A method and apparatus for arc additive manufacturing of externally particulate reinforced nickel-based superalloys

Abstract

This invention discloses a method and apparatus for arc additive manufacturing of nickel-based superalloys with added particles, belonging to the field of additive manufacturing technology. The method includes: sequentially adding a binder compound and ceramic particles prepared in a preset mass ratio to alcohol to obtain a slurry; repeatedly dripping the slurry onto a pure nickel foil strip; determining drying stability after each dripping based on the relationship between the unit-time mass change rate of the total mass of the coated pure nickel foil and a preset drying threshold; judging whether the final coating is qualified and adjusting the dripping parameters based on the relationship between the underload deviation of the single target load and the actual ceramic particle load after dripping and a set threshold; preparing a deposition layer on a substrate using arc additive manufacturing technology; cooling to the layup temperature window; and then laying a qualified coated nickel foil, coating side down, onto the surface of the deposition layer, repeating the deposition, layup, and re-deposition process until the entire additive component is completed. This invention improves particle addition accuracy, layup stability, and the level of automation in the manufacturing process.

Description

Technical Field

[0001] This invention relates to the field of additive manufacturing technology, and more specifically to an electric arc additive manufacturing method and apparatus for externally reinforced nickel-based superalloy particles. Background Technology

[0002] Nickel-based superalloys are widely used in key components such as aero-engines and gas turbines due to their excellent high-temperature performance. Arc additive manufacturing offers advantages such as high efficiency, low cost, and high material utilization, but it is prone to problems such as coarse columnar crystals, elemental segregation, and insufficient microstructure uniformity during the preparation of nickel-based superalloys. Adding an interlayer coating containing ceramic particles can improve the microstructure and properties, but existing methods still suffer from difficulties in precisely controlling the particle addition amount, cumbersome procedures, and low automation.

[0003] Therefore, there is an urgent need to provide an arc additive manufacturing method and automation system for nickel-based superalloys reinforced with added particles that can achieve precise control of particle content and has automated preparation capabilities. Summary of the Invention

[0004] In view of the above problems, the present invention is proposed to provide an arc additive manufacturing method and apparatus for nickel-based superalloys with added particles to overcome or at least partially solve the above problems.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] This invention discloses a method for arc additive manufacturing of nickel-based superalloys with externally added particles, comprising the following steps: In a first aspect, the present invention discloses a method for arc additive manufacturing of nickel-based superalloys with externally added particles, comprising the following steps: S1. The binder solid compound and ceramic particles prepared according to the preset mass ratio are added to alcohol in sequence to prepare a mixed slurry; S2. The mixed slurry is applied dropwise in stages along a preset trajectory within the effective coating area of ​​the pure nickel foil strip; S3. After each drop coating is completed, the total mass of the coated pure nickel foil strip is collected at preset time intervals, and the mass change rate per unit time is calculated. When the mass change rate per unit time in N consecutive sampling cycles is less than the preset drying threshold, it is determined that the coating formed by this drop coating has reached the drying stable state and the next drop coating is carried out. S4. After the coating reaches a dry and stable state after the last drop application, calculate the total mass of the coating and calculate the actual ceramic particle load in the coating according to the preset mass ratio. S5. Based on the difference between the single target ceramic particle load and the actual ceramic particle load in the additive component, the underload deviation is obtained. According to the relationship between the underload deviation and the set threshold, it is determined whether the coated pure nickel foil strip is qualified, and the drop coating parameters in S2 are adjusted. S6. A deposition layer is prepared on the substrate using arc additive manufacturing technology. After the deposition layer is cooled to a preset placement temperature window, a qualified coated pure nickel foil strip is placed on the surface of the deposition layer with the coating facing down. Then, the next layer is deposited on the pure nickel foil surface, so that the ceramic particles in the coating enter the molten pool and are added into the deposition layer. The above deposition, placement and re-deposition process is repeated until the particle-reinforced additive component is formed.

[0007] Further, in step S1, during the preparation of the binder solid compound and ceramic particles according to a preset mass ratio, the mass fraction of the ceramic particles is:

[0008] in, The mass fraction of ceramic particles in the mixture is preset. The quality of the ceramic particles being fed into the feed. This refers to the mass of the solid compound used as a binder.

[0009] Furthermore, in S3, the calculation of the rate of change of mass per unit time each time specifically includes the following formula:

[0010] in, This represents the rate of change of mass per unit time. This indicates the preset time interval. This represents the total mass of the coated pure nickel foil strip at time t. This indicates the total mass of the coated pure nickel foil strip at the previous moment.

[0011] Furthermore, in step S4, the actual ceramic particle loading in the coating is calculated based on a preset mass ratio, specifically including the following formula:

[0012] in, This indicates the actual ceramic particle loading in the coating. The mass fraction of ceramic particles in the dried coating formed by ceramic particles and binder solid compounds. The initial mass of the pure nickel foil strip before the mixed slurry is applied. This refers to the total mass of the coated pure nickel foil strip after all the drop coating is completed.

[0013] Furthermore, in step S5, it is determined whether the coating of the dried and stabilized pure nickel foil is qualified, and the drop-coating parameters in step S2 are adjusted, specifically including: Drop-coating increment threshold calibration: Before the formal coating, keep the dropper specifications, valve opening parameters, slurry ratio and effective coating area consistent, and select multiple moving speeds within the allowable moving speed range for single drop coating; After each drop coating is completed, the material supply is stopped immediately. After the coating has dried and stabilized, the amount of ceramic particles added per drop coating at this moving speed is determined based on the weighing results. Take the maximum value among all movement speeds corresponding to a single load increment as the first threshold. ; The minimum value among all moving speeds corresponding to a single load increment, or the larger value among the maximum measurement errors of the weighing device, is taken as the second threshold. And satisfy ; Coating qualification criteria: Assume actual ceramic particle loading With single target ceramic particle loading The difference is the underload deviation. : ; When the underload deviation satisfy: At that time, the current coated pure nickel foil strip is deemed unqualified; When the underload deviation satisfy: At that time, the coated pure nickel foil strip is deemed qualified; Feedback adjustment of drop coating parameters: When the underload deviation satisfy: At the same time, reduce the moving speed of the dispensing mechanism during the dispensing process to increase the amount of slurry on the surface of a unit length of pure nickel foil strip; When the underload deviation satisfy: At the same time, increase the moving speed of the dispensing mechanism during the dispensing process to reduce the amount of material dispensed per batch and avoid over-drip.

[0014] Furthermore, in step S5, the single target ceramic particle loading in the additive component can be pre-calculated based on the target mass fraction of ceramic particles in each deposition layer of the additive component, wire feed speed, welding speed, welding wire diameter, welding wire density, deposition layer length, nickel foil density, nickel foil width, and nickel foil thickness using the following formula:

[0015] in, This refers to the target ceramic particle loading amount in a single operation. d is the wire feeding speed; d is the wire diameter; Density of nickel-based alloys; The length of the sedimentary layer; For welding speed; This refers to the density of the nickel foil. , These are the width and thickness of the nickel foil, respectively. This represents the target mass fraction of particles in each deposited layer of the additive component.

[0016] Furthermore, step S6 also includes: controlling the interlayer temperature based on the relationship between the average temperature of the deposition layer surface and the preset temperature value set in the laying temperature window.

[0017] Furthermore, interlayer temperature control is achieved based on the relationship between the average temperature of the deposition layer surface and the preset laying temperature window value, specifically including the following steps: Define the preset laying temperature window as ; When the average temperature of the surface of each deposition layer Temperatures exceeding the preset laying temperature window upper limit At that time, the interlayer cooling air branch is opened, and the temperature deviation D between the average temperature and the upper temperature limit is calculated. Adjust the inert protective gas flow rate until the laying conditions are met: .

[0018] Furthermore, the flow rate of the inert protective gas is adjusted through the following steps: Preset temperature deviation switching threshold A first preset protective gas flow rate and a second preset protective gas flow rate, wherein the first preset protective gas flow rate is greater than the second preset protective gas flow rate; When the temperature deviation D between the average temperature and the upper temperature limit is greater than or equal to At the same time, the auxiliary cooling device is controlled to blow inert protective gas onto the surface of the deposition layer at a first preset protective gas flow rate; When 0 <D< At that time, the auxiliary cooling device is controlled to blow protective gas at a second preset protective gas flow rate.

[0019] In a second aspect, the present invention also discloses an electric arc additive manufacturing apparatus for externally reinforced nickel-based superalloy particles, used to implement the method described in any one of the first aspects, including: An automated coating preparation system, an electric arc additive manufacturing system, a foil strip laying robot, and a control system; wherein, the automated coating preparation system is used to realize the fixing, conveying, weighing, dispensing, and drying of pure nickel foil strips; The electric arc additive manufacturing system is used for layer-by-layer deposition of nickel-based superalloy components; The foil laying robot is used to hold coated pure nickel foil strips, lay them on the surface of the deposition layer, and cut them. The control system is used to collect quality and interlayer temperature information and control the coordinated operation of various parts.

[0020] As can be seen from the above technical solution, compared with the prior art, the present invention discloses a method and apparatus for arc additive manufacturing of nickel-based superalloys with externally added particles, which has the following beneficial effects: Compared with existing technologies, this invention pre-fabricates ceramic particles on the surface of pure nickel foil strips and combines weighing feedback and interlayer temperature measurement feedback to achieve automatic control of ceramic particle loading, protective gas-assisted cooling, and interlayer placement timing, thereby improving particle addition accuracy, placement stability, and the level of automation in preparation. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0022] Figure 1 This is an overall control flowchart of the arc additive manufacturing method for enhanced nickel-based superalloys provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the interlayer placement and protective gas-assisted cooling closed-loop control process provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the overall structure of an automated system for arc additive manufacturing of nickel-based superalloys with externally added particles, provided in an embodiment of the present invention. Figure 4 This is a schematic diagram of the structure of the automated coating preparation system provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of the foil tape fixing device provided in an embodiment of the present invention.

[0023] Explanation of reference numerals in the attached figures: 1. Foil laying robot; 11. Gripping end gripper; 12. Cutting component; 2. Arc additive manufacturing robot; 21. Arc welding torch; 22. Auxiliary cooling nozzle; 3. Automated coating preparation system; 31. Small gantry coating preparation mechanism; 311. Main support frame; 312. Worktable; 313. Gantry moving mechanism; 314. Slurry storage box; 315. Switch valve; 316. Conical dropper; 32. Conveyor belt; 33. Foil fixing device; 331. Platform limiting device; 332. Vacuum adsorption platform; 333. Coating area limiting component; 334. Weighing pressure sensor; 4. Arc additive manufacturing power supply; 5. Protective gas device; 6. Industrial control computer; 7. Control cabinet; 8. Additive manufacturing worktable; 9. Non-contact infrared temperature measurement device. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below 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.

[0025] The first aspect of this invention discloses a method for arc additive manufacturing of nickel-based superalloys with externally added particles, referring to... Figure 1 , Figure 2 The method includes the following steps: S1. The binder solid compound and ceramic particles prepared according to the preset mass ratio are added to alcohol in sequence to prepare a mixed slurry; In this embodiment of the invention, the ceramic particles are one or more of TiC, TiN, and B4C; the binder can be polyvinylpyrrolidone (PVP) for bonding and dispersing the ceramic particles; the slurry is prepared by mixing ceramic particles, alcohol, and binder in a preset mass ratio, followed by ultrasonic stirring. The alcohol in the slurry evaporates during the drying process.

[0026] During the preparation of the binder solid compound and ceramic particles according to the preset mass ratio, the mass fraction of the ceramic particles is... for:

[0027] in, The quality of the ceramic particles being fed into the feed. This refers to the mass of the solid compound used as a binder.

[0028] Because the alcohol in the mixed slurry evaporates during the drying process, the mass fraction of ceramic particles in the dried coating remains [missing information]. .

[0029] S2. The mixed slurry obtained in S1 is applied dropwise along the preset trajectory of the effective coating area of ​​the pure nickel foil strip.

[0030] In this step, completing one coating cycle refers to the system's moving mechanism, such as a gantry moving mechanism, driving the conical dropper along a preset trajectory of the effective coating area of ​​the pure nickel foil strip to complete one coating movement. In this invention, the middle of the pure nickel foil strip has an effective coating area corresponding to the effective forming area of ​​the deposition layer in the additive component, and both ends have clamping allowance areas that are not coated with the mixed slurry, so that the total length of the pure nickel foil strip is greater than the effective length of the deposition layer; the effective coating area is used to coat the mixed slurry, and the clamping allowance areas are used for clamping during the laying process.

[0031] In this invention, the pure nickel foil strip has a thickness of 0.01 mm and a width smaller than the width of the additive component deposition layer, so as to ensure that the pure nickel foil strip can be completely laid on the deposition layer surface and improve the sufficiency of ceramic particles in the coating entering the molten pool.

[0032] S3. After each drop coating is completed, the total mass of the coated pure nickel foil strip is collected at preset time intervals, and the mass change rate per unit time is calculated. When the mass change rate per unit time is less than the preset drying threshold in N consecutive sampling periods, it is determined that the coating formed by this drop coating has reached the drying stable state and the next drop coating is carried out.

[0033] The rate of change of mass per unit time is calculated using the following formula:

[0034] in, This represents the rate of change of mass per unit time. This indicates the preset time interval. This represents the total mass of the coated pure nickel foil strip at time t. This indicates the total mass of the coated pure nickel foil strip at the previous moment.

[0035] In one specific embodiment, let The maximum permissible error of a single mass measurement for a weighing pressure sensor after zeroing, calibration, and negative pressure compensation is given. Since the rate of change of mass per unit time R(t) is obtained by dividing the difference between two adjacent mass measurements by the sampling time interval Δt, the maximum permissible error of the difference between two adjacent mass measurements is 2δ. M Therefore, a preset drying threshold is set. Can be taken as When the rate of change of mass per unit time R(t) is less than the preset drying threshold for N consecutive sampling periods. When the coating reaches a stable drying state, N is determined to be a positive integer not less than 3.

[0036] S4. After the coating reaches a dry and stable state following the last drop application, calculate the total mass of the coating and, based on the preset mass ratio, calculate the actual ceramic particle load in the coating:

[0037] in, This indicates the actual ceramic particle loading in the coating. This represents the mass fraction of ceramic particles in the dried coating. The initial mass of the pure nickel foil strip before the mixed slurry is applied. This refers to the total mass of the coated pure nickel foil strip after all the drop coating is completed.

[0038] In this step This indicates the quality of the dried coating on the surface of the pure nickel foil strip. The dried coating consists of ceramic particles and a binder solid compound; therefore, the actual ceramic particle loading in the coating can be obtained from the mass fraction of the ceramic particles. .

[0039] S5. Based on the single-stage target ceramic particle loading in additive components With actual ceramic particle loading The difference is used to obtain the underload deviation. According to underload deviation The relationship with the set threshold is used to determine whether the coated pure nickel foil strip is qualified, and the drop coating parameters in S2 are adjusted accordingly.

[0040] In one specific embodiment, the above steps specifically include: Drop-coating increment threshold calibration: Before the formal coating, keep the dropper specifications, valve opening parameters, slurry ratio and effective coating area consistent, and select multiple moving speeds within the allowable moving speed range for single drop coating; After each drop coating is completed, the material supply is stopped immediately. After the coating has dried and stabilized, the amount of ceramic particles added per drop coating at this moving speed is determined based on the weighing results. Take the maximum value among all movement speeds corresponding to a single load increment as the first threshold. ; The minimum value among all moving speeds corresponding to a single load increment, or the larger value among the maximum measurement errors of the weighing device, is taken as the second threshold. And satisfy ; Coating qualification criteria: When the underload deviation satisfy: If the coated pure nickel foil strip is deemed unqualified, the unqualified foil strip will not proceed to the subsequent additive manufacturing process.

[0041] When the underload deviation satisfy: At that time, the coated pure nickel foil strip is determined to be qualified, and the qualified foil strip is put into the subsequent additive manufacturing process.

[0042] Feedback adjustment of drop coating parameters: When the underload deviation satisfy: At the same time, reduce the moving speed of the next dispensing mechanism during the dispensing process to increase the amount of slurry on the surface of a unit length of pure nickel foil strip; When the underload deviation satisfy: At the same time, increase the moving speed of the dispensing mechanism during the dispensing process to reduce the amount of material dispensed per batch and avoid over-drip.

[0043] The above judgment is repeated when the coating reaches a stable drying state after each drop coating. Each time the process returns to step S2 (drop coating process), the same Δt, N, and preset drying threshold are used as in step S2. The drying and stabilization status is checked again until a qualified pure nickel foil strip is obtained.

[0044] The single-pass target ceramic particle load in the additive component can be pre-calculated using the following formula, based on the target mass fraction of ceramic particles in each deposition layer of the additive component, wire feed speed, welding speed, wire diameter, wire density, deposition layer length, nickel foil density, nickel foil width, and nickel foil thickness:

[0045] in, This refers to the target ceramic particle loading amount for a single operation. d is the wire feeding speed; d is the wire diameter; Density of nickel-based alloys; The length of the sedimentary layer; For welding speed; This refers to the density of the nickel foil. , These are the width and thickness of the nickel foil, respectively. This represents the target mass fraction of particles in each deposited layer of the additive component.

[0046] It should be noted that, based on and The deviation affects the closed-loop adjustment of subsequent drop coating parameters. The value is within the preset allowable range and does not exceed The value.

[0047] After obtaining qualified coated pure nickel foil strips, the process proceeds to the additive manufacturing process. In this invention, to improve work efficiency, the coated pure nickel foil strips can be prefabricated to obtain a number of qualified coated pure nickel foil strips in advance. The specific additive manufacturing process is as follows.

[0048] S6. A deposition layer is prepared on the substrate using arc additive manufacturing technology. After the deposition layer cools to the preset layup temperature window, a qualified coated pure nickel foil strip is laid on the surface of the deposition layer with the coating facing down. Then, the next layer is deposited on the pure nickel foil surface, so that the ceramic particles in the coating enter the molten pool and are added into the deposition layer. The above deposition, layup and re-deposition process is repeated until the particle-reinforced additive component is formed.

[0049] This step belongs to the arc additive manufacturing of nickel-based superalloys. In this process, the preset layup temperature window temperature is pre-set to... After each layer of deposition is completed and the electric arc is extinguished, the average surface temperature of the current deposition layer is obtained using a temperature measuring device. ;when Greater than the upper limit of the preset laying temperature window At that time, the control system opens the interlayer cooling gas branch and simultaneously controls the auxiliary cooling device to blow inert protective gas onto the surface of the deposited layer, maintaining an average temperature. and The difference is taken as the temperature deviation D; during the auxiliary cooling process, the temperature is continuously measured, and the gas flow rate is adjusted according to the updated temperature deviation to form a closed-loop feedback; when the average temperature When the preset laying temperature window is reached, the coated foil strip with qualified particle loading is laid and attached to the surface of the deposition layer; after trimming the clamping allowance area, the next layer is deposited, and the above process is repeated until the component is formed.

[0050] In specific practice, As a final laying condition that needs to be met.

[0051] In one specific embodiment, a preset temperature deviation switching threshold is provided. The flow rates of the first and second protective gases, with the first protective gas flow rate being greater than the second protective gas flow rate; when D ≥ At that time, auxiliary cooling is performed using the first protective gas flow rate; when 0 <D< At this time, a second protective gas flow is used for auxiliary cooling. During the auxiliary cooling process, the temperature measuring device continuously acquires the surface temperature information of the deposited layer and adjusts the protective gas flow rate accordingly; until... ≤ ≤ At that time, the interlayer cooling gas branch is closed, and the laying conditions are determined to be met.

[0052] Once the laying conditions are met, the foil laying robot clamps the clamping allowance areas at both ends of the pure nickel foil strip, moves the pure nickel foil strip above the deposition layer, and flips it so that the coated side is attached to the deposition layer surface with the pure nickel foil side facing upwards. After the pure nickel foil strip is laid, the clamping allowance areas at both ends are trimmed to prevent it from entering the subsequent arc deposition path.

[0053] In the process of arc additive manufacturing, a larger heat input is used for the first 3 to 4 layers to achieve good molten metal spreading; after the 4th layer, the welding current, wire feed speed and welding speed are adjusted layer by layer to reduce heat input and ensure good forming; around the 10th layer, after the deposited layer size tends to stabilize, the process parameters are fixed for subsequent deposition.

[0054] A second aspect of this invention discloses an arc additive manufacturing apparatus for externally reinforced nickel-based superalloys to implement the above-described method, such as... Figure 3 As shown, the system includes an automated coating preparation system 3, an arc additive manufacturing system, a foil placement robot 1, and a control system. The automated coating preparation system 3 is used to fix, transport, weigh, drop-coat, and dry pure nickel foil strips; the arc additive manufacturing system is used to perform layer-by-layer deposition of nickel-based superalloy components; the foil placement robot 1 is used to hold the coated pure nickel foil strips, place them on the surface of the deposition layer, and cut them; the control system is used to collect quality and interlayer temperature information and control the coordinated operation of each part.

[0055] refer to Figure 3 and Figure 4 In one specific embodiment, the automated coating preparation system 3 mainly includes a small gantry-type coating preparation mechanism 31, a conveyor belt 32, and a foil strip fixing device 33. The small gantry-type coating preparation mechanism 31 mainly includes a main support frame 311, a worktable 312, a small gantry moving mechanism 313, a slurry storage box 314, a switching valve 315, and a conical dropper 316. The main support frame 311 is used to install and support the various functional components; the worktable 312 is used to position the foil strip fixing device 33; the slurry storage box 314 is used to store ceramic particle slurry; the small gantry moving mechanism 313 is used to move the slurry storage box 314, the switching valve 315, and the conical dropper 316 along a preset direction; the switching valve 315 is used to control the slurry output; and the conical dropper 316 is used to drop the slurry onto the effective area surface of the pure nickel foil strip fixed on the foil strip fixing device 33.

[0056] refer to Figure 4 and Figure 5The foil strip fixing device 33 comprises a platform limiting device 331, a vacuum adsorption platform 332, a coating area limiting component 333, and a weighing pressure sensor 334. The platform limiting device 331 limits the vacuum adsorption platform 332 in both length and width directions. The vacuum adsorption platform 332 has several parallel adsorption strips, each with multiple vacuum adsorption holes spaced along its length, used to fix the pure nickel foil strip by negative pressure adsorption. The coating area limiting component 333 includes adjustable shielding members located at both ends of the pure nickel foil strip. The shielding member facing the coating area has an anti-stick coating and is magnetically fixed to the vacuum adsorption platform 332. Its position can be adjusted along the length of the pure nickel foil strip to prevent slurry from entering the clamping allowance area during drop coating. The weighing pressure sensor 334 is located below the vacuum adsorption platform 332 and is used to detect the total mass of the pure nickel foil strip and the coating, and to perform zeroing, calibration, or negative pressure compensation after the vacuum adsorption pressure stabilizes.

[0057] refer to Figure 3 The electric arc additive manufacturing system includes an electric arc additive robot 2, an electric arc welding gun 21, an auxiliary cooling nozzle 22, an electric arc additive power supply 4, a protective gas device 5, an additive worktable 8, a cooling device, and a non-contact infrared temperature measuring device 9, wherein the cooling device is not shown in the figure.

[0058] The arc additive manufacturing robot 2 can drive the arc welding torch 21 to move along a preset trajectory; the arc additive manufacturing power supply 4 is used to provide welding current and welding voltage to the arc welding torch 21; the shielding gas device 5 is used to provide inert shielding gas during the deposition process, and to provide auxiliary cooling through the auxiliary cooling nozzle 22 when the interlayer temperature is too high; the additive manufacturing worktable 8 is used to support the substrate or the component to be formed; the cooling device is used to continuously cool the arc welding torch 21; the non-contact infrared temperature measuring device 9 can be set as an infrared thermal imaging camera or a dual-color infrared thermometer, used to detect the surface temperature of the deposited layer after each layer is deposited in real time.

[0059] The foil strip laying robot 1 includes a laying robot body, a gripping end jaw 11, and two sets of cutting components 12. The laying robot body is used to drive the gripping end jaw 11 to move; the gripping end jaw 11 is used to grip the gripping allowance areas at both ends of the coated pure nickel foil strip, and lays the pure nickel foil strip on the surface of the deposited layer after the laying conditions are met (including the surface temperature of the deposited layer entering a preset laying temperature window). The two sets of cutting components 12 are respectively arranged inside the gripping end jaw 11, and the cutting blades are arranged along the width direction of the pure nickel foil strip to cut the gripping allowance area after laying.

[0060] The control system includes an industrial control computer 6 and a control cabinet 7. The industrial control computer 6 is used to generate or output control commands, and the control cabinet 7 is used to receive and execute control commands.

[0061] The present invention will be further illustrated below by taking the preparation of nickel-based superalloy components reinforced with external particles using TiC particles as an example.

[0062] (1) Determine the target particle loading M of a single layer based on the target mass fraction of TiC particles in the component to be prepared and the additive manufacturing process parameters. g Polyvinylpyrrolidone (PVP) and TiC ceramic particles, prepared according to a predetermined mass, were added sequentially to alcohol and mixed using ultrasonic stirring to obtain a slurry. The PVP compound was used to bind and disperse the TiC particles. The mass fraction α of TiC particles after the coating dried was... c This is the ratio of the mass of TiC particles after alcohol evaporation to the sum of the mass of TiC particles and the mass of PVP solids.

[0063] (2) Prepare a pure nickel foil strip with a thickness of 0.01 mm. The middle part of the pure nickel foil strip is the effective coating area, and the two ends are the clamping allowance areas without coating the mixed slurry. Lay the pure nickel foil strip on the surface of the vacuum adsorption platform 332 and fix it by negative pressure adsorption. Adjust the position of the two adjustable shielding parts according to the length of the required effective coating area so that the area between them corresponds to the effective coating area.

[0064] (3) After the vacuum adsorption pressure stabilizes, the weighing pressure sensor 334 records the initial mass M0 of the pure nickel foil strip. The control system controls the gantry moving mechanism 313 and the switching valve 315 to operate, so that the conical dropper 316 outputs the mixed slurry only in the area between the two adjustable shielding parts, thereby dripping the mixed slurry onto the effective coating area and avoiding the formation of a coating in the clamping margin area.

[0065] (4) After each coating, the weighing pressure sensor 334 collects the total mass M(t) of the coated pure nickel foil strip at preset time intervals Δt, and calculates the rate of mass change per unit time according to the formula R(t)=|M(t)-M(t-Δt)| / Δt. Let δ M The maximum permissible error for a single mass measurement of the weighing pressure sensor 334 after zeroing, calibration, and negative pressure compensation is given. The maximum permissible error for the difference between two adjacent mass measurements is 2δ. M Preset drying threshold ε d Let ε d =2δ M / Δt. When the rate of change of mass per unit time R(t) is less than the preset drying threshold ε for N consecutive sampling periods. d When the coating reaches a stable drying state, N is determined to be a positive integer not less than 3.

[0066] (5) After the coating reaches a dry and stable state, the total mass M(t) of the coated pure nickel foil strip at the last sampling time is recorded as the stable mass M. sCalculate the mass of the dried coating on the surface of the pure nickel foil strip as M. s -M0. According to formula M c =α c ×(M s -M0) Calculate the actual ceramic particle loading M c Actual ceramic particle loading M c With the target ceramic particle loading M g The difference is the underload deviation ΔM c =M g -M c The first threshold ε1 and the second threshold ε2 are determined through pre-calibration: Under the condition that the dropper specifications, slurry ratio, and drop coating area remain unchanged, multiple moving speeds are selected within the allowable moving speed range for single drop coating; after the coating reaches a dry and stable state, the single ceramic particle load increment corresponding to each moving speed is determined based on the weighing results. The maximum value of the load increment is determined as ε1, and the larger of its minimum stable value and the maximum measurement error of the weighing pressure sensor 334 is determined as ε2, where ε1>ε2>0. When ΔM c When ε1 is greater than 1, the small gantry moving mechanism 313 is controlled to perform drop coating at a lower moving speed to increase the amount of slurry on the surface of the pure nickel foil strip per unit length, and to determine whether the coating has reached a dry and stable state; when ΔM c When ΔM is greater than ε2 but not greater than ε1, increase the moving speed of the small gantry moving mechanism 313 to reduce the amount of slurry on the surface of the pure nickel foil strip per unit length, and determine whether the coating has reached a dry and stable state; when ΔM c When ΔM is greater than or equal to zero and not greater than ε2, the current pure nickel foil strip is deemed qualified and the coating process is stopped; when ΔM c When the value is less than zero, the coating process is stopped and the current pure nickel foil strip is deemed unqualified. This judgment is repeated after each coating process until a qualified pure nickel foil strip is obtained.

[0067] (6) Fix the substrate onto the additive manufacturing table 8, and control the arc additive manufacturing robot 2 to drive the arc welding torch 21 to perform single-layer deposition. After each layer is deposited and the arc is extinguished, the average temperature T on the surface of the deposited layer is obtained by the non-contact infrared temperature measuring device 9. avg The preset laying temperature window is [200℃, 300℃]. When T avg When the temperature exceeds 300℃, the control system activates the interlayer cooling gas branch and adjusts the temperature deviation D=T. avg-T2 to adjust the flow rate of the inert shielding gas. A temperature deviation switching threshold D0, a first preset shielding gas flow rate and a second preset shielding gas flow rate are preset, and the first preset shielding gas flow rate is greater than the second preset shielding gas flow rate; when D≥D0, the first preset shielding gas flow rate is adopted for auxiliary cooling; when 0<D<D0, the second preset shielding gas flow rate is adopted for auxiliary cooling. During the auxiliary cooling process, the infrared temperature measuring device continuously acquires the surface temperature information of the deposited layer, and feeds back to adjust the shielding gas flow rate, until T1≤T avg ≤T2, it is determined that the laying condition is satisfied, and the interlayer cooling gas branch is closed. Subsequently, the control system controls the foil strip laying robot to clamp the clamping allowance regions at both ends of the qualified pure nickel foil strip through the clamping end gripper, move the pure nickel foil strip to the upper part of the deposited layer and then turn it over, so that the side attached with the coating is attached to the surface of the deposited layer, and the pure nickel foil faces upward; after the laying is completed, the cutting assembly is controlled to cut the clamping allowance regions at both ends along the width direction of the pure nickel foil strip, and then the arc additive robot is controlled to perform the deposition of the next layer, and the cycle is repeated until the entire component is completed.

[0068] (7) In the arc additive manufacturing process, a relatively high heat input is adopted for the first 3 to 4 layers to ensure the spread of the deposited metal; after the 4th layer, the welding current, wire feeding speed and welding speed are adjusted layer by layer to reduce the heat input and ensure the forming stability; when reaching about the 10th layer, after the size of the layer to be deposited tends to be stable, the process parameters are fixed for subsequent deposition.

[0069] Regarding the single-layer ceramic particle target load M g , it can be determined according to the target mass fraction of ceramic particles in each deposited layer, wire feeding speed, welding speed, welding wire diameter, welding wire density, deposited layer length, nickel foil density, nickel foil width and nickel foil thickness, for example, it can be calculated by the following formula: (1) In the formula, is the wire feeding speed; d is the diameter of the wire material; is the density of the nickel-based alloy; is the length of the deposited layer; is the welding speed; is the density of the nickel foil; , are respectively the width and thickness of the nickel foil; is the target mass fraction of particles in each deposited layer of the additive component.

[0070] The embodiments in this specification are described in a progressive manner, each embodiment focuses on the differences from other embodiments, and the same and similar parts between the embodiments can be referred to each other. As for the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the description of the method part.

[0071] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for arc additive manufacturing of nickel-based superalloys with externally added particles, characterized in that, Includes the following steps: S1. The binder solid compound and ceramic particles prepared according to the preset mass ratio are added to alcohol in sequence to prepare a mixed slurry; S2. The mixed slurry is applied dropwise in stages along a preset trajectory within the effective coating area of ​​the pure nickel foil strip; S3. After each drop coating is completed, the total mass of the coated pure nickel foil strip is collected at preset time intervals, and the mass change rate per unit time is calculated. When the mass change rate per unit time in N consecutive sampling cycles is less than the preset drying threshold, it is determined that the coating formed by this drop coating has reached the drying stable state and the next drop coating is carried out. S4. After the coating reaches a dry and stable state after the last drop application, calculate the total mass of the coating and calculate the actual ceramic particle load in the coating according to the preset mass ratio. S5. Based on the difference between the single target ceramic particle load and the actual ceramic particle load in the additive component, the underload deviation is obtained. According to the relationship between the underload deviation and the set threshold, it is determined whether the coated pure nickel foil strip is qualified, and the drop coating parameters in S2 are adjusted. S6. A deposition layer is prepared on the substrate using arc additive manufacturing technology. After the deposition layer is cooled to a preset placement temperature window, a qualified coated pure nickel foil strip is placed on the surface of the deposition layer with the coating facing down. Then, the next layer is deposited on the pure nickel foil surface, so that the ceramic particles in the coating enter the molten pool and are added into the deposition layer. The above deposition, placement and re-deposition process is repeated until the particle-reinforced additive component is formed.

2. The method as described in claim 1, characterized in that, In step S1, where the binder solid compound and ceramic particles are prepared according to a preset mass ratio, the mass fraction of the ceramic particles is: in, The mass fraction of ceramic particles in the mixture is preset. The quality of the ceramic particles being fed into the feed. This refers to the mass of the solid compound used as a binder.

3. The method as described in claim 1, characterized in that, In step S3, the rate of mass change per unit time for each drop coating is calculated using the following formula: in, This represents the rate of change of mass per unit time. This indicates the preset time interval. This represents the total mass of the coated pure nickel foil strip at time t. This indicates the total mass of the coated pure nickel foil strip at the previous moment.

4. The method as described in claim 1, characterized in that, In step S4, the actual ceramic particle loading in the coating is calculated based on a preset mass ratio, specifically including the following formula: in, This indicates the actual ceramic particle loading in the coating. The mass fraction of ceramic particles in the dried coating formed by ceramic particles and binder solid compounds. The initial mass of the pure nickel foil strip before the mixed slurry is applied. This refers to the total mass of the coated pure nickel foil strip after all the drop coating is completed.

5. The method as described in claim 1, characterized in that, In step S5, it is determined whether the coated pure nickel foil strip is qualified, and the drop-coating parameters in step S2 are adjusted, specifically including: Drop-coating increment threshold calibration: Before the formal coating, keep the dropper specifications, valve opening parameters, slurry ratio and effective coating area consistent, and select multiple moving speeds within the allowable moving speed range for single drop coating; After each drop coating is completed, the material supply is stopped immediately. After the coating has dried and stabilized, the amount of ceramic particles added per drop coating at this moving speed is determined based on the weighing results. Take the maximum value among all movement speeds corresponding to a single load increment as the first threshold. ; The minimum value among all moving speeds corresponding to a single load increment, or the larger value among the maximum measurement errors of the weighing device, is taken as the second threshold. And satisfy ; Coating qualification criteria: Assume actual ceramic particle loading With single target ceramic particle loading The difference is the underload deviation. : ;When the underload deviation satisfy: At that time, the current coated pure nickel foil strip is deemed unqualified; When the underload deviation satisfy: At that time, the coated pure nickel foil strip is deemed qualified; Feedback adjustment of drop coating parameters: When the underload deviation satisfy: At the same time, reduce the moving speed of the dispensing mechanism during the dispensing process to increase the amount of slurry on the surface of a unit length of pure nickel foil strip; When the underload deviation satisfy: At the same time, increase the moving speed of the dispensing mechanism during the dispensing process to reduce the amount of material dispensed per batch and avoid over-drip.

6. The method as described in claim 1, characterized in that, In step S5, the single target ceramic particle loading in the additive component can be pre-calculated based on the target mass fraction of ceramic particles in each deposition layer of the additive component, wire feed speed, welding speed, wire diameter, wire density, deposition layer length, nickel foil density, nickel foil width, and nickel foil thickness using the following formula: in, This refers to the target ceramic particle loading amount in a single operation. d is the wire feeding speed; d is the wire diameter; Density of nickel-based alloys; The length of the sedimentary layer; For welding speed; This refers to the density of the nickel foil. , These are the width and thickness of the nickel foil, respectively. This represents the target mass fraction of particles in each deposited layer of the additive component.

7. The method as described in claim 1, characterized in that, Step S6 further includes: performing interlayer temperature feedback control based on the relationship between the average temperature of the deposition layer surface and the preset temperature value set in the laying temperature window.

8. The method as described in claim 7, characterized in that, Interlayer temperature control is achieved by considering the relationship between the average temperature of the deposition layer surface and the preset temperature value within a pre-defined laying temperature window. This includes the following steps: Define the preset laying temperature window as ; When the average temperature of the surface of each deposition layer Temperatures exceeding the preset laying temperature window upper limit At that time, the interlayer cooling air branch is opened, and the temperature deviation D between the average temperature and the upper temperature limit is calculated. Adjust the inert protective gas flow rate until the laying conditions are met: 。 9. The method as described in claim 8, characterized in that, The inert protective gas flow rate is adjusted by the following steps: Preset temperature deviation switching threshold A first preset protective gas flow rate and a second preset protective gas flow rate, wherein the first preset protective gas flow rate is greater than the second preset protective gas flow rate; When the temperature deviation D between the average temperature and the upper temperature limit is greater than or equal to At the same time, the auxiliary cooling device is controlled to blow inert protective gas onto the surface of the deposition layer at a first preset protective gas flow rate; When 0 <D< At that time, the auxiliary cooling device is controlled to blow protective gas at a second preset protective gas flow rate.

10. An electric arc additive manufacturing apparatus for externally reinforced nickel-based superalloys, used to implement the method described in any one of claims 1-9, characterized in that, include: An automated coating preparation system, an electric arc additive manufacturing system, a foil strip laying robot, and a control system; wherein, the automated coating preparation system is used to realize the fixing, conveying, weighing, dispensing, and drying of pure nickel foil strips; The electric arc additive manufacturing system is used for layer-by-layer deposition of nickel-based superalloy components; The foil laying robot is used to hold coated pure nickel foil strips, lay them on the surface of the deposition layer, and cut them. The control system is used to collect quality and interlayer temperature information and control the coordinated operation of various parts.

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