Method for obtaining and determining high-temperature alloy casting process parameters and casting process

Abstract

The present invention provides a method for acquiring and determining high-temperature alloy casting process parameters and a casting process. The acquisition method uses a data-driven approach to extract known casting process parameters of known high-temperature alloy materials. The method for determining high-temperature alloy casting process parameters includes: taking IN718 high-temperature alloy as a benchmark high-temperature alloy, using the above-mentioned acquisition method to acquire known casting process parameters of IN718 high-temperature alloy, and determining the benchmark casting process parameters of IN718 high-temperature alloy; using thermodynamic calculation software to calculate the thermophysical parameters of IN718 high-temperature alloy related to casting process performance; for the target grade high-temperature alloy actually cast, using thermodynamic calculation software to calculate the thermophysical parameters of the target grade high-temperature alloy related to casting process performance, thereby obtaining the casting process parameters of the target grade high-temperature alloy. The present invention utilizes the common thermophysical properties of high-temperature alloy materials and their similar casting process performance, and has the advantages of low cost, fastness, and accuracy.

Description

Technical Field

[0001] The present invention relates to the technical field of high-temperature alloy precision casting and molding, and in particular to a method for acquiring and determining high-temperature alloy casting process parameters and a casting process. Background Art

[0002] Nickel-based high-temperature alloys have high high-temperature strength, good oxidation and corrosion resistance, good fatigue performance, fracture toughness and other comprehensive properties, and are widely used in the aerospace field. Precision manufacturing can form complex thin-walled structures, which is very suitable for the precision molding of complex high-temperature alloy structural parts. High-temperature alloy castings and precision casting technology are indispensable and irreplaceable. In modern aircraft engines, the amount of high-temperature alloy materials used accounts for approximately 40%-60% of the total engine mass, of which high-temperature alloy castings account for 20%. In major aerospace equipment, high-temperature alloy castings account for about 30%. Due to the large number of high-temperature alloy grades and the large differences in casting process performance, the accurate determination of casting process parameters is crucial to the preparation of high-quality high-temperature alloy castings.

[0003] Existing technologies often use an empirical trial-and-error method, where casting engineers manually set certain shrinkage rates, pouring temperatures, and mold preheating temperatures based on their experience. After preliminary exploration of orthogonal process test pieces, they determine that a relatively narrow casting process window is applied to the development of large-scale engineering castings. This method is inefficient, time-consuming, and costly.

[0004] A search revealed a Chinese invention patent with publication number CN113642121A, which discloses a method for optimizing aluminum alloy brake caliper casting process parameters based on response surface design and a multi-objective evolutionary algorithm. The method involves determining experimental variables and optimization objectives to construct a response surface experiment; obtaining response values ​​through numerical casting simulations to establish multiple response surface models reflecting the input-output relationship; and optimizing and solving the response surface models using a multi-objective evolutionary algorithm to obtain optimal process parameters. However, this invention still suffers from the following issues: The patent utilizes numerical casting simulations to obtain response values ​​and establish multiple response surface models reflecting the input-output relationship. This fundamentally prevents high-precision prediction and simulation. While applicable to low-quality aluminum alloy brake discs, it cannot be applied to high-quality high-temperature alloy castings for aerospace applications, which have extremely stringent requirements for internal casting quality. Summary of the Invention

[0005] In response to the defects in the existing technology, the purpose of the present invention is to provide a method for obtaining and determining high-temperature alloy casting process parameters and a casting process, so as to solve the shortcomings of the existing high-temperature alloy precision casting technology solutions that are heavily dependent on the experience of engineers, have long cycles, high costs, and low efficiency, and to achieve rapid and accurate determination of diverse high-temperature alloy precision casting process parameters.

[0006] According to a first aspect of the present invention, a method for acquiring high-temperature alloy casting process parameters is provided. The method comprises: extracting known casting process parameters of known high-temperature alloy materials in a data-driven manner.

[0007] Furthermore, the casting process parameters of high-temperature alloys in known literature are captured by Python to obtain the known casting process parameters of known high-temperature alloys.

[0008] According to a second aspect of the present invention, a method for quickly determining high-temperature alloy casting process parameters is provided, the method comprising:

[0009] Taking IN718 high-temperature alloy as a benchmark high-temperature alloy, the above-mentioned method for obtaining high-temperature alloy casting process parameters is used to obtain known casting process parameters of IN718 high-temperature alloy, and determining the benchmark casting process parameters of IN718 high-temperature alloy based on the known casting process parameters;

[0010] Thermodynamic calculation software is used to calculate the thermophysical properties of IN718 superalloy related to casting process performance;

[0011] For the target grade of high-temperature alloy actually cast, thermodynamic calculation software is used to calculate the thermophysical parameters of the target grade of high-temperature alloy related to the casting process performance;

[0012] According to the thermophysical property parameters related to the casting process performance of IN718 superalloy and target grade superalloy, the casting process parameters of the target grade superalloy are obtained.

[0013] Furthermore, the benchmark casting process parameters include: an average value of the pouring temperature Ta, an average value Tb of the difference between the pouring temperature and the mold shell preheating temperature, and an average value S of the shrinkage rate.

[0014] Furthermore, the thermophysical parameters of the IN718 high-temperature alloy related to the casting process performance include: liquidus temperature Tl, solidus temperature Ts, crystallization temperature interval ΔT and cumulative shrinkage Sa from liquidus to solidus of the high-temperature alloy.

[0015] Furthermore, the thermophysical properties of the target grade high-temperature alloy related to casting process performance include: liquidus temperature Tl plus, solidus temperature Ts plus, crystallization temperature interval ΔT plus and cumulative shrinkage Sa plus from liquidus to solidus of the high-temperature alloy.

[0016] Furthermore, the casting process parameters of the target grade high-temperature alloy are obtained based on the thermophysical property parameters related to the casting process performance of the IN718 high-temperature alloy and the target grade high-temperature alloy, including:

[0017] The calculation method of pouring temperature Ta plus is:

[0018] Furthermore, the method of obtaining the casting process parameters of the target grade high-temperature alloy based on the thermophysical property parameters related to the casting process performance of the IN718 high-temperature alloy and the target grade high-temperature alloy further includes:

[0019] The calculation method of mold shell preheating temperature Tb plus is:

[0020] Furthermore, according to the thermophysical property parameters related to the casting process performance of the IN718 superalloy and the target superalloy, the casting process parameters of the target superalloy are obtained, which also includes:

[0021] The calculation method of casting shrinkage S plus is:

[0022] According to a third aspect of the present invention, a casting process is provided, wherein the casting process adopts the above-mentioned method for quickly determining the casting process parameters of the high-temperature alloy to determine the casting process parameters of the high-temperature alloy.

[0023] Compared with the prior art, the present invention has at least one of the following beneficial effects:

[0024] 1. The present invention adopts a data-driven method for determining the casting process parameters of high-temperature alloys, utilizing the common thermophysical properties of materials such as high-temperature alloys and their similar casting process performance. It effectively overcomes the problems that the existing empirical method is difficult to accurately extend to the determination of casting process parameters of new brands of high-temperature alloys, and the trial-and-error method is high in cost and long in cycle. The present invention has the advantages of low cost, fast and accurate.

[0025] 2. This invention fully utilizes the research results of previous scholars, conducts data mining, obtains the intrinsic connection between casting process parameters and alloy materials, and further establishes the correlation between casting process parameters and material intrinsic thermophysical parameters. Taking into account the difference in crystallization temperature intervals of high-temperature alloy materials, and finally combining the calculation of material thermophysical properties, the applicability is expanded. It can quickly and accurately determine the casting process parameters of high-temperature alloys, and has a strong guiding role in the smooth development of various high-temperature alloy castings for aerospace vehicles. In addition, the calculation of the benchmark alloy casting process parameters selected by this method can not only conveniently incorporate the latest scientific research results in the literature, but also can be well extended to the determination of casting process parameters of other alloys. DETAILED DESCRIPTION

[0026] The present invention is described in detail below with reference to specific embodiments. The following examples will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that, for those skilled in the art, several variations and improvements can be made without departing from the spirit of the present invention. These all fall within the scope of protection of the present invention. In the description of the embodiments of the present invention, it should be noted that the terms "first", "second", etc. in the specification and claims of the present invention are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein.

[0027] High-temperature alloys essentially have certain similar characteristics and are used unevenly. By making full use of the large number of high-temperature alloy forming process parameters reported in existing literature, conducting systematic sorting and data mining, and combining thermodynamic calculations to perform similarity analogies, it is hoped that key high-temperature alloy casting process parameters can be quickly determined to meet the urgent needs of major aerospace projects.

[0028] To this end, an embodiment of the present invention provides a method for acquiring high-temperature alloy casting process parameters, the method comprising: extracting known casting process parameters of known high-temperature alloy materials in a data-driven manner.

[0029] In some specific embodiments, Python is used to capture the casting process parameters of high-temperature alloys in known literature to obtain known casting process parameters of known high-temperature alloys. Taking IN718 high-temperature alloy as an example, in order to obtain the pouring temperature and mold shell preheating temperature, Python is used to capture the published IN718 high-temperature alloy literature, and Chinese searches are performed using pouring temperature and mold shell preheating temperature, and English searches are performed using pouring temperature and mold shell preheating temperature. The average pouring temperature is obtained based on all pouring temperatures and pouring temperatures, and the average mold shell preheating temperature is obtained based on all mold shell preheating temperatures and mold shell preheating temperatures. These are used as benchmark data for IN718 high-temperature alloy, and a data-driven method is implemented to determine the known casting process parameters of known high-temperature alloys. It will be understood by those skilled in the art that in some other embodiments, the known casting process parameters also include overall shrinkage, etc., and the specific type of process parameters can be determined according to specific circumstances and actual needs.

[0030] In order to improve the accuracy of obtaining known casting process parameters of known high-temperature alloy materials, in some preferred embodiments, the process of capturing data also includes screening the captured data. Specifically, data with a pouring temperature below the liquidus line and data with a pouring temperature above the liquidus line by more than 300°C are deleted; data with a mold preheating temperature below 500°C and above 1100°C are deleted; and shrinkage rate data that differs from the theoretical calculation results by more than 50% is deleted. After screening, data that differs greatly from the actual casting process parameters can be avoided, thereby improving the accuracy of data acquisition.

[0031] An embodiment of the present invention further provides a method for quickly determining high-temperature alloy casting process parameters, the method comprising:

[0032] S1. Using IN718 superalloy as a benchmark superalloy, the known casting process parameters of the IN718 superalloy are obtained using the method for obtaining superalloy casting process parameters described in the above embodiment. The benchmark casting process parameters for the IN718 superalloy are then determined based on the known casting process parameters. Since IN718 superalloy accounts for approximately 50% of the total superalloy weight, its thermophysical properties and casting performance are well-researched, with a vast amount of detailed and reliable data available in the literature. Therefore, key casting process parameters for IN718 superalloys with different structural characteristics, such as pouring temperature, mold preheating temperature, and overall shrinkage, can be easily retrieved. Casting process parameters are systematically extracted from the literature, and big data mining is performed to obtain the benchmark casting process parameters for the benchmark IN718 superalloy.

[0033] In some specific embodiments, the benchmark casting process parameters include, but are not limited to: an average pouring temperature Ta, an average value Tb of the difference between the pouring temperature and the mold shell preheating temperature, and an average shrinkage rate S.

[0034] S2. Use thermodynamic calculation software, such as JMatPro, to calculate the thermophysical parameters of IN718 high-temperature alloy related to casting process performance.

[0035] In some specific embodiments, the thermophysical parameters of the IN718 high-temperature alloy related to the casting process performance include: liquidus temperature Tl, solidus temperature Ts, crystallization temperature interval ΔT, and cumulative shrinkage Sa from liquidus to solidus of the high-temperature alloy.

[0036] S3. For the target grade of high-temperature alloy actually cast, thermodynamic calculation software such as thermodynamic calculation software JMatPro is used to calculate the thermophysical property parameters of the target grade of high-temperature alloy related to the casting process performance.

[0037] In some specific embodiments, the thermophysical properties of the target grade high-temperature alloy related to the casting process performance include: liquidus temperature Tl plus, solidus temperature Ts plus, crystallization temperature interval ΔT plus, and cumulative shrinkage rate Sa plus from liquidus to solidus of the high-temperature alloy, wherein the crystallization temperature interval ΔT plus is the difference between the liquidus temperature Tl plus and the solidus temperature Ts plus.

[0038] S4. Obtain casting process parameters of the target grade high-temperature alloy based on the thermophysical property parameters related to casting process performance of the IN718 high-temperature alloy and the target grade high-temperature alloy, respectively.

[0039] When calculating the pouring temperature, the ratio of the theoretically calculated liquidus temperature of the IN718 superalloy to the actual pouring temperature used in the actual casting process is first calculated. This ratio should be closely related to the theoretically calculated liquidus temperature of the target superalloy and the pouring temperature required for actual casting. However, the crystallization temperature interval parameter is also a key factor affecting the filling capacity and must be fully considered when designing the pouring temperature. Therefore, the crystallization temperature interval modification item needs to be added. In some specific embodiments, based on the thermophysical parameters related to the casting process performance of the IN718 superalloy and the target grade superalloy, the pouring process parameters of the target grade superalloy are obtained, including:

[0040] The pouring temperature Tb plus is calculated as follows:

[0041] When calculating the mold shell preheating temperature, the mold shell preheating temperature does not make much difference to materials such as high-temperature alloys as a whole, and is only closely related to the crystallization temperature interval. Therefore, only the crystallization temperature interval modification item needs to be added. Furthermore, based on the thermophysical properties related to the casting process performance of IN718 high-temperature alloy and the target grade high-temperature alloy, the casting process parameters of the target grade high-temperature alloy are obtained, which also include:

[0042] The calculation method of the mold shell preheating temperature Tb plus is:

[0043] When calculating shrinkage, the ratio of the theoretically calculated shrinkage of the IN718 superalloy to the actual shrinkage used in the actual casting process is first calculated. This ratio should be the same as the theoretically calculated shrinkage of the target superalloy and the shrinkage required for actual casting. This reflects the similarity of superalloys as a class of materials, making it very easy to obtain the actual casting shrinkage required for the target superalloy. Furthermore, based on the thermophysical parameters related to casting process performance of the IN718 superalloy and the target superalloy, the casting process parameters of the target superalloy are obtained, including:

[0044] The calculation method of casting shrinkage S plus is:

[0045] By using the method in the embodiment of the present invention, the three key casting process parameters of high-temperature alloy pouring temperature, mold preheating temperature and shrinkage rate can be calculated conveniently, accurately and quickly. In order to expand the operability at the casting process site, the specific application can add a ±5°C parameter fluctuation range for the pouring temperature and mold preheating temperature based on the calculation results.

[0046] An embodiment of the present invention also provides a casting process that uses the method for rapidly determining high-temperature alloy casting process parameters described in the above embodiment to determine the high-temperature alloy casting process parameters. This method can quickly and accurately determine the casting process parameters of the target high-temperature alloy casting, thereby obtaining a high-temperature alloy casting that meets the technical requirements. The changes in thermophysical parameters of the melt from high temperature to low temperature during the casting process and the changes in the casting-mold interface gap caused by solidification shrinkage cause a significant change in the interfacial heat transfer coefficient. Compared to existing casting simulation software that does not consider the impact of time-varying thermophysical parameters and interfacial heat transfer coefficient disturbances on casting defects, the embodiment of the present invention uses real experimental data reported in the literature as benchmark parameters, combined with accurate time-varying thermophysical property calculations, to ensure the reliability of the results, thereby meeting the service safety requirements of critical aerospace castings.

[0047] The following uses specific examples to describe in more detail the method for obtaining high-temperature alloy casting process parameters, the method for quickly determining high-temperature alloy casting process parameters, and the casting process in the above embodiments of the present invention.

[0048] Example 1

[0049] Using Python to extract IN718 superalloy casting process parameters from domestic and international literature, cumulative average calculations were performed. The average pouring temperature was 1492°C, the mold shell preheat temperature was 970°C, and the casting shrinkage was 0.025. JMatPro thermodynamic calculations for IN718 superalloy showed a liquidus temperature of 1361°C, a solidus temperature of 1216°C, and a shrinkage coefficient of 18.97 × 10-6 1 / K at the solidus temperature. A K418B superalloy casting for an aviation industry was used. JMatPro thermodynamic calculations showed a liquidus temperature of 1350°C, a solidus temperature of 1160°C, and a shrinkage coefficient of 20.01 × 10-6 1 / K at the solidus temperature. A quick calculation shows that the pouring temperature of the K418B high-temperature alloy is 1502±5°C, the predicted mold shell temperature is 972.5±5°C, and the casting shrinkage is 0.025. Using the above parameters for pouring tests, a K418B high-temperature alloy aviation casting that meets the technical requirements was obtained, indicating that the present invention can quickly and accurately determine the casting process parameters of the K418B high-temperature alloy casting.

[0050] Example 2

[0051] Using Python to extract IN718 superalloy casting process parameters from domestic and international literature, cumulative average calculations were performed. The average pouring temperature was 1492°C, the mold shell preheat temperature was 970°C, and the casting shrinkage was 0.025. JMatPro thermodynamic calculations for IN718 superalloy showed a liquidus temperature of 1361°C, a solidus temperature of 1216°C, and a shrinkage coefficient of 18.97 × 10-6 1 / K at the solidus temperature. A K4002 superalloy casting for an aerospace high-temperature alloy casting was also calculated using JMatPro to have a liquidus temperature of 1360°C, a solidus temperature of 1100°C, and a shrinkage coefficient of 18.54 × 10-6 1 / K at the solidus temperature. A quick calculation shows that the pouring temperature of the K4002 high-temperature alloy is 1548±5°C, the predicted mold shell temperature is 1027.5±5°C, and the casting shrinkage is 0.021. Using the above parameters for a pouring test, a K4002 high-temperature alloy aerospace casting that meets the technical requirements was obtained, indicating that the present invention can quickly and accurately determine the casting process parameters of the K4002 high-temperature alloy casting. In addition, it has strong applicability.

[0052] The embodiment of the present invention adopts a data-driven method for determining the casting process parameters of high-temperature alloys, utilizing the common thermophysical properties of materials such as high-temperature alloys and their similar casting process performance, effectively overcoming the problems that the existing empirical method is difficult to accurately extend to the determination of casting process parameters of new brands of high-temperature alloys, and the trial-and-error method is high in cost and long in cycle. The present invention has the advantages of low cost, fast and accurate.

[0053] The embodiment of the present invention makes full use of the research results of previous scholars, conducts data mining, obtains the intrinsic connection between casting process parameters and alloy materials, and further establishes the correlation between casting process parameters and intrinsic thermophysical parameters of materials, and takes into account the differences in crystallization temperature intervals of high-temperature alloy materials. Finally, combined with the calculation of material thermophysical properties, applicability is expanded; specifically, the intrinsic connection between casting process parameters and alloy materials is temperature. The thermophysical properties of alloys vary greatly at different temperatures. The key to selecting casting process parameters is to base it on the time-varying thermophysical properties of alloy materials. Alloy thermophysical properties control the material's fluidity and shrinkage behavior, among other factors. Casting process parameter selection relies on fluidity to address mold filling issues and shrinkage behavior to address scalability issues during mold design. The material's time-varying viscosity affects the mold filling distance; therefore, for materials with high viscosity, the pouring temperature and mold preheating temperature should be increased. The time-varying thermal expansion coefficient determines the shrinkage of the casting. Based on this time-varying thermal expansion parameter, the mold shrinkage ratio is designed and the pouring temperature and mold preheating temperature are adjusted. The present invention establishes relationships between temperature and time-varying thermophysical properties, and between temperature and casting process parameters. Using temperature as a bridge, the mapping of alloy material thermophysical properties to casting process parameters is achieved. This invention enables rapid and accurate determination of high-temperature alloy casting process parameters, providing strong guidance for the successful development of various high-temperature alloy castings for aerospace vehicles. Furthermore, the method's selection of benchmark alloy casting process parameter calculations not only conveniently incorporates the latest research findings from the literature, but can also be readily applied to the determination of casting process parameters for other alloys.

[0054] The above describes specific embodiments of the present invention. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art may make various modifications or variations within the scope of the claims without affecting the essence of the present invention. The above preferred features may be used in any combination as long as they do not conflict with each other.

Claims

1. A method for quickly determining process parameters of high-temperature alloy casting, characterized in that: include: Taking IN718 high-temperature alloy as a benchmark high-temperature alloy, using a high-temperature alloy casting process parameter acquisition method to acquire known casting process parameters of IN718 high-temperature alloy, and determining benchmark casting process parameters of IN718 high-temperature alloy based on the known casting process parameters; Thermodynamic calculation software is used to calculate the thermophysical properties of IN718 superalloy related to casting process performance; For the target grade of high-temperature alloy actually cast, thermodynamic calculation software is used to calculate the thermophysical parameters of the target grade of high-temperature alloy related to the casting process performance; According to the thermophysical properties of IN718 superalloy and target superalloy related to casting process performance, the casting process parameters of the target superalloy are obtained; The method for obtaining high-temperature alloy casting process parameters includes: extracting known casting process parameters of known high-temperature alloy materials in a data-driven manner; Among them: Python is used to capture the casting process parameters of high-temperature alloys in known literature to obtain the known casting process parameters of known high-temperature alloys; the process of capturing data also includes screening the captured data to improve the accuracy of data acquisition.

2. The method for rapidly determining high-temperature alloy casting process parameters according to claim 1, characterized in that: The reference casting process parameters include: an average pouring temperature Ta, an average value Tb of the difference between the pouring temperature and the mold shell preheating temperature, and an average shrinkage rate S.

3. The method for quickly determining high-temperature alloy casting process parameters according to claim 2, characterized in that: The thermophysical properties of the IN718 high-temperature alloy related to casting process performance include: liquidus temperature Tl, solidus temperature Ts, crystallization temperature interval ΔT, and cumulative shrinkage Sa from liquidus to solidus of the high-temperature alloy.

4. The method for quickly determining high-temperature alloy casting process parameters according to claim 3, characterized in that: The thermophysical parameters of the target grade high-temperature alloy related to casting process performance include: liquidus temperature Tlplus, solidus temperature Tsplus, crystallization temperature interval ΔTplus and cumulative shrinkage from liquidus to solidus of the high-temperature alloy Saplus.

5. The method for quickly determining high-temperature alloy casting process parameters according to claim 4, characterized in that: The method of obtaining the casting process parameters of the target grade high-temperature alloy based on the thermophysical property parameters related to the casting process performance of the IN718 high-temperature alloy and the target grade high-temperature alloy includes: The calculation method of pouring temperature Ta plus is:

6. The method for quickly determining high-temperature alloy casting process parameters according to claim 5, characterized in that: The method of obtaining the casting process parameters of the target grade high temperature alloy based on the thermophysical property parameters related to the casting process performance of the IN718 high temperature alloy and the target grade high temperature alloy further includes: The calculation method of mold shell preheating temperature Tb plus is:

7. The method for quickly determining high-temperature alloy casting process parameters according to claim 6, characterized in that: Based on the thermophysical properties of IN718 superalloy and target superalloy that are related to casting process performance, the casting process parameters of the target superalloy are obtained, including: The calculation method of casting shrinkage S plus is:

8. A casting process, characterized in that: The high-temperature alloy casting process parameters are determined by using the method for quickly determining the high-temperature alloy casting process parameters described in any one of claims 1 to 7.

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