Automatic manufacturing method for aero-engine turbine blade tip coating

Abstract

The invention relates to the field of automatic spraying of aero-engine parts, in particular to an automatic manufacturing method for a blade tip coating of a turbine blade of an aero-engine. The method comprises the following steps: (1) part clamping: clamping the turbine blade of the aero-engine to a spraying clamp and using an upper baffle for sand blasting; (2) sand blasting is carried out, and blade tip surface cleaning and roughening are carried out; (3) a clamp is replaced, and an upper blocking piece for sand blasting above the blade tip is replaced with an upper blocking piece for spraying; (4) spraying processing is conducted, specifically, plasma spraying is conducted on the spraying area of the blade tip; and (5) parts are unloaded, the clamp is removed, and the aero-engine turbine blade is unloaded. The problems that the blade tip coating of the aero-engine turbine blade is poor in manufacturing quality consistency, low in production efficiency, large in labor intensity, large in raw material consumption and the like are solved, and the performance of the coating is guaranteed by determining the protection method for the part of the aero-engine turbine blade and cooperating with the automatic spraying control technology.

Description

Technical Field

[0001] The invention relates to the field of automated spraying of aircraft engine parts, and in particular to an automated manufacturing method for coatings on blade tips of aircraft engine turbine blades. Background Art

[0002] The low-pressure turbine of an aircraft engine needs to withstand the high-temperature and high-pressure combustion gas flowing out of the combustion chamber and convert most of the energy into mechanical work, so that the turbine rotates at high speed and generates large power, which is output by the turbine shaft. The energy conversion requires the combustion gas to be realized through the rotation of the turbine blades. During the rotation process, the tips of the turbine blades rub against the honeycomb on the casing to form a sealed cavity for each stage of the turbine. The tips of these turbine blades are prone to wear during the grinding process with the honeycomb. Therefore, a thermal spraying process is used to prepare a wear-resistant protective coating on the tip surface of the turbine blade to extend the service life of the worn blades.

[0003] The processing methods generally used in thermal spraying process are divided into manual processing and automated processing. Manual processing is that the operator holds a sandblasting gun and a spray gun to process the parts, while automated processing is that the robot clamps the sandblasting gun and the spray gun to process the parts. The disadvantage of manual processing is that it requires high skills from the operator, cannot guarantee quality consistency, has low processing efficiency, and will cause damage to the health of the operator. The protection method generally uses high-temperature pressure-sensitive tape to protect the non-spraying area of ​​the processed parts. Although this method has a wide range of applications, the protection quality is very dependent on the technical level of the operator, which is easy to cause obstruction of the spraying area and pollution of the non-spraying area, and is only suitable for the spraying processing of large-sized sprayed parts. Small-sized sprayed parts are very easy to burn the tape during processing, thereby polluting the non-spraying area. Single-piece processing is generally used during spraying, and quality consistency cannot be guaranteed. With the above production modes, the operator's work intensity is high and the part production cycle is long, which cannot meet the growing production capacity needs.

[0004] In recent years, aero-engine manufacturing technology is being fully promoted with information technology and automation, and thermal spraying production has gradually shifted from manual operation to automated processing. However, due to the complicated thermal spraying process and the large amount of processing involved, the manufacturing development level is still in its early stages. The automated processing technology for specific parts has not been further studied, and there is a lack of engineering application and verification in aero-engines and other equipment. Summary of the invention

[0005] The purpose of the present invention is to provide an automated manufacturing method for aero-engine turbine blade tip coatings, so as to solve the problems of poor manufacturing quality consistency, low production efficiency, high labor intensity, and high raw material consumption of aero-engine turbine blade tip coatings.

[0006] In order to achieve the above object, the technical solution of the present invention is:

[0007] An automated manufacturing method for a coating on a tip of an aero-engine turbine blade comprises the following steps:

[0008] (1) Parts clamping: clamp the aircraft engine turbine blade to the spraying fixture and use the upper baffle for sandblasting;

[0009] (2) Sand blasting to clean and roughen the blade tip surface;

[0010] (3) Replace the fixture and replace the upper baffle plate for sandblasting above the blade tip with the upper baffle plate for spraying;

[0011] (4) Spraying process: plasma spraying is performed on the spraying area of ​​the blade tip;

[0012] (5) Parts unloading, removing fixtures and unloading aircraft engine turbine blades.

[0013] In the automated manufacturing method for the tip coating of an aircraft engine turbine blade, the upper baffles used to fix the aircraft engine turbine blades are divided into upper baffles for sandblasting and upper baffles for spraying.

[0014] The automated manufacturing method for the blade tip coating of an aircraft engine turbine blade comprises horizontally arranging upper baffles for sandblasting around the blade tip, and the upper baffles for sandblasting completely expose the blade tip to prevent the surface to be sandblasted from being blocked during sandblasting, thereby affecting the bonding strength of the coating.

[0015] The automated manufacturing method for the blade tip coating of an aircraft engine turbine blade comprises upper spray baffles horizontally arranged around the spraying area of ​​the blade tip, a boss is arranged on the top of each upper spray baffle, one side of the boss faces the blade tip, and the boss blocks the spray flame flow from accumulating at the root of the blade tip, thereby preventing the coating from leaving the arc during spraying.

[0016] In the automated manufacturing method for the tip coating of an aircraft engine turbine blade, the upper baffle for spraying has four bosses of different heights, and the positions and heights of the bosses are set according to the height and angle of the blade tip.

[0017] The automated manufacturing method for the blade tip coating of an aircraft engine turbine blade adopts an anode-cathode atmospheric plasma spray gun to sequentially prepare nickel-chromium-aluminum-yttrium and zirconium oxide coatings in the spraying area 7 of the blade tip.

[0018] The design concept of the present invention is:

[0019] The core point of the present invention is to determine the protection method of aircraft engine turbine blade parts, and cooperate with the automatic spraying control technology to ensure the coating performance. The present invention modularizes the protection and spraying of aircraft engine turbine blade parts, and ensures the consistency of the coating quality of aircraft engine turbine blade parts by a unified protection fixture, and ensures the accurate positioning of aircraft engine turbine blade parts, so as to improve the quality and production efficiency of aircraft engine turbine blade parts.

[0020] The use of metal fixtures to protect aircraft engine turbine blade parts not only reduces the problem of tape protection blocking the spraying area, but also improves the efficiency of protection. After sandblasting, you only need to replace the upper baffle of the fixture to start spraying work, and there is no need to check and repair the damaged tape, which reduces the workload before spraying. The upper baffles for sandblasting around the fixture and the upper baffles for spraying configured in the spraying area of ​​the aircraft engine turbine blade parts can effectively prevent contamination of non-spraying areas. According to the size and angle of the blade tip, the upper baffle for spraying is set with a boss to block the spray flame from accumulating at the root of the blade tip to avoid rework caused by the coating arc. The matching automated spraying program can ensure the consistency of the coating quality of each production, and the adjusted spray gun speed can ensure that the temperature of the aircraft engine turbine blade parts does not exceed the standard requirements. After spraying, the metal fixture can be directly removed without additional cleaning work, eliminating the hidden danger of damage to the aircraft engine turbine blade parts during cleaning and reducing the workload of operators.

[0021] Compared with the prior art, the present invention has the following main advantages and beneficial effects:

[0022] The aircraft engine turbine blades produced by the coating automation manufacturing technology of the present invention have good coating quality consistency and low raw material consumption, which meets the wear resistance requirements of the blade tip under the working state of the engine. Compared with single-piece production, the production efficiency is increased by 500% and the raw material consumption is reduced by 80%. At the same time, this technology can also be used for the coating production of small-sized spray-processed aircraft engine turbine blade parts in the aircraft engine related industry, with high economic benefits. It is expected to save about 4 million yuan in production costs each year in the future. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of the upper baffle for sandblasting.

[0024] Figure 2 Schematic diagram of the baffle for spraying.

[0025] Figure 3 The coating microstructure of aircraft engine turbine blade parts.

[0026] In the figure, 1 is the blade body, 2 is the blade tip, 3 is the upper baffle for sandblasting, 4 is the upper baffle for spraying, 5 is the boss, 6 is the spraying flame, and 7 is the spraying area. DETAILED DESCRIPTION

[0027] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0028] Example

[0029] In this embodiment, the blade tip 2 and the blade body 1 of the aircraft engine turbine blade are an integral structure, and the upper baffle for fixing the aircraft engine turbine blade is divided into a sandblasting ( Figure 1 ) and spraying ( Figure 2 ) two specifications.

[0030] like Figure 1 As shown, upper baffles 2 for sandblasting are horizontally arranged around the blade tip 2, and the upper baffles 3 for sandblasting completely expose the blade tip 2 to prevent the surface to be sandblasted from being blocked during sandblasting, thereby affecting the bonding strength of the coating.

[0031] like Figure 2 As shown, the spraying upper baffle 4 is horizontally arranged around the spraying area 7 of the blade tip 2, and a boss 5 is arranged on the top of each spraying upper baffle 4, with one side of the boss 5 facing the blade tip 2. The boss 5 blocks the spraying flame 6 from accumulating at the root of the blade tip 2 to prevent the coating from leaving the arc during spraying. The spraying upper baffle 4 has four bosses 5 of different heights, and the position and height of the boss 5 are set according to the height and angle of the blade tip 2. 10 blades can be clamped at a time, and the number can also be increased or decreased according to the processing environment and needs.

[0032] like Figure 1-Figure 2 As shown, an automated spraying test was carried out on aircraft engine turbine blades, and the process flow is: part clamping (clamping the aircraft engine turbine blades to the spraying fixture and using the upper baffle 3 for sandblasting) → sandblasting (cleaning and roughening the surface of the blade tip 2) → replacing the fixture (replacing the upper baffle 3 for sandblasting above the blade tip 2 with the upper baffle 4 for spraying) → spraying (plasma spraying the spraying area 7 of the blade tip 2) → part unloading (removing the fixture and unloading the aircraft engine turbine blade).

[0033] The nickel-chromium-aluminum-yttrium and zirconium oxide coatings were prepared in the spraying area 7 of the blade tip 2 by using an anode-cathode atmospheric plasma spray gun, with the main gas being Ar and the secondary gas being H 2 The specific process parameters are shown in Table 1. During the spraying process, the temperature of the aircraft engine turbine blade substrate must be controlled not to exceed 200°C to avoid the coating from forming a large internal stress due to excessive temperature, causing cracks or peeling.

[0034] Table 1 Process parameters of nickel-chromium-aluminum-yttrium and zirconium oxide coatings

[0035]

[0036] The coating surface after spraying is uniformly white, without overburning discoloration, cracks, warping, peeling, etc., meeting the use requirements.

[0037] The tip of the sprayed blade test piece was sampled and its metallographic structure was observed.

[0038] Table 2 Microstructure inspection results of coatings on aircraft engine turbine blade parts

[0039]

[0040] like Figure 3 As shown, the typical metallographic structure of the coating under 200 times magnification, the inspection results are shown in Table 2, which meet the standard requirements.

Claims

1. An automated manufacturing method for aeroengine turbine blade tip coating, characterized in that: The steps include: (1) Parts clamping: clamp the aircraft engine turbine blade to the spraying fixture and use the upper baffle for sandblasting; (2) Sand blasting to clean and roughen the blade tip surface; (3) Replace the fixture and replace the upper baffle plate for sandblasting above the blade tip with the upper baffle plate for spraying; (4) Spraying process: plasma spraying is performed on the spraying area of ​​the blade tip; (5) Parts unloading, removing fixtures and unloading aircraft engine turbine blades.

2. The automated manufacturing method for the coating on the tip of an aircraft engine turbine blade according to claim 1, characterized in that: The upper baffles used to fix the turbine blades of aircraft engines are divided into upper baffles for sandblasting and upper baffles for spraying.

3. The automated manufacturing method for the coating on the tip of an aircraft engine turbine blade according to claim 1 or 2, characterized in that: Upper baffles for sandblasting are horizontally arranged around the blade tip, and the upper baffles for sandblasting completely expose the blade tip to prevent the surface to be sandblasted from being blocked during sandblasting, thereby affecting the bonding strength of the coating.

4. The automated manufacturing method for the tip coating of an aircraft engine turbine blade according to claim 1 or 2, characterized in that: Upper spray baffles are horizontally arranged around the spraying area of ​​the blade tip. A boss is arranged on the top of each upper spray baffle, one side of the boss faces the blade tip. The boss blocks the spray flame flow from accumulating at the root of the blade tip to prevent the coating from leaving the arc during spraying.

5. The automated manufacturing method for the coating on the tip of an aircraft engine turbine blade according to claim 4, characterized in that: The upper baffle for spraying has four bosses of different heights, and the positions and heights of the bosses are set according to the height and angle of the blade tip.

6. The automated manufacturing method for the coating on the tip of an aircraft engine turbine blade according to claim 1, characterized in that: Nickel-chromium-aluminum-yttrium and zirconium oxide coatings were prepared in turn in the spraying area 7 of the blade tip using an anode-cathode atmospheric plasma spray gun.

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