrasonic vibration, the molding performance of the material can be better utilized. After molding, the dimensional accuracy of the workpiece is inspected, and the dimensional deviation is controlled within ±0.05mm. The microstructure of the material is observed by scanning electron microscopy to evaluate the effect of ultrasonic vibration on improving the uniformity of the structure. Digital image correlation (DIC) technology is used to monitor the deformation behavior of the material in real time during the molding process and analyze the deformation law of the material under the action of ultrasonic vibration, providing data support for process optimization.

[0050] S4. The workpiece is subjected to hot isostatic pressing (HIP) treatment using a hot isostatic pressing (HIP) apparatus to obtain the treated part; in S4, the heating rate of the HIP apparatus is 1-10℃ / min, the pressure is 50-200MPa, and the vacuum degree is 10. -3 -10 -4 Pa.

[0051] Specifically, after the workpiece is obtained by secondary forming, it is placed in a hot isostatic pressing (HIP) equipment for processing. The HIP equipment mainly includes a heating system, a pressure system, and a vacuum system.

[0052] The heating system employs resistance heating, with a heating rate adjustable from 1-10℃ / min and a temperature control accuracy of ±5℃. Slow heating prevents thermal stress on the workpiece due to rapid temperature changes. The pressure system provides pressure via a high-pressure pump, ranging from 50-200MPa, with pressure fluctuations controlled within ±1MPa. The vacuum system uses a combination of mechanical and molecular pumps to evacuate the furnace to a vacuum level of 10. -3 -10 -4 Pa is equipped with multiple temperature and pressure sensors installed inside the equipment to monitor the temperature and pressure at different locations in real time, ensuring uniform temperature and pressure distribution inside the furnace. The data acquisition and processing system analyzes and records the sensor data in real time to detect abnormal equipment operation in a timely manner.

[0053] The workpiece is placed in the high-pressure container of a hot isostatic pressing (HIP) apparatus, sealed, and evacuated. The temperature is first raised to a predetermined temperature at a rate of 5-8°C / min. This predetermined temperature is determined based on the characteristics of the silicon carbide aluminum alloy material and is generally 0.6-0.8 times the material's melting point. Then, the pressure is slowly increased to a set pressure and held for 2-4 hours. During this holding period, high temperature and high pressure act on the workpiece. The high temperature provides sufficient energy for the material atoms to diffuse, while the high pressure promotes the migration of atoms from pores and shrinkage defects within the material to the voids, gradually filling them and making the material structure more compact. After processing, the closure of the internal pores is observed using a metallographic microscope, and the material density is measured using a density measuring device to calculate the compactness, ensuring it reaches over 99%. A transmission electron microscope (TEM) is used to conduct an in-depth analysis of the material's microstructure, observing dislocation configurations, second-phase particle distribution, etc., to evaluate the impact of HIP on the material's microstructure and provide a basis for research on performance improvement mechanisms.

[0054] S5. The workpiece is processed by electrical discharge machining (EDM) to obtain a finished part. In S5, the pulse power supply output voltage of the EDM machine tool is 60-120V, the pulse width is 1-50μs, the pulse interval is 5-100μs, and deionized water is used as the working fluid with a working fluid temperature of 20-30℃.

[0055] Specifically, after the hot isostatic pressing process is completed, the processed parts are comprehensively measured using a three-dimensional measuring instrument according to the final precision requirements of the product. Combined with the product design drawings, the parts that need to be finely processed are accurately determined and then processed using an electrical discharge machining (EDM) machine.

[0056] Select the appropriate tool electrode according to the shape of the part being processed. For example, tungsten electrodes are used for machining small holes, while graphite electrodes are used for machining complex curved surfaces. The manufacturing accuracy of the electrode is controlled within ±0.005mm. High-precision electrodes can ensure machining accuracy. During the machining process, the pulse power supply output voltage is 60-120V, the pulse width is 1-50μs, and the pulse interval is 5-100μs. By adjusting these parameters, the discharge energy is precisely controlled to adapt to the requirements of different processing parts and materials. For harder silicon carbide aluminum alloys, the pulse voltage and width are appropriately increased to improve the discharge energy and enhance the material removal effect. During the processing, deionized water is used as the working fluid. The cleanliness and temperature stability of the working fluid are maintained through a circulation system. The working fluid temperature is controlled at 20-30℃. Deionized water can effectively cool the processing area, remove the heat generated by the discharge, and prevent the workpiece from deforming or being damaged due to overheating. At the same time, the working fluid can also flush away processing debris to ensure the smooth progress of the processing. After processing, the microstructure of the processed surface is observed using a scanning electron microscope to detect the surface roughness. Laser-induced breakdown spectroscopy (LIBS) is used to analyze the elemental composition of the processed surface to detect whether impurities are introduced during the processing and to evaluate the impact of processing on the surface properties of the material.

[0057] S6. Surface treatment of the precision-machined parts is performed using physical vapor deposition (PVD) or laser surface alloying (LAI) equipment to obtain forgings, and a collaborative optimization model is established based on various parameters. In S6, the argon flow rate of the PVD equipment is 20-50 sccm, the nitrogen flow rate is 5-20 sccm, the substrate bias voltage is -50 to -200V, the deposition temperature is 200-500℃, the deposition time is 2-4h, and the coating thickness is 1-5μm. The laser power of the LAI equipment is 1-5kW, the scanning speed is 5-20mm / s, the spot diameter is 0.5-2mm, and the instantaneous melting depth of the workpiece surface is 0.1-0.5mm.

[0058] Specifically, after obtaining the finished part through electrical discharge machining, surface treatment is carried out using physical vapor deposition equipment or laser surface alloying equipment, depending on the product's requirements for surface performance.

[0059] If physical vapor deposition (PVD) equipment is used, the machined part is placed in a vacuum chamber, and a hard coating is deposited on the workpiece surface using magnetron sputtering with titanium nitride (TiN) or titanium carbide (TiC) as the target material. During the deposition process, the argon flow rate is controlled at 20-50 sccm, and the nitrogen flow rate is adjusted according to the coating composition requirements, generally 5-20 sccm. The substrate bias voltage is -50 to -200V, the deposition temperature is 200-500℃, and the deposition time is 2-4 hours. By adjusting these parameters, the coating thickness is controlled within the range of 1-5 μm. X-ray photoelectron spectroscopy (XPS) is used to analyze the coating composition, and nanoindentation is used to test the coating hardness to ensure that the coating hardness reaches 20-30 GPa. Atomic force microscopy (AFM) is used to analyze the surface morphology of the coating, detect the surface roughness and microscopic defects, and evaluate the coating quality. Scratch tests are performed on the coating to test the adhesion between the coating and the substrate to ensure that the adhesion meets the application requirements.

[0060] If laser surface alloying equipment is used, it can be used to treat parts with special requirements for surface corrosion resistance and oxidation resistance. The laser power is 1-5kW, the scanning speed is 5-20mm / s, and the spot diameter is 0.5-2mm. Before processing, specific alloying elements (such as chromium, molybdenum, etc.) are uniformly coated on the workpiece surface in the form of powder or coating. During the laser scanning process, the base material of a certain depth on the workpiece surface is instantly melted, with a depth of 0.1-0.5mm, so that the alloying elements and the base material are quickly mixed and solidified to form an alloyed layer with special composition and properties. The composition distribution of the alloyed layer is detected by energy dispersive spectroscopy (EDS), and the corrosion resistance of the alloyed layer is tested using an electrochemical workstation to ensure that its corrosion current density in a specific corrosive medium is reduced by more than one order of magnitude. The phase composition of the alloyed layer is analyzed by X-ray diffraction (XRD) to study the crystal structure and phase transformation of the alloyed layer, providing a basis for the study of the performance improvement mechanism.

[0061] The steps involved in establishing a collaborative optimization model based on various parameters in S6 are as follows:

[0062] S601, take the parameters of additive manufacturing, the parameters of medium and low temperature forming rough machining, the parameters of secondary forming, the parameters of hot isostatic pressing, the parameters of electrical discharge machining, and the parameters of surface treatment as variables.

[0063] S602. Construct an objective function based on the properties of the forming material and the quality indicators of the forging;

[0064] S603. Using an intelligent optimization algorithm, a model is constructed based on variables and an objective function, and the model is solved. Through iterative calculation, the optimized parameters are obtained.

[0065] In S602, performance includes strength, hardness, plasticity, and fatigue life; quality indicators include dimensional accuracy, surface roughness, and internal defect rate; and intelligent optimization algorithms in S603 include genetic algorithm, particle swarm optimization algorithm, and simulated annealing algorithm.

[0066] Specifically, parameters for additive manufacturing (such as laser scanning speed, layer thickness, powder characteristics, etc.), parameters for medium- and low-temperature forming rough machining (such as forging temperature, deformation per pass, and forging pressure in medium- and low-temperature forging, and rolling temperature, reduction per pass, and rolling force in medium- and low-temperature rolling), parameters for secondary forming (such as ultrasonic generator output frequency, power, mold surface amplitude, and mold temperature in low-temperature processing equipment, etc.), parameters for hot isostatic pressing (such as heating rate, pressure, and vacuum degree, etc.), parameters for electrical discharge machining (such as pulse power supply output voltage, pulse width, pulse interval, and working fluid temperature, etc.), and parameters for surface treatment (such as argon flow rate, nitrogen flow rate, substrate bias, deposition temperature, deposition time, and coating thickness in physical vapor deposition equipment, and laser power, scanning speed, spot diameter, and instantaneous melting depth of the workpiece surface in laser surface alloying equipment, etc.) are used as variables.

[0067] An objective function is constructed based on the properties of silicon carbide aluminum alloy materials (including strength, hardness, plasticity, fatigue life, etc.) and the quality indicators of forgings (including dimensional accuracy, surface roughness, internal defect rate, etc.). The weight coefficients are set according to actual needs and the importance of each indicator.

[0068] Intelligent optimization algorithms (such as genetic algorithms, particle swarm optimization, and simulated annealing) are used to construct models based on variables and objective functions, and then solve these models. Taking genetic algorithms as an example, variables are encoded to form an initial population, and the objective function value corresponding to each individual in the population is calculated as the fitness. Genetic operations such as selection, crossover, and mutation are used to iterate and calculate the fitness. In each iteration, individuals with higher fitness are retained, while those with lower fitness are eliminated. After multiple generations of evolution, a set of process parameter combinations that optimize the objective function is obtained. These optimized parameters can be applied to actual production to further improve product quality and production efficiency.

[0069] By employing ultra-low plasticity, high strength, and high hardness materials as forming materials, and combining additive manufacturing, low-temperature forming roughing, ultrasonic-assisted low-temperature secondary forming, hot isostatic pressing, electrical discharge machining, and surface treatment, key parameters in each process step, such as laser power, scanning speed, temperature, pressure, and vibration parameters, are precisely controlled to achieve synergistic effects of multiple processes. Through the cooperation of these processes, the forming performance of the material is improved, and the deformation resistance is reduced. Additive manufacturing constructs complex blanks, providing a foundation for subsequent processing; low-temperature forming roughing forges or rolls the blanks at suitable temperatures, improving the material's microstructure; ultrasonic-assisted secondary forming reduces the coefficient of friction, promotes atomic diffusion, and improves material fluidity; hot isostatic pressing eliminates internal defects, making the material microstructure dense; electrical discharge machining achieves high-precision processing; and surface treatment improves the material's surface properties. This solves the difficulties of forging precision forgings and difficult-to-deform alloys that require extremely large tonnage equipment and have poor forming performance. High-quality, high-precision thin-walled, thin-webbed, high-ribbed, and other complex forgings can be formed under loads much lower than conventional forging.

[0070] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for low-temperature forming of ultra-low plasticity, high-strength, and high-hardness silicon carbide aluminum alloy, characterized in that, It comprises the following steps: S1, according to the demand, select the forming material, and build the blank through additive manufacturing; S2, the blank is rough machined by low temperature processing equipment, so as to obtain the rough blank; S3, the rough blank is secondarily formed by ultrasonic vibration equipment and ultrasonic assisted low temperature processing equipment, so as to obtain the workpiece; S4, the workpiece is subjected to hot isostatic pressing treatment by hot isostatic pressing equipment, so as to obtain the treated piece; S5, the treated piece is subjected to electric spark machining by electric spark machining machine tool, so as to obtain the finished piece; S6, the finished piece is subjected to surface treatment by physical vapor deposition equipment or laser surface alloying equipment, so as to obtain the forging piece, and a collaborative optimization model is established according to various parameters; The forming material in S1 includes silicon carbide aluminum alloy material, and the additive manufacturing of blank comprises the following steps: S101, according to the demand, design the product model, and prepare the forming material into powder by gas atomization method; S102, active groups are introduced on the surface of the powder by plasma treatment technology, and the powder is subjected to surface modification treatment; S103, a selective laser melting equipment equipped with a fiber laser is used to build in a closed forming cavity filled with argon, and a self-adaptive scanning strategy is used according to the structural complexity of different parts of the model, and the scanning path adopts a partitioned alternating scanning mode, so as to build the blank; The low temperature forming rough machining in S2 includes low temperature forging and low temperature rolling, the forging temperature of the low temperature forging is 400-700℃, the deformation amount of each pass is 10%-20, the forging pressure is 50-200MPa, the rolling temperature of the low temperature rolling is 400-700℃, the reduction of each pass is 0.5-2mm, and the rolling force is 30-150kN; The ultrasonic generator of the ultrasonic vibration equipment in S3 outputs a frequency of 20-40kHz and a power of 50-1500W, the mold surface amplitude is 0.01-0.1mm, and the mold temperature of the low temperature processing equipment is 240-260℃.

2. The method of claim 1, wherein the method is a low temperature forming method of the ultra-low plasticity high strength high hardness silicon carbide aluminum alloy. The power of the fiber laser is 400-1000W, the oxygen content of the closed forming cavity is controlled below 0.1%, the laser scanning speed of the laser melting equipment is 800-1200mm / s, and the layer thickness is 0.02-0.05mm.

3. The method of claim 1, wherein the method is a low temperature forming method of the ultra-low plasticity high strength high hardness silicon carbide aluminum alloy. The heating rate of the hot isostatic pressing equipment in S4 is 1-10℃ / min, the pressure is 50-200MPa, and the vacuum degree is 10-3-10-4Pa.

4. The method of claim 1, wherein the method is a low temperature forming method of an ultra-low plasticity high strength high hardness silicon carbide aluminum alloy. The pulse power supply output voltage of the electric spark machining machine tool in S5 is 60-120V, the pulse width is 1-50μs, the pulse interval is 5-100μs, deionized water is used as working liquid, and the working liquid temperature is 20-30℃.

5. The method of claim 1, wherein the method is a low temperature forming method of an ultra-low plasticity high strength high hardness silicon carbide aluminum alloy. The physical vapor deposition equipment in S6 has an argon flow rate of 20-50 sccm, a nitrogen flow rate of 5-20 sccm, a substrate bias voltage of -50 to -200V, a deposition temperature of 200-500℃, a deposition time of 2-4h, and a coating thickness of 1-5μm. The laser surface alloying equipment has a laser power of 1-5kW, a scanning speed of 5-20mm / s, a spot diameter of 0.5-2mm, and an instantaneous melting depth of 0.1-0.5mm on the workpiece surface.

6. The method of claim 1, wherein the method is a low temperature forming method of an ultra-low plasticity high strength high hardness silicon carbide aluminum alloy. The steps involved in establishing the collaborative optimization model based on various parameters in S6 are as follows: S601, take the parameters of additive manufacturing, the parameters of medium and low temperature forming rough machining, the parameters of secondary forming, the parameters of hot isostatic pressing, the parameters of electrical discharge machining, and the parameters of surface treatment as variables. S602. Construct an objective function based on the properties of the forming material and the quality indicators of the forging; S603. Using an intelligent optimization algorithm, a model is constructed based on variables and an objective function, and the model is solved. Through iterative calculation, the optimized parameters are obtained.

7. The method of claim 6, wherein the method is a low temperature forming method of the ultra-low plasticity high strength high hardness silicon carbide aluminum alloy. The performance in S602 includes strength, hardness, plasticity, and fatigue life; the quality indicators include dimensional accuracy, surface roughness, and internal defect rate; and the intelligent optimization algorithms in S603 include genetic algorithm, particle swarm optimization algorithm, and simulated annealing algorithm.

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