A method for processing coatings on multi-unit stacked thin-walled casings

Abstract

This invention discloses a multi-unit superimposed thin-walled casing coating processing method, comprising the following steps: after cleaning the parts, plasma spraying is used to spray the parts to be coated. The coating material is an Al / BN coating with a thickness in the range of 0.4-0.5mm. → Grinding the part reference surface, performing planar grinding on the reference surface, with a colored area of ​​more than 80% and continuous grinding. → Turning the parts, using a "bow" shaped tool path, processing the metal part and the coated part separately, and performing three turning operations. The first bow-shaped tool path bypasses the coating and turns the metal. The second bow-shaped tool path bypasses the metal and turns the coating. The third turning operation covers the entire surface, with the coating and metal working together in one pass. Each of the three operations uses different processing parameters. This processing method improves the accuracy of the reference surface, achieves high-precision machining of the parts, ensures that the runout of both the metal substrate and the coating is qualified, and ensures that the runout is qualified in one pass, preventing overall peeling, large-area or localized chipping of the coating caused by repeated processing.

Description

Technical Field

[0001] This invention belongs to the field of component processing and manufacturing technology, specifically relating to a multi-unit superimposed thin-walled casing coating processing method. Background Technology

[0002] In multi-unit stacked thin-walled casings, taking the adjustable flow controller casing as an example, the casing material is mostly TC1 alloy. Its complex structure is mainly composed of a zero-stage rectifier outer ring, a first-stage rectifier outer ring, a second-stage rectifier outer ring, a front ring, and a rear ring, resulting in extremely poor rigidity. The adjustable flow controller casing has a wall thickness of 1.85mm, classifying it as a thin-walled component. However, its parallelism, perpendicularity, positional accuracy, and coating runout requirements are 0.04mm, 0.02mm, φ0.04mm, and 0.1mm, respectively. Simultaneously, a total of 22 high-precision pin holes and 256 precision radial step holes need to be machined on each component. The coating material is an Al / BN coating, typically 1.5mm thick, while the metal substrate material is TC1. The two have different processing properties and significant hardness differences. To ensure that both the metal substrate and coating runout are within acceptable limits, repeated measurements and machining are often required during processing, and it is difficult to guarantee that the runout will be acceptable in one go.

[0003] The difference between the coating material and the metal substrate material has a significant impact on multi-unit stacked thin-walled casing parts. Especially after multi-stage assembly, the gaps between parts are large, making it difficult to ensure the runout of the coating surface. Regarding the difficulty in ensuring the runout of the coating surface, a study of the current toolpath revealed that all turning programs perform continuous cutting when machining the internal flow channel surface, without taking into account the differences in machining characteristics between different materials.

[0004] Chinese Patent No. CN109530192B discloses a method for processing a casing coating, including spraying and machining the coating. The spraying method involves applying a GH3030 coating to the area of ​​the casing to be coated using a flame melting method, with a coating thickness of less than 0.7 mm. The machining method involves machining the coating twice, starting from the axial bisecting surface, with each machining operation machining half of the circumferential surface. This invention can achieve high-precision machining of the casing and prevent problems such as overall coating peeling, large-area or localized chipping. However, it does not solve the problem of coating runout.

[0005] Chinese Patent No. CN110607494A discloses a high-temperature oxidation-resistant coating modified by plasma spraying and electron beam cladding on a titanium alloy surface. Using a titanium alloy as the substrate, the substrate undergoes cleaning, degreasing, rust removal, and surface roughening. First, an alloy transition layer and a multiphase ceramic coating are prepared by plasma spraying onto the substrate surface. Then, electron beam cladding modification is performed, melting the alloy transition layer and softening the multiphase ceramic coating, allowing for sufficient element diffusion and forming a metallurgically bonded coating with a thickness of 80–200 μm. This invention's multiphase ceramic coating significantly reduces thermal conductivity, protecting the titanium alloy substrate from high-temperature oxidation and corrosion. The alloy transition layer alleviates stress concentration within the coating, improves the bonding strength between the titanium alloy substrate and the multiphase ceramic coating, and broadens the application fields of titanium alloys. Furthermore, the preparation method is simple, easy to control, and low-cost, making it suitable for industrial application. However, no specific solutions are provided for the problems of vibration and coating peeling. Summary of the Invention

[0006] To address the aforementioned problems, this invention aims to provide a method for processing a multi-unit stacked thin-walled casing coating.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: a multi-unit superimposed thin-walled casing coating processing method, comprising the following steps:

[0008] Step 1: After cleaning the parts, use plasma spraying to spray the parts to be sprayed. The coating material is Al / BN coating, and the coating thickness is in the range of 0.4-0.5mm.

[0009] Step 2: Grind the reference surface of the part. Perform planar grinding on the reference surface, with a colored area of ​​more than 80% and without interruption.

[0010] Step 3: Machining the part. The tool path adopts a "bow" shape. The metal part and the coated part of the part are machined separately. The turning is done in three steps. The first step is a bow-shaped tool path to bypass the coating and turn the metal. The second step is a bow-shaped tool path to bypass the metal and turn the coating. The third step is to turn the entire surface, with the coating and metal together in one cut. Different machining parameters are used for each of the three steps.

[0011] Preferably, in step 3, the part includes a coated part and a metal part, and the material of the metal part is TC1 alloy.

[0012] Preferably, in step 3, the turning process uses UG programming, including adjusting the cutting area, cutting strategy and cutting parameters, to turn the metal substrate and coating separately, so that the runout of the two references is no more than 0.1mm.

[0013] Preferably, in step 1, the cleaning of the parts includes washing and drying to keep the surface of the parts dry, clean, and free of debris and dirt.

[0014] Preferably, after the machining is completed, the burrs on the surface of the parts are cleaned, and then the parts are washed and dried to keep the surface of the parts dry, clean, and free of debris and dirt.

[0015] Compared with the prior art, the present invention has the following advantages: by controlling the coating thickness and turning path, the coating thickness is between 0.4-0.5mm. The turning parameters are adjusted by using a "bow" shaped tool path to turn the coating part and the metal part separately. At the same time, a grinding reference surface is added to improve the reference accuracy, realize high-precision machining of parts, ensure that the runout of both the metal substrate and the coating is qualified, and ensure that the runout is qualified in one turn, preventing the coating from peeling off as a whole, or large-area or localized chipping caused by repeated machining. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the specific embodiments of the present invention, the drawings used in the description of the embodiments 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.

[0017] Figure 1 This is a schematic diagram of a multi-unit stacked thin-walled casing structure according to the present invention;

[0018] Figure 2 This is a schematic diagram of the reference structure of a multi-unit stacked thin-walled casing in this invention;

[0019] Figure 3 This is a schematic diagram of the machining path structure of the multi-unit stacked thin-walled casing in this invention. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. However, it should not be construed that the scope of the subject matter of the present invention is limited to the following embodiments. All modifications, substitutions and alterations made based on ordinary technical knowledge and common practices in the art without departing from the above-described technical concept of the present invention are included within the scope of the present invention.

[0021] Step 1: Clean and spray paint the thin-walled casing, refer to... Figure 1After washing and drying, the thin-walled casing is kept dry and clean, free of debris and contaminants. Then, plasma spraying is applied to the areas of the casing to be coated. The coating material is Al / BN, with a thickness of 0.4-0.5mm. Since coating thickness is inversely proportional to adhesion, thicker coatings are more prone to peeling. Therefore, to ensure a final thickness of 0.15mm, the smaller the coating allowance, the less likely it is to peel off. Thus, the coating thickness needs to be modified from 1.5mm to 0.4-0.5mm. Too thick a coating is prone to peeling, while too thin a coating can cause deformation of the part's roundness. After machining, some areas may not be machined, leading to under-coating.

[0022] Step 2: Grinding reference, see Figure 2 To better ensure that the coating runout is no greater than 0.1, the reference surface is subjected to planar grinding, requiring the colored area to be more than 80% without interruption, thereby improving the accuracy of the reference.

[0023] Step 3: Machining the coating. Due to differences in hardness, density, and machining parameters of the coating layers, the machining parameters also vary. A "bow" shaped tool path can be used for machining. UG programming is employed, including adjusting the cutting area, cutting strategy, and cutting parameters, to separate the metal substrate and coating layers for high-speed, layered machining. The machining process is divided into three steps: the first step uses a bow-shaped tool path to bypass the coating and machine the metal; the second step uses a bow-shaped tool path to bypass the metal and machine the coating layer; the third step machines the entire surface, combining the coating and metal, with a allowance of 0.1mm. This is completed in one pass to ensure a smooth finish, ensuring that the runout between the two references is no more than 0.1mm.

[0024] Step 4: Remove burrs. Clean the burrs from the surface of the parts, and wash and dry them to ensure the surface is dry and clean, free of debris and dirt.

[0025] The above provides a detailed description of a multi-unit superimposed thin-walled casing coating processing method provided by the present invention. Specific examples have been used to illustrate the structure and working principle of the invention. The descriptions of the embodiments above are merely for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make various improvements and modifications to the present invention without departing from its principles, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A method for processing a multi-unit stacked thin-walled casing coating, characterized in that: Includes the following steps: Step 1: After cleaning the parts, use plasma spraying to spray the parts to be sprayed. The coating material is Al / BN coating, and the coating thickness is within the range of 0.4-0.5mm to prevent peeling and deformation. Step 2: Grind the reference surface of the part. Perform planar grinding on the reference surface, with a colored area of ​​more than 80% and without interruption, to ensure that the coating runout is no more than 0.1mm; Step 3: Machining the part. The tool path adopts a "bow" shape. The metal part and the coated part of the part are machined separately. The turning is done in three steps. The first step is a bow-shaped tool path to bypass the coating and turn the metal. The second step is a bow-shaped tool path to bypass the metal and turn the coating. The third step is to turn the entire surface, with the coating and metal together in one cut. Different machining parameters are used for each of the three steps.

2. The multi-unit superimposed thin-walled casing coating processing method according to claim 1, characterized in that: In step 3, the part includes a coated part and a metal part, and the material of the metal part is TC1 alloy.

3. The multi-unit superimposed thin-walled casing coating processing method according to claim 1, characterized in that: In step 3, the turning process uses UG programming, including adjusting the cutting area, cutting strategy and cutting parameters, to turn the metal substrate and coating separately, so that the runout of the dual reference is no more than 0.1mm.

4. The multi-unit superimposed thin-walled casing coating processing method according to claim 1, characterized in that: In step 1, cleaning the parts includes washing and drying them to keep the surface of the parts dry, clean, and free of debris and dirt.

5. The multi-unit superimposed thin-walled casing coating processing method according to claim 1, characterized in that: After the machining is completed, the burrs on the surface of the parts are removed, and then the parts are washed and dried to keep the surface of the parts dry, clean, and free of debris and dirt.

Images