A thermal spraying intelligent control system and manufacturing method

Abstract

The present invention belongs to the technical field of automatic control systems, and in particular to an intelligent thermal spraying control system and a manufacturing method. The system includes a central controller, a multi-parameter sensing module, a motion actuator, and a process parameter database. The central controller is configured to integrate sensing data with a physical model to achieve multi-parameter joint adjustment of gas flow, spray gun movement, and suspension supply. The multi-parameter sensing module is configured to collect flame temperature, suspension flow, atomizing air pressure, and substrate surface temperature in real time. The motion actuator is configured to control the six-degree-of-freedom motion of the spray gun and the rotation of the substrate. The process parameter database is configured to store nozzle structural parameters, suspension physical properties, and coating thickness target values. The present invention realizes global scheduling of multiple subsystems through the central controller, and controls the islandization of subsystems of the system.

Description

Technical Field

[0001] The present invention relates to the technical field of automatic control systems, and in particular to a thermal spraying intelligent control system and a manufacturing method thereof. Background Art

[0002] Thermal spraying technology also plays a vital role in the national economy, reducing energy consumption, raw material usage, lowering overall material performance requirements, and enabling the repair and reuse of parts with excessive wear. Nanocoatings have become a crucial research area in the international surface engineering field in recent years. Thermal spraying has been extensively researched in the preparation of nanocoatings due to their potential to improve strength, reduce microcracks, provide superior thermal shock resistance, and reduce wear. In recent years, a new spraying technology for preparing nanocoatings—liquid phase thermal spraying—has emerged. It is a highly efficient nanocoating preparation technique. High-viscosity suspension thermal spraying (HVSFS) technology, with its high density and low porosity, is widely used in various industries.

[0003] However, the existing control system of HVSFS technology still has certain defects. The process operates independently for subsystems such as temperature control, motion trajectory, and suspension supply, lacks a coordination mechanism, and does not integrate real-time feedback on the three-dimensional morphology of the substrate. This leads to a decrease in the bonding strength of the surface mutation area and ultimately leads to unstable coating quality. Therefore, it is necessary to propose new solutions to meet higher production and manufacturing requirements. Summary of the Invention

[0004] The purpose of the present invention is to provide a thermal spraying intelligent control system and a manufacturing method to solve the problems raised in the background technology.

[0005] To achieve the above objectives, the present invention provides the following technical solutions: a thermal spraying intelligent control system, comprising:

[0006] The central controller is configured to integrate sensor data with physical models to achieve multi-parameter coordination of gas flow, spray gun movement, and suspension supply;

[0007] A multi-parameter sensing module is configured to collect flame temperature, suspension flow, atomizing air pressure, and substrate surface temperature in real time;

[0008] a motion actuator configured to control the six-degree-of-freedom motion of the spray gun and the rotation of the substrate;

[0009] The process parameter database is configured to store nozzle structural parameters, suspension physical properties, and coating thickness target values.

[0010] The thermal spraying intelligent control system of the present invention, wherein the central controller integrates:

[0011] The spray trajectory planning module is configured to generate a path based on the three-dimensional model of the substrate and adapt to the uneven wall surface;

[0012] The dynamic parameter compensation module is configured to adjust the ratio of fuel gas and combustion-supporting gas in real time in response to the sensor data.

[0013] In the thermal spraying intelligent control system of the present invention, the spraying trajectory planning module performs the following operations:

[0014] By importing a 3D and / or 2D model of the workpiece and identifying the area where the wall surface curve suddenly changes;

[0015] Automatically reduces the speed of the spray gun when the detection radius is smaller than the preset value.

[0016] The thermal spraying intelligent control system of the present invention, wherein the multi-parameter sensing module comprises:

[0017] A two-color infrared pyrometer, configured to measure the flame core temperature with an accuracy of ±20°C;

[0018] Ultrasonic suspension concentration sensor, configured to detect solid content fluctuations online.

[0019] To achieve the above object, the present invention further provides a suspension thermal spraying process control method, which is applied to the above thermal spraying intelligent control system. The process control method comprises the following steps:

[0020] The steps include:

[0021] Step S1: establishing a suspension evaporation kinetic model;

[0022] Step S2: Calculate the atomization pressure setting value based on the suspension evaporation dynamics model to ensure the particle size D p ≤10μm, particle proportion>80%.

[0023] The suspension thermal spraying process control method of the present invention further includes the following steps:

[0024] Step S3: Constructing the coating growth rate equation.

[0025] The suspension thermal spraying process control method of the present invention includes dynamically controlling the gas flow rate:

[0026] Take the flame temperature setting value T0 as the benchmark;

[0027] When the measured temperature T<T0-50℃, increase the C2H2 flow rate by ΔQ=K t (T0-T)².

[0028] The suspension thermal spraying process control method of the present invention is as follows:

[0029] Switch to high-frequency pulse spraying mode in the groove area, with a switching cycle of ≤0.1s;

[0030] Simultaneously increase the carrier gas pressure to 120-150% of the standard value.

[0031] To achieve the above object, the present invention further provides a suspension thermal spraying manufacturing process, comprising:

[0032] Stage 1: Substrate pretreatment:

[0033] Sand blasting makes the surface roughness Ra=5-8μm;

[0034] Preheat to 380±10℃;

[0035] Stage 2: Layered spraying:

[0036] The first layer is scanned at a high speed of 80 mm / s to form a porous bottom layer;

[0037] The outer layer was densified by low-speed scanning at 50 mm / s.

[0038] The suspension thermal spraying manufacturing process of the present invention further includes online quality closed-loop control:

[0039] Every time 2mm of coating thickness is completed, start the laser thickness gauge to scan the surface;

[0040] If the thickness variance σ²>0.25, the current layer spraying will be automatically repeated;

[0041] When the proportion of unmelted particles is detected to be greater than 5%, the flame temperature is increased by 30°C.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] Through the central controller, the sensor data and physical model are integrated to achieve the joint adjustment of many parameters such as gas flow, spray gun movement, suspension supply, flame temperature, suspension flow, atomizing air pressure, substrate surface temperature, spray gun movement, substrate rotation, etc., realizing global scheduling of multiple subsystems, reducing the isolation of the overall control system, and significantly improving the collaborative response efficiency of multiple subsystems. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0045] Figure 1 The control system of the present invention is far away from the logic diagram.

[0046] Figure 2 The internal structure of the nozzle used in the control system of the present invention.

[0047] Figure 3 This is a logic flow chart of the closed-loop system detection of the present invention. DETAILED DESCRIPTION

[0048] The terms "first," "second," "third," and "fourth," etc., in the specification, claims, and accompanying drawings of the present invention are used to distinguish between different items, not to describe a specific order. Furthermore, the terms "including," "having," and any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or elements is not limited to the listed steps or elements, but may optionally include steps or elements not listed, or may optionally include other steps or elements inherent to the process, method, product, or apparatus.

[0049] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present invention. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute a separate or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0050] "Multiple" refers to two or more. "And / or" describes the relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can mean: A exists alone, A and B exist simultaneously, or B exists alone. The character " / " generally indicates that the associated objects are in an "or" relationship.

[0051] Moreover, the terms "up, down, left, right, upper end, lower end, longitudinal" and the like indicating directions are all based on the posture and position of the device or apparatus described in this solution during normal use.

[0052] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the following will be a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work shall fall within the scope of protection of the present invention.

[0053] Example 1

[0054] This embodiment discloses Figure 1 The thermal spraying intelligent control system shown includes:

[0055] The central controller is configured to integrate sensor data with physical models to achieve multi-parameter coordination of gas flow, spray gun movement, and suspension supply;

[0056] A multi-parameter sensing module is configured to collect flame temperature, suspension flow, atomizing air pressure, and substrate surface temperature in real time;

[0057] a motion actuator configured to control the six-degree-of-freedom motion of the spray gun and the rotation of the substrate;

[0058] a process parameter database configured to store nozzle structural parameters, suspension physical properties, and coating thickness target values;

[0059] Among them, the nozzle adopts a circumferential multi-port feeding structure, such as Figure 2 As shown, it is ensured that the suspension can be evenly distributed 360 degrees on the outside of the ejected ion beam, ensuring the uniformity of spraying. Compared with the structure with single-side liquid outlet, it can effectively avoid the splashing waste of the suspension outside the flow beam due to inertia and the force between droplets. The specific structure of the suction nozzle includes an inner sleeve 10, an outer sleeve 20 sleeved on the outside of the inner sleeve 10, and a replaceable nozzle ring 30 coaxially connected to the outlet of the outer sleeve 20; the inner cavity of the inner sleeve 10 is used for coaxial installation of the electrode needle 100 and ejection of gas. Specifically, there is a circulation channel 40 for circulation of coolant between the inner sleeve 10 and the outer sleeve 20 to avoid the overall temperature of the suction nozzle being too high.

[0060] Furthermore, the front end of the inner sleeve 10 has an end portion with synchronously narrowed inner and outer diameters, and a hollow connecting shaft portion 101 of equal diameter is coaxially extended at the front end of the end portion. The outer wall of the connecting shaft portion 101 is coaxially threaded with the inner wall of the front end of the outer sleeve 20, and a compression flow channel 201 with a diameter gradually narrowing forward is provided on the inner wall of the front end of the outer sleeve 20. The rear end of the compression flow channel 201 is of equal diameter to the inner cavity of the connecting shaft portion 101 to ensure smooth compression of the high-speed ion beam, reduce interference with end flow, and ensure the initial velocity of the ejection.

[0061] Furthermore, a radial liquid inlet nozzle 50 is provided on the outer wall of the outer sleeve 20, and the channel 501 inside the liquid inlet nozzle 50 is L-shaped and its lateral end faces the replaceable nozzle ring 30, and the inner cavity of the nozzle ring 30 forms a docking flow channel 31 docking with the channel 501, and an annular flow channel 32 is coaxially provided inside the nozzle ring 30, and a plurality of liquid outlets 33 connected to the annular flow channel 32 are provided circumferentially on the inner side wall of the nozzle; wherein, the diameter of the inner cavity of the nozzle ring 30 gradually increases axially toward the rear, so that the ejected ion beam quickly diffuses after passing through the compression flow channel 201, thereby increasing the coverage diameter of the ion beam, and in order to ensure the carrying and mixing effect of the ion beam, the liquid outlet is located at the rear third of the inner cavity of the nozzle ring 30.

[0062] In addition, the nozzle ring 30 is coaxially threadedly connected to the inner wall of the mounting groove 34 provided on the front end surface of the outer sleeve 20, the front port of the compression flow channel 201 is located on the bottom surface of the mounting groove 34, and the outlet diameter of the compression flow channel 201 is consistent with the inner cavity inlet diameter of the nozzle ring 30, wherein the thermal expansion coefficients of the inner sleeve 10 and the nozzle ring 30 are both greater than the thermal expansion coefficient of the outer sleeve 20, so as to utilize the residual heat to strengthen the connection strength and sealing strength during operation, and avoid leakage and loosening due to excessive assembly clearance between the three.

[0063] This system integrates sensor data and physical models through a central controller, realizes the joint adjustment of many parameters such as gas flow, spray gun movement, suspension supply, flame temperature, suspension flow, atomization pressure, substrate surface temperature, spray gun movement, substrate rotation, etc., realizes global scheduling of multiple subsystems, reduces the isolation of the overall control system, and significantly improves the collaborative response efficiency of multiple subsystems.

[0064] The thermal spraying intelligent control system of the present invention, wherein the central controller integrates:

[0065] The spray trajectory planning module is configured to generate a path based on the three-dimensional model of the substrate and adapt to the uneven wall surface;

[0066] The dynamic parameter compensation module is configured to adjust the ratio of fuel gas and combustion-supporting gas in real time in response to the sensor data.

[0067] In the thermal spraying intelligent control system of the present invention, the spraying trajectory planning module performs the following operations:

[0068] By importing a 3D and / or 2D model of the workpiece and identifying the area where the wall surface curve suddenly changes;

[0069] Automatically reduce the speed of the spray gun when the identification radius is smaller than the preset value;

[0070] The three-dimensional model recognizes the mutation area + curvature response deceleration, which can solve the problem of disconnection between the motion control of the traditional system and the process parameters, and avoid the disadvantage of uneven coating coverage of the grooves on the substrate surface.

[0071] The thermal spraying intelligent control system of the present invention, wherein the multi-parameter sensing module comprises:

[0072] A two-color infrared pyrometer, configured to measure the flame core temperature with an accuracy of ±20°C;

[0073] Ultrasonic suspension concentration sensor, configured to detect solid content fluctuations online.

[0074] Example 2

[0075] The present invention also provides a suspension thermal spraying process control method, which is applied to the above-mentioned thermal spraying intelligent control system. The process control method includes the following steps:

[0076] The steps include:

[0077] Step S1: Establish a suspension evaporation kinetic model. Specifically, the model can be:

[0078] Where,

[0079] Indicates the rate of change of droplet size over time, in micrometers per second (μm / s).

[0080] D p : instantaneous droplet size, in micrometers (μm),

[0081] t: time (unit: s),

[0082] k g : Gas phase thermal conductivity, in watts per meter Kelvin (W / m·K),

[0083] ρ p : suspension density (unit: kg / m³),

[0084] c p : Specific heat capacity of suspension at constant pressure (unit: J / kg·K),

[0085] B m : Mass transfer number, a dimensionless parameter, its expression is , where Y F,s is the fuel vapor mass fraction on the droplet surface, Y F,∞ is the ambient fuel vapor mass fraction;

[0086] Step S2: Calculate the atomization pressure setting value based on the suspension evaporation dynamics model to ensure the particle size Dp ≤10μm, particle proportion>80%.

[0087] The suspension thermal spraying process control method of the present invention further includes the following steps:

[0088] Step S3: Construct a coating growth rate equation, which is specifically:

[0089] Where,

[0090] Indicates the rate of change of coating thickness over time in micrometers per second (μm / s). The scanning speed is determined by the servo motor.

[0091] h represents the coating thickness in micrometers (μm).

[0092] Indicates the particle mass flow rate in grams per second (g / s),

[0093] represents the deposition efficiency, which is a dimensionless parameter.

[0094] θ represents the angle between the axis of the spray gun and the normal line of the substrate surface (incident angle), the unit is degree (°),

[0095] k v Indicates the volume conversion factor, the unit is cubic meter per gram second (m³ / (g·s));

[0096] The coating growth rate equation reveals the quantitative relationship between the coating thickness growth rate, mass flow rate, and incident angle. cosθ reflects the optimal vertical incidence. The production control logic is shown in Table 1:

[0097] The suspension thermal spraying process control method of the present invention includes dynamically controlling the gas flow rate:

[0098] Take the flame temperature setting value T0 as the benchmark;

[0099] When the measured temperature T<T0-50℃, increase the C2H2 flow rate by ΔQ=K t (T0-T)²;

[0100] ΔQ=K t In (T0-T)²:

[0101] ΔQ: Acetylene (C2H2) flow adjustment amount (unit: L / min),

[0102] K t : Temperature-flow conversion coefficient (unit: L / min·℃²), calibrated through nozzle characteristic experiments,

[0103] T0: target flame temperature (unit: °C),

[0104] T: Measured flame temperature (unit: °C).

[0105] When the temperature difference |T0-T| is less than or equal to 50°C, linear regulation is used (ΔQ ∝ |T0-T|). When |T0-T| is greater than 50°C, quadratic regulation is used (ΔQ ∝ (T0-T)²). This implements a quadratic compensation mechanism, allowing for rapid compensation of large temperature differences. For example, when the temperature drops by 100°C, the gas increment is 2-4 times that of the linear mode. This also prevents overshoot, automatically attenuating the regulation amount as the target temperature approaches, resulting in faster recovery than traditional PID control. The production control logic is shown in Tables 2 and 3 below:

[0106] The suspension thermal spraying process control method of the present invention is as follows:

[0107] Switch to high-frequency pulse spraying mode in the groove area, with a switching cycle of ≤0.1s;

[0108] Simultaneously increase the carrier gas pressure to 120-150% of the standard value.

[0109] Example 3

[0110] This embodiment provides a suspension thermal spraying manufacturing process, including:

[0111] Stage 1: Substrate pretreatment:

[0112] Sandblasting can achieve a surface roughness of Ra=5-8μm, compared to traditional sandblasting Ra=3-10μm, which can improve the bonding strength of nickel-based high-temperature alloys or titanium alloys;

[0113] Preheat to 380±10℃ to eliminate micro cracks caused by the difference in thermal expansion coefficient between substrate and coating, and activate the surface oxide diffusion layer (such as ), improve chemical bonding;

[0114] Stage 2: Layered spraying:

[0115] The first layer is formed by high-speed scanning at 80mm / s to form a porous bottom layer, so that the molten droplet will shear and break when it hits the substrate instead of spreading completely, forming a controllable porosity of 15-20%;

[0116] The outer layer was densified by low-speed scanning at 50 mm / s to reduce the speed so that the molten droplets could fully spread and the pores were closed by the capillary filling effect.

[0117] The suspension thermal spraying manufacturing process of the present invention further includes online quality closed-loop control, specifically Figure 3 As shown:

[0118] Every time 2mm of coating thickness is completed, start the laser thickness gauge to scan the surface;

[0119] If the thickness variance σ²>0.25, the current layer spraying will be automatically repeated;

[0120] When the proportion of unmelted particles is detected to be greater than 5%, the flame temperature is increased by 30°C.

[0121] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all such improvements and changes should fall within the scope of protection of the appended claims of the present invention.

Claims

1. A thermal spraying intelligent control system, characterized in that: include: The central controller is configured to integrate sensor data with physical models to achieve multi-parameter coordination of gas flow, spray gun movement, and suspension supply; A multi-parameter sensing module is configured to collect flame temperature, suspension flow, atomizing air pressure, and substrate surface temperature in real time; a motion actuator configured to control the six-degree-of-freedom motion of the spray gun and the rotation of the substrate; a process parameter database configured to store nozzle structural parameters, suspension physical properties, and coating thickness target values; Among them, the manufacturing process of thermal spraying includes: Stage 1: Substrate pretreatment Sand blasting makes the surface roughness Ra=5-8μm; Preheat to 380±10 ; Stage 2: Layered spraying The first layer is scanned at a high speed of 80 mm / s to form a porous bottom layer; The outer layer was densified using low-speed scanning at 50 mm / s; Online quality closed-loop control: Every time 2mm of coating thickness is completed, start the laser thickness gauge to scan the surface; If the thickness variance , automatically repeat the current layer spraying; When the proportion of unmelted particles is greater than 5%, the flame temperature is increased by 30 .

2. The thermal spraying intelligent control system according to claim 1, characterized in that: The central controller integrates: The spray trajectory planning module is configured to generate a path based on the three-dimensional model of the substrate and adapt to the uneven wall surface; The dynamic parameter compensation module is configured to adjust the ratio of fuel gas and combustion-supporting gas in real time in response to the sensor data.

3. The thermal spraying intelligent control system according to claim 2, characterized in that: The spray trajectory planning module performs the following operations: By importing a 3D and / or 2D model of the workpiece and identifying the area where the wall surface curve suddenly changes; Automatically reduces the speed of the spray gun when the detection radius is smaller than the preset value.

4. The thermal spraying intelligent control system according to claim 1, characterized in that: The multi-parameter sensing module comprises: Two-color infrared pyrometer, configured to measure flame core temperature with an accuracy of ±20 ; Ultrasonic suspension concentration sensor, configured to detect solid content fluctuations online.

5. A suspension thermal spraying process control method, using the thermal spraying intelligent control system according to any one of claims 1 to 4, characterized in that: The steps include: Step S1: establishing a suspension evaporation kinetic model; Step S2: Calculate the atomization pressure setting value based on the suspension evaporation dynamics model to ensure the particle size ≤10μm, particle proportion>80%.

6. The suspension thermal spraying process control method according to claim 5, characterized in that: The following steps are also included: Step S3: Constructing the coating growth rate equation.

7. The suspension thermal spraying process control method according to claim 6, characterized in that: Dynamically control gas flow: Flame temperature setting value as a benchmark; When the measured temperature T< -50 When the C2H2 flow rate is increased proportionally .

8. The suspension thermal spraying process control method according to claim 7, characterized in that: For uneven wall surfaces: Switch to high-frequency pulse spraying mode in the groove area, with a switching cycle of ≤0.1s; Simultaneously increase the carrier gas pressure to 120-150% of the standard value.

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