Processing and preparing method of novel functional ceramic impeller

Abstract

The invention discloses a processing and preparing method of a novel functional ceramic impeller, and relates to the technical field of impeller processing, and the processing and preparing method comprises the following steps: step S2, simulating injection molding processing of a ceramic impeller; s3, a hub raw material and a blade raw material are sequentially injected into the mold through the injection molding channel, and gradient machining is conducted on a hub and blades of the impeller; and S4, the hub and blade raw materials in the mold in the step S3 are cooled and solidified through a cooling loop, and the hub and blade raw materials are cooled and solidified from the far-end position of the blade to the connecting interface of the hub and the blade. High-pressure gas is injected into the junction of the hub and the impeller in the mold cavity through the gas inlet channel, a gas film is formed, the impeller raw material and the hub raw material are blocked, and the impeller raw material and the hub raw material in the mold are cooled and solidified through the multiple cooling loops correspondingly; and gradually cooling the blade raw material and the hub raw material towards the connecting interface, and performing injection molding to form the whole ceramic impeller.

Description

Technical Field

[0001] This invention relates to the field of impeller processing technology, and in particular to a method for processing and preparing a novel functional ceramic impeller. Background Technology

[0002] Ceramic impellers are impellers made using advanced engineering ceramic materials. Through fundamental innovations in materials science, they break through the performance bottlenecks of traditional metal impellers. By using ceramic raw materials, they achieve longer service life, extremely low maintenance frequency, and higher system reliability, thereby achieving lower overall costs and higher safety benefits throughout the product's life cycle.

[0003] In the common production and manufacturing of ceramic impellers, injection molding, isostatic pressing, and additive manufacturing are commonly used processing methods. Among them, injection molding involves injecting fluid raw materials into the cavity of an impeller injection mold, and then cooling and solidifying them to obtain the impeller blank. However, current injection molding processes often use the same raw material for processing. In order to ensure the overall strength of the ceramic impeller and the hub connecting it to the motor shaft, high-strength materials are usually used. The use of high-strength materials also increases the overall mass of the impeller. The increased weight of the impeller can easily increase the inertial force experienced by the impeller during operation, accelerate the wear of the impeller, and reduce its service life. Summary of the Invention

[0004] The purpose of this invention is to provide a novel method for processing and preparing functional ceramic impellers to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a method for processing and preparing a novel functional ceramic impeller, comprising the following steps:

[0006] Step S1: Weigh the raw materials for hub preparation according to the proportion, and weigh the raw materials for blade preparation according to the proportion;

[0007] Step S2: Simulate the injection molding process of the ceramic impeller, simulate the advancement process of the melt front in the cavity, predict the location of cavitation, guide the venting settings, and analyze the pressure holding, cooling solidification, stress changes and sintering during the injection molding process;

[0008] Step S3: Based on the simulation and analysis results in Step S2, set up the ceramic impeller injection mold and perform injection molding. Set up the injection dual flow channel, air intake channel, cooling circuit and exhaust channel on the mold. Inject hub preparation material into the mold through the injection channel to fill the hub area of ​​the mold. Inject high pressure nitrogen gas into the connection between the hub and the blade through the air intake channel to form a gas film at the connection interface to separate the hub preparation material and the blade preparation material. Then inject blade preparation material into the blade area of ​​the mold through the injection channel to perform gradient processing on the hub and blade of the impeller.

[0009] Step S4: The hub and blade raw materials in the mold in step S3 are cooled and solidified through the cooling circuit. The cooling and solidification proceeds from the far end of the blade to the interface between the hub and the blade, so that the hub raw materials and blade raw materials are mixed and connected at the interface. After demolding, the ceramic impeller is sintered.

[0010] Step S5: Perform laser ablation on a localized area of ​​the formed impeller surface from step S4, and then apply a coating to the impeller surface.

[0011] Preferably, the raw material ratio for the ceramic impeller in step S1 includes the following steps:

[0012] Step S11: Weigh alumina according to the proportion as the raw material for preparing the impeller hub, add 1%-5% chromium oxide to it, disperse the raw material powder in an organic solvent containing a monomer crosslinking agent to form a hub slurry for injection molding.

[0013] Step S12: Weigh alumina according to the proportion as the raw material for preparing impeller blades, add 1%-2% chromium oxide to it, disperse the raw material powder in an organic solvent containing a monomer crosslinking agent to form a blade slurry for injection molding.

[0014] Preferably, the injection molding simulation of the ceramic impeller in step S2 includes the following steps:

[0015] Step S21: By cleaning and repairing the geometry of the impeller CAD model, removing minor features, and establishing a three-dimensional model of the injection molding mold cavity based on the impeller model;

[0016] Step S22: Obtain rheological data, PVT data and thermophysical property data of the specific batch of feed through experiments, and perform numerical calculations using Moldex3D simulation software based on the set physical model;

[0017] Step S23: Use visualization tools to analyze the model and data from step S22, identify the location and cause of defects in the injection mold, and calibrate and verify the simulation model through actual trial molding results.

[0018] Preferably, the model creation of the injection mold in step S21 includes the following steps:

[0019] Step S211: Import the mold cavity model using CAD software, divide the geometry into multiple micro-units using 3D solid mesh, and perform precise analysis on the model;

[0020] Step S212: Obtain rheological data, PVT data and thermophysical data of the raw material during the injection molding process through experiments. Combine the raw material data and injection mold model to set the parameters of injection time and speed, melt temperature, mold temperature and holding pressure curve.

[0021] Step S213: Accurately model the cooling water system and gating system by importing the runner, gate, and cooling water path into the software.

[0022] Preferably, the model and data analysis in step S23 includes the following steps:

[0023] Step S231: Simulate the advancement process of the melt front in the cavity, predict the location of air cavities in the mold cavity, set up the exhaust channel, and predict the junction of the hub and the blade.

[0024] Step S232: After the raw material is filled, the cooling shrinkage process is compensated by continuously applying pressure to predict the pressure distribution, density change and subsequent volume shrinkage in the cavity;

[0025] Step S233: Simulate the change of mold temperature field over time, evaluate the efficiency and uniformity of the cooling system, predict the temperature distribution of the parts, and set up the mold cooling circuit.

[0026] Step S234: Based on the analysis results of steps S231 to S233, a custom material model is coupled using finite element software to simulate the densification process of powder particles through diffusion mechanism at high temperature.

[0027] Preferably, the mold setting in step S3 includes the following steps:

[0028] Step S31: Based on the modeling of the imported runner in step S213, set up a dual runner on the mold for injection molding, which is used for the wheel hub material and the blade material to be injected into the mold cavity respectively;

[0029] Step S32: Based on the location of the cavitation in step S231, an exhaust channel system is set on the mold, and an air intake channel is opened at the junction of the hub and the blade, so that high-pressure nitrogen is injected into the junction of the hub and the blade in the cavity to form a barrier gas film.

[0030] Step S33: Based on the component temperature distribution in step S233, multiple cooling circuits are embedded in the mold to provide gradient cooling for the mold, gradually cooling and solidifying from the far end of the blade to the hub and blade connection interface.

[0031] Preferably, the gradient injection molding process in step S3 includes the following steps:

[0032] Step S34: Inject the wheel hub material into the cavity through the injection channel at the wheel hub of the mold, filling the preset volume of the wheel hub cavity, in a state of incomplete filling;

[0033] Step S35: High-pressure nitrogen gas is immediately injected into the molten leading edge area of ​​the wheel hub material through the air inlet channel on the mold. The gas pushes the wheel hub material to continue to flow forward, and at the same time, a gas-melt interface is formed between the gas and the wheel hub material.

[0034] Step S36: While injecting high-pressure nitrogen, inject impeller material through the injection channel at the impeller of the mold. The front edge of the impeller material melt meets the gas, and the gas film is used to block the impeller material and the hub material, forming a buffer area between the impeller material and the hub material.

[0035] Step S37: As the impeller material is continuously injected, the gas is compressed and discharged from the mold through the preset exhaust channel. After the gas is completely discharged, the melt fronts of the hub material and the blade material contact, fuse and solidify at the connection interface under pressure.

[0036] Step S38: After the impeller material is injected, the cooling circuit is turned on sequentially from the far end of the blade and the cooling circuit at the hub, so that the blade material and the hub material are cooled in a gradient towards the interface between them, thus completing the cooling and solidification of the hub and the impeller.

[0037] Preferably, the sintering treatment of the ceramic impeller in step S4 includes the following steps:

[0038] Step S41: By immersing the demolded ceramic impeller blank in trichloroethylene organic solvent, the soluble binder component is dissolved and extracted, forming interconnected capillary channels within the blank.

[0039] Step S42: Place the degreased ceramic impeller blank on a refractory sintering plate and sinter it in a high-temperature furnace under normal pressure.

[0040] Preferably, the surface treatment of the ceramic impeller in step S5 includes the following steps:

[0041] Step S51: Use a high-energy laser beam to soften the uneven areas on the surface of the ceramic impeller, and then use a grinding tool to smooth the area.

[0042] Step S52: The surface of the ceramic impeller is subjected to wear-resistant processing by preparing a titanium nitride thin film on the surface of the ceramic impeller.

[0043] Preferably, the ceramic impeller injection mold in step S includes:

[0044] Upper mold;

[0045] The lower mold is positioned below the upper mold, and the positions of the lower mold and the upper mold are corresponding.

[0046] The injection molding dual runner is set on the upper mold, and the injection dual runner is used for the injection of hub material and impeller material respectively;

[0047] The exhaust port is provided on the upper mold and is located at the junction of the hub and the blade.

[0048] A gas needle valve is fixedly installed on the upper mold and is located at the junction of the hub and the blade.

[0049] Liquid cooling pipes are fixedly embedded in the bottom of the lower mold, and the liquid cooling pipes are arranged in a straight line at intervals.

[0050] The technical effects and advantages of this invention are as follows:

[0051] This invention injects high-pressure gas into the junction of the hub and impeller in the mold cavity through an air intake channel, forming an air film that isolates the impeller and hub raw materials. Multiple cooling circuits are used to cool and solidify the impeller and hub raw materials separately within the mold, allowing them to gradually cool towards the interface. The two materials contact, fuse, and solidify at the interface, forming a single ceramic impeller through injection molding. This achieves gradient processing of the ceramic impeller. Using raw materials with different chromium oxide contents to prepare the hub and blades ensures the impeller's integrity while reducing its mass, achieving lightweight manufacturing. Using hub raw materials with high chromium oxide content ensures high strength and toughness, ensuring a stable connection between the hub and the motor shaft. Using blade raw materials with low chromium oxide content achieves lightweight blades, reducing the overall mass of the ceramic impeller. Attached Figure Description

[0052] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention, but do not constitute a limitation thereof. In the drawings:

[0053] Figure 1 This is a schematic diagram of the ceramic impeller processing and manufacturing process of the present invention;

[0054] Figure 2 This is a schematic diagram of the raw material proportioning process for the ceramic impeller of the present invention;

[0055] Figure 3 This is a schematic diagram of the injection molding process simulation of the present invention;

[0056] Figure 4 This is a schematic diagram of the process for establishing the injection mold model of the present invention;

[0057] Figure 5 This is a schematic diagram of the model and data analysis process of the present invention;

[0058] Figure 6 This is a schematic diagram of the mold setup process of the present invention;

[0059] Figure 7 This is a schematic diagram of the gradient injection molding process of the present invention;

[0060] Figure 8 This is a schematic diagram of the upper mold structure of the present invention;

[0061] Figure 9 This is a front cross-sectional view of the gas needle valve of the present invention.

[0062] Figure 10 This is a front cross-sectional view of the exhaust port of the present invention;

[0063] Figure 11 This is a top sectional view of the liquid cooling pipeline structure of the present invention.

[0064] In the attached image:

[0065] 1. Upper mold 1; 2. Lower mold; 3. Injection double runner; 4. Vent hole; 5. Gas needle valve; 6. Liquid cooling pipeline. Detailed Implementation

[0066] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0067] This invention provides, for example Figures 1-7 The method for processing and preparing a novel functional ceramic impeller, as shown, includes the following steps:

[0068] Step S1: Weigh the raw materials for hub preparation according to the proportion, and weigh the raw materials for blade preparation according to the proportion;

[0069] Step S2: Simulate the injection molding process of the ceramic impeller, simulate the advancement process of the melt front in the cavity, predict the location of cavitation, guide the venting settings, and analyze the pressure holding, cooling solidification, stress changes and sintering during the injection molding process;

[0070] Step S3: Based on the simulation and analysis results in Step S2, set up the ceramic impeller injection mold and perform injection molding. Set up a dual flow channel, air intake channel, cooling circuit and exhaust channel on the mold. The injection molding machine injects hub preparation material into the mold through the injection channel to fill the hub area of ​​the mold. High-pressure nitrogen is injected into the connection between the hub and the blade through the air intake channel to form a gas film at the connection interface to separate the hub preparation material and the blade preparation material. Then, the blade preparation material is injected into the blade area of ​​the mold through the injection channel to perform gradient processing on the hub and blade of the impeller.

[0071] Step S4: The hub and blade raw materials in the mold in step S3 are cooled and solidified through the cooling circuit. The cooling and solidification proceeds from the far end of the blade to the interface between the hub and the blade, so that the hub raw materials and blade raw materials are mixed and connected at the interface. After demolding, the ceramic impeller is sintered.

[0072] Step S5: Perform laser ablation on a localized area of ​​the formed impeller surface from step S4, and then apply a coating to the impeller surface.

[0073] By setting an air intake channel on the ceramic impeller injection mold, high-pressure gas is injected into the junction of the hub and impeller in the mold cavity through the air intake channel to form an air film, which isolates the impeller material and the hub material. Multiple cooling circuits are used to cool and solidify the impeller material and the hub material in the mold separately, so that the blade material and the hub material are gradually cooled towards the interface. The two materials contact, fuse and solidify at the interface, and the ceramic impeller is formed by injection molding. The ceramic impeller is subjected to gradient processing. The hub material with high chromium oxide content is used to ensure high strength and high toughness of the hub, so that the hub is stably connected to the motor shaft. The blade material with low chromium oxide content is used to achieve lightweight blades, reduce the overall mass of the ceramic impeller, reduce rotational inertia, improve energy efficiency and dynamic response, and reduce the load on the bearings and shaft.

[0074] The raw material ratio for the ceramic impeller in step S1 includes the following steps:

[0075] Step S11: Weigh alumina according to the proportion as the raw material for preparing the impeller hub, add 1%-5% chromium oxide to it, disperse the raw material powder in an organic solvent containing a monomer crosslinking agent to form a hub slurry for injection molding.

[0076] Step S12: Weigh alumina according to the proportion as the raw material for preparing impeller blades, add 1%-2% chromium oxide to it, disperse the raw material powder in an organic solvent containing a monomer crosslinking agent to form a blade slurry for injection molding.

[0077] Chromium corundum material is a high-performance pink or rose-red artificial abrasive and refractory material made by adding a certain proportion of chromium oxide to white corundum. It has high wear resistance and high toughness. It is used to prepare impeller hubs, improve the strength and wear resistance of the hubs, ensure the stable connection between the impeller hub and the motor shaft, and greatly improve the durability and service life of the impeller. Chromium corundum powder with different chromium oxide contents is dispersed in an organic solvent containing a monomer crosslinking agent to form hub slurry and blade slurry with high solid content and low viscosity. After being injected into a mold, monomer polymerization is initiated by an initiator, causing the slurry to solidify in situ into a high-strength wet blank.

[0078] The injection molding simulation of the ceramic impeller in step S2 includes the following steps:

[0079] Step S21: By cleaning and repairing the geometry of the impeller CAD model, removing minor features, and establishing a three-dimensional model of the injection molding mold cavity based on the impeller model;

[0080] Step S22: Obtain rheological data, PVT data and thermophysical property data of the specific batch of feed through experiments, and perform numerical calculations using Moldex3D simulation software based on the set physical model;

[0081] Step S23: Use visualization tools to analyze the model and data from step S22, identify the location and cause of defects in the injection mold, and calibrate and verify the simulation model through actual trial molding results.

[0082] Rheological data is a series of quantitative data obtained by applying controllable stress or strain to a material using a rheometer and measuring its response. It is used to reveal the viscosity and elasticity of a material. PVT data is a collective term for pressure, volume, and temperature, reflecting the change in the specific volume of a unit mass of polymer under different pressures and temperatures. Thermophysical property data is a set of core parameters describing the basic properties of a material's heat storage, conduction, and change. The entire process of Moldex3D model flow analysis includes creating groups, importing models, setting materials and molding conditions, performing analysis, and post-processing. Creating groups is done by opening Moldex3D Studio and selecting "Add". Importing models is done by selecting "Import Geometry" in the "Model" tab on the home page and selecting the geometry file to be imported. Setting materials and molding conditions is done by adding materials, returning to the home page, and selecting the corresponding material data. Performing analysis is done by returning to the home page, calculating parameters and performing analysis, with the default values ​​used automatically. Post-processing is done by viewing the analysis results. After all analysis work is completed, the newly added project will appear in the results branch under the project tree diagram for viewing.

[0083] Step S21, the creation of the injection mold model, includes the following steps:

[0084] Step S211: Import the mold cavity model using CAD software, divide the geometry into multiple micro-units using 3D solid mesh, and perform precise analysis on the model;

[0085] Step S212: Obtain rheological data, PVT data and thermophysical data of the raw material during the injection molding process through experiments. Combine the raw material data and injection mold model to set the parameters of injection time and speed, melt temperature, mold temperature and holding pressure curve.

[0086] Step S213: Accurately model the cooling water system and gating system by importing the runner, gate, and cooling water path into the software.

[0087] By using the cavity command in CAD software, cavities are cut out from the mold block using the product model to create the mold cavity. In the main assembly or mold part, the main runner, branch runner, and gate are modeled using solid models, and the cooling water channel is modeled using solid cylindrical tubes. The model is then saved by selecting the desired format. Moldex3D software is opened, a new project is created, the model is imported, and small features are detected and removed using Moldex3D software. In the laboratory, instruments such as capillary rheometer, thermal analyzer, and densitometer are used to conduct fluid mechanics, heat transfer, and solid mechanics experiments on the hub and blade raw materials to obtain rheological data, PVT data, and thermophysical property data of the raw materials, providing a data foundation for the simulation of ceramic impeller injection molding.

[0088] Step S23, model and data analysis, includes the following steps:

[0089] Step S231: Simulate the advancement process of the melt front in the cavity, predict the location of air cavities in the mold cavity, set up the exhaust channel, and predict the junction of the hub and the blade.

[0090] Step S232: After the raw material is filled, the cooling shrinkage process is compensated by continuously applying pressure to predict the pressure distribution, density change and subsequent volume shrinkage in the cavity;

[0091] Step S233: Simulate the change of mold temperature field over time, evaluate the efficiency and uniformity of the cooling system, predict the temperature distribution of the parts, and set up the mold cooling circuit.

[0092] Step S234: Based on the analysis results of steps S231 to S233, a custom material model is coupled using finite element software to simulate the densification process of powder particles through diffusion mechanism at high temperature.

[0093] Simulation of ceramic impeller injection molding is a highly complex multi-physics, multi-scale, and nonlinear process. It is a virtual experimental platform that deeply integrates materials science, fluid mechanics, heat transfer, and solid mechanics. Before expensive mold manufacturing and actual mold trials, computer models can accurately predict and optimize the entire molding process to ensure high-quality, defect-free green blanks, thereby reducing development costs and risks. Based on experimental data and models, the simulation of fluid motion, heat transfer, and pressure changes of impeller hub and blade raw materials in the mold cavity is used to analyze the filling, holding pressure, cooling, and warpage deformation of raw materials during impeller injection molding, providing an experimental basis for mold design.

[0094] Step S3, mold setup, includes the following steps:

[0095] Step S31: Based on the modeling of the imported runner in step S213, set up a dual runner on the mold for injection molding, which is used for the wheel hub material and the blade material to be injected into the mold cavity respectively;

[0096] Step S32: Based on the location of the cavitation in step S231, an exhaust channel system is set on the mold, and an air intake channel is opened at the junction of the hub and the blade, so that high-pressure nitrogen is injected into the junction of the hub and the blade in the cavity to form a barrier gas film.

[0097] Step S33: Based on the component temperature distribution in step S233, multiple cooling circuits are embedded in the mold to provide gradient cooling for the mold, gradually cooling and solidifying from the far end of the blade to the hub and blade connection interface.

[0098] Based on the simulation results of ceramic impeller injection molding, a dual flow channel for the injection of hub and blade raw materials is opened on the mold to facilitate the sequential injection of the two materials into the mold cavity. Vent holes 4 are set according to the location of air cavities in the mold cavity to ensure complete exhaust of gas during injection. Simultaneously, an air inlet channel is opened at the junction of the hub and blade in the mold cavity to install a gas needle valve 5, facilitating gas injection into the cavity. A barrier gas film is formed at the junction of the hub and blade raw materials. Multiple sets of liquid cooling pipes 6 are installed at the bottom of the mold to form multiple cooling circuits. By utilizing the operation of cooling circuits at different locations, different parts of the mold are cooled, achieving gradient cooling of the hub and blade raw materials. This ensures that the hub and blade raw materials are completely mixed at the junction before cooling, improving the stability of the hub-blade connection. Through this highly controllable gradient cooling in space and time, a high-quality ceramic impeller green body with high dimensional accuracy, low residual stress, controllable microstructure, and minimal deformation after debinding and sintering is obtained.

[0099] Step S3, gradient injection molding, includes the following steps:

[0100] Step S34: Inject the wheel hub material into the cavity through the injection channel at the wheel hub of the mold, filling the preset volume of the wheel hub cavity, in a state of incomplete filling;

[0101] Step S35: High-pressure nitrogen gas is immediately injected into the molten leading edge area of ​​the wheel hub material through the air inlet channel on the mold. The gas pushes the wheel hub material to continue to flow forward, and at the same time, a gas-melt interface is formed between the gas and the wheel hub material.

[0102] Step S36: While injecting high-pressure nitrogen, inject impeller material through the injection channel at the impeller of the mold. The front edge of the impeller material melt meets the gas, and the gas film is used to block the impeller material and the hub material, forming a buffer area between the impeller material and the hub material.

[0103] Step S37: As the impeller material is continuously injected, the gas is compressed and discharged from the mold through the preset exhaust channel. After the gas is completely discharged, the melt fronts of the hub material and the blade material contact, fuse and solidify at the connection interface under pressure.

[0104] Step S38: After the impeller material is injected, the cooling circuit is turned on sequentially from the far end of the blade and the cooling circuit at the hub, so that the blade material and the hub material are cooled in a gradient towards the interface between them, thus completing the cooling and solidification of the hub and the impeller.

[0105] The hub material is injected into the mold cavity through one of the dual runners on the injection mold, filling the cavity. When the cavity is 90% full, high-pressure nitrogen is injected into the cavity through the gas needle valve 5 in the air inlet channel of the mold. The high-pressure gas forms a barrier gas film at the interface between the hub material and the blade material. At the same time, blade material is injected into the mold cavity through the other injection port of the dual runner, filling the cavity. When the blade material contacts the gas film, the cooling circuit at the bottom of the mold is activated, causing the blade material and hub material to gradually cool towards their interface. As hub material and blade material are continuously injected, the gas at the interface between the blade and the hub is squeezed out, causing them to fuse and solidify at the interface. Finally, the interface between the hub and the blade is cooled and solidified, achieving gradient processing of the ceramic impeller. By using materials with different contents to prepare the hub and blades, the overall integrity of the impeller is maintained while reducing the mass of the impeller, achieving lightweight manufacturing of the impeller.

[0106] The sintering treatment of the ceramic impeller in step S4 includes the following steps:

[0107] Step S41: By immersing the demolded ceramic impeller blank in trichloroethylene organic solvent, the soluble binder component is dissolved and extracted, forming interconnected capillary channels within the blank.

[0108] Step S42: Place the degreased ceramic impeller blank on a refractory sintering plate and sinter it in a high-temperature furnace under normal pressure.

[0109] First, the injection-molded ceramic impeller is degreased to effectively remove the soluble binder inside the impeller blank. The resulting capillary channels are used to pre-construct channels for gas discharge in the subsequent thermal degreasing stage. Then, the degreased impeller is sintered at high temperature. The diffusion motion of atoms at high temperature causes the powder particles to form a strong metallurgical or chemical bond, resulting in a compact structure inside the ceramic impeller.

[0110] The surface treatment of the ceramic impeller in step S5 includes the following steps:

[0111] Step S51: Use a high-energy laser beam to soften the uneven areas on the surface of the ceramic impeller, and then use a grinding tool to smooth the area.

[0112] Step S52: The surface of the ceramic impeller is subjected to wear-resistant processing by preparing a titanium nitride thin film on the surface of the ceramic impeller.

[0113] The irregularities on the ceramic impeller blank are softened and removed by laser treatment to ensure the flatness of the impeller surface. Then, a coating process is performed on the impeller surface. The titanium nitride coating is mainly prepared by physical vapor deposition technology. In a vacuum chamber, titanium is used as the cathode target. Nitrogen gas is introduced and a high current is applied to generate an electric arc. The electric arc moves at high speed on the titanium target surface, instantly evaporating and ionizing titanium atoms to form a high-energy titanium plasma. Titanium ions react with nitrogen ions / atoms on the impeller surface to form titanium nitride, resulting in a titanium nitride film on the impeller surface. Its high wear resistance improves the wear resistance of the impeller.

[0114] like Figure 8-11As shown, in step S3, the ceramic impeller injection mold includes an upper mold 1, a lower mold 2, a dual injection runner 3, an vent 4, a gas needle valve 5, and a liquid cooling pipe 6. The lower mold 2 is positioned below the upper mold 1, and their positions correspond. The ceramic impeller injection mold consists of the upper mold 1 and the lower mold 2. The upper mold 1 is mounted on the injection molding machine and connected to the hydraulic system of the machine. The hydraulic system drives the upper mold 1 to move vertically. The lower mold 2 is fixedly mounted on the injection molding machine's base. During the injection process, the hydraulic system drives the upper mold 1 to move downwards and fit tightly against the lower mold 2. This creates a cavity for impeller injection molding between the inner cavities of the upper mold 1 and the lower mold 2. A dual injection runner 3 is installed on the upper mold 1, used for injecting hub material and impeller material respectively. The dual injection runners 3 are located at the hub and blade positions of the upper mold 1, close to the junction of the hub and blade. Hub material and blade material are injected into the cavity sequentially through the dual injection runners 3. The dual injection runners 3 are connected to the material conveying pipes on the injection molding machine, allowing the material to enter the cavity through the pipes. An vent 4 is located on the upper mold 1 at the junction of the hub and blade. Raw material is injected into the cavity between the upper mold 1 and the lower mold 2, compressing the gas in the cavity and causing it to exit through the vent hole 4 at the junction of the hub and the blade. The vent hole 4 is convex in shape, with its bottom diameter smaller than its top diameter. A polyvinylidene fluoride (PVDF) filter plate is fixedly installed at the bottom of the vent hole 4. The gas in the cavity passes through the PVDF filter plate and exits, while also blocking the raw material from the impeller. A gas needle valve 5 is fixedly installed on the upper mold 1, located at the junction of the hub and the blade. The gas needle valve 5 is installed in the air inlet channel on the upper mold 1 and is connected to the external air supply device. The system is connected to the gas needle valve 5, allowing high-pressure nitrogen gas to be injected into the junction of the hub and the blade cavity. The liquid cooling pipes 6 are fixedly embedded in the bottom of the lower mold 2. The liquid cooling pipes 6 are arranged in a straight line at intervals. The liquid cooling pipes 6 are used to transport coolant, so that the coolant circulates in the corresponding position of the mold, absorbs the heat of the corresponding position of the mold, and achieves the purpose of cooling. Multiple liquid cooling pipes 6 form independent circulation channels with the external multi-channel mold temperature controller. As the multi-channel mold temperature controller operates, it drives the coolant to circulate in the liquid cooling pipes 6, and the multi-channel mold temperature controller controls multiple liquid cooling pipes 6 individually.

[0115] Principle of this invention:

[0116] By setting an air intake channel on the ceramic impeller injection mold, high-pressure gas is injected into the interface between the hub and the impeller in the mold cavity through the air intake channel, forming an air film that isolates the impeller material and the hub material. Multiple cooling circuits are used to cool and solidify the impeller material and the hub material in the mold separately, so that the blade material and the hub material are gradually cooled towards the interface. The two materials contact, fuse and solidify at the interface, and are injection molded into a whole ceramic impeller, realizing the gradient processing of the ceramic impeller. Using materials with different contents to prepare the hub and blades ensures the integrity of the impeller while reducing the mass of the impeller, achieving lightweight manufacturing of the impeller. Using hub material with high chromium oxide content ensures high strength and high toughness of the hub, so that the hub is stably connected to the motor shaft. Using blade material with low chromium oxide content achieves lightweight blades. Lightweight processing of blades reduces the overall mass of the ceramic impeller, reduces rotational inertia, improves energy efficiency and dynamic response, and also reduces the load on bearings and shafts.

[0117] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for processing and preparing a novel functional ceramic impeller, characterized in that, Includes the following steps: Step S1: Weigh the raw materials for hub preparation according to the proportion, and weigh the raw materials for blade preparation according to the proportion; Step S2: Simulate the injection molding process of the ceramic impeller, simulate the advancement process of the melt front in the cavity, predict the location of cavitation, guide the venting settings, and analyze the pressure holding, cooling solidification, stress changes and sintering during the injection molding process; Step S3: Based on the simulation and analysis results in Step S2, set up the ceramic impeller injection mold and perform injection molding. Set up a dual flow channel, air intake channel, cooling circuit and exhaust channel on the mold. Inject hub preparation material into the mold through the injection channel to fill the hub area of ​​the mold. Inject high-pressure nitrogen gas into the connection between the hub and the blade through the air intake channel to form a gas film at the connection interface to separate the hub preparation material and the blade preparation material. Then inject blade preparation material into the blade area of ​​the mold through the injection channel to perform gradient processing on the hub and blade of the impeller. Step S4: The hub and blade raw materials in the mold in step S3 are cooled and solidified through the cooling circuit. The cooling and solidification proceeds from the far end of the blade to the interface between the hub and the blade, so that the hub raw materials and blade raw materials are mixed and connected at the interface. After demolding, the ceramic impeller is sintered. Step S5: Perform laser ablation on a localized area of ​​the formed impeller surface from step S4, and then apply a coating to the impeller surface.

2. The processing and preparation method of the novel functional ceramic impeller according to claim 1, characterized in that, The raw material formulation for the ceramic impeller in step S1 includes the following steps: Step S11: Weigh alumina according to the proportion as the raw material for preparing the impeller hub, add 1%-5% chromium oxide to it, disperse the raw material powder in an organic solvent containing a monomer crosslinking agent to form a hub slurry for injection molding. Step S12: Weigh alumina according to the proportion as the raw material for preparing impeller blades, add 1%-2% chromium oxide to it, disperse the raw material powder in an organic solvent containing a monomer crosslinking agent to form a blade slurry for injection molding.

3. The processing and preparation method of a novel functional ceramic impeller according to claim 2, characterized in that, The injection molding simulation of the ceramic impeller in step S2 includes the following steps: Step S21: By cleaning and repairing the geometry of the impeller CAD model, removing minor features, and establishing a three-dimensional model of the injection molding mold cavity based on the impeller model; Step S22: Obtain rheological data, PVT data and thermophysical property data of the specific batch of feed through experiments, and perform numerical calculations using Moldex3D simulation software based on the set physical model; Step S23: Use visualization tools to analyze the model and data from step S22, identify the location and cause of defects in the injection mold, and calibrate and verify the simulation model through actual trial molding results.

4. The processing and preparation method of a novel functional ceramic impeller according to claim 3, characterized in that, The model creation of the injection mold in step S21 includes the following steps: Step S211: Import the mold cavity model using CAD software, divide the geometry into multiple micro-units using 3D solid mesh, and perform precise analysis on the model; Step S212: Obtain rheological data, PVT data and thermophysical data of the raw material during the injection molding process through experiments. Combine the raw material data and injection mold model to set the parameters of injection time and speed, melt temperature, mold temperature and holding pressure curve. Step S213: Accurately model the cooling water system and gating system by importing the runner, gate, and cooling water path into the software.

5. The processing and preparation method of a novel functional ceramic impeller according to claim 4, characterized in that, The model and data analysis in step S23 includes the following steps: Step S231: Simulate the advancement process of the melt front in the cavity, predict the location of air cavities in the mold cavity, set up the exhaust channel, and predict the junction of the hub and the blade. Step S232: After the raw material is filled, the cooling shrinkage process is compensated by continuously applying pressure to predict the pressure distribution, density change and subsequent volume shrinkage in the cavity; Step S233: Simulate the change of mold temperature field over time, evaluate the efficiency and uniformity of the cooling system, predict the temperature distribution of the components, and set up the distribution of the mold cooling circuit. Step S234: Based on the analysis results of steps S231 to S233, a custom material model is coupled using finite element software to simulate the densification process of powder particles through diffusion mechanism at high temperature.

6. The processing and preparation method of a novel functional ceramic impeller according to claim 5, characterized in that, The mold setup in step S3 includes the following steps: Step S31: Based on the modeling of the imported runner in step S213, set up a dual runner on the mold for injection molding, which is used for the wheel hub material and the blade material to be injected into the mold cavity respectively; Step S32: Based on the location of the air cavitation in step S231, an exhaust channel system is set on the mold, and an air intake channel is opened at the junction of the hub and the blade, so that high-pressure nitrogen is injected into the junction of the hub and the blade in the cavity to form a barrier gas film. Step S33: Based on the component temperature distribution in step S233, multiple cooling circuits are embedded in the mold to provide gradient cooling for the mold, gradually cooling and solidifying from the far end of the blade to the interface between the hub and the blade.

7. The processing and preparation method of a novel functional ceramic impeller according to claim 6, characterized in that, The gradient injection molding process in step S3 includes the following steps: Step S34: Inject the wheel hub material into the cavity through the injection channel at the wheel hub of the mold, filling the preset volume of the wheel hub cavity, in a state of incomplete filling; Step S35: High-pressure nitrogen gas is immediately injected into the molten leading edge area of ​​the wheel hub material through the air inlet channel on the mold. The gas pushes the wheel hub material to continue to flow forward, and at the same time, a gas-melt interface is formed between the gas and the wheel hub material. Step S36: While injecting high-pressure nitrogen, inject impeller material through the injection channel at the impeller of the mold. The front edge of the impeller material melt meets the gas, and the gas film is used to block the impeller material and the hub material, forming a buffer area between the impeller material and the hub material. Step S37: As the impeller material is continuously injected, the gas is compressed and discharged from the mold through the preset exhaust channel. After the gas is completely discharged, the melt fronts of the hub material and the blade material contact, fuse and solidify at the connection interface under pressure. Step S38: After the impeller material is injected, the cooling circuit is turned on sequentially from the far end of the blade and the cooling circuit at the hub, so that the blade material and the hub material are cooled in a gradient towards the interface between them, thus completing the cooling and solidification of the hub and the impeller.

8. The method for processing and preparing a novel functional ceramic impeller according to claim 7, characterized in that, The sintering treatment of the ceramic impeller in step S4 includes the following steps: Step S41: By immersing the demolded ceramic impeller blank in trichloroethylene organic solvent, the soluble binder component is dissolved and extracted, forming interconnected capillary channels within the blank. Step S42: Place the degreased ceramic impeller blank on a refractory sintering plate and sinter it in a high-temperature furnace under normal pressure.

9. The processing and preparation method of a novel functional ceramic impeller according to claim 8, characterized in that, The surface treatment of the ceramic impeller in step S5 includes the following steps: Step S51: Use a high-energy laser beam to soften the uneven areas on the surface of the ceramic impeller, and then use a grinding tool to smooth the area. Step S52: The surface of the ceramic impeller is subjected to wear-resistant processing by preparing a titanium nitride thin film on the surface of the ceramic impeller.

10. The method for processing and preparing a novel functional ceramic impeller according to claim 9, characterized in that, The ceramic impeller injection mold in step S3 includes: Upper mold 1 (1); The lower mold (2) is located below the upper mold 1 (1), and the lower mold (2) is positioned opposite to the upper mold 1 (1). The injection molding double runner (3) is set on the upper mold 1 (1) and the injection molding double runner (3) is used for the injection of hub material and impeller material respectively; Exhaust hole (4), the exhaust hole (4) is opened on the upper mold 1 (1), and the exhaust hole (4) is located at the junction of the hub and the blade; Gas needle valve (5), the gas needle valve (5) is fixedly installed on the upper mold 1 (1), the gas needle valve (5) is located at the junction of the hub and the blade; Liquid cooling pipes (6) are fixedly embedded in the bottom of the lower mold (2) and are arranged in a straight line at intervals.

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