Method for processing cyanide surface of aircraft parts

Abstract

This invention relates to a method for processing cyanide-coated surfaces of aerospace parts, belonging to the technical field of aerospace part processing, and solving the technical problem of low finished product processing efficiency in existing technologies. The method includes: initial processing of a sample to form a first sample to be processed; cyanide treatment of the first sample to be processed to form a second sample to be processed, wherein a cyanide layer is formed on the surface of the second sample; and machining the cyanide layer on the second sample to be processed to a predetermined precision using a lathe to form a finished product. This method of using turning instead of grinding for cyanide surface cutting improves surface finish, eliminates thermal cracks, facilitates operation, and increases processing efficiency.

Description

Technical Field

[0001] This invention belongs to the field of machining methods for aerospace parts, and particularly relates to a machining method for the cyanide surface of aerospace parts. Background Technology

[0002] The flexible support components of the turbine section of an aero-engine require cyanidation treatment in certain areas to improve surface hardness, corrosion resistance, and wear resistance. After cyanidation, the components need to be machined again to meet design dimensional requirements. Due to the high hardness of the cyanided surface, traditional machining methods involve grinding. This process removes 1.4 mm of cyanided surface material, with a single grinding pass controlled at 0.005-0.01 mm, resulting in a machining time of approximately 15 hours per part, which is inefficient.

[0003] In view of this, the present invention is hereby proposed. Summary of the Invention

[0004] The purpose of this invention is to provide a method for processing the cyanide surface of aerospace parts, at least solving the technical problem of low processing efficiency in the prior art. The technical solution of this invention has many beneficial effects, as described below:

[0005] A method for processing the cyanide surface of an aerospace part is provided, the method comprising:

[0006] The initial processing of the sample forms the first sample to be processed;

[0007] The first sample to be processed is treated with a cyanide process to form a second sample to be processed, and a cyanide layer is formed on the surface of the second sample to be processed.

[0008] The second sample to be processed is machined on a lathe to a predetermined precision to form a finished product.

[0009] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects:

[0010] The method of machining cyanide surfaces by replacing grinding with turning improves surface finish, eliminates hot cracks, facilitates operation, increases processing efficiency, and reduces processing time. A single piece can be completed in 4-6 hours. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. 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.

[0012] Figure 1 This is a flowchart of the method of the present invention. Detailed Implementation

[0013] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. The present invention 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 the present invention. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0014] 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 invention, 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 structures and / or functionalities other than one or more of the aspects set forth herein.

[0015] For the processing method of the cyanide surface of the aerospace parts of the present invention, see [link to relevant documentation]. Figure 1 As shown, the method includes:

[0016] S101: Initial processing of the sample to form the first sample to be processed. Specifically, the material of the sample is alloy structural steel, such as 12Cr2Ni4A. The raw material itself has low hardness and good processing performance. The initial processing of the sample can be carried out using traditional processes, such as cutting, surface grinding, cleaning and deburring.

[0017] S102: The first sample to be processed is treated with cyanidation to form the second sample to be processed. A cyanide layer is formed on the surface of the second sample. The cyanidation process (carbonitriding process) is used to improve the surface hardness, corrosion resistance and wear resistance. Generally, the cyanidation process is added to the surface of the part or the outer groove area. Alternatively, the part may have a preset number of grooves, and the grooves are also treated with cyanidation to improve the surface hardness, corrosion resistance and wear resistance of the part to meet the engine operation requirements.

[0018] S103: The second sample to be processed is machined on a lathe to a predetermined precision to form a finished product. Specifically:

[0019] After cyanidation, the hardness of the cyanided area of ​​the part increases from HRC31.5-41.5 to HRC≥60, making cutting more difficult and placing higher demands on tool performance. As a result, in the past few years, the traditional method of grinding with abrasive wheels has been used. The abrasive wheel covers the sample to be processed, and the coolant spray from the grinding equipment is thrown out over a large area along the tangential direction of the wheel's rotation, which cannot be evenly washed on the surface of the part. This causes the heat generated by grinding to act directly on the part, resulting in thermal cracks on the cyanided surface. The processing pass rate is only about 60%, which is costly and inefficient. Generally, the efficiency of a senior high-precision grinding machine is: the mechanical removal of cyanided surface diameter is 1.4mm, and the single grinding amount is controlled within 0.005-0.01mm, resulting in a processing time of about 15 hours per piece.

[0020] To address the shortcomings of traditional methods, the existing technology of turning is used to replace the traditional grinding method, thereby improving the processing efficiency and yield of parts in the aerospace field. Since the coolant spraying method in grinding is scattering, the cooling effect on the grinding area is not good. In contrast, the coolant in turning can be concentrated and sprayed onto the processing area during processing, and it is done in a point-machining manner, which has a better cooling effect and can reduce or avoid the generation of thermal cracks.

[0021] As a preferred embodiment of this case, the second sample to be processed is machined to a predetermined precision by turning, including:

[0022] The lathe tool selected is a ceramic-coated external turning tool, with the preferred insert type being VCMT160408-PF4WSM10. The cyanide layer is treated to a preset thickness accuracy using spot machining, with the surface roughness controlled below Ra0.8. Machining is performed using the external turning tool according to preset lathe parameters. Specifically:

[0023] 1) The processing time requirement is 5-6 hours. Machining parameters:

[0024] When the lathe feed rate is 0.05 mm / s and the depth of cut is 0.1 mm, the lathe speed is less than 30 r / min.

[0025] 2) The processing time requirement is 4-5 hours. Machining parameters:

[0026] When the lathe speed is 20 r / min and the depth of cut is 0.1 mm, the lathe feed rate is less than 0.06 mm / s.

[0027] 3) The processing time requirement is 3-4 hours. Machining parameters:

[0028] The lathe has a rotational speed of 20 r / min, a feed rate of 0.06 mm / s, and a depth of cut of 0.15 mm.

[0029] Furthermore, a predetermined number of grooves are formed on the first sample to be processed, and the grooves are machined using an external turning tool according to predetermined lathe parameters, including:

[0030] The groove is machined with a grooving tool to a preset precision on the cyanide layer, and the grooving tool is equipped with an aluminum oxide composite coating.

[0031] The processing parameters are shown in Table 1:

[0032]

[0033]

[0034] Table 1

[0035] By setting different spindle speeds, feed rates, and depths of cut, and testing the machining effects, the optimal solution was found based on machining time, surface finish, and tool wear. The optimal machining parameters were a spindle speed of 20 rpm, a feed rate of 0.06 mm / s, and a depth of cut of 0.15 mm. Parts were verified using these parameters, and the surface finish met the Ra0.8 requirement. Machining efficiency was improved while tool wear was reduced: the machining time per part was reduced from 15 hours to 5 hours, and tool wear was reduced from using a set of two grinding wheels (approximately 400 RMB) to machine two parts to using a set of two inserts (approximately 50 RMB) to machine one part, significantly reducing machining costs. Magnetic particle nondestructive testing confirmed that no cracks were generated in the turned area of ​​the cyanide surface, proving that turning instead of grinding for machining cyanide surfaces significantly improved part quality and machining efficiency while ensuring the surface finish met the requirements, and simultaneously reduced machining costs.

[0036] Furthermore, the cutting tools on current lathes are automatically switched. When the part to be machined has grooves, the machining can be completed simply by automatically switching the cutting tools. Compared with the traditional grinding method, where it is not possible to use the same grinding wheel to machine the grooves and other grinding wheels need to be changed midway, which is inconvenient, the turning method can reduce unnecessary time consumption in terms of tool changing.

[0037] It is important to emphasize that the purpose of the coating on the external turning tools and / or grooving tools of this invention is as follows: the coating components include a composite compound containing alumina, carbides, nitrides, borides, and silicides, or a novel alumina composite layer, or a composite compound of alumina, carbides, titanium aluminum nitride, and silicides. For the aforementioned machining parameters, when machining parts using both general-purpose coated inserts and Silver Tiger inserts, the effective service life of the general-purpose coated insert tip is only 15-20 minutes, while the effective service life of the Silver Tiger insert tip can reach 60-70 minutes. The Silver Tiger insert (WSM**S) coating features: the alumina composite coating resists high cutting heat, enabling rapid cutting; furthermore, the coating makes the tool surface smooth, reducing friction and frictional cutting heat during cutting; and the fine-grained matrix resists notch wear. The coating increases sharpness and reduces cutting heat. The titanium aluminum nitride coating resists flank wear.

[0038] The product provided by this invention has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are merely for the purpose of helping to understand the core ideas of this invention. It should be noted that those skilled in the art can make various improvements and modifications to the invention without departing from the principles of the invention, and these improvements and modifications also fall within the protection scope of the invention claims.

Claims

1. A method of processing a cyanided surface of an aircraft part, characterized in that, The method includes: The initial processing of the sample forms a first sample to be processed, wherein a preset number of grooves are formed on the first sample to be processed, and the material of the sample is alloy structural steel; The first sample to be processed is treated with a cyanide process to form a second sample to be processed, and a cyanide layer is formed on the surface of the second sample to be processed. The second sample to be processed is machined on a lathe to a predetermined precision to form a finished product, wherein... The groove is processed by a grooving tool to achieve a preset precision on the cyanide layer, and the grooving tool is provided with an alumina composite coating. The lathe tool is an external turning tool with an alumina composite coating. The cyanide layer is processed to a preset thickness accuracy by point machining, and the roughness is controlled below Ra0.

8. The external turning tool is used to machine according to preset lathe parameters. The hardness of the cyanide layer is HRC≥60.

2. The method of claim 1, wherein Machining is performed using an external turning tool according to preset lathe parameters, including: When the lathe feed rate is 0.05 mm / s and the depth of cut is 0.1 mm, the lathe speed is less than 30 r / min.

3. The method of claim 2, wherein the cyaniding of the aeronautical part is performed by immersing the aeronautical part in a cyanide bath. Machining is performed using an external turning tool according to preset lathe parameters, including: When the lathe speed is 20 r / min and the depth of cut is 0.1 mm, the lathe feed rate is less than 0.06 mm / s.

4. The processing method for the cyanide surface of aerospace parts according to claim 3, characterized in that, Machining is performed using an external turning tool according to preset lathe parameters, including: The lathe has a rotational speed of 20 r / min, a feed rate of 0.06 mm / s, and a depth of cut of 0.15 mm.

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