Method for high efficiency plasma spraying of deposition round-square profiled structural members

Abstract

The present invention provides a method for high-efficiency plasma spraying of irregularly shaped components with a circular-to-square profile, comprising: S1: driving a large turntable to rotate, spraying the square ends of all parts at a first position using a jet spray method; after spraying, moving to the next first position under the drive of a six-axis robot to spray the square ends of all parts again, until spraying is completed at all first positions; S2: moving the large turntable to any second position while keeping the small turntable of the current part continuously rotating, performing contour spraying in a spiral path using a spray gun; after spraying, the current small turntable stops rotating; the large turntable rotates to move the next part to the current second position, driving the small turntable to start rotating and performing contour spraying using a spray gun; at this time, the sprayed parts are cooling, and this cycle is repeated until the spraying thickness inside the circular ends of all parts reaches the design requirements, thereby improving spraying efficiency.

Description

Technical Field

[0001] This invention belongs to the technical field of aerospace irregular part spraying process, and particularly relates to a method for efficient plasma spraying of deposited round to square irregular structural parts. Background Technology

[0002] Plasma spraying technology utilizes high-temperature plasma jets (temperatures can reach 10,000-20,000K) to melt or partially melt powder materials and then spray them at high speed onto the substrate surface, forming a coating with special functions such as wear resistance, corrosion resistance, thermal barrier properties, insulation, or conductivity. Plasma spraying technology has been widely used in aerospace aircraft, military and civilian aircraft, and ship engines. By thermally spraying a coating material onto the surface of engineering parts, giving them specific functionalities, it is a very effective and important technical means to improve the performance of engineering parts, reduce their weight, and save expensive materials. For small-sized irregularly shaped parts with a circular-to-square cross-section, their geometric characteristics are: one end is a circular cross-section, the other end is a square or rectangular cross-section, and the middle section is a continuous and smooth transition. The internal wall spraying of such parts faces the following technical challenges:

[0003] 1) Coating uniformity is difficult to control. For example, traditional spraying often adopts the same parameter and same path spraying strategy, which cannot adapt to the differences in deposition characteristics of surfaces with varying curvature. In the round-square transition zone where curvature changes abruptly, the inner wall spraying gun cannot be rotated at will to change curvature, and the coating thickness fluctuation can reach more than ±100μm, far exceeding the process requirement of ±50μm. 2) The quality of the sprayed coating is unstable. The reachability of spraying is poor in some areas of the inner wall of small-sized round to square irregular structure parts. Traditional methods cannot ensure that key parameters such as spraying angle and distance are within the effective range, and the coating performance cannot meet the standards.

[0004] 3) Low processing efficiency: Traditional spraying can only be done on a single piece, and the cooling must be interrupted after each spraying to prevent the part from overheating. The cooling time and clamping interval are long, resulting in extremely low overall processing efficiency. Summary of the Invention

[0005] In view of this, the method for high-efficiency plasma spraying of irregularly shaped structural parts for deposition of round to square parts of the present invention solves the technical problem of low efficiency of existing processes for spraying irregularly shaped parts.

[0006] A method for high-efficiency plasma spraying of irregularly shaped components (round to square) involves processing multiple parts using a spraying equipment platform. The platform includes a large, independently set turntable and multiple smaller turntables. The equipment is equipped with spray guns and a six-axis robot. The method is characterized by comprising... S1: The part is mounted on a small turntable with its square end facing upwards and its round end facing downwards. The small turntable is then mounted on a large turntable with its rotation limited. Multiple first positions are set on the large turntable. The large turntable is driven to rotate, and the spray gun sprays coating on the square ends of all parts in a jet manner at one of the four positions (e.g., positions a, b, c, and d). After spraying, it moves to the next first position driven by a six-axis robot to spray the square ends of all parts again, until spraying is completed at all first positions. The purpose is to ensure the optimal angle between the jet and the surface by adjusting the spray gun's attitude and speed, thereby solving the problem of coating uniformity, effectively controlling the spraying parameters and path within the effective range, and ensuring reliable coating quality. S2: The part is mounted on the small turntable with its square end facing down and its round end facing up. Multiple secondary positions (six positions: A, B, C, D, E, and F) are provided on the large turntable. The large turntable moves to any second position while the small turntable of the current part continues to rotate. The part is then coated using a spray gun in a spiral path. After the coating is applied, the small turntable stops rotating. The large turntable rotates, moving the next part to the current second position. This drives the small turntable to rotate and performs contour spraying via the spray gun. The already sprayed parts are cooling. This cycle continues until the spray thickness inside the rounded ends of all parts reaches the design requirements. The purpose is to create a flowing spray pattern, avoid localized overheating, enable simultaneous and continuous spraying of multiple parts, and reduce cooling time, equipment shutdown time for single-part spraying, and the interval between part clamping. Preferably or optionally, when spraying in S1 or S2, a partitioned reciprocating scanning path is adopted, and the overlap rate and dwell time of the edge area of ​​the part are greater than those of the non-edge area.

[0007] The beneficial effects of the present invention are as follows: The coating uniformity is significantly improved. The segmented and regional flexible spraying strategy is adopted to adapt to the curvature characteristics of round to square. The spray gun attitude, speed, overlap rate and residence time are precisely controlled. The angle between the jet and the surface is optimal. The coating thickness fluctuation is reduced by more than 70%, with fluctuation < ±30μm, which meets the requirements of high-precision spraying.

[0008] The coating quality is stable and reliable. Key parameters such as spraying angle and distance are optimized to improve the accessibility of spraying complex areas on the inner wall of parts. The coating performance is stable and meets the standards, and the process repeatability is good.

[0009] The processing efficiency is greatly improved by adopting multi-station flow spraying, which enables multiple parts to be clamped and sprayed continuously at the same time. The sprayed parts are cooled synchronously, eliminating the time spent on single-part spraying shutdown, frequent clamping and individual cooling. The processing efficiency is more than twice that of traditional single-station spraying.

[0010] It is suitable for mass production, with simple operation, high degree of automation and low cost. It is applicable to the mass coating preparation of irregularly shaped structural parts in aerospace, energy equipment and other fields. Attached Figure Description

[0011] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0012] Figure 1 A schematic diagram showing the part with the square end facing upwards for spraying. Figure 2 A schematic diagram of the spraying path from the square end of the part upwards; Figure 3 A schematic diagram showing the part with the rounded end facing upwards for spraying. Figure 4 This is a schematic diagram of the spraying path from the round end of the part upwards. Detailed Implementation

[0013] The embodiments of this disclosure will now be described in detail with reference to the accompanying drawings.

[0014] The following specific examples illustrate the implementation of this disclosure. Those skilled in the art can easily understand other advantages and effects of this disclosure from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this disclosure, and not all of them. This disclosure can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this disclosure. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0015] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this disclosure, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using other structures and / or functionalities besides one or more of the aspects set forth herein.

[0016] The spraying equipment used in this invention includes a large, independently set turntable and multiple small turntables, equipped with spray guns and a six-axis robot. The specific technical solution is as follows: In the S1 square-mouth end spraying stage, among which... like Figures 1 to 2 As shown, the parts are mounted on a small turntable with the square ends facing upwards and the round ends facing downwards. The small turntable is mounted on a large turntable with a limited rotation mechanism. The large turntable has four first positions with the same arc angle. The large turntable is driven to rotate, and the spray gun sprays the square ends of all parts at one of the first positions. The six-axis robot moves the spray gun to the next first position to continue spraying until all four first positions are sprayed.

[0017] During spraying, a partitioned reciprocating scanning path is adopted. For the edge areas of the parts, the overlap rate and dwell time are set to be greater than those of the non-edge areas. By adjusting the spray gun posture and speed, the jet and the surface of the parts are kept at the best angle, so as to achieve uniform spraying of the inner wall of the square end.

[0018] In the S2 round end spraying stage, among which... like Figures 3 to 4 The part is mounted on a small turntable with its square end facing down and its round end facing up. The large turntable has six secondary positions: A, B, C, D, E, and F. The large turntable rotates to any of these secondary positions and positions itself. The corresponding small turntable at that position continues to rotate, and the spray gun performs contour spraying on the inner wall of the round end in a spiral path. Once spraying is complete, the current small turntable stops rotating.

[0019] The large turntable continues to rotate, sending the next part to the spraying station. The corresponding small turntable rotates and starts spraying. The sprayed parts rotate with the large turntable to the non-spraying station to cool naturally. This cycle continues until the coating thickness at the round ends of all parts reaches the design requirements, forming a continuous spraying operation. At the same time, to ensure the spraying quality, the parts must be cleaned with acetone before spraying, sanded with 60-mesh brown corundum sand to a roughness of 2.0-3.8µm, and residual sand particles must be removed with compressed air. The powder used in the spray gun must be dried in an oven at 66-80℃ for at least 1 hour before being loaded into the special powder feeder.

[0020] Example 1 In this embodiment, the object to be sprayed is a nickel-based high-temperature alloy round-to-square irregularly shaped part, with a round end diameter of Φ100mm and a square end size of 100×40mm. A thermal barrier coating is prepared using atmospheric plasma spraying. Specific steps are as follows: Pretreatment: Clean the parts with acetone, sand them with 60-mesh brown corundum sand to a roughness of 3.0µm, and remove residual sand with compressed air; dry the powder coating in an oven at 70℃ for 1.5h and load it into the powder feeder.

[0021] Square end spraying: Six parts with square ends facing upwards are clamped on a small turntable and fixed to the center of a large turntable; the large turntable rotates at 80 RPM, and a six-axis robot drives a 2086A plasma internal hole spray gun to scan back and forth in four sections: a, b, c, and d. The overlap rate of the edge area is increased by 20%, and the dwell time is extended by 0.5s, thus completing the square end spraying.

[0022] Round-mouth end flow spraying: The part is flipped so that the round mouth end is facing upward and clamped on the multi-station small turntable; the large turntable is positioned at station A, corresponding to the rotation of the small turntable, and the spray gun sprays in a spiral path to follow the shape; after the spraying is completed, the large turntable is rotated, station B enters the spraying position, station A cools simultaneously, and the cycle continues until the coating thickness meets the standard.

[0023] Testing showed that the coating thickness of the parts in this embodiment fluctuated by ±25μm, meeting the requirement of <±30μm. The processing efficiency was 2.3 times higher than that of the traditional process, and the coating bonding strength and density both met the standards.

[0024] Example 2 The object to be sprayed in this embodiment is a round-to-square irregular part for special vehicle transmission. The diameter of the round end is Φ80mm and the size of the square end is 80×35mm. The steps are the same as in embodiment 1, but the parameters are adjusted as follows: the rotation speed of the large turntable is 70RPM, the powder drying temperature is 75℃, the drying time is 1h, and the overlap rate of the edge area is increased by 15%.

[0025] Test results: Coating thickness fluctuated by ±22μm, processing efficiency increased by 2.1 times, and the coating's corrosion resistance and wear resistance met the usage standards.

[0026] Example 3 This embodiment describes the spraying of irregularly shaped connectors for energy equipment. The round end has a diameter of Φ90mm and the square end has dimensions of 90×38mm. The spraying method of this invention is used, with the pretreatment roughness controlled at 2.5µm, the powder drying temperature at 66℃, and the drying time at 1.2h.

[0027] Test results: Coating thickness fluctuated by ±28μm, continuous spraying with no local overheating, production cycle time was shortened by 60%, suitable for batch continuous production.

[0028] The above are merely specific embodiments of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A method for high-efficiency plasma spraying of irregularly shaped components (round to square), comprising processing multiple parts using a spraying equipment, wherein the platform of the spraying equipment includes a large independently set turntable and multiple small turntables, and the spraying equipment is equipped with spray guns and a six-axis robot, characterized in that... The method includes, S1: The part is mounted on a small turntable with its square end facing upwards and its round end facing downwards. The small turntable is then mounted on a large turntable with its rotation limited. Multiple first positions are set on the large turntable. The large turntable is driven to rotate, and the spray gun sprays the square ends of all parts in a jet manner at a first position. After spraying, it moves to the next first position driven by the six-axis robot to spray the square ends of all parts again until spraying is completed at all first positions. S2: The part is mounted on the small turntable with its square end facing down and its round end facing up. Multiple secondary positions are provided on the large turntable. The large turntable moves to any second position while the small turntable of the current part continues to rotate. The part is then coated using a spray gun in a spiral path. After the coating is applied, the small turntable stops rotating. The large turntable rotates to move the next part to the current second position, drives the small turntable to start rotating and performs contour spraying through the spray gun. At this time, the sprayed part is cooling down. This cycle continues until the spraying thickness inside the round end of all parts reaches the design requirements.

2. The method according to claim 1, characterized in that, In S1, the radian angles of any adjacent first positions are the same.

3. The method according to claim 2, characterized in that, There are 4 in total.

4. The method according to claim 1, characterized in that, When spraying through the square end in S1, a partitioned reciprocating scanning path is adopted, and the overlap rate and dwell time of the edge area of ​​the part are greater than those of the non-edge area.

5. The method according to claim 1, characterized in that, Before spraying, the parts are cleaned with acetone and sanded with 60-mesh brown corundum sand to a roughness of 2.0-3.8µm, and any remaining sand particles are blown away with compressed air.

6. The method according to claim 1, characterized in that, The powder used in the spray gun should be dried in an oven at 66-80℃ for at least 1 hour.

7. The method according to claim 1, characterized in that, The spraying equipment is a plasma spraying equipment.

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