Surface treatment method for mold cavity of precision casting wax mold

Abstract

The invention relates to a surface treatment method for a mold cavity of a precision casting wax mold, which comprises the following steps of: a) correspondingly connecting an upper mold core with a loose piece group, reserving a cavity of a turbine rotor wax mold between the upper mold core and the loose piece group, and arranging a mold sealing line of the upper mold core and the loose piece group on a blade body of the turbine rotor wax mold; and b) carrying out gas mold coating treatment on the loose piece group and the upper mold core, wherein a coating comprises an aluminum-based special hardening and reinforcing layer, a ceramic particle wear-resistant layer and a PETF (Polyethylene Terephthalate) coating. The turbine rotor wax mold is compact and reasonable in structure and convenient to operate, the quality of the turbine rotor wax mold is improved through the improvement of the mold structure, especially the optimization of the position of the film sealing line, and follow-up coating machining is simplified. By means of the design, mold opening is quicker, fewer mold edges are generated, and the overall quality of the turbine rotor wax mold is remarkably improved. Through an innovative coating structure and an optimized processing method, the hardness and the wear resistance of the mold are remarkably improved.

Description

Technical Field

[0001] The invention relates to the technical field of precision casting, in particular to a method for treating the surface of a precision casting wax mold cavity. Background Art

[0002] In the field of aviation turbojet engines, the integral turbine rotor wax model is a key component of the turbine chamber, and its manufacturing accuracy and performance are crucial. Traditionally, the integral turbine rotor wax model is formed using investment casting technology. This process covers mold manufacturing, wax model pressing, shell making, dewaxing, smelting and pouring, post-processing, machining, assembly and testing. Among them, the pressing of the wax model is the core step, and its dimensional accuracy directly determines the accuracy of the turbine rotor wax model casting, which in turn affects the overall performance and reliability of the engine.

[0003] However, existing technologies face multiple challenges in practical applications:

[0004] Mold manufacturing and assembly accuracy limitations: Although investment casting technology itself has a high dimensional accuracy control capability, mold manufacturing and assembly accuracy are still key factors affecting wax mold accuracy. Minor errors in the mold may be magnified during the wax mold pressing process, ultimately affecting the quality of the casting.

[0005] Deformation problem during wax model removal: After the wax pressing process is completed, when the wax model is removed from the mold, the blades are often pulled and deformed due to the surface tension between the blade block group and the wax model. This deformation not only affects the accuracy of the wax model, but will also be inherited to the casting in the subsequent casting process, seriously reducing the aerodynamic efficiency of the engine.

[0006] Limitations of traditional mold materials: At present, S136 heat-treated mold steel is often used in mold manufacturing. Although it has certain strength and heat resistance, it is difficult to machine and has high cost. In addition, its thermal conductivity is uneven, which affects the cooling effect of the wax mold. On the other hand, some mold components such as guide rails are made of brass or copper, while the upper and lower mold blocks are made of 7075 forged aluminum. Although these material choices have their own advantages, the forged aluminum material has the problems of low hardness and poor wear resistance, which directly restricts the quality of the wax mold and the service life of the mold.

[0007] In summary, the inadequacy of mold manufacturing and assembly accuracy, deformation during wax mold removal, limitations of traditional mold materials, and environmental pressure in the existing technology together constitute the technical bottleneck that restricts the improvement of the overall turbine rotor wax mold manufacturing accuracy and performance. Therefore, developing a precision casting wax mold mold cavity surface treatment method that can effectively solve the above problems, improve the wax mold accuracy and performance, and take into account environmental protection and sustainability is of great significance to promoting the advancement of aero-engine technology.

[0008] Therefore, we propose a method for surface treatment of precision casting wax mold cavity. Summary of the invention

[0009] In view of the shortcomings of the above-mentioned existing production technology, the applicant provides a method for surface treatment of the cavity of a precision casting wax mold. The combined effect of these improvement measures makes the manufactured wax mold have high precision and high quality, providing a reliable guarantee for the subsequent casting process.

[0010] The technical solution adopted by the present invention is as follows:

[0011] A method for treating a cavity surface of a precision casting wax mold, comprising:

[0012] a) The upper die core and the movable block group are connected correspondingly, and a cavity of the turbine rotor wax model is reserved between the upper die core and the movable block group, and the sealing line of the upper die core and the movable block group is set on the blade of the turbine rotor wax model;

[0013] b) performing an inflatable coating process on the movable block group and the upper mold core, wherein the coating comprises an aluminum-based special hardening reinforcement layer, a ceramic particle wear-resistant layer and a PETF coating, and the specific coating processing method comprises the following steps;

[0014] S1. Preparation of aluminum-based hardened layer: the upper mold core and loose block completed above are placed in a 3% concentration nitric acid solution for etching, and then rinsed with clean water until neutral;

[0015] S2, oxidation reaction: put the etched mold core and loose block into the electrolytic cell, the electrolyte solution in the electrolytic cell is composed of 20% sulfuric acid, 0.8% oxalic acid, 1% copper sulfate and deionized water, the temperature is 38±2℃; start the electrolytic cell and energize it, the current is 0.5A / dm 2 , voltage 8-12V;

[0016] S3, ceramic particle wear-resistant layer processing: the mold core and the loose block with the hardened layer obtained in S2 are placed on a plasma spraying machine, heated to 210±10°C, and isothermal and isobaric spraying is performed;

[0017] S4, PETF coating processing: spray primer and PETF polymer material on the mold core and loose block with the ceramic wear-resistant layer completed above.

[0018] Furthermore, the mold includes a loose block group, a turbine rotor cavity and an upper mold core, wherein the loose block group is composed of a plurality of loose block monomers, which are rotatably connected to the lower mold through a guide rail to form a structure that can be quickly opened; the loose block group includes a plurality of loose block monomers, which are distributed in a ring to form an annular structure corresponding to the turbine rotor wax mold blade, and each loose block monomer is provided with a first mold cavity and a first groove covering the trailing edge of the turbine rotor wax mold blade.

[0019] Furthermore, the upper mold core is arranged corresponding to the movable block group, and the upper mold core is provided with a plurality of second mold cavities corresponding to the number of turbine rotor wax mold blades, and a second groove covering the leading edge of the turbine rotor wax mold blades, to ensure the precise positioning and molding of the blades in the upper mold core.

[0020] Furthermore, the movable block group and the upper die core and the lower die core are made of 7075 forged aluminum material to reduce the difficulty and cost of mechanical processing and improve thermal conductivity.

[0021] Furthermore, the chemical principle of the oxidation reaction is: Al+H20→AL2O3+H++e-, and the aluminum-based hardened layer obtained by S2 has a thickness of 0.05 to 0.15 μm.

[0022] Furthermore, in the processing of the ceramic particle wear-resistant layer, the sprayed wear-resistant ceramic materials are Al2O3 and TiO2, and the ceramic particle size is 0.05 to 0.15 μm.

[0023] Furthermore, before the PETF coating process, the mold needs to be cleaned, dried, and placed in a PETF coating device to be heated to 350±10 degrees Celsius.

[0024] Furthermore, the total thickness of the gas mold coating is 30±1 μm, and the wear fatigue resistance is greater than 1.9 million times, which significantly improves the service life of the mold.

[0025] Furthermore, it also includes S5, high temperature curing: the mold core and the loose block having completed the above-mentioned PETF coating are heated to 450-460°C for curing, kept warm for 1 hour, cooled to room temperature and then cleaned to obtain the mold core and the loose block having a 30±1μm wear-resistant composite coating.

[0026] The beneficial effects of the present invention are as follows:

[0027] The present invention has a compact and reasonable structure and is easy to operate. Through the improvement of the mold structure, especially the optimization of the sealing line position, it not only improves the quality of the turbine rotor wax mold, but also simplifies the subsequent coating processing. This design makes the mold opening faster and produces less mold edge, which significantly improves the overall quality of the turbine rotor wax mold. Secondly, through the innovative coating structure and optimized processing method, the hardness and wear resistance of the mold are significantly improved. The three-layer design of the aluminum-based hardening layer, the ceramic wear-resistant layer and the PETF coating not only enhances the durability of the mold, but also provides excellent lubrication and demolding properties, reduces wax mold damage, and improves manufacturing accuracy. In short, the surface treatment method of the present invention is effective in improving the quality and performance of the turbine rotor wax mold, plays an important role in promoting the development of aviation turbojet engine technology, and realizes efficient and accurate wax mold manufacturing.

[0028] At the same time, the present invention also has the following advantages:

[0029] Significantly improve the quality and precision of wax models: This embodiment significantly improves the manufacturing precision and performance of turbine rotor wax models by optimizing the mold structure and coating processing method. First, the film sealing line is set on the blade body of the turbine rotor wax model blade, which not only improves the quality of the wax model body, but also facilitates the subsequent coating processing. Secondly, through the design of the movable block group, rapid mold opening is achieved, and mold edges are not easy to produce during the mold opening process, and even if they are produced, they can be easily handled. Furthermore, the three-layer coating structure of the aluminum-based special hardened reinforcement layer, the ceramic particle wear-resistant layer and the PETF coating significantly improves the hardness and wear resistance of the mold, ensuring the stability and precision of the wax model during the manufacturing process. The combined effect of these improvement measures makes the manufactured wax molds have high precision and high quality, providing reliable guarantees for the subsequent casting process.

[0030] Optimize the mold opening process and reduce the risk of damage: The design of the movable block group in this embodiment not only improves the mold opening efficiency, but also reduces the risk of damage to the turbine rotor wax mold during the mold opening process. The movable block unit is rotatably connected to the lower mold through a guide rail. When the mold is opened, it can rotate and slide out along the guide rail, avoiding excessive stress concentration and deformation that may occur in traditional mold opening methods. In addition, since the airflow size requirements at the blade position are relatively low, even if the sealing line is located at the blade position and produces slight marks or mold edges, it will not have a significant impact on the aerodynamic performance of the turbine rotor wax mold. This design not only ensures the convenience of mold opening, but also ensures the overall quality of the turbine rotor wax mold, and improves the manufacturing efficiency and yield rate of the product.

[0031] Extend the service life of the mold and reduce costs: Traditional mold materials such as S136 heat-treated mold steel have the disadvantages of being difficult to machine, high cost and poor thermal conductivity. This embodiment uses 7075 forged aluminum as the mold material. Although the hardness is not high and it is not wear-resistant, the hardness and wear resistance of the mold are significantly improved through the treatment of the three-layer coating structure. The aluminum-based hardened layer forms a dense hardened layer through electrolytic oxidation reaction, the ceramic wear-resistant layer enhances the wear resistance of the mold, and the PETF coating provides good lubricity and demoulding properties. These coatings not only improve the service life of the mold, but also reduce the replacement and maintenance costs caused by mold wear. At the same time, compared with mold steel, forged aluminum materials have the advantages of low difficulty in machining, low cost and high speed, which further reduces the manufacturing cost of the mold. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is an exploded view of the mold in the present invention.

[0033] Figure 2 for Figure 1 Bottom view of .

[0034] Figure 3 It is a cross-sectional view of the mold in the present invention.

[0035] Figure 4 It is the front view of the turbine rotor wax model in the present invention.

[0036] Figure 5 for Figure 1 A partial enlarged view of part A in the middle.

[0037] Figure 6 for Figure 2 A partial enlarged view of part B in the middle.

[0038] Figure 7 It is a schematic diagram of the connection structure between the movable block group and the lower mold in the present invention.

[0039] Figure 8 It is a schematic diagram of the multi-layer coating structure in the medium-sized cavity of the present invention.

[0040] Fig. 9 This is a comparison diagram of heat conduction between 7075 forged aluminum and S136 steel at 20-60°C according to the present invention.

[0041] Fig.10 This is a comparison diagram of the wax mold size of the present invention depending on whether there is a coating in the mold.

[0042] Among them: 100, movable block group; 101, first mold cavity; 102, first groove; 103, guide rail; 200, turbine rotor wax mold; 201, trailing edge; 202, leading edge; 300, upper mold core; 301, second mold cavity; 302, second groove; 400, lower mold. DETAILED DESCRIPTION

[0043] The specific implementation of the present invention is described below in conjunction with the accompanying drawings.

[0044] like Figure 1-Figure 9 As shown, in order to improve the manufacturing accuracy and performance of the turbine rotor wax model, the present embodiment discloses a method for surface treatment of the precision casting wax model mold cavity, which significantly improves the quality of the turbine rotor wax model by improving the mold structure, optimizing the coating processing method, and innovating the coating structure design, thereby improving the overall manufacturing level of the turbine rotor wax model.

[0045] like Figure 1-Figure 6As shown, this embodiment improves the mold structure and sets the film sealing line to the blade body of the turbine rotor wax mold 200 blade. On the one hand, it improves the quality of the turbine rotor wax mold 200 body, and on the other hand, it also facilitates the subsequent coating processing. The wax mold mold structure in this embodiment includes a movable block group 100, a turbine rotor wax mold 200 and an upper mold core 300. The movable block group 100 is composed of a number of movable block monomers, which are screwed out through a guide rail. This design allows the mold opening position to be set at the blade body of the turbine rotor wax mold 200, realizing rapid mold opening, and mold edges are not easily generated during the mold opening process. Even if mold edges are generated, due to the characteristics of the blade body position, they can be easily processed, thereby significantly improving the quality of the turbine rotor wax mold 200.

[0046] The movable block group 100 includes a plurality of movable block monomers. In this embodiment, there are 23 movable block monomers in the movable block group 100. These movable block monomers are rotatably connected to the lower mold 400 through the guide rail 103, and the plurality of movable block monomers are distributed in an annular shape to form an annular structure corresponding to the blades on the turbine rotor wax mold 200. Each movable block monomer is provided with a first mold cavity 101 that fits the bottom surface of the turbine rotor wax mold 200, and the bottom wall of the first mold cavity 101 is provided with a first groove 102 for covering the trailing edge 201 of the blade of the turbine rotor wax mold 200. This design ensures the precise positioning and molding of the trailing edge 201 during the casting process, avoids deformation and dimensional deviation of the trailing edge, and thus improves the overall accuracy and performance of the turbine rotor wax mold.

[0047] The loose block unit is rotatably connected to the rotary groove opened on the lower mold 400 through the guide rail 103. When opening the mold, the loose block group 100 can rotate and slide out along the guide rail 103, realizing a fast and convenient mold opening operation. This design not only improves the mold opening efficiency, but also reduces the risk of damage to the turbine rotor wax mold during the mold opening process, which helps to improve the overall quality and manufacturing efficiency of the product.

[0048] The upper mold core 300 is arranged corresponding to the movable block group 100. Through the contact between the upper mold core 300 and the movable block group 100, a cavity for processing the turbine rotor wax mold 200 is provided. The upper mold core 300 is provided with a plurality of second mold cavities 301 corresponding to the number of blades on the turbine rotor wax mold 200. The second mold cavities 301 fit the upper surface of the blades to ensure the accurate positioning and molding of the blades in the upper mold core 300. At the same time, the upper end of the second mold cavity 301 is provided with a second groove 302 covering the leading edge 202 of the blade of the turbine rotor wax mold 200. This design ensures the accurate positioning and molding of the leading edge 202 during the casting process, avoids deformation and dimensional deviation of the leading edge, and thus improves the overall accuracy and aerodynamic performance of the turbine rotor wax mold.

[0049] After the upper mold core 300 and the movable block group 100 are vertically connected, the sealing line of the two will be located at the blade position of the turbine rotor wax model 200. This design has significant advantages: on the one hand, the airflow size requirements of the blade are not as high as the leading edge 202 and the trailing edge 201, so even if the sealing line produces a slight mark or mold edge at the blade position, it will not have a significant impact on the aerodynamic performance of the turbine rotor wax model; on the other hand, since the blade position is relatively smooth and flat, it is not easy to leave a sealing line. Even if there is a sealing line, it can be easily removed and processed, which reduces the difficulty and cost of subsequent processing and improves the overall quality of the turbine rotor wax model.

[0050] The mold opening movable block group 100 at the blade body can be rotated out parallel to the upper and lower molds. This mold opening method has a lower stress impact on the turbine rotor wax mold 200. Since the movable block group 100 is rotated out parallel to the upper and lower molds during the mold opening process, it is possible to avoid excessive stress concentration and deformation of the turbine rotor wax mold 200, ensure the stability and accuracy of the turbine rotor wax mold during the casting process, improve the manufacturing quality of the turbine rotor wax mold, and reduce the scrap rate.

[0051] like Fig. 9 As shown, the thermal conductivity of 7075 forged aluminum is more uniform, while the thermal conductivity of S136 steel is more concentrated, which is not conducive to heat dissipation. The movable block group 100, the upper die core 300, and the lower die core required by the present invention are 7075 forged aluminum. Compared with mold steel, forged aluminum has the advantages of less difficulty in machining, low cost, and high speed, so the mold cost is low. At the same time, the thermal conductivity of aluminum-based materials is faster than that of steel molds, and the heat conduction is more uniform, so that when the wax mold is cooled from 60°C to 22°C, it cools faster and more evenly. However, forged aluminum materials also have the disadvantages of low hardness and poor wear resistance.

[0052] like Figure 7 As shown, the completed mold block group 100 has an upper and lower mold core part that is subjected to an air mold coating. The coating consists of three layers: an aluminum-based special hardened reinforcement layer, a ceramic particle wear-resistant layer, and a PETF coating. The thickness is 30±1μm, and the wear fatigue resistance is greater than 1.9 million times, which is much greater than the design life of the mold (20,000 times). This coating can solve the shortcomings of the above steps, such as low hardness and poor wear resistance.

[0053] At the same time, in this embodiment, by setting the sealing line on the blade body, after the coating is set in the cavity, it can be ensured that the coating covers the leading edge and the trailing edge of the turbine rotor wax mold 200 more evenly in the cavity, thereby improving the overall effect and durability of the coating. That is, if the sealing line is located at the leading edge and the trailing edge of the turbine rotor wax mold 200, the leading edge and the trailing edge of the turbine rotor wax mold 200 cannot be evenly attached to the coating of the cavity during processing, thereby affecting the actual effect. Fig.10 As shown, Fig.10The left picture shows that there is no coating in the cavity, so the edge size accuracy of the wax model is poor. The right picture shows that after multiple layers of coating are set in the cavity, its shape is more symmetrical and the effect is better.

[0054] Moreover, due to the reduction of stress, deformation caused by excessive stress is avoided, ensuring the stability and accuracy of the turbine rotor wax model 200 during the casting process, thereby improving the bonding strength between the coating and the substrate.

[0055] By improving the material to optimize the heat dissipation performance, the thermal conductivity of 7075 forged aluminum is more uniform than that of traditional mold steel, allowing the wax mold to reach the required temperature faster and more evenly during the cooling process, thereby improving the manufacturing quality of the turbine rotor wax mold.

[0056] An air-filled coating is applied on the surface of the movable block group 100 to increase hardness and wear resistance. The specific coating processing method includes the following steps:

[0057] S1: Aluminum-based hardened layer, the upper mold core 300 and the movable block group 100 are placed in a 3% nitric acid solution for etching, and then rinsed with clean water until neutral. This step can remove impurities and oxides on the mold surface, providing a clean surface for subsequent electrolytic oxidation.

[0058] S2: Electrolytic oxidation, put the etched upper mold core 300 and the loose block group 100 into the electrolytic tank, the electrolyte solution in the electrolytic tank is composed of 20% sulfuric acid, 0.8% oxalic acid, 1% copper sulfate and deionized water, the temperature is 38±2℃. Start the electrolytic tank and energize it, the current is 0.5A / dm 2 , voltage 8-12V. Electrolytic oxidation. Its chemical principle is

[0059] Al+H20→AL2O3+H++e-

[0060] Through electrolytic oxidation reaction, a dense aluminum-based hardened layer with a thickness of 0.05 to 0.15 μm is formed on the mold surface. This hardened layer can significantly improve the hardness and wear resistance of the mold;

[0061] S3: Ceramic wear-resistant layer processing. The upper mold core 300 and the movable block group 100 with a hardened layer obtained in S2 are placed on a plasma spraying machine, heated to 210±10°C, and isothermal and isobaric spraying is performed. The sprayed wear-resistant ceramic materials are AL2O3 and TiO2, and the ceramic particle size is 0.05-0.15μm. This layer of ceramic wear-resistant layer can further enhance the wear resistance of the mold and extend the service life of the mold.

[0062] S4: PETF coating processing; the upper mold core 300 and the movable block group 100 with the ceramic wear-resistant layer completed above are cleaned and dried, and then placed in a PETF coating device for heating to 350±10 degrees Celsius, sprayed with primer, and sprayed with PETF polymer material. The PETF coating has good lubricity and demoulding properties, which can reduce the friction between the wax mold and the mold, and reduce damage and deformation during the demoulding process.

[0063] S5: curing treatment; the upper mold core 300 and the movable block group 100 which have completed the above-mentioned PETF coating are heated to 450-460°C for curing, kept warm for 1 hour, cooled to room temperature and then cleaned to obtain the upper mold core 300 and the movable block group 100 having a 30±1μm wear-resistant composite coating. Through the curing treatment, the coating can be more firmly attached to the mold surface, the stability and durability of the coating can be improved, and the quality and precision of the wax model can be significantly improved.

[0064] The aluminum-based special hardened reinforcement layer is the first layer of the coating structure. Its main function is to enhance the hardness and wear resistance of the mold substrate. A dense aluminum-based hardened layer is formed on the mold surface through electrolytic oxidation reaction. This hardened layer can effectively resist the friction and wear of the wax mold during the manufacturing process and extend the service life of the mold.

[0065] The ceramic particle wear-resistant layer is the second layer of the coating structure, and its main function is to further improve the wear resistance of the mold. Wear-resistant ceramic materials AL2O3 and TiO2 are sprayed on the mold surface through plasma spraying technology to form a uniform ceramic wear-resistant layer. This ceramic wear-resistant layer has excellent wear resistance and high temperature stability, and can maintain stable performance under high temperature and high pressure environments, ensuring the accuracy and quality of the wax model.

[0066] PETF coating is the third and final layer of the coating structure. Its main function is to provide good lubricity and demoulding properties, reduce the friction between the wax model and the mold, and reduce damage and deformation during demoulding. PETF coating has good chemical stability and thermal stability, and can maintain stable performance at high temperatures, ensuring smooth demoulding and high quality of the wax model.

[0067] Improve the hardness and wear resistance of the mold. Through the treatment of the aluminum-based special hardening reinforcement layer and the ceramic particle wear-resistant layer, the hardness and wear resistance of the mold have been significantly improved. This can not only extend the service life of the mold, but also reduce the damage and deformation of the mold during the manufacturing process, and improve the accuracy and quality of the wax mold.

[0068] By using the processing method of the present application, the surface roughness of the integral turbine rotor wax mold 200 model obtained is Ra1.6, and the surface contour of the flow channel and blade wax mold meets the requirement of 0.1mm, which is a major breakthrough in the precision casting of integral turbine blade castings of aircraft engines.

[0069] The application of the present invention adopts forged aluminum to replace the use of die steel, which greatly reduces the die cost.

[0070] The demoulding difficulty and damage are reduced. The PETF coating has good lubricity and demoulding properties, which can reduce the friction between the wax model and the mold, and reduce the damage and deformation during the demoulding process. The wax model processed by the present invention does not require a demoulding machine, which reduces the cleaning of the demoulding agent and the treatment of the generated wastewater, and reduces the pollution to the environment.

[0071] The wax model quality and precision are improved. The molds processed by the coating processing method can produce high-precision and high-quality wax models. These wax models can maintain stable shapes and sizes in the subsequent casting process, ensuring the overall manufacturing quality of the turbine rotor wax model. The wax model processed by the present invention has better surface finish due to the absence of mold release agents, which is convenient for the subsequent shell coating slurry.

[0072] Environmentally friendly and pollution-free, the polymer composite coating used in the present invention is a food-grade polymer material, which is non-toxic and tasteless and will not cause environmental pollution. At the same time, the processed wax mold can be easily separated from the mold without a demolding machine. This feature greatly reduces the waste and chemical residues that may be generated in the traditional demolding process, further reflecting the environmental advantages of the present invention. During the entire life cycle of production and use, the polymer composite coating material can maintain a high degree of stability and safety, will not release harmful substances into the environment, and is harmless to the soil, water and air, which is in line with the current global pursuit of green and sustainable development.

[0073] In addition, the easy demoulding property of wax models not only saves the use of release agents, but also reduces the wastewater treatment and discharge problems caused by them, and reduces the risk of water pollution. This innovative technology reduces the pressure of manufacturing on the environment from the source and provides strong support for the realization of clean production and circular economy.

[0074] What is more worth mentioning is that the polymer composite coating of the present invention has good recyclability. After the product life cycle ends, it can be reused through appropriate recycling processes to form a closed-loop resource recycling system, minimizing resource waste and environmental burden. This is in sharp contrast to the difficult-to-degrade or recyclable materials commonly used in traditional manufacturing methods, demonstrating the positive contribution of the present invention in promoting the industry's transformation to a more environmentally friendly and low-carbon future.

[0075] In summary, the application of the present invention can not only improve production efficiency and reduce costs, but more importantly, its environmentally friendly and pollution-free characteristics provide a practical solution for protecting the earth's ecological environment and promoting harmonious coexistence between man and nature. It is an important direction for the future development of materials science and manufacturing technology.

[0076] The above description is an explanation of the present invention, not a limitation of the present invention. The scope of the present invention is defined in the claims. Any form of modification may be made within the scope of protection of the present invention.

Claims

1. A method for surface treatment of a precision casting wax mold cavity, characterized in that: include: a) The upper die core and the movable block group are connected correspondingly, and a cavity of the turbine rotor wax model is reserved between the upper die core and the movable block group, and the sealing line of the upper die core and the movable block group is set on the blade of the turbine rotor wax model; b) performing an inflatable coating process on the movable block group and the upper mold core, wherein the coating comprises an aluminum-based special hardening reinforcement layer, a ceramic particle wear-resistant layer and a PETF coating, and the specific coating processing method comprises the following steps; S1. Preparation of aluminum-based hardened layer: Place the upper mold core and loose block completed above into a 3% nitric acid solution for etching, and then rinse with clean water until neutral; S2, oxidation reaction: put the etched mold core and loose block into the electrolytic cell, the electrolyte solution in the electrolytic cell is composed of 20% sulfuric acid, 0.8% oxalic acid, 1% copper sulfate and deionized water, the temperature is 38±2℃; start the electrolytic cell and energize it, the current is 0.5A / dm 2 , voltage 8-12V; S3, ceramic particle wear-resistant layer processing: the mold core and the loose block with the hardened layer obtained in S2 are placed on a plasma spraying machine, heated to 210±10°C, and isothermal and isobaric spraying is performed; S4, PETF coating processing: spray primer and PETF polymer material on the mold core and loose block with the ceramic wear-resistant layer completed above.

2. A method for surface treatment of a precision casting wax mold cavity according to claim 1, characterized in that: The mold includes a loose block group, a turbine rotor cavity and an upper mold core, wherein the loose block group is composed of a plurality of loose block monomers, which are rotatably connected to the lower mold through a guide rail to form a structure that can be quickly opened; the loose block group includes a plurality of loose block monomers, which are distributed in a ring to form an annular structure corresponding to the turbine rotor wax mold blade, and each loose block monomer is provided with a first mold cavity and a first groove covering the trailing edge of the turbine rotor wax mold blade.

3. A method for treating the surface of a precision casting wax mold cavity according to claim 1, characterized in that The upper mold core is arranged corresponding to the movable block group. The upper mold core is provided with a plurality of second mold cavities corresponding to the number of turbine rotor wax mold blades, and a second groove covering the leading edge of the turbine rotor wax mold blades, to ensure the precise positioning and molding of the blades in the upper mold core.

4. A method for treating the surface of a precision casting wax mold cavity according to claim 1, characterized in that The movable block group and the upper die core and the lower die core are made of 7075 forged aluminum material to reduce the difficulty and cost of mechanical processing and improve thermal conductivity.

5. The method for surface treatment of a precision casting wax mold cavity according to claim 1, characterized in that: The chemical principle of the oxidation reaction is: Al+H20→AL2O3+H++e-, and the aluminum-based hardened layer obtained by S2 has a thickness of 0.05 to 0.15 μm.

6. A method for treating the surface of a precision casting wax mold cavity according to claim 5, characterized in that: In the processing of the ceramic particle wear-resistant layer, the sprayed wear-resistant ceramic materials are Al2O3 and TiO2, and the ceramic particle size is 0.05-0.15 μm.

7. The method for treating the surface of a precision casting wax mold cavity according to claim 5, characterized in that: Before the PETF coating process, the mold needs to be cleaned, dried, and placed in a PETF coating device to be heated to 350±10 degrees Celsius.

8. The method for surface treatment of a precision casting wax mold cavity according to claim 1, characterized in that: The total thickness of the gas mold coating is 30±1 μm, and the wear fatigue resistance is greater than 1.9 million times, which significantly improves the service life of the mold.

9. The method for treating the surface of a precision casting wax mold cavity according to claim 1, characterized in that: The process also includes S5, high temperature curing: heating the mold core and the loose block having the above PETF coating to 450-460°C for curing, keeping the temperature for 1 hour, cooling to room temperature and then cleaning to obtain the mold core and the loose block having a 30±1μm wear-resistant composite coating.

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