High-throughput material additive processing method and equipment

Abstract

The invention relates to a high-flux material additive processing method, which belongs to the field of additive manufacturing, and comprises the following steps: feeding wires to an additive area to provide energy for the wires; multiple laser beams are emitted into a molten pool area around the wire, and the multiple laser beams are polymerized in a molten pool; powder is conveyed in multiple paths, and each path of powder is coaxially conveyed around one path of laser. The method has the effect of improving the preparation efficiency, the flexibility and the forming quality of the high-flux material.

Description

Technical Field

[0001] The present application relates to the field of additive manufacturing technology, and in particular to a high-throughput material additive processing method and equipment. Background Art

[0002] In the field of materials science, high-throughput material preparation is of great significance for the rapid screening and development of new materials. Traditional material preparation methods are often time-consuming and inefficient, and it is difficult to meet the needs of high-throughput preparation. With the development of additive manufacturing technology, it has shown unique advantages in material preparation, but the existing additive manufacturing process still has some limitations in the preparation of high-throughput materials. For example, traditional additive manufacturing technology usually relies on a single energy source. For different types of materials and different molding requirements, a single energy source cannot achieve the best material heat treatment effect in some cases. Moreover, the powder is transported from the laser side axis to the molten pool area, and the uniform distribution and melting efficiency of the powder are difficult to ensure, resulting in directional anisotropy of the molding material. At the same time, the absorption rate of lasers by different powders varies greatly, which may lead to insufficient energy utilization, increase processing time and reduce efficiency. Summary of the invention

[0003] In order to improve the preparation efficiency, flexibility and molding quality of high-throughput materials, the present application provides a high-throughput material additive processing method and equipment.

[0004] A high-throughput material additive processing method provided in this application adopts the following technical solution: A high-throughput material additive processing method comprises the following steps: Feeding wire to the additive area to provide energy to the wire; Multiple laser beams are injected into the molten pool area around the wire, and the multiple laser beams are aggregated in the molten pool; The powder is transported in multiple paths, and each path of powder is coaxially transported around a laser.

[0005] By adopting the above technical solution, the power supply for energizing the wire can be a hot wire power supply or a fuse power supply. When a multi-laser processing technology is used to prepare high-throughput materials, the hot wire power supply can preheat the wire. When an arc laser composite process is used to prepare high-throughput materials, the arc and multiple lasers act simultaneously to provide multi-source energy, quickly melt the material, and significantly improve the processing efficiency and molten pool stability. In addition, multiple lasers can be set to different wavelengths to adapt to the absorption characteristics of different powders to light, enhance the melting efficiency of powders, further improve processing efficiency, and ensure the optimization of energy absorption of different materials; when each powder feeding nozzle delivers the same mixture, regardless of the movement direction of the deposition head, the mixture is always evenly distributed around the laser spot, which reduces the problem of directional anisotropy of the material and ensures the uniformity of the deposited material; When each powder feeding nozzle delivers different single powders, the arc action can enhance the stirring of the molten pool, promote the uniform distribution of powders in the molten pool, and improve the organizational structure of the material by refining the grains, reducing directional differences and improving deposition quality; the powder is evenly transported around the laser. Compared with the traditional single-side powder feeding method, this distribution method allows more powder to directly contact the high-temperature area, fully absorb laser energy, and improve melting efficiency and material utilization; The powder feeding amount of each powder feeding nozzle can be adjusted independently, supporting the manufacturing of variable component gradient materials, meeting the diverse needs of different material performance requirements, and improving the flexibility and adaptability of additive manufacturing.

[0006] Optionally, before the arc is introduced, an inner layer of shielding gas is delivered to the current additive area, and an outer layer of shielding gas is delivered around the additive area, and the outer layer of shielding gas is controlled to be sprayed from behind the moving direction of the deposition head.

[0007] By adopting the above technical solution, the inner layer of protective gas mainly acts on the current additive area. By protecting the atmosphere in the molten pool area, the molten pool is ensured to be stable and pure, and oxygen or moisture in the air is prevented from entering the molten pool, thereby reducing the oxidation reaction of the material, significantly improving the deposition quality and material properties, and ensuring the purity of the material during the additive process; The outer layer of protective gas acts around the additive area, especially to protect the area where the additive process has just been completed. Since the temperature of the area after the additive process is still high and the risk of oxidation is high, the outer layer of protective gas can effectively prevent material oxidation, ensure that there is no excessive oxidation reaction during the additive process, and maintain an ideal chemical environment in the additive area. In addition, the outer layer of protective gas can also accelerate the cooling of the area after the additive process is completed to avoid overheating and reduce material performance; At the same time, the outer layer of shielding gas can also reduce the temperature between the additive layers, reduce the thermal gradient, and prevent excessive grain growth caused by overheating between layers. By reducing the temperature fluctuation in the additive area, the outer layer of shielding gas helps to refine the grains, thereby improving the strength and durability of the material and providing better structural performance for the finished product in the additive manufacturing process.

[0008] Optionally, preset laser parameters, arc parameters, shielding gas parameters, powder feeding parameters and wire feeding parameters; During the deposition process, the molten pool status is monitored in real time to obtain molten pool information. According to the equipment conditions, the system automatically corrects the laser parameters, arc parameters, shielding gas parameters, powder feeding parameters and wire feeding parameters.

[0009] By adopting the above technical solution, the system can automatically adapt to changes in actual processing by real-time monitoring of the molten pool state and dynamically correcting the laser parameters, arc parameters, shielding gas parameters, powder feeding parameters and wire feeding parameters according to the molten pool information. This real-time adjustment ensures the stability of the molten pool and the uniformity of the material deposition process, and corrects the process parameters according to the actual situation, which can effectively control the microstructure of the material and thus improve the processing accuracy. Especially in complex additive processes, different materials and different processing environments may cause fluctuations in the molten pool state. This adaptive adjustment can effectively cope with these fluctuations, reduce human operation errors, ensure the high quality of the final product, and ensure the repeatability and reliability of high-throughput material preparation; The energy input of the laser and arc, the amount of powder and wire fed, and the flow rate of shielding gas all directly affect the energy utilization efficiency during the additive process. By automatically adjusting these parameters based on real-time melt pool information, the system can accurately control energy input and avoid unnecessary energy waste.

[0010] Optionally, the method for setting and correcting laser parameters is: Preset laser parameter values ​​according to material type and target performance; During the deposition process, according to the formula Where P is the laser power, m is the mass of material melted per unit time, C p is the specific heat capacity of the material, △T is the temperature change from room temperature to melting point, L f is the melting latent heat of the material, t is the laser action time, η is the laser energy utilization rate, the laser action time is adjusted in combination with process factors, and then the laser power is corrected.

[0011] By adopting the above technical solution, the laser processing power is preset based on experience. In the process of manufacturing high-throughput materials, the laser action time depends on multiple factors, such as material type, processing area, process parameters and part geometry, and the system re-corrects the laser power based on the adjusted laser action time. By synchronously adjusting the laser power and action time, the utilization rate of the laser energy can be effectively improved, the molten pool temperature and melting process can be accurately controlled, the deformation and residual stress during the processing process can be reduced, and the quality and performance of the material can be improved.

[0012] Optionally, when using a composite laser for deposition, according to the absorption characteristics of lasers of different wavelengths in the material, according to the formula: and P1:P2:P3...p n =α(λ1)×η1:α(λ2)×η2:α(λ3)×η3...α(λ n )×η n, the power parameters of each laser are adjusted and allocated, where A and n are constants related to the material, λ is the wavelength, η is the laser energy utilization rate, and P is the laser power.

[0013] By adopting the above technical solution, in the multi-wavelength laser composite process, the power distribution of lasers of different wavelengths also needs to consider the absorption characteristics of each wavelength in the material. The above method can further fine-tune the adjusted laser power to achieve the best energy coupling effect and further improve the deposition quality.

[0014] Optionally, the method for setting and correcting arc parameters is: According to the type of material and target performance, the preset parameter values ​​of arc current and wire feeding speed can be obtained to obtain the preset parameter values ​​of arc voltage and arc power; During the deposition process, according to the formula Q arc =μv s (C wire (T m -T0)+L melt ) to adjust the arc power, where Q arc is the heat input of the arc, μ is the arc efficiency, Vs is the wire feeding speed, L melt is the melting latent heat of the wire, C wire is the specific heat capacity of the wire, T m is the melting point of the wire, and T0 is the room temperature.

[0015] By adopting the above technical solution, the laser processing power is preset based on experience. In the process of manufacturing high-throughput materials, especially in variable-component gradient materials, the proportion of the wire composition will also change. Therefore, according to the change of wire feeding speed and the detected room temperature change (usually negligible), the system also promptly corrects the arc power. It can adapt to changes in material concentration. The adjustment of arc power can ensure that the appropriate melting conditions are always maintained, avoid energy waste or insufficient energy due to excessive or low heat input, achieve efficient energy transfer, improve deposition efficiency, reduce defects caused by thermal fluctuations, and ensure that the performance of gradient materials meets expectations.

[0016] Optionally, the method for setting and modifying the shielding gas is: Preset the inner layer shielding gas flow rate and the outer layer shielding gas flow rate; During the deposition process, the inner layer shielding gas flow rate and the outer layer shielding gas flow rate are adjusted according to the formula Q=vAα, where Q is the shielding gas flow rate, v is the flow velocity of the shielding gas on the surface of the molten pool, A is the surface area of ​​the molten pool, and α is the flow coefficient, which is determined according to the actual situation; At the same time, the inner protective gas pressure P should also be guaranteed. g ≥ ρ l gh , where P gis the inner layer protective gas pressure, h is the molten pool depth, ρ l is the metal density, g is the acceleration due to gravity.

[0017] By adopting the above technical solution, the shielding gas flow rate is preset based on experience. During the deposition process, under the action of different laser arcs, factors such as the surface area of ​​the molten pool will also change, and the flow coefficient also needs to be adjusted. At the same time, the inner layer of shielding gas should also have a corresponding gas pressure to prevent the molten pool metal from overflowing. Therefore, after the shielding gas flow rate is adjusted once, it can be corrected again according to the gas pressure of the inner layer of shielding gas.

[0018] Combining the above methods, the flow rates of the outer and inner shielding gases can be adjusted in real time, and the coverage effect of the shielding gases can be precisely controlled to ensure the stability of the molten pool. The appropriate inner shielding gas pressure can provide sufficient support to avoid excessive expansion or splashing of the metal, reduce the risk of molten pool overflow, enhance gas flow stability and avoid turbulence, optimize the surface atmosphere of the molten pool, and thus effectively optimize the deposition quality. At the same time, it can also improve the utilization efficiency of the shielding gas and reduce excessive waste of shielding gas.

[0019] Optionally, the method for setting and modifying powder feeding and wire feeding parameters is as follows: Preset each wire / powder feed rate according to material composition and structural requirements; During the deposition process, according to the formula F = ρVAC , and then set the proportional coefficient K according to the equipment conditions to adjust the powder / wire feeding rate, F is the powder / wire feeding rate, ρ is the powder / wire material density, V is the deposition rate, A is the cross-sectional area of ​​the molten pool, and C is the proportion of the powder / wire material in the target composition; When making a multi-layer structure with gradient composition, a mathematical model of the material composition changing with time and space is established to control it, according to the formula: Where C is the component concentration, t is the time, and D is the diffusion coefficient, which is used to preset the time point t when the component concentration is switched; During the deposition process, according to the formula: Where D0 is the diffusion constant, Q is the diffusion activation energy, R is the gas constant, and T is the molten pool temperature. The time t for switching the component concentration can be corrected by real-time monitoring of the molten pool temperature.

[0020] By adopting the above technical solution, the wire feeding rate and powder feeding rate are preset based on experience. In the manufacturing process of high-throughput materials, especially in the deposition process of variable component gradient materials and parts with complex geometric shapes, the wire feeding rate and powder feeding rate are corrected in time according to the actual cross-sectional area of ​​the molten pool. In addition, the switching process of the powder and wire concentration of each layer of material also requires precise control of the switching time and transition area to avoid sudden changes in composition affecting material properties. The mathematical model established first presets the time point when the corresponding material concentration is switched, and then adjusts it according to the detected molten pool temperature during the actual deposition process to achieve precise control of the composition, which is beneficial to improving the quality of variable component gradient materials.

[0021] Optionally, during the deposition process, the laser power and arc power should be corrected secondary according to the molten pool temperature detection data, according to the formula: P new =P old +K p (T ref -T actual ), where P new is the adjusted power, P old is the current power, K p is the proportionality coefficient, T ref is the reference temperature, T actual is the actual molten pool temperature.

[0022] By adopting the above technical solution, according to the monitored molten pool temperature, the laser power and arc power are corrected again using the above method, which is beneficial to further enhance the stability of the molten pool, improve energy utilization and adapt to the dynamic changes of the molten pool, thereby further improving the molten pool morphology and material properties.

[0023] A high-throughput material additive processing device provided in this application adopts the following technical solution: A high-throughput material additive processing device, used to implement the above-mentioned high-throughput material additive processing method, comprising a wire feeding assembly and a mounting seat, the mounting seat is provided with a plurality of coaxial powder feeding nozzles and a plurality of lens group modules, the lens group modules correspond to the coaxial powder feeding nozzles one by one, the lens group modules are connected with optical fiber plugs, the plurality of coaxial powder feeding nozzles are arranged around the wire feeding assembly, and the wire feeding assembly is provided with an electric tube; The wire passes through the power tube and is transported by the wire feeding assembly, and the laser is emitted from the center axis of the coaxial powder feeding nozzle. The coaxial powder feeding nozzle is provided with an annular powder feeding channel around its own center axis, so that the powder is sent around the laser, and the center axes of several lasers and wires intersect at the same point. An air inlet is provided on the lens group module, and the air inlet is connected to the laser delivery channel of the coaxial powder feeding nozzle. An air inlet pipe is provided on the side of the coaxial powder feeding nozzle away from the wire feeding assembly. The air inlet is used to deliver an inner layer of protective gas, and the air inlet pipe is used to deliver an outer layer of protective gas. The coaxial powder feeding nozzle is provided with a powder feeding pipe connected to the annular powder feeding channel.

[0024] By adopting the above technical solution, each fiber optic plug can independently emit different types of lasers and realize independent real-time adjustment. Multiple coaxial powder feeding nozzles can also realize independent powder adjustment. The arc additive function can be realized by energizing the power tube. The coordination of the air inlet and the air inlet pipe realizes the delivery of the inner and outer protective gases, and the powder can be evenly distributed around the laser, so that the powder absorbs the laser energy evenly. Therefore, the above equipment can realize multiple additive methods such as arc fuse additive, laser fuse additive, laser powder feeding additive, laser arc composite wire feeding additive, laser arc composite wire powder co-feeding additive, etc., thereby realizing the above processing method and improving the manufacturing efficiency and quality of high-throughput materials.

[0025] In summary, the present application includes at least one of the following beneficial technical effects: 1. This method realizes the synergistic effect of multiple energy sources and raw materials, greatly improving the efficiency and flexibility of material preparation, and is especially suitable for the preparation of high-throughput materials. Multi-wavelength laser compounding can select the best wavelength combination according to the material characteristics to improve energy absorption efficiency; laser arc compounding can enhance the stirring of the molten pool, refine the grains, and improve the material performance; dual-path protective gas compounding ensures the stability and purity of the molten pool; silk powder compounding realizes the diversified control of composition; 2. By precisely controlling process parameters such as multi-wavelength laser, laser arc, dual-path shielding gas and silk powder, precise element quantification can be achieved, component segregation can be effectively avoided, and high-quality variable component gradient materials, in-situ alloying materials, high-entropy alloys and other high-throughput materials can be prepared, and the molding complexity and size range are greatly expanded. Complex process parameter calculation formulas and control strategies ensure precise control of material composition and structure during the preparation process, meeting the requirements of high-throughput materials for composition diversity and performance uniformity; 3. The ability to adjust parameters in the preparation process in real time improves the stability and accuracy of the preparation process and ensures the repeatability and reliability of high-throughput material preparation. The closed-loop control system and model-based parameter optimization method enable the equipment to dynamically adjust process parameters according to actual conditions and adapt to changes in different materials and process conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a flow chart of an embodiment of the present application for embodying a high-throughput material manufacturing method.

[0027] Figure 2It is a schematic diagram of the overall structure of Example 3 of the present application.

[0028] Figure 3 It is a structural schematic diagram of Example 3 of the present application for reflecting the annular powder feeding channel and the laser output channel.

[0029] Explanation of the reference numerals: 1. Wire feeding assembly; 2. Mounting seat; 3. Coaxial powder feeding nozzle; 31. Annular powder feeding channel; 32. Laser delivery channel; 33. Powder feeding pipe; 34. Air inlet pipe; 4. Mirror module; 41. Air inlet; 5. Fiber optic plug; 6. Power supply pipe. DETAILED DESCRIPTION

[0030] The following is combined with Figure 1-3 This application is described in further detail.

[0031] The embodiments of the present application disclose a high-throughput material additive processing method.

[0032] like Figure 1 , the high-throughput material additive processing method includes the following steps: S1. According to the characteristics and requirements of the materials to be prepared, select the appropriate equipment configuration, and accurately prepare a variety of metal powders or wire raw materials according to the design composition of high-throughput materials. The particle size, purity and other parameters of the raw materials must meet the equipment requirements, and preset the laser parameters, arc parameters, shielding gas parameters, powder feeding parameters, wire feeding parameters and other process parameters; S2, open the inner layer protective gas and the outer layer protective gas; S3, feeding the wire vertically to the additive area and connecting the power supply to the wire; S4, injecting multiple laser beams into the molten pool area around the wire, the multiple laser beams converge in the molten pool, so that the multiple laser beams intersect with the central axis of the wire at the same point, and the multiple laser beams are asymmetric with respect to the central axis of the wire; S5. The powder is transported in multiple ways, and each way of powder is coaxially transported around a laser. S6, start the equipment, control the robot to drive the deposition head to move according to the preset slicing path planning, and perform layer-by-layer deposition of the material; S7. During the deposition process, the Tardis IGNIS MP200 molten pool camera and image acquisition software (including dry elongation recognition) in the extended configuration are used to monitor the molten pool status in real time and obtain information such as molten pool size and temperature distribution. At the same time, based on the dry elongation recognition data, the process technology intelligent collaborative optimization plug-in automatically optimizes the wire feeding rate, powder feeding rate, laser power, arc power, inner layer shielding gas flow, outer layer shielding gas flow and robot movement speed, and corrects the layer height; S8. After preparation, the molded parts are post-processed as necessary, such as removing the support structure (if any), performing heat treatment to eliminate residual stress, surface polishing, etc., to improve the performance and surface quality of the material. The selection of heat treatment process parameters (temperature, time, heating rate and cooling rate, etc.) needs to be determined according to the type of material, the residual stress state during the molding process, and the target performance, which can be predicted and optimized through thermal simulation analysis software; The prepared high-throughput materials are subjected to performance testing and analysis, such as using X-ray diffraction (XRD), scanning electron microscopy (SEM), mechanical properties testing and other means to evaluate the material's organizational structure, composition uniformity, mechanical properties and other indicators, to verify the effectiveness of the preparation method and whether the material performance meets expectations.

[0033] In step S1, the power, frequency, scanning speed and other parameters of the multi-wavelength laser are preset according to the type of material and the target performance. For example, for some refractory metal materials, the laser power can be appropriately increased (such as the total power can reach 1500W or higher) and the scanning speed can be reduced to ensure that the material is fully melted and fused; for heat-sensitive materials, the laser power can be reduced and the scanning speed can be increased to reduce the thermal impact.

[0034] In step S7, during the deposition process, according to the formula Where P is the laser power, m is the mass of material melted per unit time, Cp is the specific heat capacity of the material, △T is the temperature change of the material from room temperature to the melting point, Lf is the latent heat of melting of the material, t is the laser action time, η is the laser energy utilization rate, and the laser action time is adjusted in combination with process factors, and then the laser power is corrected.

[0035] If there are multiple types of lasers and powders, multiple lasers need to be corrected twice. When using composite lasers for deposition, according to the absorption characteristics of lasers of different wavelengths in the material, according to the formula: and P1:P2:P3...P n =α(λ1)×η1:α(λ2)×η2:α(λ3)×η3...α(λ n )×η n , the power parameters of each laser are adjusted and allocated, where A and n are constants related to the material, λ is the wavelength, η is the laser energy utilization rate, and P is the laser power.

[0036] At the same time, after the above correction, the laser power should also be finally corrected according to the detected molten pool temperature. According to the formula: P new =P old +K p (T ref -T actual ), where P newis the adjusted power, P old is the current power, K p is the proportionality coefficient, T ref is the reference temperature, T actual is the actual molten pool temperature. Therefore, through the above method, during the deposition process, the laser power can be adjusted in time, effectively improving the utilization rate of laser energy, accurately controlling the molten pool temperature and melting process, reducing deformation and residual stress during processing, and improving the quality and performance of the material.

[0037] In step S1, in the hybrid laser-arc deposition process, the arc power is preset based on the type of material, target performance, and heat input requirements during deposition. First, the arc current, voltage, and wire feed rate are preset to calculate the preliminary value of the arc power. For details, please refer to the following empirical formula: Where I is the arc current, k is a coefficient related to the material, P arc is the arc power and V is the arc voltage.

[0038] For refractory metal materials, such as tungsten and molybdenum, the arc power can be appropriately increased (e.g., the arc power can be set to 200-400W) to enhance the melting ability of the material; for heat-sensitive materials, such as aluminum and magnesium, the arc power can be reduced (e.g., 50-150W) and the wire feeding rate can be adjusted to control the heat input and avoid thermal damage caused by excessive temperature.

[0039] In step S7, during the deposition process, according to the formula Q arc =μv s (C wire (T m -T0)+L melt ) to adjust the arc power, where Q arc is the heat input of the arc, μ is the arc efficiency, Vs is the wire feeding speed, L melt is the melting latent heat of the wire, C wire is the specific heat capacity of the wire, T m is the melting point of the wire, and T0 is the room temperature.

[0040] In variable composition gradient materials, the composition ratio of the wire will also change. Therefore, according to the change of wire feeding speed and the detected room temperature change (usually negligible), the system will also correct the arc power in time.

[0041] At the same time, after the arc power is corrected as above, it should also be corrected according to the detected molten pool temperature. According to the formula: P new =P old +K p (T ref -T actual ), where P new is the adjusted power, Pold is the current power, K p is the proportionality coefficient, T ref is the reference temperature, T actual is the actual molten pool temperature. Therefore, through the above method, during the deposition process, the arc power can be adjusted in time, effectively improving the utilization rate of laser energy, accurately controlling the molten pool temperature and melting process, reducing deformation and residual stress during processing, and improving the quality and performance of the material.

[0042] In step S1, the flow rate of the shielding gas is preset according to the type of material, the heat input during the deposition process, and the stability requirements of the molten pool. First, the inner shielding gas flow rate and the outer shielding gas flow rate are preset to ensure the protection of the molten pool and avoid material oxidation. For high-melting-point metal materials, such as titanium alloys and stainless steel, the inner shielding gas flow rate is usually set to a larger value (such as 10-20L / min) to provide sufficient atmosphere protection to prevent oxidation and contamination; the outer shielding gas flow rate is set to 5-10L / min according to actual conditions to effectively avoid the influence of the surrounding gas on the additive area, while quickly cooling the area just deposited to avoid oxidation of the material at high temperatures. For heat-sensitive materials (such as aluminum alloys), the outer shielding gas flow rate can be increased to quickly take away excess heat and improve the molding quality of the material.

[0043] In step S7, during the deposition process, the changes of factors such as the molten pool surface are detected, and the inner layer shielding gas flow rate and the outer layer shielding gas flow rate are adjusted according to the formula Q=vAα, where Q is the shielding gas flow rate, v is the flow rate of the shielding gas on the molten pool surface, A is the surface area of ​​the molten pool, and α is the flow coefficient, which is determined according to actual conditions, such as the molten pool temperature, shielding gas type, gas flow mode, and environmental factors, etc.; At the same time, the inner protective gas pressure P should also be guaranteed. g ≥ ρ l gh , where Pg is the inner layer protective gas pressure, h is the molten pool depth, ρ l is the metal density, and g is the acceleration due to gravity. In general, the Pg value meets the above requirements. If the Pg value does not meet the above requirements, the inner layer shielding gas flow rate needs to be appropriately increased. This ensures that the molten pool is stable and pure, effectively avoids material oxidation, and provides better structural performance for the finished product in the additive manufacturing process.

[0044] In step S1, the feeding rate of the wire and each powder is preset according to the material composition, target performance and deposition process requirements. The feeding rate of the wire and powder will affect the material supply and component distribution of the molten pool, and further affect the melting process and final quality of the material.

[0045] Preset the appropriate wire feeding rate according to the wire diameter, material, melting point, and proportion of the target component. For example, for high-melting-point metal wires, a lower wire feeding rate may be required to ensure sufficient melting and synthesis; The powder feeding rate is preset according to the powder particle size, melting point, absorption characteristics and the proportion of the target component. For powders with smaller particle sizes, a higher feeding rate is usually required to improve deposition efficiency.

[0046] In step S7, during the deposition process, according to the formula F= ρVAC , and then set the proportional coefficient K according to the equipment situation to adjust the powder / wire feeding rate, F is the powder / wire feeding rate, ρ is the powder / wire material density, V is the deposition rate, A is the molten pool cross-sectional area, C is the proportion of the powder / wire material in the target component, and the wire feeding rate and powder feeding rate are corrected in time according to the changes in the monitoring molten pool cross-sectional area, the changes in the equipment deposition rate and the changes in the proportion of the powder / wire material; In step S1, when making a multi-layer structure with gradient composition, the concentration switching process of the powder and wire of each layer of material needs to accurately control the switching time and transition area to avoid the sudden change of composition affecting the material performance. Therefore, it is also necessary to establish a mathematical model of the material composition changing with time and space for control. According to the formula: Where C is the component concentration, t is the time, and D is the diffusion coefficient, which is used to preset the time point t when the component concentration is switched; In step S7, during the deposition process, according to the formula: Where D0 is the diffusion constant, Q is the diffusion activation energy, R is the gas constant, and T is the molten pool temperature. By real-time monitoring of the molten pool temperature, the time t for component concentration switching can be corrected to achieve precise control of the composition, which is beneficial to improving the quality of variable component gradient materials.

[0047] Example 1 Fabrication of variable composition gradient materials using arc laser composite process In the equipment selection and preparation, we selected equipment with red and blue composite wavelength laser, six-way powder feeding, arc and hot wire functions. According to the product configuration table, we installed and debugged the components of the equipment to ensure the normal operation of the laser system, powder feeding system, arc system and robot motion system. We prepared three metal powders with different compositions and loaded them into the corresponding powder feeders respectively. The powder particle size was controlled at 80-150μm.

[0048] Set process parameters and make corrections during deposition Set the laser power: set the near-infrared laser power to 800W, the blue light laser power to 300W; the laser scanning speed to 50mm / s; the laser spot diameter to 1mm.

[0049] Set the arc parameters: arc current is set to 150A, voltage is set to 20V, and wire feeding speed is set to 5m / min.

[0050] Set the shielding gas parameters: the inner shielding gas argon flow rate is set to 15L / min, and the inner shielding gas argon flow rate is 8L / min.

[0051] Set the powder feeding rate: According to the gradient material design, from the bottom layer to the top layer, the powder feeding rates of the three powders gradually change from 2 g / min to 0.5 g / min, from 0.5 g / min to 1.5 g / min, and from 1.5 g / min to 0.5 g / min, respectively.

[0052] Start the equipment, and control the robot to drive the deposition head to deposit layer by layer through the path generated by the slice path planning software. The slice path planning uses the finite element analysis optimization algorithm to simulate the stress distribution under different paths and select the path with the least stress for deposition. During the deposition process, the melt pool camera is used to monitor the melt pool state in real time, and each parameter and robot movement speed are automatically optimized according to the monitoring data.

[0053] According to the monitoring molten pool data, the laser and arc power are adjusted in real time: The laser power was corrected for the first time. The laser power was estimated based on the thermophysical properties of the material. The specific heat capacity of the first material was 0.5 J / (g.℃), the melting point was 1500℃, the room temperature was 25℃, the latent heat of melting was 300 J / g, the mass of the melted material per unit time was 0.5 g / s, the laser action time was 0.1s, and the laser energy utilization rate was 0.6. Substituting the formula into the calculation, the near-infrared laser power was about 792 W. Similarly, the blue laser power can be determined based on factors such as the material's absorption characteristics of blue light.

[0054] At the same time, considering that the wavelength of blue light is 450nm and the wavelength of near infrared light is 1064nm, for this material, assuming that A=10000, n=4 in the blue light absorption coefficient formula, A=5000, n=3 in the near infrared absorption coefficient formula, the blue light energy utilization rate is 0.55, and the near infrared energy utilization rate is 0.65, it can be calculated according to the power allocation ratio formula, That is, the ratio of blue light power to near infrared power is about 0.37:1, so the red and blue light can be corrected again. Here, blue light is generally used as a variable for adjustment. Finally, according to the actual molten pool temperature monitored, combined with the formula P new =P old +K p (T ref -T actual ) Fine-tune the power of red and blue light to complete the third correction.

[0055] The first correction of arc power is based on the arc heat input formula, assuming that the wire specific heat capacity is 0.4 J / (g.℃), the melting point is 1400℃, the room temperature is 25℃, the melting latent heat is 350 J / g, the arc efficiency is 0.7, the wire feeding speed is 5 m / min, and the wire density is 7 g / cm 3 , the diameter is 1.2mm, and the arc heat input is calculated to be about 3200W. In the arc additive process, it is generally considered that electrical energy is completely converted into thermal energy, so the set arc power of 3000W is corrected to 3200W, and then according to the molten pool state and material forming effect, combined with the formula P new =P old +K p (T ref -T actual ) to further correct the arc parameters.

[0056] The first correction of the shielding gas flow rate is based on the size of the molten pool (the molten pool is 5 mm long, 5 mm wide, and the surface area is 25 mm2 = 2.5 × 10-5 m 2 ) and the protective gas flow rate on the surface of the molten pool is 0.5m / s, the flow coefficient is 1.2, and the inner layer protective gas flow rate is about 15L / min, so it does not need to be adjusted. The outer layer protective gas flow rate can be adjusted and calculated according to the actual situation. At the same time, considering that the molten pool depth is 2mm and the liquid metal density is 8g / cm 3 , gravity acceleration 9.8m / s 2 According to the shielding gas pressure formula, the shielding gas pressure is at least 156.8Pa. In actual operation, the shielding gas pressure can be adjusted within an appropriate range according to the equipment conditions and the stability of the molten pool to complete the secondary correction.

[0057] Powder / wire feeding rate correction, the density of the first powder material is ρ1=8g / cm 3 , the deposition rate is V1 = 1 cm / min, and the cross-sectional area of ​​the molten pool is A1 = 0.1 cm 2 , the proportion of the powder material in the target component at the bottom layer is C1=0.8 (the initial value is higher), then the bottom layer powder feeding rate F1=ρ1V1 A1 C1=8×1×0.1×0.8=0.64g / min. According to the equipment conditions, the correction coefficient K value is 3, so the bottom layer powder feeding rate of the first material is finally corrected from 2g / min to 0.96×3=1.92g / min. In this way, the powder feeding rate corresponding to each layer is calculated, and the powder feeding rate and wire feeding rate of the other two powders can be calculated in the same way. In the calculation process, the fluidity of the powder and the accuracy of the powder feeding system must also be considered. Through actual testing and adjustment, the accuracy of the powder feeding rate is ensured.

[0058] The time point of switching the composition ratio is corrected. According to the preset program, different powder feeding channels are switched layer by layer to achieve the gradient change of the composition and prepare a variable composition gradient material with a thickness of 10mm. The raw material switching process controls the composition gradient according to the diffusion equation, and the diffusion coefficient is 10-6cm 2 / s, and the switching time and transition area are controlled by calculation to ensure a smooth transition of the composition. For example, when switching between two powders, the length of the transition area is estimated based on the size of the molten pool and the deposition rate. Assuming that the molten pool length is 5mm and the deposition rate is 1cm / min, the length of the transition area is about 5mm. The time required to achieve a smooth transition of the composition in this transition area is calculated based on the diffusion equation, so as to correct the time point of raw material switching, and then make a secondary correction to the time point of raw material switching based on the actual temperature of the detected molten pool.

[0059] Post-processing and testing The supporting structure of the molded part is removed, and the part is heat treated at 500℃ for 2 hours to eliminate residual stress, and then the surface is polished. The heat treatment process parameters are optimized by thermal simulation analysis software to ensure that the residual stress is effectively eliminated without affecting the material properties. During the heat treatment process, the stress changes during the heat treatment process are predicted based on parameters such as the thermal expansion coefficient and elastic modulus of the material, and the appropriate heating rate, holding time and cooling rate are selected to avoid new cracks or deformation.

[0060] The materials were tested using XRD and SEM, and the results showed that the material composition was distributed in a gradient, the organization was uniform, and there were no obvious defects, which verified the effectiveness of the method of the present invention in preparing variable component gradient materials. XRD analysis showed that the crystal structure and phase composition of different layers were in line with expectations, and SEM observed that the material microstructure was uniform, without obvious holes, cracks, and component segregation, which further proved the reliability of the process.

[0061] Example 2 Fabrication of high entropy alloys using multi-laser processing Select the appropriate model of equipment, which is full blue wavelength, dual-channel powder feeding and has hot wire function. Complete the installation and commissioning of the equipment to ensure the normal operation of each system. Prepare five kinds of high-purity metal powders (Fe, Co, Ni, Cr, Mn), mix them evenly and load them into the dual-channel powder feeder. The powder particle size is 80-150μm.

[0062] Process parameter setting and correction The blue laser power is set to 1200W, the laser frequency is 50KHz, and the scanning speed is 30mm / s. The laser power is corrected according to the average thermophysical properties of the high entropy alloy. The average specific heat capacity of the mixed powder is 0.45J / (g.℃), the average melting point is 1400℃, the room temperature is 25℃, the average melting latent heat is 280J / g, the mass of the melted material per unit time is 0.4g / s, the laser action time is 0.12s, and the energy utilization rate is 0.55. Substituting it into the formula, the power is about 1185W, and the first correction is made.

[0063] During the deposition process, the molten pool is monitored by the molten pool camera, and the process parameters are adjusted using the intelligent collaborative optimization plug-in to ensure the stability of the molten pool. The molten pool temperature monitoring data is fed back to control the laser power. The reference temperature is 1500°C, the actual monitoring temperature is 1480°C, the proportionality coefficient Kp=50, and the current blue laser power is 1185W. The adjusted power Pnew is calculated according to the formula = 1185 + 50 × (1500-1480) = 1285W, and the laser power is adjusted in real time to maintain the molten pool temperature stable.

[0064] The hot wire current is set to 100A, and the hot wire feeding speed is 3m / min. The hot wire current is determined according to the heat demand of the material and the heating efficiency of the hot wire to ensure that enough heat is provided to melt the powder evenly. The heating power Pwire of the hot wire is related to the hot wire resistance R and the current I, which can be calculated by the formula Pwire=I2R. The resistance R is determined according to the material characteristics and size of the hot wire, and then the heating power is calculated. It is compared with the heat required for material melting, and the hot wire current is adjusted to achieve the best heating effect.

[0065] The inner layer shielding gas flow rate is set to argon 12L / min, and the outer layer shielding gas flow rate is set to argon 6L / min. According to the size of the molten pool (the molten pool is 4mm long, 4mm wide, and has a surface area of ​​16mm 2 =1.6×10-5m 2 ) and shielding gas velocity (0.4m / s), flow coefficient 1.1, the main flow is calculated to be about 11.5L / min and corrected. At the same time, considering the molten pool depth of 1.5mm and the liquid metal density of 7.5g / cm 3 , gravitational acceleration g = 9.8 m / s 2 , calculate the shielding gas pressure to be at least 110.25Pa, and adjust the shielding gas pressure in actual operation to ensure the stability of the molten pool.

[0066] The powder feeding rate of both channels is set to 1.5 g / min. Powder feeding rate calculation: Assume that the average density of the mixed powder is ρ mix =7g / cm 3 , the deposition rate is V2 = 0.8 cm / min, and the cross-sectional area of ​​the molten pool is A2 = 0.08 cm 2Since the proportions of the five powders in the high entropy alloy are roughly the same (C equal =0.2), then the powder feeding rate F mix =ρ mix V2 A2C equal =7×0.8×0.08×0.2=0.896g / min. According to the factors such as the fluidity of the powder, the accuracy of the powder feeding system and the appropriate overfeeding to ensure the uniformity of the high entropy alloy composition, the correction factor K is taken as 2, that is, the powder feeding rate is corrected to F mix =2×0.896g=1.792g / min. During the powder feeding process, the vibration frequency and gas flow rate of the powder feeder must be adjusted according to parameters such as the particle size distribution and shape factor of the powder to ensure stable powder delivery.

[0067] The deposition is continued until a high-entropy alloy sample with a size of 50mm×50mm×5mm is prepared. During the deposition process, the layer height change is monitored in real time, and the layer height error is corrected using the intelligent collaborative optimization plug-in to ensure the dimensional accuracy of the sample. For example, when the layer height deviation is detected to exceed 0.05mm, the powder feeding rate and robot movement speed are automatically adjusted to restore the layer height to the normal range.

[0068] Post-processing and testing The sample was wire cut to obtain the test specimen, and then hardness test and microstructure analysis were performed. The test results showed that the hardness of the prepared high entropy alloy was uniform, and the microstructure showed a typical disordered structure, which proved the feasibility of the method of the present invention in the preparation of high entropy alloys. The hardness test results showed that the hardness value fluctuated slightly within a certain range, indicating that the composition uniformity was good. Microstructure analysis SEM observed that the elements in the high entropy alloy were uniformly distributed, without obvious segregation and agglomeration. XRD analysis confirmed the formation of the expected solid solution phase, further verifying the effectiveness of the process.

[0069] Example 3 The present application also provides a high-throughput material additive processing device for implementing the high-throughput material additive processing method of the embodiment of the present application.

[0070] like Figure 2 and Figure 3 A high-throughput material additive processing device includes a wire feeding assembly 1 and a mounting seat 2. The wire feeding assembly 1 passes through and is fixed on the mounting seat 2. The wire feeding assembly 1 is located at the center of the mounting seat 2. The wire feeding assembly 1 is used to transport wire and keep the wire coaxial with the mounting seat 2.

[0071] Six coaxial powder feeding nozzles 3 are installed at the bottom of the mounting seat 2. The coaxial powder feeding nozzles 3 are provided with an annular powder feeding channel 31 and a laser feeding channel 32. The annular powder feeding channel 31 is arranged around the laser feeding channel 32. The six coaxial powder feeding nozzles 3 are arranged around the wire feeding assembly 1 and are all facing the wire feeding assembly 1. All the coaxial powder feeding nozzles 3 are asymmetric with respect to the central axis of the mounting seat 2, and the central axes of all the coaxial powder feeding nozzles 3 are compared with the central axis of the mounting seat 2 at the same point.

[0072] Six lens modules 4 are installed on the top of the mounting base 2. The lens modules 4 correspond to the coaxial powder feeding nozzles 3 one by one. Each lens module 4 is connected to an optical fiber plug 5. After passing through the lens module 4, the laser is sent out through the laser delivery channel 32 of the coaxial powder feeding nozzle 3, and the laser is coaxial with the central axis of the coaxial powder feeding nozzle 3. Therefore, during processing, the central axes of all lasers intersect with the central axis of the wire at one point.

[0073] An air inlet 41 is provided on the lens module 4, and the air inlet 41 is connected to the laser delivery channel 32 of the coaxial powder feeding nozzle 3. An air inlet pipe 34 is provided on the side of the coaxial powder feeding nozzle 3 away from the wire feeding assembly 1. The coaxial powder feeding nozzle 3 is also provided with at least two powder feeding pipes 33, and the powder feeding pipes 33 are connected to the annular powder feeding channel 31. The air inlet 41 is used to deliver the inner layer shielding gas, and the air inlet pipe 34 is used to deliver the outer layer shielding gas. The wire feeding assembly 1 is provided with an electric tube 6, and the wire passes through the electric tube 6.

[0074] The optical fiber plug 5 can use various existing suitable products, usually SMA905, D80, QCS, QBH, etc. The power supply tube 6 can be connected to a hot wire power supply / MIG additive fuse power supply / MAG additive fuse power supply, etc.

[0075] The lens module 4 includes a collimating lens group and a focusing lens group. The collimating lens group collimates the laser beam introduced through the optical fiber plug 5 so that the laser rays in the laser beam are parallel to each other; the focusing lens group focuses the parallel laser beam so that it irradiates the workpiece within a set range, melting the workpiece substrate and the additive material to form a molten pool.

[0076] Each optical fiber plug 5 can independently emit different types of lasers and realize independent real-time adjustment. Multiple coaxial powder feeding nozzles 3 can also realize independent powder adjustment. By energizing the power tube 6, the hot wire and arc additive functions can be realized. The cooperation of the air inlet 41 and the air inlet pipe 34 realizes the delivery of the inner layer of protective gas and the outer layer of protective gas, and the powder can be evenly distributed around the laser, so that the powder absorbs the laser energy evenly. Therefore, the above equipment can realize multiple additive methods such as arc fuse additive, laser fuse additive, laser powder additive, laser arc composite wire additive, laser arc composite wire powder additive, etc., so as to realize the above processing method and improve the manufacturing efficiency and quality of high-throughput materials.

[0077] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A high-throughput material additive processing method, characterized in that: The following steps are involved: Feeding wire to the additive area to provide energy to the wire; Multiple laser beams are injected into the molten pool area around the wire, and the multiple laser beams are aggregated in the molten pool; The powder is transported in multiple paths, and each path of powder is coaxially transported around a laser.

2. The high-throughput material additive processing method according to claim 1, characterized in that: Before the arc is introduced, an inner layer of shielding gas is delivered to the current additive area, and an outer layer of shielding gas is delivered around the additive area, and the outer layer of shielding gas is controlled to be sprayed from behind the moving direction of the deposition head.

3. The high-throughput material additive processing method according to claim 2, characterized in that: Preset laser parameters, arc parameters, shielding gas parameters, powder feeding parameters and wire feeding parameters; During the deposition process, the molten pool status is monitored in real time to obtain molten pool information. According to the equipment conditions, the system automatically corrects the laser parameters, arc parameters, shielding gas parameters, powder feeding parameters and wire feeding parameters.

4. The high-throughput material additive processing method according to claim 3, characterized in that: The method for setting and correcting laser parameters is: Preset laser parameter values ​​according to material type and target performance; During the deposition process, according to the formula Where P is the laser power, m is the mass of material melted per unit time, Cp is the specific heat capacity of the material, △T is the temperature change of the material from room temperature to the melting point, Lf is the latent heat of melting of the material, t is the laser action time, η is the laser energy utilization rate, and the laser action time is adjusted in combination with process factors, and then the laser power is corrected.

5. The high-throughput material additive processing method according to claim 4, characterized in that: When using a composite laser for deposition, according to the absorption characteristics of lasers of different wavelengths in the material, according to the formula: and P1:P2:P3...P n =α(λ1)×η1:α(λ2)×η2:α(λ3)×η3...α(λ n )×η n , the power parameters of each laser are adjusted and allocated, where A and n are constants related to the material, λ is the wavelength, η is the laser energy utilization rate, and P is the laser power.

6. The high-throughput material additive processing method according to claim 3, characterized in that: The method for setting and correcting arc parameters is: According to the type of material and target performance, the preset parameter values ​​of arc current and wire feeding speed can be obtained to obtain the preset parameter values ​​of arc voltage and arc power; During the deposition process, according to the formula Q arc =μv s (C wire (T m -T0)+L melt ) to adjust the arc power, where Q arc is the heat input of the arc, μ is the arc efficiency, Vs is the wire feeding speed, L melt is the melting latent heat of the wire, C wire is the specific heat capacity of the wire, T m is the melting point of the wire, and T0 is the room temperature.

7. The high-throughput material additive processing method according to claim 3, characterized in that: The method for setting and correcting the shielding gas is as follows: Preset the inner layer shielding gas flow rate and the outer layer shielding gas flow rate; During the deposition process, the inner layer shielding gas flow rate and the outer layer shielding gas flow rate are adjusted according to the formula Q=vAα, where Q is the shielding gas flow rate, v is the flow velocity of the shielding gas on the surface of the molten pool, A is the surface area of ​​the molten pool, and α is the flow coefficient, which is determined according to the actual situation; At the same time, the inner protective gas pressure P should also be guaranteed. g ≥ ρ l gh , where Pg is the inner layer protective gas pressure, h is the molten pool depth, ρ l is the metal density, g is the acceleration due to gravity.

8. The high-throughput material additive processing method according to claim 3, characterized in that: The method for setting and correcting powder feeding and wire feeding parameters is as follows: Preset each wire / powder feed rate according to material composition and structural requirements; During the deposition process, according to the formula F = ρVAC , and then set the proportional coefficient K according to the equipment conditions to adjust the powder / wire feeding rate, F is the powder / wire feeding rate, ρ is the density of the powder / wire material, V is the deposition rate, A is the cross-sectional area of ​​the molten pool, and C is the proportion of the powder / wire material in the target composition; When making a multi-layer structure with gradient composition, a mathematical model of the material composition changing with time and space is established to control it, according to the formula: Where C is the component concentration, t is the time, and D is the diffusion coefficient, which is used to preset the time point t when the component concentration is switched; During the deposition process, according to the formula: Where D0 is the diffusion constant, Q is the diffusion activation energy, R is the gas constant, and T is the molten pool temperature. The time t for switching the component concentration can be corrected by real-time monitoring of the molten pool temperature.

9. The high-throughput material additive processing method according to claim 3, characterized in that: During the deposition process, the laser power and arc power should be corrected secondary according to the molten pool temperature detection data, according to the formula: P new =P old +K p (T ref -T actual ), where P new is the adjusted power, P old is the current power, K p is the proportionality coefficient, T ref is the reference temperature, T actual is the actual molten pool temperature.

10. A high-throughput material additive processing device, characterized in that: A method for high-throughput material additive processing for realizing any one of 1 to 9, comprising a wire feeding assembly (1) and a mounting seat (2), wherein the mounting seat (2) is provided with a plurality of coaxial powder feeding nozzles (3) and a plurality of lens group modules (4), wherein the lens group modules (4) correspond to the coaxial powder feeding nozzles (3) one by one, and the lens group modules (4) are connected with optical fiber plugs (5), and the plurality of coaxial powder feeding nozzles (3) are arranged around the wire feeding assembly (1), and the wire feeding assembly (1) is provided with an electric conduction tube (6); The wire passes through the power supply tube (6) and is transported through the wire feeding assembly (1), and the laser is emitted from the center axis of the coaxial powder feeding nozzle (3). The coaxial powder feeding nozzle (3) is provided with an annular powder feeding channel (31) around its own center axis, so that the powder is sent out around the laser, and the center axes of several lasers and the wire intersect at the same point. The lens assembly module (4) is provided with an air inlet (41), the air inlet (41) is connected to the laser delivery channel (32) of the coaxial powder feeding nozzle (3), an air inlet pipe (34) is provided on the side of the coaxial powder feeding nozzle (3) away from the wire feeding assembly (1), the air inlet (41) is used to deliver an inner layer of protective gas, the air inlet pipe (34) is used to deliver an outer layer of protective gas, and the coaxial powder feeding nozzle (3) is provided with a powder feeding pipe (33) connected to the annular powder feeding channel (31).

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