A composite rotating pressurized powder feeding control method, system, device and storage medium for friction stir welding additive manufacturing

Abstract

This invention discloses a composite rotary pressurized powder feeding control method, system, equipment, and storage medium for friction stir welding additive manufacturing, relating to the fields of solid-state welding and metal additive manufacturing technology. The method includes: determining a structural constant; calibrating a minimum pressure as a pressure reference and determining a reference speed as a speed reference; setting a working pressure and applying a constant force to form a powder column injection channel; driving the cylinder to rotate and roll the powder forward, obtaining the friction factor; multiplying the structural constant by the angular velocity to obtain the theoretical basic mass flow; introducing the pressure reference, friction factor, speed reference, and experimental calibration coefficients to correct and obtain a preliminary combined mass flow; further introducing a powder stability coefficient to correct and obtain the final powder feeding target value; and adjusting the angular velocity or working pressure to make the actual powder feeding amount track the target value. This invention can significantly improve powder feeding stability and process adaptability, enhance the interlayer bonding strength and dimensional accuracy of formed parts, and reduce defects and material waste.

Description

Technical Field

[0001] This invention relates to the field of solid-state welding and metal additive manufacturing technology, and in particular to a composite rotary pressurized powder feeding control method, system, equipment and storage medium for friction stir welding additive manufacturing. Background Technology

[0002] Friction stir welding (FSW) additive manufacturing is increasingly used in the forming of lightweight alloy components. This process relies on the rotation and plastic deformation of the stirring head to complete material deposition, requiring high stability in powder supply. In actual processing, powder needs to be continuously fed into the stirring zone, but existing powder feeding methods do not perform ideally in a rotating environment. Traditional gravity feeding and pneumatic powder feeding are significantly affected by the orientation of the powder, nozzle direction, and powder accumulation state. The density of the powder in the channel often changes, and the flow trend changes with the nozzle angle, easily causing fluctuations in the powder supply. During deposition, it is difficult to maintain a consistent rhythm between the powder and the stirring head, which can easily affect the thickness and stability of the formed layers. The movement of powder within the powder feeding channel is also unstable. When the powder slides on the tube wall, it is affected by friction, adhesion, and the particle's own accumulation morphology. The area near the stirring head is also affected by the combined effects of rotational inertia and temperature, making it prone to local accumulation or bridging structures. Once this stagnation occurs, the channel cross-section will be partially blocked, and the powder flow rate will suddenly decrease or even be interrupted.

[0003] Common axial feeding methods include structures such as cylinders, springs, or screws, which rely on external force to propel the powder forward. In actual use, slight changes in powder density, particle morphology, and packing pattern will alter the feeding effect. Within a rotating field, the powder is simultaneously affected by centrifugal force, frictional resistance, and thermal field, resulting in a complex stress state. A single feeding structure cannot maintain a stable conveying rhythm. Existing powder feeding systems mainly control flow rate by adjusting feeding pressure or changing screw speed, but lack control criteria that describe the stability of powder flow. Changes in process materials, powder particle size, or processing parameters often render existing control methods ineffective, leading to decreased powder supply stability. The actual flow of powder in the channel is difficult to predict, and control methods rely heavily on experience, making it difficult for powder feeding systems to adapt to the processing requirements of friction stir welding additive manufacturing. Summary of the Invention

[0004] In view of the above-mentioned problems, the present invention provides a composite rotary pressurized powder feeding control method, system, equipment and storage medium for friction stir welding additive manufacturing.

[0005] Therefore, the technical problem solved by the present invention is that the existing powder feeding control method of friction stir welding additive manufacturing relies on experience adjustment and lacks quantifiable and predictable model basis, resulting in poor powder feeding stability and insufficient process adaptability under complex working conditions such as rotation and changing posture.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: In a first aspect, the present invention provides a composite rotary pressurized powder feeding control method for additive manufacturing using friction stir welding, comprising: The structural constants are determined based on the cross-sectional area, lead, and bulk density of the spiral channel with a circular cross-section inside the rotating powder feeding cylinder. During the low-speed trial operation of the control device, the minimum effective pressure required to maintain continuous powder feeding is calibrated by adjusting the preload of the upper constant force pressurization mechanism, and used as the pressure reference. The reference travel speed at which the powder deposition rate and the stirring head travel speed reach equilibrium is determined through process experiments and used as the speed matching benchmark. The working pressure is set according to the process requirements. The upper constant force pressurization mechanism is activated to apply axial constant force to the powder, forming a continuous powder column with stable density and pressing it into the spiral channel inlet of the rotating powder feeding cylinder. The powder feeding cylinder is driven to rotate at a set angular velocity, causing the powder to roll and advance within the arc-shaped spiral channel, and the friction factor between the powder and the channel wall is obtained. Based on the determined structural constants and set angular velocities, the theoretical basis of mass flow is obtained; By introducing pressure reference, friction factor between current powder and channel wall, velocity matching reference, and experimentally calibrated pressure enhancement coefficient, friction attenuation coefficient and velocity matching coefficient, the theoretical mass flow is corrected to obtain a preliminary combined mass flow. Based on the powder's flowability characteristics, a powder stability coefficient is introduced to correct the initial combined mass flow, thereby obtaining the final powder delivery target value. By adjusting the rotational angular velocity or working pressure, the actual powder delivery amount tracks the final powder delivery target value, achieving closed-loop stable powder delivery.

[0007] As a preferred embodiment of a composite rotary pressurized powder feeding control method for additive manufacturing using friction stir welding, wherein: During the low-speed trial operation of the control device, the minimum effective pressure required to maintain continuous powder feeding is calibrated by adjusting the preload of the upper constant force pressurization mechanism, which serves as the pressure reference. By adjusting the preload step by step and observing the continuity of powder feeding, the minimum effective pressure that just maintains continuous powder feeding is determined as the pressure reference. The actual working pressure is normalized relative to the pressure reference to obtain a dimensionless pressure characterization value that describes the degree of influence of pressure on powder feeding efficiency.

[0008] As a preferred embodiment of a composite rotary pressurized powder feeding control method for additive manufacturing using friction stir welding, wherein: The reference travel speed, determined through process experiments, at which the powder deposition rate and the stirring head travel speed reach equilibrium, serves as the speed matching benchmark, including: The travel speed of friction stir welding additive manufacturing is used as an external input to the powder consumption rhythm, while a reference travel speed is introduced when the powder deposition rate and consumption rate are in balance. By normalizing the actual travel speed relative to the reference travel speed, a dimensionless travel speed characterization value is obtained to characterize the degree of matching between the powder supply rhythm and the processing consumption rhythm.

[0009] As a preferred embodiment of a composite rotary pressurized powder feeding control method for additive manufacturing using friction stir welding, wherein: The process of setting the working pressure according to process requirements, activating the upper constant force pressurization mechanism to apply axial constant force to the powder, forming a continuous powder column with stable density and pressing it into the spiral channel inlet of the rotating powder feeding cylinder includes: The working pressure is set according to the process requirements, and the upper constant force pressurization mechanism is activated. Within the effective stroke, an approximately constant axial thrust is applied to the powder, which is compacted into a continuous powder column with stable density. Under the drive of axial pressure, the powder column is continuously pressed into the spiral channel inlet of the rotating powder feeding cylinder, forming a continuously pressurized powder belt output.

[0010] As a preferred embodiment of a composite rotary pressurized powder feeding control method for additive manufacturing using friction stir welding, wherein: The driving rotary powder feeding cylinder rotates at a set angular velocity, causing the powder to roll and advance within the arc-shaped spiral channel, and the friction factor between the current powder and the channel wall is obtained, including: The driving rotation of the powder feeding cylinder and the internal circular cross-section spiral channel is rotated at a set angular velocity, causing the powder to undergo a rolling-sliding mixed motion on the arc groove surface. Under the combined action of circumferential friction drag and spiral guidance, the circumferential drive is converted into axial propulsion. The friction factor between the current powder and the channel wall is obtained as an input quantity characterizing the propulsion efficiency.

[0011] As a preferred embodiment of a composite rotary pressurized powder feeding control method for additive manufacturing using friction stir welding, wherein: The introduction of pressure reference, friction factor between the current powder and channel wall, velocity matching reference, and experimentally calibrated pressure enhancement coefficient, friction attenuation coefficient, and velocity matching coefficient corrects the theoretical mass flow, resulting in a preliminary combined mass flow including: Based on the rolling-sliding mixed motion mechanism of powder in a rotating spiral groove, three physical correction factors are constructed: axial pressure enhancement, friction attenuation, and travel speed matching. These three physical correction factors are multiplied by the theoretical mass flow to obtain a preliminary combined mass flow that comprehensively considers the effects of pressure, friction, and travel speed.

[0012] As a preferred embodiment of a composite rotary pressurized powder feeding control method for additive manufacturing using friction stir welding, wherein: The process of introducing a powder stability coefficient based on the powder's flowability characteristics to correct the initial combined mass flow, obtaining the final powder delivery target value, and then adjusting the rotational angular velocity or working pressure to ensure the actual powder delivery volume tracks the final powder delivery target value, thereby achieving closed-loop stable powder delivery, includes: Based on the powder's flowability, particle size distribution, and particle morphology, a powder stability coefficient is determined to compensate for differences in flow fluctuations and flow consistency among different powder systems. The initial combined mass flow is multiplied by the powder stability coefficient to obtain the final powder delivery target value required to achieve stable additive deposition under the current operating conditions and powder characteristics. The final powder delivery target value is used as the setpoint for the control system. The actual powder delivery rate is detected in real time and compared with the target value. The rotational angular velocity or working pressure is then adjusted in a closed loop based on the deviation.

[0013] In a second aspect, the present invention provides a composite rotary pressurized powder feeding control system for friction stir welding additive manufacturing, comprising: The structural constant calibration module is used to determine the structural constant based on the cross-sectional area, lead, and bulk density of the spiral channel with a circular cross-section inside the rotating powder feeding cylinder. The pressure reference calibration module is used to calibrate the minimum effective pressure required to maintain continuous powder feeding by adjusting the preload of the upper constant force pressurization mechanism during the low-speed trial operation of the control device, and to serve as the pressure reference. The speed reference calibration module is used to determine, through process experiments, the reference travel speed at which the powder deposition rate and the stirring head travel speed reach equilibrium, serving as the speed matching reference. The constant force powder feeding module is used to set the working pressure according to process requirements, start the upper constant force pressurization mechanism to apply axial constant force to the powder, form a continuous powder column with stable density and press it into the spiral channel inlet of the rotating powder feeding cylinder. The rotary conveying and friction detection module is used to drive the rotary powder feeding cylinder to rotate at a set angular velocity, so that the powder rolls and propels within the arc-shaped spiral channel, and to obtain the friction factor between the powder and the channel wall. The basic flow calculation module is used to obtain the theoretical basic mass flow based on the determined structural constants and set angular velocity; The combined flow correction module is used to introduce the pressure reference, the friction factor between the current powder and the channel wall, the velocity matching reference, and the experimentally calibrated pressure enhancement coefficient, friction attenuation coefficient and velocity matching coefficient to correct the theoretical mass flow and obtain the preliminary combined mass flow. The powder stabilization control module is used to introduce a powder stabilization coefficient based on the powder's flowability characteristics, correct the initial combined mass flow, obtain the final powder delivery target value, and adjust the rotational angular velocity or working pressure to make the actual powder delivery amount track the final powder delivery target value, thereby achieving closed-loop stable powder delivery.

[0014] Thirdly, the present invention provides a computer device, comprising: Memory and processor; The memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions, which, when executed by the processor, implement the steps of a composite rotary pressurized powder feeding control method for friction stir welding additive manufacturing.

[0015] Fourthly, the present invention provides a computer-readable storage medium storing computer-executable instructions that, when executed by a processor, implement the steps of a composite rotary pressurized powder feeding control method for friction stir welding additive manufacturing.

[0016] The beneficial effects of this invention are as follows: This invention significantly improves the process stability and forming quality of the friction stir welding additive manufacturing process. By combining composite rotary pressurized powder feeding with an established flow control model, it achieves precise, stable, and predictable control of the powder delivery volume, fundamentally solving the problems of uneven deposition layer thickness, increased internal defects, and poor dimensional accuracy of formed parts caused by unstable powder feeding. It can effectively suppress bridging and blockage of powder in the conveying channel and flow pulsation, ensuring that the powder can still continuously and uniformly enter the stirring zone under the rotation, change of posture, and complex motion trajectory of the welding head. This improves the uniformity of single-pass deposition layers in additive manufacturing, the interlayer bonding strength of multi-layer stacking, and the dimensional consistency of the overall component. It enhances the process adaptability to different powder materials, reduces the process debugging time and scrap rate caused by powder characteristic fluctuations, improves production efficiency and material utilization, and reduces overall manufacturing costs. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is an overall flowchart of a composite rotary pressurized powder feeding control method for additive manufacturing using friction stir welding, provided by the present invention. Detailed Implementation

[0019] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0020] Example 1, referring to Figure 1 This is the first embodiment of the present invention, which provides a composite rotary pressurized powder feeding control method for friction stir welding additive manufacturing, comprising: S1: Determine the structural constants based on the cross-sectional area, lead, and bulk density of the spiral channel with a circular cross-section inside the rotating powder feeding cylinder; S2: Under the low-speed test run state of the control device, the minimum effective pressure required to maintain continuous powder feeding is calibrated by adjusting the pre-tightening force of the upper constant force pressurization mechanism, and used as the pressure reference. S3: Determine the reference travel speed at which the powder deposition rate and the stirring head travel speed reach equilibrium through process experiments, and use it as the speed matching benchmark; S4: Set the working pressure according to the process requirements, start the upper constant force pressurization mechanism to apply axial constant force to the powder, form a continuous powder column with stable density and press it into the spiral channel inlet of the rotating powder feeding cylinder; S5: Drive the rotating powder feeding cylinder to rotate at a set angular velocity, so that the powder rolls and propels within the arc-shaped spiral channel, and obtain the friction factor between the current powder and the channel wall. S6: Based on the determined structural constants and set angular velocity, the theoretical mass flow is obtained; S7: By introducing the pressure reference, the friction factor between the current powder and the channel wall, the velocity matching reference, and the experimentally calibrated pressure enhancement coefficient, friction attenuation coefficient, and velocity matching coefficient, the theoretical mass flow is corrected to obtain the preliminary combined mass flow. S8: Based on the flowability characteristics of the powder, a powder stability coefficient is introduced to correct the initial combined mass flow, obtain the final powder feeding target value, and adjust the rotational angular velocity or working pressure to make the actual powder feeding amount track the final powder feeding target value, thereby achieving closed-loop stable powder feeding.

[0021] It should be noted that the composite rotary pressurized powder feeding control method for friction stir welding additive manufacturing described in this invention operates on the basis of a composite rotary pressurized powder feeding control device for friction stir welding additive manufacturing. This device consists of an upper pressurized powder feeding mechanism, a lower rotary powder feeding cylinder, and a powder supply outlet located at the lowermost welding area. Through the combined action of axial pressurization and rotary conveying, the powder maintains continuous forward movement within the rotating field, preventing accumulation and material interruption. The rotary powder feeding cylinder is equipped with a circular cross-section spiral channel. This channel has no sharp-corner retention areas, allowing the powder to undergo a rolling-sliding mixed motion during rotation to reduce bridging and accumulation. A pressurized powder feeding mechanism is located at the upper end of the device to apply a stable axial thrust to the powder column. This invention employs a constant-force spring preload structure as the pressurizing unit. This structure consists of a preload spring, a guide rod, and a pressure head. The preload force remains approximately constant throughout the working stroke, ensuring that the density of the powder column remains within a stable range and does not fluctuate significantly with changes in filling height. The powder enters the lower rotating channel with a stable density, providing consistent input conditions for subsequent rotary conveying.

[0022] The rotary powder conveying cylinder has a hollow structure with a continuous circular cross-section spiral channel inside. The spiral grooves are composed of arc surfaces, eliminating sharp corners and stagnation areas. The powder slides smoothly on the arc surfaces and rolls forward during rotation, making it less prone to bridging or localized accumulation. The cylinder is driven to rotate by an external drive module. The rotation process creates a screw-like conveying effect in the spiral channel, ensuring stable axial advancement of the powder. The conveying speed is determined by both the rotational angular velocity and the spiral lead.

[0023] The powder forms a continuous force chain within the pressurization and rotation sections. The upper constant force spring maintains the density of the powder column, while the lower spiral groove provides rotational drive, ensuring that the powder moves steadily forward throughout the entire conveying process without significant flow fluctuations due to changes in posture, thermal disturbances, or differences in the powder's own shape.

[0024] Example 2, refer to Figure 1 As one embodiment of the present invention, based on the previous embodiment, a composite rotary pressurized powder feeding control method for additive manufacturing using friction stir welding is provided, comprising: In this embodiment, determining the structural constants in step S1 based on the cross-sectional area, lead, and bulk density of the spiral channel with a circular cross-section inside the rotating powder feeding cylinder includes: The geometric parameters of the lower circular cross-section spiral channel of the control device (including the cross-sectional area of ​​the spiral groove, the spiral lead, the channel size and groove shape, etc.) and the basic structural and material quantities that affect the conveying capacity, such as the powder bulk density, are uniformly classified into the structural constant C, thereby solidifying the influence of the "basic ability of the geometric structure to push the powder by a unit angular displacement" into a constant output C.

[0025] It should be noted that the constant output C represents the mass of powder that can be propelled by a unit angular displacement. This solidifies the fixed geometric features of the device into a quantifiable basic conveying capacity coefficient, which is continuously called as the structural input for mass flow calculation in subsequent steps. This allows real-time operation to focus only on adjustable operating conditions without having to repeatedly process geometric influences.

[0026] In this embodiment, in step S2 above, during the low-speed trial operation of the control device, the minimum effective pressure required to maintain continuous powder feeding is calibrated by adjusting the preload of the upper constant force pressurization mechanism, which serves as the pressure reference. After obtaining the constant output C, in order to ensure continuous filling of the powder inlet and avoid material interruption, the minimum continuous powder feeding pressure of the upper constant force spring pressurization mechanism needs to be calibrated under the premise of low-speed operation of the device. Specifically, by adjusting the constant force spring preload / pressure level step by step and observing the criterion of "whether powder feeding is continuous and uninterrupted", the minimum effective pressure that can just achieve continuous powder feeding is determined and recorded as P0. Then, the actual working pressure P is normalized to a dimensionless pressure as the pressure input and output rule for the powder feeding process of this device, expressed as: in, P0 represents the pressure reference, which is dimensionless pressure.

[0027] It should be noted that the outputs P0 and P from this step will be directly used as the basis inputs for subsequent powder compaction, inlet filling, and flow enhancement terms.

[0028] In this embodiment, the reference travel speed at which the powder deposition rate and the stirring head travel speed reach equilibrium, determined through process experiments in step S3 above, serves as the speed matching benchmark, including: Establishing a pressure reference P0 and dimensionless pressure Then, the travel speed of friction stir welding additive manufacturing will be... As an external input to the powder consumption rhythm, a reference rate is also introduced when the powder deposition rate and consumption rate are in balance. Based on this, the dimensionless speed of travel is calculated and expressed as: in, It represents a dimensionless speed of movement.

[0029] It should be noted that this output serves as a quantitative measure of the degree to which the powder supply rhythm matches the processing and consumption rhythm; In subsequent steps, a speed matching term will be used to closely link the device's powder feeding capacity with actual additive manufacturing travel conditions.

[0030] In this embodiment, step S4 above, which involves setting the working pressure according to process requirements, activating the upper constant force pressurization mechanism to apply a constant axial force to the powder, forming a continuous powder column with stable density, and pressing it into the spiral channel inlet of the rotating powder feeding cylinder, includes: The upper constant force spring pressurization mechanism is activated to provide an approximately constant axial thrust / pressure within its effective stroke, thereby compacting the powder in the hopper into a continuous and stable powder column and maintaining its density within a stable range. At the same time, the compressed powder column continuously enters the lower circular cross-section spiral channel inlet under the axial pressure drive and forms a continuous powder belt output of "pressurized filling".

[0031] It should be noted that, since rotary propulsion requires a continuous and uniform supply of material at the inlet, the output state of this step (continuous pressurized filling) is a direct input prerequisite for the stable propulsion of the subsequent rotary section.

[0032] In this embodiment, the step S5 above, which involves driving the rotating powder feeding cylinder to rotate at a set angular velocity, causing the powder to roll and advance within the arc-shaped spiral channel, and obtaining the friction factor between the current powder and the channel wall, includes: After a continuous pressurized powder-filled belt is formed within the spiral channel, the lower powder feeding cylinder and its internal circular cross-section spiral channel rotate at an angular velocity ω. This causes the powder to undergo a "rolling-slipping mixed motion" on the arc groove surface. Under the combined action of circumferential friction drag and spiral guidance, the circumferential drive is converted into axial propulsion, thereby enabling the powder to continuously move forward along the spiral channel and output a stable forward movement. Simultaneously, the friction factor μ between the powder and the channel wall serves as an important input for this propulsion efficiency. For example, the angular velocity can be set to 3 rad·s. -1 Up to 30 rad·s -1 .

[0033] It should be noted that the circular arc cross-section structure helps to reduce the stagnation area at sharp corners, lower the risk of bridging and local accumulation, and provide a stable motion mechanism basis for establishing a calculable relationship of mass flow.

[0034] In this embodiment, the theoretical mass flow obtained in step S6 above, based on the determined structural constants and the set angular velocity, includes: After the powder moves forward continuously along the spiral channel, based on the basic conveying law of "spiral rotation driving powder forward movement", the determined structural constant and the set angular velocity ω are used as the core input for mass flow calculation. By solidifying the geometric influence in C and mainly reflecting the unit time propulsion capacity as a function of ω, the basic term output of the theoretical conveying capacity under undisturbed state is formed.

[0035] Specifically, by multiplying the determined structural constants by the set angular velocity, the theoretical basis mass flow under undisturbed conditions is obtained; It should be noted that the output of this basic term will serve as the starting point input for subsequent superposition of physical effects such as pressure enhancement, friction decay, and velocity matching, thereby ensuring that the model structure is clear and consistent with the mechanism of the device itself.

[0036] In this embodiment, step S7 above introduces a pressure reference, the friction factor between the current powder and the channel wall, a velocity matching reference, and experimentally calibrated pressure enhancement coefficient, friction attenuation coefficient, and velocity matching coefficient to correct the theoretical mass flow, resulting in a preliminary combined mass flow including: Dimensionless pressure Friction factor μ and dimensionless travel speed As a key input affecting conveying efficiency and powder supply demand, experimental calibration correction coefficients γ, α, β are introduced to adjust the sensitivity and attenuation intensity, thereby forming a combined flow relationship on the basis of the basic terms; Specifically, based on the rolling-slip mixed motion mechanism of powder within the rotating spiral groove, three independent physical correction factors are constructed: Axial pressure enhancement factor (1+γ·P*): This describes the effect of axial pressure on conveying efficiency. Increased pressure makes the powder column denser and improves the meshing efficiency with the spiral groove, thereby enhancing the propulsion effect. This effect is described in the form of linear gain, and its sensitivity is adjusted by the experimentally calibrated pressure enhancement coefficient γ (typically ranging from 0.2 to 0.6).

[0037] Friction attenuation factor exp(-α·μ): This describes the hindering effect of friction on conveying efficiency. As the friction factor μ between the powder and the channel wall increases, the rolling-slip motion of the powder is impeded, leading to a decrease in conveying efficiency. This attenuation trend is described by an exponential function, and its intensity is adjusted by an experimentally calibrated friction attenuation coefficient α (typically ranging from 1.0 to 3.0).

[0038] Travel speed matching factor (1+β·v*): This describes the pulling effect of external processing rhythm on powder supply demand. The faster the travel speed v of the stirring head, the faster the powder is consumed, requiring a synchronous increase in powder feed to meet deposition equilibrium. This matching effect is described in the form of linear gain, and its response gain is adjusted by the experimentally calibrated speed matching coefficient β (typically ranging from 0.1 to 0.4).

[0039] Multiplying the three physical correction factors by the theoretically based mass flow C·ω yields the preliminary combined mass flow Q, which comprehensively considers the effects of pressure, friction, and travel speed. com ,Right now: Q com =(C·ω)·(1+γ·P*)·exp(-α·μ)·(1+β·v*) Wherein, γ, α, and β are the pressure enhancement coefficient, friction attenuation coefficient, and velocity matching coefficient calibrated in the experiment.

[0040] In this embodiment, step S8 above introduces a powder stability coefficient based on the powder's flowability characteristics to correct the initial combined mass flow, obtaining the final powder delivery target value. The actual powder delivery amount is then adjusted to track the final powder delivery target value by regulating the rotational angular velocity or working pressure, thus achieving closed-loop stable powder delivery. Based on the material properties of the powder, such as its flowability, particle size distribution, and particle morphology, the powder stability coefficient K is determined. K is a dimensionless number with a typical value range of 0.80 to 1.05. It is used to compensate for differences in flow fluctuations, accumulation tendencies, and flow consistency exhibited by different powder systems in engineering applications: when the powder flow consistency is good and the fluctuation is small, K is taken as a higher value within the stability range (close to 1.05) to reflect a higher effective conveying capacity; when the powder flowability is poor or the fluctuation is large, K is taken as a lower value (close to 0.80) to reflect a decrease in effective conveying capacity.

[0041] The initial combination of mass flow Q com Multiplying this by the powder stability coefficient K yields the final powder delivery target value Q, i.e., Q = K·Q com The target value Q represents the powder feed rate required to achieve stable additive deposition under the current operating conditions and powder characteristics.

[0042] Using the final powder delivery target value Q as the setpoint for the control system, the actual powder delivery rate is monitored in real time (e.g., by weighing, flow metering, etc.) and compared with Q. Based on the deviation, the rotational angular velocity ω or working pressure P is adjusted in a closed loop: when the actual powder delivery rate is lower than Q, ω or P is increased to improve the delivery rate; when the actual powder delivery rate is higher than Q, ω or P is decreased to reduce the delivery rate. Through continuous closed-loop tracking control, the actual powder delivery rate is kept stable near the final powder delivery target value Q, thereby achieving highly consistent powder delivery under different powder materials and different process conditions.

[0043] Example 3: The above is an illustrative scheme of a composite rotary pressurized powder feeding control method for friction stir welding additive manufacturing according to this embodiment. It should be noted that the technical solution of a composite rotary pressurized powder feeding control system for friction stir welding additive manufacturing is based on the same concept as the above-described composite rotary pressurized powder feeding control method for friction stir welding additive manufacturing. Details not described in detail in the technical solution of the composite rotary pressurized powder feeding control system for friction stir welding additive manufacturing in this embodiment can be found in the description of the above-described composite rotary pressurized powder feeding control method for friction stir welding additive manufacturing.

[0044] This embodiment also provides a composite rotary pressurized powder feeding control system for friction stir welding additive manufacturing, including: The structural constant calibration module is used to determine the structural constant based on the cross-sectional area, lead, and bulk density of the spiral channel with a circular cross-section inside the rotating powder feeding cylinder. The pressure reference calibration module is used to calibrate the minimum effective pressure required to maintain continuous powder feeding by adjusting the preload of the upper constant force pressurization mechanism during the low-speed trial operation of the control device, and to serve as the pressure reference. The speed reference calibration module is used to determine, through process experiments, the reference travel speed at which the powder deposition rate and the stirring head travel speed reach equilibrium, serving as the speed matching reference. The constant force powder feeding module is used to set the working pressure according to process requirements, start the upper constant force pressurization mechanism to apply axial constant force to the powder, form a continuous powder column with stable density and press it into the spiral channel inlet of the rotating powder feeding cylinder. The rotary conveying and friction detection module is used to drive the rotary powder feeding cylinder to rotate at a set angular velocity, so that the powder rolls and propels within the arc-shaped spiral channel, and to obtain the friction factor between the powder and the channel wall. The basic flow calculation module is used to obtain the theoretical basic mass flow based on the determined structural constants and set angular velocity; The combined flow correction module is used to introduce the pressure reference, the friction factor between the current powder and the channel wall, the velocity matching reference, and the experimentally calibrated pressure enhancement coefficient, friction attenuation coefficient and velocity matching coefficient to correct the theoretical mass flow and obtain the preliminary combined mass flow. The powder stabilization control module is used to introduce a powder stabilization coefficient based on the powder's flowability characteristics, correct the initial combined mass flow, obtain the final powder delivery target value, and adjust the rotational angular velocity or working pressure to make the actual powder delivery amount track the final powder delivery target value, thereby achieving closed-loop stable powder delivery.

[0045] This embodiment also provides an electronic device applicable to a composite rotary pressurized powder feeding control method for friction stir welding additive manufacturing, including: The memory and processor are used to store computer-executable instructions and execute the computer-executable instructions to implement the composite rotary pressurized powder feeding control method for additive manufacturing of friction stir welding as proposed in the above embodiments.

[0046] This embodiment also provides a storage medium storing a computer program that, when executed by a processor, implements a composite rotary pressurized powder feeding control method for additive manufacturing using friction stir welding as proposed in the above embodiment.

[0047] The storage medium proposed in this embodiment belongs to the same inventive concept as the composite rotary pressurized powder feeding control method for additive manufacturing of friction stir welding proposed in the above embodiment. Technical details not described in detail in this embodiment can be found in the above embodiment, and this embodiment has the same beneficial effects as the above embodiment.

[0048] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A composite rotary pressurized powder feeding control method for additive manufacturing using friction stir welding, characterized in that, include: The structural constants are determined based on the cross-sectional area, lead, and bulk density of the spiral channel with a circular cross-section inside the rotating powder feeding cylinder. During the low-speed trial operation of the control device, the minimum effective pressure required to maintain continuous powder feeding is calibrated by adjusting the preload of the upper constant force pressurization mechanism, and used as the pressure reference. The reference travel speed at which the powder deposition rate and the stirring head travel speed reach equilibrium is determined through process experiments and used as the speed matching benchmark. The working pressure is set according to the process requirements. The upper constant force pressurization mechanism is activated to apply axial constant force to the powder, forming a continuous powder column with stable density and pressing it into the spiral channel inlet of the rotating powder feeding cylinder. The powder feeding cylinder is driven to rotate at a set angular velocity, causing the powder to roll and advance within the arc-shaped spiral channel, and the friction factor between the powder and the channel wall is obtained. Based on the determined structural constants and set angular velocities, the theoretical basis of mass flow is obtained; By introducing pressure reference, friction factor between current powder and channel wall, velocity matching reference, and experimentally calibrated pressure enhancement coefficient, friction attenuation coefficient and velocity matching coefficient, the theoretical mass flow is corrected to obtain a preliminary combined mass flow. Based on the powder's flowability characteristics, a powder stability coefficient is introduced to correct the initial combined mass flow, thereby obtaining the final powder delivery target value. By adjusting the rotational angular velocity or working pressure, the actual powder delivery amount tracks the final powder delivery target value, achieving closed-loop stable powder delivery.

2. The composite rotary pressurized powder feeding control method for additive manufacturing using friction stir welding as described in claim 1, characterized in that, The process of adjusting the preload of the upper constant force pressurization mechanism to calibrate the minimum effective pressure required to maintain continuous powder feeding during the low-speed trial operation of the control device, and using this as a pressure reference, includes: By adjusting the preload step by step and observing the continuity of powder feeding, the minimum effective pressure that just maintains continuous powder feeding is determined as the pressure reference. The actual working pressure is normalized relative to the pressure reference to obtain a dimensionless pressure characterization value that describes the degree of influence of pressure on powder feeding efficiency.

3. The composite rotary pressurized powder feeding control method for additive manufacturing using friction stir welding as described in claim 2, characterized in that, The reference travel speed, determined through process experiments, at which the powder deposition rate and the stirring head travel speed reach equilibrium, serves as the speed matching benchmark, including: The travel speed of friction stir welding additive manufacturing is used as an external input to the powder consumption rhythm, while a reference travel speed is introduced when the powder deposition rate and consumption rate are in balance. By normalizing the actual travel speed relative to the reference travel speed, a dimensionless travel speed characterization value is obtained to characterize the degree of matching between the powder supply rhythm and the processing consumption rhythm.

4. The composite rotary pressurized powder feeding control method for additive manufacturing using friction stir welding as described in claim 3, characterized in that, The process involves setting the working pressure according to process requirements, activating the upper constant force pressurization mechanism to apply a constant axial force to the powder, forming a continuous powder column with stable density, and pressing it into the spiral channel inlet of the rotating powder feeding cylinder, including: The working pressure is set according to the process requirements, and the upper constant force pressurization mechanism is activated. Within the effective stroke, an approximately constant axial thrust is applied to the powder, which is compacted into a continuous powder column with stable density. Under the drive of axial pressure, the powder column is continuously pressed into the spiral channel inlet of the rotating powder feeding cylinder, forming a continuously pressurized powder belt output.

5. The composite rotary pressurized powder feeding control method for additive manufacturing using friction stir welding as described in claim 4, characterized in that, The driving rotary powder feeding cylinder rotates at a set angular velocity, causing the powder to roll and advance within the arc-shaped spiral channel, and the friction factor between the current powder and the channel wall is obtained, including: The driving rotation of the powder feeding cylinder and the internal circular cross-section spiral channel is rotated at a set angular velocity, causing the powder to undergo a rolling-sliding mixed motion on the arc groove surface. Under the combined action of circumferential friction drag and spiral guidance, the circumferential drive is converted into axial propulsion. The friction factor between the current powder and the channel wall is obtained as an input quantity characterizing the propulsion efficiency.

6. The composite rotary pressurized powder feeding control method for additive manufacturing using friction stir welding as described in claim 5, characterized in that, The theoretical mass flow is modified by introducing a pressure reference, the friction factor between the current powder and the channel wall, a velocity matching reference, and experimentally calibrated pressure enhancement coefficient, friction attenuation coefficient, and velocity matching coefficient, resulting in a preliminary combined mass flow, including: Based on the rolling-sliding mixed motion mechanism of powder in a rotating spiral groove, three physical correction factors are constructed: axial pressure enhancement, friction attenuation, and travel speed matching. These three physical correction factors are multiplied by the theoretical mass flow to obtain a preliminary combined mass flow that comprehensively considers the effects of pressure, friction, and travel speed.

7. The composite rotary pressurized powder feeding control method for additive manufacturing using friction stir welding as described in claim 6, characterized in that, The process involves introducing a powder stability coefficient based on the powder's flowability characteristics to correct the initial combined mass flow, obtaining the final powder delivery target value, and then adjusting the rotational angular velocity or working pressure to ensure the actual powder delivery volume tracks the final powder delivery target value, thus achieving closed-loop stable powder delivery. This includes: Based on the powder's flowability, particle size distribution, and particle morphology, a powder stability coefficient is determined to compensate for differences in flow fluctuations and flow consistency among different powder systems. The initial combined mass flow is multiplied by the powder stability coefficient to obtain the final powder delivery target value required to achieve stable additive deposition under the current operating conditions and powder characteristics. The final powder delivery target value is used as the setpoint for the control system. The actual powder delivery rate is detected in real time and compared with the target value. The rotational angular velocity or working pressure is then adjusted in a closed loop based on the deviation.

8. A composite rotary pressurized powder feeding control system for additive manufacturing using friction stir welding, employing the method described in any one of claims 1 to 7, characterized in that, include: The structural constant calibration module is used to determine the structural constant based on the cross-sectional area, lead, and bulk density of the spiral channel with a circular cross-section inside the rotating powder feeding cylinder. The pressure reference calibration module is used to calibrate the minimum effective pressure required to maintain continuous powder feeding by adjusting the preload of the upper constant force pressurization mechanism during the low-speed trial operation of the control device, and to serve as the pressure reference. The speed reference calibration module is used to determine, through process experiments, the reference travel speed at which the powder deposition rate and the stirring head travel speed reach equilibrium, serving as the speed matching reference. The constant force powder feeding module is used to set the working pressure according to process requirements, start the upper constant force pressurization mechanism to apply axial constant force to the powder, form a continuous powder column with stable density and press it into the spiral channel inlet of the rotating powder feeding cylinder. The rotary conveying and friction detection module is used to drive the rotary powder feeding cylinder to rotate at a set angular velocity, so that the powder rolls and propels within the arc-shaped spiral channel, and to obtain the friction factor between the powder and the channel wall. The basic flow calculation module is used to obtain the theoretical basic mass flow based on the determined structural constants and set angular velocity; The combined flow correction module is used to introduce the pressure reference, the friction factor between the current powder and the channel wall, the velocity matching reference, and the experimentally calibrated pressure enhancement coefficient, friction attenuation coefficient and velocity matching coefficient to correct the theoretical mass flow and obtain the preliminary combined mass flow. The powder stabilization control module is used to introduce a powder stabilization coefficient based on the powder's flowability characteristics, correct the initial combined mass flow, obtain the final powder delivery target value, and adjust the rotational angular velocity or working pressure to make the actual powder delivery amount track the final powder delivery target value, thereby achieving closed-loop stable powder delivery.

9. An electronic device, characterized in that, include: Memory and processor; The memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions, which, when executed by the processor, implement the steps of the method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, It stores computer-executable instructions that, when executed by a processor, implement the steps of the method according to any one of claims 1 to 7.

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