Physical non-stick structure, cooking utensil and processing method

Abstract

The invention discloses a physical non-stick structure, a cooking utensil and a processing method, the physical non-stick structure is applied to the surface of a metal base material, and the physical non-stick structure comprises a shot blasting layer arranged on the surface of the metal base material and a physical vapor deposition layer arranged on the surface of the shot blasting layer. And the morphology of the surface of the physical vapor deposition layer is similar to that of the surface of the shot blasting layer covered by the physical vapor deposition layer. The physical non-stick structure and the cooking utensil have the physical non-stick performance, and compared with a traditional method, the process is simple, and the cost is low.

Description

Technical Field

[0001] The present application relates to the technical field of cooking utensils, and in particular to a physical non-stick structure, a cooking utensil and a processing method. Background Art

[0002] Existing cooking utensils achieve non-stick properties by coating the surface of the cooking utensils with a chemical coating, generally polytetrafluoroethylene. The polytetrafluoroethylene coating is non-toxic under normal conditions, but when the coating is heated to 260°C, it will begin to volatilize, and when the temperature reaches 350°C, the polytetrafluoroethylene coating will begin to decompose. Therefore, the use temperature of non-stick pans with polytetrafluoroethylene coatings generally cannot exceed 250°C. However, the heating temperature of general cooking utensils such as frying pans often exceeds 260°C, so there are safety hazards. In addition, the coating is not wear-resistant and there is a risk of falling off. It is easy to be accidentally eaten with food, affecting health. Summary of the invention

[0003] In order to solve the above technical problems, the present application provides a physical non-stick structure, cooking utensils and processing methods, which can not only improve the non-stick performance of the surface of the cooking utensils, but also have the advantages of wear resistance and not easy to fall off.

[0004] In the first aspect, the present application provides a physical non-stick structure applied to the surface of a metal substrate, the physical non-stick structure comprising a shot peening layer arranged on the surface of the metal substrate and a physical vapor deposition layer arranged on the surface of the shot peening layer, the morphology of the surface of the physical vapor deposition layer being similar to the morphology of the surface of the shot peening layer covered by it.

[0005] By adopting the above technical solution, a concave-convex structure is firstly processed on the surface of the metal substrate by shot peening. The concave-convex structure can form a hydrophobic structure on the surface of the metal substrate, but this hydrophobic structure is not wear-resistant. After the concave-convex structure is processed by shot peening, a physical vapor deposition layer is plated on the surface of the concave-convex structure. The physical vapor deposition layer has wear-resistant characteristics. Because the physical vapor deposition layer has a morphology similar to that of the concave-convex structure, the surface of the physical vapor deposition layer has a hydrophobicity similar to that of the concave-convex structure. Therefore, the physical non-stick structure processed on the surface of the metal substrate makes the metal surface have both wear-resistant and non-stick characteristics.

[0006] In combination with the first aspect, in a further solution, the shot peening layer and the metal substrate are an integral structure, and the physical vapor deposition layer is in direct contact with the shot peening layer.

[0007] By adopting the above technical solution, the concave-convex structure is directly processed on the surface of the metal substrate by shot peening, and the one-piece structure has higher strength, which can reduce the risk of falling off caused by the two-body structure. The physical vapor deposition layer is directly in contact with the concave-convex structure without a transition layer in between, which can reduce the processing steps and processing costs while also achieving wear-resistant and non-stick properties.

[0008] In combination with the first aspect, in a further solution, an electrolytic layer is further provided between the shot peening layer and the physical vapor deposition layer.

[0009] By adopting the above technical solution, the surface of the shot peening layer is structured with micron, nanometer-level V-shaped, C-shaped, U-shaped or randomly sized concave bodies under the action of electrolysis, which can further reduce the contact area between the food and the pot body. In addition, the double effect of the repulsive force formed by the heat expansion of the air in the concave bodies can well achieve the non-stick effect. In addition, electrolysis can also form an oxide film on the surface of the shot peening layer to change its color and improve its performance, thereby improving the performance and grade of the product.

[0010] In combination with the first aspect, in a further solution, a plasma polishing layer is further provided between the shot peening layer and the physical vapor deposition layer.

[0011] By adopting the above technical solution, the surface of the shot peening layer can be further processed into a micron or nanometer-level concave-convex structure, further improving the hydrophobicity and the non-stick performance of the product surface. The plasma polishing layer can also increase the brightness of the product surface and improve the quality of the product.

[0012] In combination with the first aspect, in a further scheme, the Vickers hardness of the metal substrate is greater than or equal to 100; the shot peening layer has a plurality of pits, the spherical diameter of the pits is 0.3-0.95 mm, preferably 0.4-0.65 mm; the center distance of the pits ranges from 0.3-0.8 mm, preferably 0.6 mm.

[0013] Through experimental tests, it was found that the physical vapor deposition (PVD) processing technology applied to the surface of a metal substrate with a Vickers hardness greater than 100 forms a shot peening layer with a spherical diameter of 0.3-0.95 mm, preferably 0.4-0.65 mm, and the center distance of the pits ranges from 0.3-0.8 mm, preferably 0.6 mm. The pits have better non-stick and wear resistance.

[0014] In a second aspect, the present application further provides a cooking utensil, comprising a body formed from a metal substrate, wherein the surface of the body is provided with the physical non-stick structure as described in the first aspect.

[0015] By adopting the above technical solution, the cooking utensils with a physical non-stick structure can improve the non-stick performance when cooking food, reduce the probability of food sticking to the surface of the body, make it easier to clean the cooking utensils, and enhance the cooking pleasure.

[0016] In combination with the second aspect, in a further scheme, the shot peening layer is formed by shot peening the inner surface of the main body after the main body is formed to form a concave-convex structure with a height difference of 45-85 microns, preferably a concave-convex structure with a height difference of 55-75 microns, and the thickness of the physical vapor deposition layer is 0.8-1.45 microns.

[0017] Through experimental tests, it was found that the concave-convex structure with a height difference of 45-85 microns, or the concave-convex structure with a height difference of 55-75 microns is easy to process and has good hydrophobic properties. The thickness of the physical vapor deposition layer is 0.8-1.45 microns, which can effectively achieve that when the physical vapor deposition layer covers the surface of the shot peening layer, the physical vapor deposition layer can have a morphology similar to the concave-convex structure of the shot peening layer, so that the surface of the physical vapor deposition layer has better non-stick properties and wear resistance.

[0018] In a third aspect, the present application provides a physical non-stick structure processing method for processing the physical non-stick structure as described in the first aspect on the surface of a metal substrate, the processing method comprising: Forming: Processing the metal substrate into a predetermined size and shape; Shot peening: Shot peening is performed on the cut metal substrate or the formed product to form a shot peening layer; Coating: The metal substrate after shot peening or the formed product is heated to 200°C-500°C and placed in a vacuum environment, and PVD coating is performed on the surface of the shot peening layer.

[0019] By adopting the above technical solution, the processing cost is low and the processing efficiency is high.

[0020] In a fourth aspect, the present application further provides a cooking utensil processing method, which is applicable to the cooking utensil described in the second aspect, and the processing method comprises: Forming: Processing the metal substrate to form the cooking utensil body; Shot peening: Shot peening is performed on the inner surface of the main body to form a shot peening layer with spherical pits on the inner surface of the main body; Coating: The shot peened body is heated to 200°C-500°C and placed in a vacuum environment, and PVD coating is performed on the inner surface of the main body.

[0021] By adopting the above technical solution, the traditional process of first processing the metal sheet into a concave-convex structure and then stretching it into the body of the device is abandoned. The metal sheet is first stretched into the body and then the inner surface of the body is shot peened to form the concave-convex structure. The process is simple and low in cost, and there is no risk of destroying the morphology of the concave-convex structure after stretching. The hydrophobic performance of the concave-convex structure is better protected, and the consistency of the non-stick performance of the product is higher.

[0022] In combination with the fourth aspect, in a further solution, an electrolytic or plasma polishing process step is also included between the shot peening and coating steps to form an electrolytic layer or a plasma layer on the surface of the shot peening layer.

[0023] By adopting the above technical solution, a nanometer or micrometer-level concave-convex structure can be further formed on the surface of the concave-convex structure formed by shot peening to further improve the hydrophobic performance. In addition, the discoloration problem during the processing of the metal substrate can be reduced.

[0024] In summary, the present application has at least one of the following beneficial technical effects: 1. The physical non-stick structure of the present invention makes the metal surface both wear-resistant and physically non-stick.

[0025] 2. The physical non-stick structure of this application can reduce the risk of falling off caused by the two-body structure and has higher strength.

[0026] 3. The physical non-stick structure of the present application, the physical vapor deposition layer is in direct contact with the shot peening layer, and there is no transition layer in between, which can not only ensure the bonding strength but also reduce the processing steps and reduce the processing cost.

[0027] 4. The cooking utensil of the present application can meet the requirements of wear resistance and non-stick performance of the cooking utensil during normal cooking, and can also improve the cost performance of the cooking utensil.

[0028] 5. The processing method of the present application can form a concave-convex structure on the surface of a metal substrate or the body of a cooking utensil, thereby improving the non-stick performance of the product and making it easier to clean the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a schematic structural diagram of a metal substrate having a first embodiment of the physical non-stick structure of the present application; Figure 2 yes Figure 1 The enlarged schematic diagram at A in the middle; Figure 3 yes Figure 2 Schematic diagram of the middle BB section; Figure 4 is a schematic structural diagram of a metal substrate having a second embodiment of the physical non-stick structure of the present application; Figure 5 yes Figure 4 The enlarged schematic diagram at C in the middle; Figure 6 It is a structural schematic diagram of the first embodiment of the cooking utensil of the present application; Figure 7 It is a structural schematic diagram of the second embodiment of the cooking utensil of the present application.

[0030] Reference numerals: 100. Metal substrate; 200. Physical non-stick structure; 2. Shot peening layer; 21. Pits; 3. Physical vapor deposition layer; 4. Electrolytic layer; 41. Protrusions; 5. Pot body; 51. Inner surface; 511. Bottom area; 52. Outer surface; 521. Pot mouth area; 6. Handle; a. Hole center distance; b. Pits depth. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings. The components of the embodiments of the present application described and shown in the accompanying drawings can be arranged and designed in various configurations. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0032] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0033] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0034] In the description of the present application, it should be understood that the terms "up", "down", "left", "right", etc., indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present application.

[0035] Some embodiments of the present application are described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the features of the following embodiments can be combined with each other.

[0036] The cooking utensils in the present application include dining utensils and cooking utensils.

[0037] Embodiment 1 See also Figure 1-Figure 3, a schematic diagram of the structure of an embodiment of a physical non-stick structure 200. The physical non-stick structure 200 is disposed on at least a portion of the surface of a metal substrate 100, and the physical non-stick structure 200 includes a shot peening layer 2 disposed on the surface of the metal substrate 100 and a physical vapor deposition layer 3 disposed on the surface of the shot peening layer 2, and the morphology of the surface of the physical vapor deposition layer 3 is similar to the morphology of the surface of the shot peening layer 2 covered by it.

[0038] See also Figure 1 The physical non-stick structure 200 in this embodiment includes a region set on the surface of the metal substrate 100 that is integrally processed by shot peening or rolling and then PVD coated.

[0039] See also Figure 2 The physical non-stick structure 200 includes a shot peening layer 2. The shot peening layer 2 of this embodiment is a concave-convex structure processed on the surface of the metal substrate 100 by a shot peening method. The shot peening layer 2 is formed by a plurality of pits 21 arranged regularly or irregularly. The pit 21 in this embodiment has a circular cross-section, and can also be processed into a circular, elliptical or polygonal shape according to design requirements by rolling and other processing methods. The polygon is, for example, a hexagon or a quadrilateral. The diameter of the pit 21 is 0.3-0.95 mm, and the optimal range is 0.4-0.65 mm. The pit 21 is a spherical pit 21 formed by spraying 0.6-1 mm steel shot at a pressure of 2Mpa-8Mpa onto the surface of the metal substrate 100. The diameter of the pit 21 mentioned above is the spherical diameter. The hole center distance a of the pit 21 ranges from 0.3-0.8 mm, and the optimal range is 0.6 mm. The range of the hole center distance a mentioned here refers to the spherical center distance of the pit 21. If the pits 21 are polygonal, the polygons can be evenly distributed by rolling or can be designed to be irregularly arranged as needed. The diameter of the inscribed circle of the polygon is 0.3-0.95 mm, and optimally 0.4-0.65 mm.

[0040] See also Figure 3 The shot peening layer 2 is a surface formed by connecting the pits 21 formed by shot peening the inner surface 51 of the main body after the main body is formed and the protrusions 41 between the pits 21, and the pit depth b is 45-85 microns, and optimally 55-75 microns. The shot peening layer 2 and the metal substrate 100 are an integral structure, and the physical vapor deposition layer 3 is in direct contact with the shot peening layer 2.

[0041] At least part of the surface of the shot peening layer 2 is provided with a physical vapor deposition layer 3. By setting and controlling the PVD coating process parameters, the morphology of the surface of the physical vapor deposition layer 3 is similar to the morphology of the surface of the shot peening layer 2 covered by it, so as to achieve a non-stick effect on the surface of the metal substrate 100. The physical vapor deposition layer 3 is in direct contact with the shot peening layer 2, and the thickness of the physical vapor deposition layer 3 is 0.8-1.45 microns. Conventional PVD coatings cannot be directly contacted with the metal substrate 100 for bonding, and a transition layer needs to be set between the PVD coating and the metal substrate 100. For example, the patents with application numbers CN202121169683.5 and CN202222426611.5 both use a transition layer solution to achieve bonding. The transition layer can have good bonding to the coating and to the metal substrate 100, so as to ensure good bonding between the PVD coating and the metal substrate 100 and prevent it from falling off easily. The physical non-stick structure 200 of the present application has been developed through theoretical analysis and long-term experimental testing, and a new structure has been developed. The corresponding concave-convex structure is directly shot peened on the surface of the metal substrate 100, which can not only achieve good bonding between the PVD coating and the metal substrate 100, but also improve the non-stick property of the surface of the metal substrate 100, and also has wear-resistant performance, which can maintain the wear-resistant and non-stick property of the surface of the metal substrate 100 for a long time. The metal substrate 100 is a metal material such as carbon steel, alloy steel, stainless steel and titanium alloy.

[0042] Performance comparison test of different parameters: Through the performance comparison test, it can be seen that the comprehensive performance presented is optimal when the physical vapor deposition thickness of items 5-8 is in the range of 0.8-1.45um and the depth of the shot peening pit 21 is 45-85um, and the cost within this parameter range is also the most reasonable.

[0043] When the physical vapor deposition thickness is less than 0.8um and the shot peening pit depth b is less than 45um, the coating bonding strength is poor and can only reach level 3, and it is easy to fall off; the hardness is 600-800HV, the hardness is not enough, and the wear resistance is poor; the non-stick effect of fried eggs is level III, and the non-stick effect is poor.

[0044] When the physical vapor deposition thickness is less than 0.8um and the shot peening pit depth b is greater than 85um, the coating hardness is 300-800HV, the hardness is insufficient, and the wear resistance is poor; the non-stick effect of fried eggs is level III, and the non-stick effect is poor.

[0045] When the physical vapor deposition thickness is greater than 1.45um and the shot peening pit depth b is less than 45um, the coating bonding strength is very poor and can only reach level 3, and it is easy to fall off; the hardness of 1500-2000HV can meet the requirements, but the raw materials are wasted and the cost is increased, and the non-stick effect of fried eggs is level III, and the non-stick effect is poor.

[0046] When the physical vapor deposition thickness is greater than 1.45um and the shot peening pit depth b is greater than 85um, the bonding force can reach level 2 or above, and the hardness of 1500-2000HV can meet the requirements, but the raw materials are wasted and the cost is increased, and the non-stick effect of fried eggs is level III, which is poor.

[0047] When the physical vapor deposition thickness is in the range of 0.8-1.45um and the shot peening pit depth b is 45-85um, the bonding force can reach level 2, the hardness is 1500-2000HV, the non-stick effect of fried eggs is level II, and the cost performance is the highest.

[0048] Through experimental tests, the metal substrate 100 with a Vickers hardness greater than or equal to 100 combined with the physical non-stick structure 200 has the best effect.

[0049] Embodiment 2 See also Figure 4 and Figure 5 , which is different from the first embodiment, is that an electrolytic layer 4 or a plasma polishing layer is provided between the shot peening layer 2 and the physical vapor deposition layer 3 .

[0050] See also Figure 4 The convex structure is processed on the surface of the shot peening layer 2 by electrolysis or plasma polishing. In this embodiment, the convex structure is processed by electrolysis.

[0051] See also Figure 5 The convex structure includes a plurality of protrusions 41 disposed at least on at least part of the surface of the shot peening layer 2, the height of the protrusions 41 is 45-85 microns, and the electrolytic layer 4 is a surface formed by connecting the protrusions 41 and the protrusions 41. This figure only illustrates the structure of the protrusions 41. When the surface of the shot peening layer 2 is processed by electrolysis or plasma polishing, the shape of the protrusions 41 is irregular, but the height range of each protrusion 41 needs to be controlled within 45-85 microns.

[0052] An electrolytic layer 4 and / or a plasma polishing layer is provided on the surface of part of the shot peening layer 2, and a physical vapor deposition layer 3 is coated on the surface of part of the electrolytic layer 4 / plasma polishing layer, or part of the shot peening layer 2, or part of the shot peening layer 2 and part of the electrolytic layer 4 / plasma polishing layer. A variety of combined structures can be formed on the surface of the metal substrate 100 to achieve different surface effects according to different usage requirements, or different surface effects can be achieved in different areas on the surface of the metal substrate 100.

[0053] Embodiment 3 See also Figure 6 The present embodiment discloses a cooking utensil, specifically a frying pan, which includes a pot body 5 and a handle 6. The physical non-stick structure in the first embodiment is provided in the bottom area 511 of the inner surface 51 of the pot body 5 of the frying pan. In practical applications, in order to achieve better non-stick performance, the physical non-stick structure can be provided on the entire inner surface 51 of the pot body 5. The present embodiment is only illustrated by a frying pan. In practical applications, the physical non-stick structure can be applied to the surfaces of all cooking utensils, including dining utensils and cooking utensils, including but not limited to containers of cooking utensils (soymilk machine cup body, rice cooker, pressure cooker, electric hot pot liner or oven box, etc.), juicer cup body, shovel, etc.

[0054] Embodiment 4 See also Figure 7 The difference between this embodiment and the third embodiment is that the outer surface 52 of the pot body 5 of this embodiment is also provided with a physical non-stick structure, and the physical non-stick structure is provided at a pot mouth position away from the pot bottom. In practical applications, if the cost is not considered, in order to achieve good non-stick performance of the outer surface 52, the physical non-stick structure can be provided in the entire area of ​​the outer surface 52. Alternatively, the shot peening layer 2 and the convex structure are integrally provided in the pot mouth area 521 of the outer surface 52 of the pot body 5 away from the bottom.

[0055] Embodiment 5 This embodiment also discloses a physical non-stick structure processing method, which is used to process the physical non-stick structure 200 in the first embodiment on the surface of the metal substrate 100. The processing method includes: Forming: processing the metal substrate 100 into a predetermined size and shape; Shot peening: Shot peening is performed on the cut metal substrate 100 or the formed product; 0.6-1 mm steel shot is sprayed at a pressure of 2 MPa-8 MPa for 3 seconds to 5 minutes onto the surface of the metal substrate 100 or the formed product to form a shot peening layer 2 having spherical pits 21; Coating: The shot-peened metal substrate 100 or the formed product is heated to 200° C.-500° C. and placed in a vacuum environment, and the inner surface 51 is subjected to PVD coating.

[0056] Embodiment 6 This embodiment discloses a cooking utensil processing method, which is applicable to the cooking utensil in the third or fourth embodiment. The processing method includes: Forming: processing the metal substrate 100 to form a wok body 5; Shot peening: Shot peening is performed on the inner surface 51 of the pot body 5; 0.6-1 mm steel shot is sprayed at a pressure of 2Mpa-8Mpa for 3 seconds to 5 minutes onto the inner surface 51 of the pot body 5 to form a shot peening layer 2 having spherical pits 21; Electrolysis: Electrolytic processing is performed on the surface of the shot peening layer 2 to form an electrolytic layer 4; Coating: The pot body 5 after electrolysis is heated to 200° C.-500° C. and placed in a vacuum environment, and PVD coating is performed on the inner surface 51 of the pot body.

[0057] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes, modifications, substitutions and variants, and these changes, modifications, substitutions and variants all fall within the scope of the present invention claimed for protection.

Claims

1. A physical non-stick structure (200), applied to the surface of a metal substrate (100), characterized in that: The physical non-stick structure (200) comprises a shot peening layer (2) arranged on the surface of the metal substrate (100) and a physical vapor deposition layer (3) arranged on the surface of the shot peening layer (2), and the morphology of the surface of the physical vapor deposition layer (3) is similar to the morphology of the surface of the shot peening layer (2) covered by it.

2. The physical non-stick structure (200) according to claim 1, characterized in that: The shot peening layer (2) and the metal substrate (100) are an integral structure, and the physical vapor deposition layer (3) is in direct contact with the shot peening layer (2).

3. The physical non-stick structure (200) according to claim 1, characterized in that: An electrolytic layer (4) is also provided between the shot peening layer (2) and the physical vapor deposition layer (3).

4. The physical non-stick structure (200) according to claim 1, characterized in that: A plasma polishing layer is also provided between the shot peening layer (2) and the physical vapor deposition layer (3).

5. The physical non-stick structure (200) according to claim 1, characterized in that: The Vickers hardness of the metal substrate (100) is greater than or equal to 100; the shot peening layer (2) has a plurality of pits (21), the spherical diameter of the pits (21) is 0.3-0.95 mm, preferably 0.4-0.65 mm; the center distance (a) of the pits (21) ranges from 0.3-0.8 mm, preferably 0.6 mm.

6. A cooking utensil, comprising a body formed of a metal substrate (100), characterized in that: The surface of the body is provided with a physical non-stick structure (200) as described in any one of claims 1-5.

7. The cooking device according to claim 6, characterized in that: The shot peening layer (2) is obtained by shot peening the inner surface (51) of the main body after the main body is formed to form a concave-convex structure with a height difference of 45-85 microns, preferably a concave-convex structure with a height difference of 55-75 microns. The thickness of the physical vapor deposition layer (3) is 0.8-1.45 microns.

8. A method for processing a physical non-stick structure (200), characterized in that: Used for processing a physical non-stick structure (200) as described in any one of claims 1 to 5 on the surface of a metal substrate (100), the processing method comprising: Forming: processing the metal substrate (100) into a predetermined size and shape; Shot peening: Shot peening is performed on the cut metal substrate (100) or the formed product to form a shot peening layer (2); Coating: The shot-peened metal substrate (100) or the formed product is heated to 200°C-500°C and placed in a vacuum environment, and PVD coating is performed on the surface of the shot-peened layer (2).

9. A cooking utensil processing method, characterized in that: Applicable to the cooking utensil according to claim 6 or 7, the processing method comprises: Forming: processing the metal substrate (100) to form a cooking utensil body; Shot peening: Shot peening is performed on the inner surface (51) of the main body to form a shot peening layer (2) having spherical pits (21) on the inner surface (51) of the main body; Coating: The shot-peened body is heated to 200° C.-500° C. and placed in a vacuum environment, and the inner surface (51) of the body is subjected to PVD coating.

10. The processing method according to claim 9, characterized in that: An electrolytic or plasma polishing process step is also included between the shot peening and coating steps to form an electrolytic layer (4) or a plasma layer on the surface of the shot peening layer (2).

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