A high-reliability molding method for ceramic impeller blanks

Abstract

The present invention relates to a high-reliability molding method for a ceramic turbine impeller blank. First, a three-dimensional solid model of the ceramic turbine impeller product is created. The deformation and spatial distribution characteristics during the molding process are analyzed, and a three-dimensional model of the ceramic turbine impeller blank with increased deformation is further created. Next, a split-type pressing mold for the ceramic turbine impeller blank and a comprehensive molding environment system for the ceramic turbine impeller blank are designed and manufactured. The ceramic turbine impeller blank is then pressed and densified, and demolded. Finally, the structural integrity of the ceramic turbine impeller blank is inspected and its reliability evaluated. This method ensures the molding quality and density of the ceramic turbine impeller blank and improves its reliability.

Description

Technical Field

[0001] The invention belongs to the field of turbocharged power generation system structure design, and in particular relates to a high-reliability molding method for a ceramic impeller blank. Background Art

[0002] Turbocharged power generation systems convert thermal energy into mechanical energy through a thermodynamic cycle involving a gaseous working fluid, including heat absorption, expansion, heat release, and compression. They then use a motor to further convert mechanical energy into electrical energy. A turbocharged power generation system primarily consists of a turbine, compressor, and motor.

[0003] As a core component of a turbocharged power generation system, the turbine impeller is also one of the most heavily loaded components in the system, playing a decisive role in the system's stable operation, operational reliability, and service life. During operation, the turbine impeller rotates at high speed under the action of high-temperature gas working fluids. Its inlet temperature can reach over 1000°C, and its speed can reach tens of thousands of rpm, with some impellers even reaching hundreds of thousands of rpm. Failure of the turbine impeller not only prevents the turbocharged power generation system from operating normally and failing to convert thermal energy into mechanical energy, but can also cause structural damage to the system. Therefore, improving the reliability of the turbine impeller is crucial to ensuring the operational reliability of the turbocharged power generation system.

[0004] To meet the high power density requirements of turbocharged power generation systems, turbine inlet temperatures continue to rise. Therefore, turbine impellers can be made of high-temperature-resistant ceramic materials instead of high-temperature alloys. Unlike the molding process for high-temperature alloy turbine impellers, ceramic turbine impellers require the production of a blank followed by sintering. Due to the complex shape of turbine impellers, the quality of the blank directly affects the structural integrity and reliability of the ceramic turbine impeller.

[0005] In response to the high-reliability molding requirements of ceramic turbine impellers, starting from the production of the impeller blank, considering the influence of sintering process, etc., by optimizing the blank molding process of the ceramic turbine impeller, the molding quality of the blank is improved, thereby ensuring the structural integrity and reliability of the ceramic turbine impeller. Summary of the Invention

[0006] In response to the high-reliability molding requirements for ceramic turbine impellers, this paper proposes a high-reliability molding method for ceramic turbine impeller blanks. First, a three-dimensional solid model of the ceramic turbine impeller product is established. The deformation and spatial distribution characteristics of the ceramic turbine impeller molding process are analyzed, and a three-dimensional model of the ceramic turbine impeller blank with increased deformation is further established. Secondly, a split-type pressing mold for the ceramic turbine impeller blank and a comprehensive environmental system for molding the ceramic turbine impeller blank are designed and manufactured. Then, the ceramic turbine impeller blank is pressed and densified, and the ceramic turbine impeller blank is demolded. Finally, the ceramic turbine impeller blank structural integrity inspection and reliability evaluation are performed.

[0007] A high-reliability molding method for a ceramic turbine impeller blank comprises the following steps:

[0008] a. Establish a 3D solid model of the ceramic turbine impeller product: Based on the turbine impeller's flow rate, inlet and outlet temperatures and pressures, expansion ratio and other parameters, establish a 3D solid model of the ceramic turbine impeller product;

[0009] b. Analyze the deformation and spatial distribution characteristics of the ceramic turbine impeller during the forming process: Based on parameters such as the ceramic turbine impeller's structural dimensions, ceramic material properties, and sintering process, analyze and calculate the deformation and spatial distribution characteristics of the ceramic turbine impeller during the sintering forming process;

[0010] c. Establishing a 3D model of a ceramic turbine impeller blank with increased deformation: Based on the 3D solid model of the ceramic turbine impeller product, and considering the deformation amount and spatial distribution characteristics of the ceramic turbine impeller during the sintering process, a 3D model of the ceramic turbine impeller blank was established with deformation factored in.

[0011] d. Design and fabrication of a split-type pressing mold for a ceramic turbine impeller blank: Based on a three-dimensional model of a ceramic turbine impeller blank with increased deformation, a split-type pressing mold for the ceramic turbine impeller blank is designed and fabricated. The mold is provided with local temperature-controlled blind holes along the blade cavity. These blind holes can be laser-driven or pass hot and cold fluids to control the local temperature and deformation of the ceramic turbine impeller blank. A radially oriented deformation-control insulation sleeve is provided on the outer edge of the mold, and the sleeve is made of a high-temperature-resistant, low-expansion-coefficient material.

[0012] e. Design and manufacture of a comprehensive environmental system for ceramic turbine impeller blank molding: Calculate the structural characteristics of the split-piece pressing mold for the ceramic turbine impeller blank, and design and manufacture a comprehensive environmental system capable of simultaneously applying vibration, temperature, and humidity conditions based on the structural characteristics of the split-piece pressing mold and the density requirements of the ceramic turbine impeller blank;

[0013] f. Performing compression molding and densification of a ceramic turbine impeller blank: using a ceramic turbine impeller blank pressing mold produced in step d and a ceramic turbine impeller blank forming integrated environmental system produced in step e, the ceramic powder is filled into the ceramic turbine impeller blank pressing mold, and then the ceramic turbine impeller blank pressing mold filled with ceramic powder is placed in a ceramic turbine impeller blank forming integrated environmental system, and subjected to vibration, temperature and humidity environmental conditions, while the density of the blank at the blade portion is controlled by a local temperature-controlled blind hole of the ceramic turbine impeller blank pressing mold using a local hot and cold cycle loading method, thereby achieving densification molding of the ceramic turbine impeller blank;

[0014] g. Demolding the ceramic turbine impeller blank: By adjusting the temperature parameters of the integrated environmental system for molding the ceramic turbine impeller blank and the temperature parameters of the local temperature-controlled blind holes of the split pressing mold for the ceramic turbine impeller blank, the split pressing mold for the ceramic turbine impeller blank is separated from the ceramic turbine impeller blank;

[0015] h. Perform structural integrity inspection on the ceramic turbine impeller blank: perform structural integrity inspection on the ceramic turbine impeller blank according to the quality characteristic parameters of the ceramic turbine impeller blank;

[0016] Conduct reliability evaluation of the ceramic turbine impeller blank: Based on the quality characteristic characterization parameters of the ceramic turbine impeller blank obtained in step h, the reliability of the ceramic turbine impeller is evaluated according to the ceramic turbine impeller blank reliability evaluation criteria.

[0017] Beneficial effects:

[0018] 1. The molding method of the present invention designs and manufactures a split-type ceramic turbine impeller blank pressing mold based on a three-dimensional model of a ceramic turbine impeller blank with increased deformation, which can fully ensure the size of the finished ceramic turbine impeller, reduce or avoid the amount of processing after sintering the ceramic turbine impeller blank, and significantly shorten the processing cycle and cost.

[0019] 2. The ceramic turbine impeller blank pressing die of the present invention is provided with a local temperature-controlled blind hole along the blade cavity, which can be used to achieve local densification and shape control of the ceramic turbine impeller blank through laser or hot and cold fluids. The outer edge of the ceramic turbine impeller blank pressing die is provided with a radially oriented deformation control insulation sleeve and adopts high-temperature resistant and low-expansion coefficient materials, which can fully ensure the molding density of the ceramic turbine impeller blank and improve the reliability of the blank. By adopting a comprehensive environmental system that can simultaneously apply vibration, temperature and humidity conditions, a variety of energy and load inputs can be used to achieve further compaction of the ceramic powder, thereby improving the density of the ceramic turbine impeller blank and the bonding strength of the ceramic powder.

[0020] 3. By adjusting the temperature parameters of the integrated environmental system for molding the ceramic turbine impeller blank and the temperature parameters of the local temperature-controlled blind holes in the split-type pressing mold for the ceramic turbine impeller blank, the present invention utilizes the effects of thermal expansion and contraction to separate the split-type pressing mold from the ceramic turbine impeller blank, effectively preventing damage to the ceramic turbine impeller blank during demolding. Structural integrity testing and reliability evaluation of the demolded ceramic turbine impeller blank effectively eliminate unqualified ceramic impeller blanks, improve the sintering yield and structural reliability of the ceramic turbine impeller, and reduce the production cost of the ceramic turbine impeller. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of a high-reliability molding method for ceramic turbine impeller blanks. DETAILED DESCRIPTION

[0022] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0023] The present invention provides a high reliability molding method for a ceramic turbine impeller blank. Figure 1 As shown, the following steps are included:

[0024] a. Establish a 3D solid model of the ceramic turbine impeller product: Based on the turbine impeller's flow rate, inlet and outlet temperatures and pressures, expansion ratio and other parameters, establish a 3D solid model of the ceramic turbine impeller product;

[0025] b. Analyze the deformation and spatial distribution characteristics of the ceramic turbine impeller during the forming process: Based on parameters such as the ceramic turbine impeller's structural dimensions, ceramic material properties, and sintering process, analyze and calculate the deformation and spatial distribution characteristics of the ceramic turbine impeller during the sintering forming process;

[0026] c. Establishing a 3D model of a ceramic turbine impeller blank with increased deformation: Based on the 3D solid model of the ceramic turbine impeller product, and considering the deformation amount and spatial distribution characteristics of the ceramic turbine impeller during the sintering process, a 3D model of the ceramic turbine impeller blank was established with deformation factored in.

[0027] d. Design and fabrication of a split-type pressing mold for a ceramic turbine impeller blank: Based on a three-dimensional model of a ceramic turbine impeller blank with increased deformation, a split-type pressing mold for the ceramic turbine impeller blank is designed and fabricated. The mold is provided with local temperature-controlled blind holes along the blade cavity. These blind holes can be laser-driven or pass hot and cold fluids to control the local temperature and deformation of the ceramic turbine impeller blank. A radially oriented deformation-control insulation sleeve is provided on the outer edge of the mold, and the sleeve is made of a high-temperature-resistant, low-expansion-coefficient material.

[0028] e. Design and manufacture of a comprehensive environmental system for ceramic turbine impeller blank molding: Calculate the structural characteristics of the split-piece pressing mold for the ceramic turbine impeller blank, and design and manufacture a comprehensive environmental system capable of simultaneously applying vibration, temperature, and humidity conditions based on the structural characteristics of the split-piece pressing mold and the density requirements of the ceramic turbine impeller blank;

[0029] f. Performing compression molding and densification of a ceramic turbine impeller blank: using a ceramic turbine impeller blank pressing mold produced in step d and a ceramic turbine impeller blank forming integrated environmental system produced in step e, the ceramic powder is filled into the ceramic turbine impeller blank pressing mold, and then the ceramic turbine impeller blank pressing mold filled with ceramic powder is placed in a ceramic turbine impeller blank forming integrated environmental system, and subjected to vibration, temperature and humidity environmental conditions, while the density of the blank at the blade portion is controlled by a local temperature-controlled blind hole of the ceramic turbine impeller blank pressing mold using a local hot and cold cycle loading method, thereby achieving densification molding of the ceramic turbine impeller blank;

[0030] g. Demolding the ceramic turbine impeller blank: By adjusting the temperature parameters of the integrated environmental system for molding the ceramic turbine impeller blank and the temperature parameters of the local temperature-controlled blind holes of the split pressing mold for the ceramic turbine impeller blank, the split pressing mold for the ceramic turbine impeller blank is separated from the ceramic turbine impeller blank;

[0031] h. Perform structural integrity inspection on the ceramic turbine impeller blank: perform structural integrity inspection on the ceramic turbine impeller blank according to the quality characteristic parameters of the ceramic turbine impeller blank;

[0032] i. Perform reliability evaluation of the ceramic turbine impeller blank: Based on the quality characteristic parameters of the ceramic turbine impeller blank obtained in step h, the reliability of the ceramic turbine impeller is evaluated according to the reliability evaluation criteria of the ceramic turbine impeller blank.

[0033] In summary, the above are only preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A high-reliability molding method for a ceramic turbine impeller blank, characterized by: The following steps are involved: a. Establish a 3D solid model of the ceramic turbine impeller product: Based on the turbine impeller's flow rate, inlet and outlet temperatures and pressures, expansion ratio and other parameters, establish a 3D solid model of the ceramic turbine impeller product; b. Analyze the deformation and spatial distribution characteristics of the ceramic turbine impeller during the molding process; c. Establishing a 3D model of a ceramic turbine impeller blank with increased deformation: Based on the 3D solid model of the ceramic turbine impeller product, and considering the deformation amount and spatial distribution characteristics of the ceramic turbine impeller during the sintering process, a 3D model of the ceramic turbine impeller blank was established with deformation factored in. d. Design and manufacture of a split-type pressing mold for a ceramic turbine impeller blank: Based on the three-dimensional model of the ceramic turbine impeller blank with increased deformation, a split-type pressing mold for the ceramic turbine impeller blank is designed and manufactured; e. Design and manufacture a comprehensive environmental system for ceramic turbine impeller blank molding; f. Performing compression molding and densification of a ceramic turbine impeller blank: using a ceramic turbine impeller blank pressing mold produced in step d and a ceramic turbine impeller blank forming integrated environmental system produced in step e, the ceramic powder is filled into the ceramic turbine impeller blank pressing mold, and then the ceramic turbine impeller blank pressing mold filled with ceramic powder is placed in a ceramic turbine impeller blank forming integrated environmental system, and subjected to vibration, temperature and humidity environmental conditions, while the density of the blank at the blade portion is controlled by a local temperature-controlled blind hole of the ceramic turbine impeller blank pressing mold using a local hot and cold cycle loading method, thereby achieving densification molding of the ceramic turbine impeller blank; g. Demolding of the ceramic turbine impeller body; h. Perform structural integrity inspection on the ceramic turbine impeller blank: perform structural integrity inspection on the ceramic turbine impeller blank according to the quality characteristic parameters of the ceramic turbine impeller blank; i. Perform reliability evaluation of the ceramic turbine impeller blank: Based on the quality characteristic parameters of the ceramic turbine impeller blank obtained in step h, the reliability of the ceramic turbine impeller is evaluated according to the ceramic turbine impeller blank reliability evaluation criteria.

2. The high-reliability molding method for a ceramic turbine impeller blank according to claim 1, characterized in that: In step b), the deformation amount and spatial distribution characteristics of the ceramic turbine impeller during the sintering process are analyzed and calculated based on the structural dimensions of the ceramic turbine impeller, the physical properties of the ceramic material, and the sintering process parameters.

3. The high-reliability molding method for a ceramic turbine impeller blank according to claim 1, characterized in that: In step d), a local temperature-controlled blind hole is provided along the blade cavity of the ceramic turbine impeller blank pressing mold, and laser or hot and cold fluid is applied to the local temperature-controlled blind hole on the ceramic turbine impeller blank pressing mold to achieve control of the local temperature and deformation of the ceramic turbine impeller blank.

4. The high-reliability molding method for a ceramic turbine impeller blank according to claim 1, characterized in that: In step d), a radially oriented deformation control insulation sleeve is provided on the outer edge of the ceramic turbine impeller blank pressing mold, and the radially oriented deformation control insulation sleeve of the ceramic turbine impeller blank pressing mold is made of high temperature resistant and low expansion coefficient material.

5. The high-reliability molding method for a ceramic turbine impeller blank according to claim 1, characterized in that: In step e), the structural characteristics of the split-type pressing mold for the ceramic turbine impeller blank are calculated, and based on the structural characteristics of the split-type pressing mold for the ceramic turbine impeller blank and the density requirements of the ceramic turbine impeller blank, a comprehensive environmental system capable of simultaneously applying vibration, temperature and humidity conditions is designed and manufactured.

6. A high-reliability molding method for a ceramic turbine impeller blank according to claim 4 or 5, characterized in that: In step g), the separation of the ceramic turbine impeller blank split pressing mold and the ceramic turbine impeller blank is achieved by adjusting the temperature parameters of the ceramic turbine impeller blank molding integrated environmental system and the temperature parameters of the local temperature control blind holes of the ceramic turbine impeller blank split pressing mold.

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