An in-situ thermal gas flow assisted cold spray method

Abstract

The application discloses an in-situ hot airflow assisted cold spraying method, which adopts a double-arm manipulator or a linkage scheme of two single-arm manipulators, wherein the No.1 manipulator is responsible for clamping a spraying gun to prepare a cold spraying deposition body, and the No.2 manipulator clamps a hot airflow spraying gun to complete the deposition process of the in-situ hot airflow assisted cold spraying. First, according to actual requirements, the material selection for coating preparation, component additive manufacturing or damage repair is determined; second, a three-dimensional modeling software or a high-speed 3D laser profiler is used to create a three-dimensional geometric model of a deposition body, so as to plan a cold spraying track and create a spraying path of the No.1 manipulator; then, according to the requirements of the surface shape of the coating or component and the deposition performance, spraying process parameters are determined; finally, the spraying gun clamped by the No.2 manipulator and the movement track of the spraying gun clamped by the No.1 manipulator are coordinated and matched, so that the process of the in-situ hot airflow assisted cold spraying deposition is realized. The application has simple process and wide application range.

Description

Technical Field

[0001] This invention belongs to the field of additive manufacturing technology, specifically relating to an in-situ hot airflow assisted cold spraying method. Background Technology

[0002] Cold spray solid-state deposition technology based on high-speed metal particle collision is an effective method for coating deposition of metals and their composite materials, as well as for additive manufacturing / repair of components. Cold spraying is a technique that utilizes a preheated, high-pressure gas stream carrying micron-sized metal particles (10–50 μm) accelerated through a Laval nozzle to impact the substrate at high speed (300–1500 m / s). When the particle velocity exceeds a certain critical value (200–700 m / s, depending on material properties), the metal particles undergo intense plastic deformation and bond with the substrate in a completely solid form. Cold spraying avoids many problems caused by material melting in traditional laser, welding, and thermal spraying processes (such as porosity, compositional segregation, and oxidation phase transformation), and can achieve oxide-free metal deposition in atmospheric environments. Currently, cold spraying, as a relatively mature solid-state coating process in the industrial field, has successfully achieved the preparation of a series of metals and metal-based composite materials, including aluminum, titanium, nickel, and their alloys. In particular, thanks to the development of commercial high-pressure cold spraying systems in recent years, cold spraying, with its unique solid-state low temperature and the fact that material deposition does not require a sealed vacuum or inert atmosphere, has freed up manufacturing dimensions. Currently, cold spraying technology has rapidly developed into a highly efficient method for metal additive manufacturing and component repair, with deposition rates exceeding 20 kg / h, significantly higher than laser cladding additive manufacturing. It has shown remarkable effectiveness in the additive manufacturing and repair of large, heterogeneous aluminum alloy components, and its prospects in aerospace applications are particularly promising. Furthermore, regarding the cost advantage of cold spraying, currently addressing corrosion or wear problems on an expensive aerospace component costs $400,000, while cold spraying repair can reduce the cost to $2,000, meeting component performance requirements while saving substantial costs. Therefore, the efficiency-enhancing and cost-reducing advantages of cold spraying technology in component additive manufacturing / repair should not be underestimated.

[0003] During the cold spray solid deposition process, when metal particles undergo high strain rate plastic deformation caused by high-speed collisions, the local dynamic recrystallization leads to grain refinement, significant dislocation proliferation, and corresponding ceramic strengthening. This results in the deposited material exhibiting microstructure characteristics similar to those of a non-uniform, non-equilibrium state during intense cold working, as well as significant anisotropy in mechanical properties. The strength of the deposited body can be higher than that of metallurgical bulk materials of the same composition, but the elongation is usually extremely low and the plasticity is extremely poor.

[0004] Therefore, controlling the strength and toughness of the deposit to achieve high performance is a key issue in the preparation, additive manufacturing, and repair of high-quality cold-spray coatings. While subsequent heat treatment or high-temperature sintering can improve the strength of the repair layer, many components do not allow for such treatment due to assembly issues, microstructure degradation, or other factors. Therefore, optimizing the strength of the sprayed deposit and its bonding strength with the substrate is crucial for advancing the application of cold spraying. In recent years, numerous strengthening methods have been used to achieve "high strength and high toughness" in deposits, improving the microstructure and mechanical properties of cold-sprayed deposits. However, existing strengthening strategies all have certain limitations in the component repair process, such as: 1) powder preheating during spraying (easy to clog the spray gun, limited strength improvement), in-situ micro-forging assisted cold spraying (low deposition efficiency, wear of the spray gun / powder feeder, and easy mixing with shot peening particles), and laser-assisted cold spraying (melting of low-melting-point substrates, oxidation, and high thermal stress); 2) heat treatment and hot isostatic pressing after spraying (microstructure degradation, assemblies cannot be loaded into the furnace), hot rolling (for components), heat treatment and hot isostatic pressing after spraying (microstructure degradation, assemblies cannot be loaded into the furnace), hot rolling (high requirements for component geometry), and friction stir processing (unable to handle complex shaped components). Therefore, how to achieve high-performance cold-sprayed deposits in high-quality, high-efficiency, and rapid laboratory manufacturing and on-site repair is currently a research hotspot and challenge, which is also the task of this invention. Summary of the Invention

[0005] To overcome the shortcomings of existing technologies, this invention provides an in-situ hot airflow-assisted cold spraying method, employing a dual-arm robotic arm or two single-arm robotic arms working in tandem. Arm 1 holds the spray gun to prepare the cold-sprayed deposit, while Arm 2 holds the hot airflow spray gun to complete the in-situ hot airflow-assisted cold spraying deposition process. First, the material selection for coating preparation, component additive manufacturing, or damage repair is determined based on actual needs. Then, a three-dimensional geometric model of the object to be deposited is created using 3D modeling software or a high-speed 3D laser profilometer to plan the cold spraying trajectory and create the spraying path for Arm 1. Next, the spraying process parameters are determined based on the surface shape and deposition performance requirements of the coating or component. Finally, the movement trajectory of the spray gun with a specific geometry held by Arm 2 is coordinated and matched with that of Arm 1 to establish suitable in-situ hot airflow conditions, thus realizing the in-situ hot airflow-assisted cold spraying deposition process. This invention is simple in process and has a wide range of applications. It also overcomes the problem that most component repairs do not allow for post-heat treatment due to assembly and other factors. It provides an effective new method for the widespread application of cold spraying technology in the efficient and high-quality laboratory manufacturing of deposits or on-site component repair.

[0006] The technical solution adopted by this invention to solve its technical problem is as follows:

[0007] Step 1: Use 3D modeling software or a high-speed 3D laser profilometer to obtain a 3D geometric model of the area to be sprayed in advance;

[0008] Step 2: Determine the appropriate powder particle size distribution, spraying process parameters, and robotic arm kinematic parameters based on the surface shape and deposition performance requirements of the area to be sprayed, thereby controlling the thickness and surface morphology of the area to be sprayed.

[0009] Step 3: Determine the motion trajectory of robotic arm 2 based on the actual spraying area of ​​robotic arm 1, and ensure that the motion trajectory of the spray gun held by robotic arm 2 is coordinated and matched with that of robotic arm 1.

[0010] Step 4: Determine the in-situ hot airflow conditions based on the performance requirements of the area to be sprayed;

[0011] Step 5: Using a robot linkage scheme, use robotic arm 1 to hold the spray gun for cold spraying preparation; use fixed or movable robotic arm 2 to hold the hot air spray gun to complete the in-situ hot air assisted cold spraying deposition process.

[0012] Preferably, the cold spraying is used for coating preparation, additive manufacturing of components, and repair of damaged components.

[0013] Preferably, the robot linkage scheme is a single dual-arm robotic arm or two dual-arm robotic arms.

[0014] Preferably, the motion trajectory of the hot air spray gun held by the No. 2 robotic arm is determined based on the motion trajectory of the spray gun of the No. 1 robotic arm.

[0015] Preferably, the trajectory of the hot air spray gun held by the second robotic arm is fixed or movable.

[0016] Preferably, the hot gas flow is nitrogen, compressed air, or argon.

[0017] Preferably, the in-situ hot airflow conditions include the shape of the hot airflow nozzle, the angle of the hot airflow nozzle, the distance of the hot airflow nozzle, the temperature and pressure of the hot airflow.

[0018] Preferably, the powder is made of metals: Zn, Al and their alloys, Cu and their alloys, Mg and its magnesium alloys, iron and stainless steel, titanium and its titanium alloys, or Ni and nickel-based high-temperature alloys, or a mixture of the above metals and ceramics; the ceramic is SiC, TiN, WC and Al2O3.

[0019] The beneficial effects of this invention are as follows:

[0020] This invention addresses methods for cold spray coating preparation, additive manufacturing of components, and repair of damaged components. By employing an in-situ hot airflow-assisted cold spraying process, the performance of the deposited material can be significantly improved. Based on the principle of eliminating degraded structures (such as weak interparticle interfaces) under in-situ hot airflow conditions while preserving optimized structures (such as ultrafine grains) to the maximum extent, this invention achieves superior comprehensive performance. It provides a crucial theoretical basis for fundamentally solving the problem of preparing high-strength, high-toughness, and high-bonding-strength deposited materials in a sprayed state. Furthermore, the in-situ hot airflow-assisted cold spraying process is simple, overcoming the challenge of post-heat treatment being unacceptable for many component repairs due to assembly and other factors. It simultaneously ensures the service performance of repaired damaged components and extends their service life, making it one of the most effective, economical, flexible, and designable methods. It can achieve in-situ enhancement of the spraying forming performance of deposited materials of different sizes and complex components, and is easily automated. Attached Figure Description

[0021] Figure 1 A schematic diagram of coating preparation or component additive manufacturing using in-situ hot airflow-assisted cold spraying for a single dual-arm robotic arm;

[0022] Figure 2 A schematic diagram of in-situ hot airflow-assisted cold spraying for component repair using two single-arm robotic arms working in tandem.

[0023] Figure descriptions: 1. Robotic arm No. 1; 2. Robotic arm No. 2; 3. Hot air spray gun; 4. Cold spray gun; 5. Coating deposition preparation; 6. Additive manufacturing of components; 7. Substrate; 8. Damage repair. Detailed Implementation

[0024] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0025] The purpose of this invention is to overcome the shortcomings of the prior art and provide an in-situ hot airflow assisted cold spraying technology, which can significantly improve the mechanical properties of the deposit, realize high-performance forming of coatings or components through additive manufacturing, and at the same time ensure the service performance of repaired damaged components and extend their service life.

[0026] The objective of this invention is achieved through the following technical solution:

[0027] Step 1: Use 3D modeling software or a high-speed 3D laser profilometer to obtain a 3D geometric model of the area to be sprayed in advance;

[0028] Step 2: Determine the appropriate powder particle size distribution, spraying process parameters, and robotic arm kinematic parameters based on the surface shape and deposition performance requirements of the area to be sprayed, thereby controlling the thickness and surface morphology of the area to be sprayed.

[0029] Step 3: Determine the motion trajectory of robotic arm 2 based on the actual spraying area of ​​robotic arm 1, and ensure that the motion trajectory of the spray gun held by robotic arm 2 is coordinated and matched with that of robotic arm 1.

[0030] Step 4: Determine the in-situ hot airflow conditions based on the performance requirements of the area to be sprayed;

[0031] Step 5: Using a robot linkage scheme, use robotic arm 1 to hold the spray gun for cold spraying preparation; use fixed or movable robotic arm 2 to hold the hot air spray gun to complete the in-situ hot air assisted cold spraying deposition process.

[0032] The cold spraying process involves coating preparation, additive manufacturing of components, and repair of damaged components. This includes laboratory manufacturing and repair, as well as on-site manufacturing and repair.

[0033] The robot linkage solution can be a single dual-arm robotic arm or two single-arm robotic arms.

[0034] The trajectory of the hot air spray gun on robotic arm #2 is determined based on the trajectory of the spray gun on robotic arm #1.

[0035] The trajectory of the No. 2 robotic arm holding the hot air spray gun can be fixed or moving.

[0036] The hot gas flow is nitrogen, compressed air, or argon.

[0037] In-situ hot airflow conditions include the shape of the hot airflow nozzle, the angle of the hot airflow nozzle, the distance of the hot airflow nozzle, and the temperature and pressure of the hot airflow.

[0038] The powder material is a metal: Zn, Al and its alloys, Cu and its alloys, Mg and its magnesium alloys, iron and stainless steel, titanium and its titanium alloys, or Ni and nickel-based high-temperature alloys, or a mixture of the above metals and ceramics (SiC, TiN, WC and Al2O3, etc.).

[0039] The spray gun's trajectory is based on creating a three-dimensional geometric model of the component requiring coating deposition or additive manufacturing using 3D modeling software, or by pre-scanning the surface of the damaged component with a high-speed 3D laser profilometer to obtain a three-dimensional geometric model of the damaged area.

[0040] Example 1:

[0041] like Figure 1 As shown, in-situ hot airflow-assisted cold spraying technology is used to realize online coating preparation or component additive manufacturing through the linkage of a single dual-arm robotic arm. The No. 1 robotic arm is responsible for holding the spray gun to prepare the cold spray deposit and the component additive manufacturing, while the No. 2 robotic arm holds the hot airflow spray gun to complete the in-situ hot airflow-assisted cold spraying deposition process.

[0042] First, 3D geometric models of components requiring deposition coating or additive manufacturing are created using 3D modeling software in order to plan the cold spraying trajectory and create the spraying path for robotic arm No. 1.

[0043] Then, based on the surface shape and deposition performance requirements of the coating or component, the corresponding powder particle size distribution, spraying process parameters, robotic arm kinematic parameters, and other spraying strategies are determined to achieve precise control of the thickness and surface morphology of the cold spray coating or additive manufacturing deposit.

[0044] The motion trajectory of robotic arm No. 2 is determined based on the actual working area of ​​robotic arm No. 1 for coating preparation or component additive manufacturing.

[0045] Finally, the movement trajectory of the spray gun with a certain geometric shape held by the No. 2 robotic arm is coordinated and matched with that of the spray gun held by the No. 1 robotic arm to establish suitable in-situ hot airflow conditions and realize the in-situ hot airflow-assisted cold spray deposition process.

[0046] The trajectory of the hot air spray gun held by the No. 2 robotic arm can be fixed or moving. The cold spraying process can be manufactured in the laboratory or on-site. The hot air is nitrogen, compressed air or argon. The in-situ hot air conditions include the shape of the hot air spray gun, the angle of the hot air spray gun, the distance of the hot air spray gun, the temperature and pressure of the hot air. The powder material is a pure metal (Zn, Al and its alloys, Cu and its alloys, Mg and its magnesium alloys, iron and stainless steel, titanium and its titanium alloys, or Ni and nickel-based high-temperature alloys) or a mixed powder (a mixed powder of the above metals and ceramic SiC, TiN, WC, Al2O3, carbon nanotubes or graphene materials).

[0047] Example 2:

[0048] like Figure 2 As shown, a method for online repair of damaged components is achieved by using two single-arm robotic arms in conjunction to realize in-situ hot airflow-assisted cold spraying technology. The first robotic arm is responsible for holding the spray gun for cold spraying repair, while the fixed or movable second robotic arm holds the hot airflow spray gun to complete the in-situ hot airflow-assisted cold spraying deposition process.

[0049] First, a high-speed 3D laser profilometer is used to scan the surface of the damaged component to obtain a three-dimensional geometric model of the damaged area, so as to plan the cold spray trajectory and create the spraying path of the No. 1 robotic arm.

[0050] Based on the surface shape and deposition performance requirements of the coating or component, determine the corresponding powder particle size distribution, spraying process parameters, robotic arm kinematic parameters, and other spraying strategies to achieve precise control of the deposition thickness and surface morphology of the cold spray repair.

[0051] The motion trajectory of robotic arm 2 is determined based on the actual working area of ​​robotic arm 1 for repairing damaged components.

[0052] Finally, the movement trajectory of the spray gun with a certain geometric shape held by the No. 2 robotic arm is coordinated and matched with that of the spray gun held by the No. 1 robotic arm to establish suitable in-situ hot airflow conditions, so as to realize the in-situ hot airflow-assisted cold spray deposition process.

[0053] The trajectory of the hot air spray gun held by the No. 2 robotic arm can be fixed or moving. The cold spraying process can be manufactured in the laboratory or repaired on site. The hot air is nitrogen, compressed air or argon. The in-situ hot air conditions include the shape of the hot air spray gun, the angle of the hot air spray gun, the distance of the hot air spray gun, the temperature and pressure of the hot air. The powder material is a pure metal (Zn, Al and its alloys, Cu and its alloys, Mg and its magnesium alloys, iron and stainless steel, titanium and its titanium alloys, or Ni and nickel-based high-temperature alloys) or a mixture of the above metals and ceramics (SiC, TiN, WC and Al2O3, etc.).

Claims

1. An in-situ hot airflow-assisted cold spraying method, characterized in that, Includes the following steps: Step 1: Use 3D modeling software or a high-speed 3D laser profilometer to obtain a 3D geometric model of the area to be sprayed in advance; Step 2: Determine the appropriate powder particle size distribution, spraying process parameters, and robotic arm kinematic parameters based on the surface shape and deposition performance requirements of the area to be sprayed, thereby controlling the thickness and surface morphology of the area to be sprayed. Step 3: Determine the motion trajectory of robotic arm 2 based on the actual spraying area of ​​robotic arm 1, and ensure that the motion trajectory of the spray gun held by robotic arm 2 is coordinated and matched with that of robotic arm 1. Step 4: Determine the in-situ hot airflow conditions based on the performance requirements of the area to be sprayed; Step 5: Using a robot linkage scheme, use robotic arm 1 to hold the spray gun for cold spraying preparation; use fixed or movable robotic arm 2 to hold the hot air spray gun to complete the in-situ hot air assisted cold spraying deposition process.

2. The in-situ hot airflow assisted cold spraying method according to claim 1, characterized in that, The cold spraying process is used for coating preparation, additive manufacturing of components, and repair of damaged components.

3. The in-situ hot airflow assisted cold spraying method according to claim 1, characterized in that, The robot linkage scheme described herein is a single dual-arm robotic arm or two dual-arm robotic arms.

4. The in-situ hot airflow assisted cold spraying method according to claim 1, characterized in that, The trajectory of the hot air spray gun held by the No. 2 robotic arm is determined based on the trajectory of the spray gun of the No. 1 robotic arm.

5. The in-situ hot airflow assisted cold spraying method according to claim 1, characterized in that, The trajectory of the hot air spray gun held by the No. 2 robotic arm is either fixed or moving.

6. The in-situ hot airflow assisted cold spraying method according to claim 1, characterized in that, The hot gas flow is nitrogen, compressed air, or argon.

7. The in-situ hot airflow assisted cold spraying method according to claim 1, characterized in that, The in-situ hot airflow conditions include the shape of the hot airflow nozzle, the angle of the hot airflow nozzle, the distance of the hot airflow nozzle, the temperature and pressure of the hot airflow.

8. The in-situ hot airflow assisted cold spraying method according to claim 1, characterized in that, The powder material is a metal: Zn, Al and its alloys, Cu and its alloys, Mg and its magnesium alloys, iron and stainless steel, titanium and its titanium alloys, or Ni and nickel-based high-temperature alloys, or a mixed powder of the above metals and ceramics; the ceramic is SiC, TiN, WC and Al2O3.

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