Ceramic core for measuring recrystallization tendency of turbulent flow column structure of inner cavity of hollow blade and use method of ceramic core

Abstract

The invention provides a ceramic core for measuring the recrystallization tendency of a turbulent flow column structure of an inner cavity of a hollow blade and a use method of the ceramic core. The ceramic core comprises a ceramic core body and n columns of three-dimensional turbulent flow column forming units arranged in the ceramic core body, and the n columns of three-dimensional turbulent flow column forming units form a hollow structure and are used for forming turbulent flow columns of a casting. In the invention, the thickness hollowing-out ratio of different groups of three-dimensional turbulent flow column forming units in the same column is increased or decreased along the Z axis, so that the different groups of turbulent flow column forming units in the same column have different mold core thicknesses, and the shrinkage matching property of the ceramic mold core and an alloy melt is optimized by adjusting the thickness; the plastic deformation of the inner cavity of the blade is reduced, and the stress distribution of the inner cavity of the blade in the shrinkage process is improved, so that the recrystallization phenomenon caused in the subsequent vacuum heat treatment process is avoided, and the physical property and the mechanical property of the blade are improved.

Description

Technical Field

[0001] The invention belongs to the field of precision casting, and relates to a ceramic core with a special structure and a use method thereof, and in particular to a ceramic core for measuring the recrystallization tendency of a spoiler column structure in an inner cavity of a hollow blade and a use method thereof. Background Art

[0002] Turbine blades are one of the most critical hot-end components of advanced aircraft engines. In order to further increase the temperature of the front end of the turbine blades and optimize the engine thrust-to-weight ratio, air cooling structures are generally used in advanced gas turbine blades. The use of air-cooled hollow blade technology, air film cooling technology, and multi-layer wall blade impact cooling technology in high-load and high-temperature environments can effectively improve the temperature-bearing capacity of hollow blades, thereby giving the blades a higher temperature-bearing capacity.

[0003] Therefore, in order to further improve the temperature bearing capacity of single crystal blades, the complication and large-scale size of the air-cooling structure of single crystal high-temperature alloy turbine blades have become an effective means and inevitable trend to continue to improve the overall performance of key hot end components of aircraft engines. However, as the complexity of the inner cavity structure of advanced turbine blades increases, the quality of the inner cavity needs to be more strictly controlled and guaranteed. Among them, the problem of inner cavity recrystallization has become one of the key technical difficulties in the quality of the inner cavity. In addition, due to the reduction of grain boundary strengthening elements in single crystal high-temperature alloys, once any grain boundaries and recrystallized grains perpendicular to the stress principal axis are generated, they will become areas of weak performance of single crystal high-temperature alloy components. Therefore, once recrystallization occurs in single crystal components, their performance will be greatly reduced, which may cause premature failure of the components.

[0004] As a key component in forming the inner cavity structure of a single-crystal hollow blade, the ceramic core will hinder the alloy during solidification and shrinkage, which can easily lead to tiny plastic deformation in the inner cavity of the blade. The local area of ​​plastic deformation is in a metastable state, and the energy stored in the plastic deformation will be released during the heat treatment process, thereby causing recrystallization on the local surface of the blade.

[0005] Unlike the recrystallization of the outer surface, the biggest difficulty of the recrystallization of the inner cavity is that it is difficult to detect directly and the detection efficiency is low. In the actual production process, the recrystallization of the inner cavity is very likely to occur at the place where the cross-sectional area changes suddenly, especially at the spoiler column position of the inner cavity of the blade. As a key component of the air-cooled structure, this part needs to strictly control the occurrence of recrystallization. Directly using the blade for casting will have a long experimental cycle and easily cause waste of manpower and financial resources. Therefore, it is of great significance to develop a special structural ceramic core for measuring the recrystallization tendency of the spoiler column structure in the inner cavity of the hollow blade. Summary of the invention

[0006] In view of this, an object of the present invention is to provide a ceramic core for measuring the recrystallization tendency of the spoiler column structure in the inner cavity of a hollow blade and a method for using the same.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] In the first aspect, the present invention provides a ceramic core for measuring the recrystallization tendency of the spoiler column structure in the inner cavity of a hollow blade, which includes a ceramic core body and n rows of three-dimensional spoiler column forming units arranged in the ceramic core body, and the n rows of three-dimensional spoiler column forming units constitute a hollow structure for forming the spoiler columns of the casting.

[0009] In the present invention, each column of three-dimensional spoiler column forming units is divided into x groups, each group includes m spoiler column forming cells; n is any integer from 2 to 6, specifically 2, 3, 4, 5 or 6, preferably 4; x is any integer from 3 to 6, specifically 3, 4, 5 or 6, preferably 5; m is any integer from 4 to 10, specifically 4, 5, 6, 7, 8, 9 or 10, preferably 4.

[0010] It should be noted that in order to avoid deformation of the core during the preparation process, the number of spoiler column-forming cells in each column generally does not exceed 30.

[0011] In some embodiments of the present invention, n=4, x=5, m=4. That is, the structural schematic diagram of the ceramic core is as follows: Figure 1 As shown, the hollow structure is composed of 4 columns, each column includes 20 spoiler columns to form cells.

[0012] In the present invention, preferably, the three-dimensional spoiler column forming units in each column have the same length hollowing ratio and width hollowing ratio, and the three-dimensional spoiler column forming units in different columns have different length hollowing ratios and width hollowing ratios.

[0013] The length hollowing ratio = the height of a single spoiler column forming a cell / (the height difference between adjacent spoiler column forming cells in the same row). Figure 1 As shown, the length hollowing ratio = a / b. The length hollowing ratios of the three-dimensional spoiler column forming units of different columns can be expressed as: (1-1), (1-2), (1-3), (1-4). In the present invention, the length hollowing ratio ranges from 1:0.5 to 1:3.0.

[0014] The width hollowing ratio = the width of a single spoiler column forming a cell / the width of the ceramic core body on the right side of the two sides of the single spoiler column forming a cell on the x-axis. Figure 1As shown, the width hollowing ratio = d / c. The width hollowing ratios of the three-dimensional spoiler column forming units in different columns can be expressed as: (1-6), (1-7), (1-8), (1-9). In the present invention, the width hollowing ratio ranges from 1:1.0 to 1:5.0.

[0015] Preferably, the single spoiler column forming unit cell is provided with different or same transition fillet radii on both sides in the x-axis direction (e.g. Figure 1 (1-5) in the figure).

[0016] Preferably, the transition fillet radius ranges from 0.30 to 0.40 mm.

[0017] In some embodiments of the present invention, 20 spoiler column-forming cells can be divided into 5 groups, each with 4 spoiler column-forming cells (e.g. Figure 2 shown).

[0018] In the present invention, it is preferred that the thickness hollowing ratio of different groups of three-dimensional spoiler column forming units in the same row increases or decreases along the Z axis. For example, the thickness hollowing ratio of different groups of three-dimensional spoiler column forming units increases along the Z axis, specifically as follows Figure 2 As shown. Wherein, the thickness hollowing ratio = the thickness of a single spoiler column forming a unit cell / the thickness of the ceramic core body. Figure 2 As shown, the thickness hollowing ratio = e / f. The thickness hollowing ratio ranges from 8:20 to 8:60.

[0019] In the present invention, it is preferred that the cross-section of the single spoiler column forming the unit cell is in the shape of an ellipse, such as Figure 2 At this time, the thickness of the unit cell formed by the single spoiler column corresponds to the minor axis size of the ellipse.

[0020] Preferably, the raw materials for preparing the ceramic core include, by mass fraction, 80-90% ceramic powder and 10-20% plasticizer.

[0021] Preferably, the ceramic powder comprises, by mass fraction, 80-90% quartz glass powder and 10-20% mineralizer.

[0022] Preferably, the plasticizer comprises, by mass fraction, 65% to 99% paraffin, 1% to 20% polyethylene, and 0% to 15% organic additives.

[0023] Preferably, the organic additive is selected from any one or more of beeswax, resin or paraffin.

[0024] Preferably, the mineralizer is selected from any one or more of mullite, white corundum, zircon sand or cristobalite.

[0025] In a second aspect, the present invention provides a method for using the ceramic core for measuring the recrystallization tendency of the spoiler column structure in the inner cavity of a hollow blade, which comprises the following steps:

[0026] S1: pressing the ceramic core into a wax film, and combining the wax films to obtain a wax film group;

[0027] S2: After the wax film group is subjected to shell preparation, the wax is removed, and a single crystal high temperature alloy is used for casting and shell removal to obtain a single crystal high temperature alloy blank;

[0028] S3: performing vacuum heat treatment on the single crystal high temperature alloy blank to obtain a single crystal high temperature alloy casting;

[0029] S4: Dissect the single crystal high temperature alloy casting along the Z-axis direction and visually observe the recrystallization condition.

[0030] Preferably, the vacuum heat treatment is: treating at 1300-1330° C. for 3-4 hours; cooling to room temperature; treating at 1105-1160° C. for 3-5 hours; treating at 820-890° C. for 30-35 hours; cooling to room temperature.

[0031] Preferably, the single crystal high temperature alloy is selected from any one or more of a nickel-based high temperature alloy, a cobalt-based high temperature alloy or an iron-based high temperature alloy.

[0032] Preferably, the single crystal high temperature alloy includes rhenium.

[0033] Preferably, the rhenium accounts for 0-10% of the mass of the single crystal high temperature alloy.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] The present invention provides a ceramic core for measuring the recrystallization tendency of the spoiler column structure in the inner cavity of a hollow blade, which comprises a ceramic core body and n columns of three-dimensional spoiler column forming units arranged in the ceramic core body, wherein the n columns of three-dimensional spoiler column forming units constitute a hollow structure for forming spoiler columns of a casting; each column of three-dimensional spoiler column forming units is divided into x groups, each group includes m spoiler column forming cells; n is any integer from 2 to 6, x is any integer from 3 to 6, and m is any integer from 4 to 10. In the present invention, the thickness hollowing ratio of different groups of three-dimensional spoiler column forming units in the same column increases or decreases along the Z axis, and the design enables different groups of spoiler column forming units in the same column to have different core thicknesses, so as to optimize the shrinkage matching of the ceramic core and the alloy melt by adjusting the thickness, reduce the plastic deformation of the inner cavity of the blade, and improve the stress distribution of the inner cavity of the blade during the shrinkage process, thereby avoiding the recrystallization phenomenon in the subsequent vacuum heat treatment process, and improving the physical properties and mechanical properties of the blade.

[0036] The present invention is optimized to provide the above ceramic core which can not only significantly improve the quality of the blade, but also avoid the problem of blade scrapping due to recrystallization, thereby effectively reducing production costs. Therefore, this design is not only simple in process and low in cost, but also has important practical application significance for improving the production efficiency and quality of the blade. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 A front view of the ceramic core provided by the present invention;

[0038] Figure 2 A side view of a ceramic core provided by the present invention. DETAILED DESCRIPTION

[0039] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] Furthermore, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessarily obscuring the concepts disclosed in the present invention.

[0041] In the description of the present invention, it should be understood that, unless otherwise expressly specified and limited, the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the special structure ceramic core and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0042] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0043] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Instead, they are merely examples of methods and systems consistent with some aspects of the present invention as detailed in the appended claims.

[0044] Under the current technological environment, a special process is usually used to manufacture alloy blades, that is, adding spoiler columns to the internal cavity of the blade to improve its heat dissipation performance and structural strength. However, during the solidification process, due to the mismatch in shrinkage between the ceramic core and the alloy melt, slight plastic deformation may occur in the blade cavity, and residual stress may be formed inside the material. The presence of residual stress may cause recrystallization during the subsequent heat treatment process, thereby affecting the physical and mechanical properties of the blade.

[0045] Based on this, the present invention provides a ceramic core for measuring the recrystallization tendency of the spoiler column structure in the inner cavity of a hollow blade, which includes a ceramic core body and n rows of three-dimensional spoiler column forming units arranged in the ceramic core body. The ceramic core body is a rectangular plate-shaped structure, and the n rows of three-dimensional spoiler column forming units constitute a hollow structure for forming spoiler columns of castings.

[0046] It should be noted that the spoiler column forming unit is derived from the actual data integration of the spoiler column in the front cavity of the actual working blade, and is used to simulate the stress concentration of the actual blade and predict the recrystallization tendency of the actual blade inner cavity.

[0047] In the present invention, each column of three-dimensional spoiler column forming units can be divided into x groups, each group including m spoiler column forming cells.

[0048] Among them, n is any integer from 2 to 6, specifically 2, 3, 4, 5 or 6, preferably 4; x is any integer from 3 to 6, specifically 3, 4, 5 or 6, preferably 5; m is any integer from 4 to 10, specifically 4, 5, 6, 7, 8, 9 or 10, preferably 4.

[0049] It should be noted that in order to avoid deformation of the ceramic core during the preparation process, the number of spoiler column-forming cells in each column generally does not exceed 30.

[0050] For example, in some embodiments of the present invention, n=4, x=5, and m=4. That is, the structural schematic diagram of the ceramic core is as follows: Figure 1 As shown, the hollow structure is composed of 4 columns, each column including 20 spoiler columns forming cells. It should be noted that n, x, and m can be reasonably taken within the above range, which is only an example and not a limiting description.

[0051] In the present invention, preferably, the three-dimensional spoiler column forming units in each column have the same length hollowing ratio and width hollowing ratio, and the three-dimensional spoiler column forming units in different columns have different length hollowing ratios and width hollowing ratios.

[0052] Wherein, the length hollowing ratio = the height of a single spoiler column forming a cell / (the height difference of adjacent spoiler column forming cells in the same row). In the present invention, the length hollowing ratio ranges from 1:0.5 to 1:3.0, such as 1:0.5, 1:1.0, 1:1.5, 1:2.0, 1:2.5, 1:3.0, etc.

[0053] The width hollowing ratio = the width of a single spoiler column forming cell / the width of the ceramic core body on the right side of the two sides of the single spoiler column forming cell on the x-axis. In the present invention, the width hollowing ratio ranges from 1:1.0 to 1:5.0, such as 1:1.0, 1:2.0, 1:3.0, 1:4.0, 1:5.0, etc.

[0054] In some embodiments of the present invention, 20 spoiler column-forming cells can be divided into 5 groups, each with 4 spoiler column-forming cells (e.g. Figure 2 In the present invention, it is preferred that the thickness hollowing ratio of different groups of three-dimensional spoiler column forming units in the same column increases or decreases along the Z axis. Figure 2 shown.

[0055] The thickness hollowing ratio = the thickness of a single spoiler column forming unit cell / the thickness of the ceramic core body. The thickness hollowing ratio ranges from 8:20 to 8:60, such as 8:20, 8:30, 8:40, 8:50, 8:60, etc.

[0056] The above-mentioned point values ​​of length hollow ratio, width hollow ratio and thickness hollow ratio are only for enumeration. Other point values ​​within their numerical range are applicable. To avoid complexity, they will not be described one by one here.

[0057] For ease of understanding, Figure 1 As shown, the length hollowing ratio can be expressed as: a / b. The length hollowing ratios of the three-dimensional spoiler column forming units in the four columns can be expressed as: (1-1), (1-2), (1-3), (1-4) in sequence. In some embodiments of the present invention, the length hollowing ratios of (1-1), (1-2), (1-3), (1-4) are set to: 1:0.8, 1:1.0, 1:1.2, 1:1.4 in sequence.

[0058] For ease of understanding, Figure 1 As shown, the width hollowing ratio can be expressed as: d / c. The width hollowing ratios of the three-dimensional spoiler column forming units in the four columns can be expressed as: (1-6), (1-7), (1-8), (1-9) in sequence. In some embodiments of the present invention, the width hollowing ratios of (1-6), (1-7), (1-8), and (1-9) are set to: 1:1.0, 1:1.1, 1:1.2, and 1:1.3 in sequence.

[0059] exist Figure 2 In the embodiment of the present invention, the thickness hollowing ratio can be expressed as: e / f. The width hollowing ratios of the three-dimensional spoiler column forming units in each column can be expressed as: (2-1), (2-2), (2-3), (2-4) and (2-5) in sequence. In some embodiments of the present invention, the thickness hollowing ratios of (2-1), (2-2), (2-3), (2-4) and (2-5) are set to: 8:50, 8:55, 8:60, 8:65, 8:70 in sequence.

[0060] After testing, it was found that the above-mentioned different length hollowing ratios, width hollowing ratios and thickness hollowing ratios do have an impact on the recrystallization problem in the blade cavity. According to the results in Table 1, the values ​​of the length hollowing ratio, width hollowing ratio and thickness hollowing ratio in the spoiler column forming unit can be optimized.

[0061] In some embodiments of the present invention, the cross-section of the single spoiler column-forming unit cell is preferably in the shape of an ellipse, such as Figure 2 At this time, the thickness of the unit cell formed by the single spoiler column corresponds to the minor axis size of the ellipse. It should be noted that the present invention has no particular restrictions on the minor axis and major axis sizes of the ellipse, and those skilled in the art can flexibly set them according to actual needs.

[0062] In some preferred embodiments of the present invention, the single spoiler column forming unit cell is provided with different or identical transition fillet radii (such as Figure 1(1-5)) in order to introduce different degrees of smooth transition at different positions, so as to further improve the stress distribution of the subsequent single crystal alloy casting during the shrinkage process. In the present invention, the transition fillet radius ranges from 0.30 to 0.35 mm, such as 0.30 mm, 0.31 mm, 0.32 mm, 0.33 mm, 0.34 mm, 0.35 mm, etc.

[0063] The above-mentioned point values ​​of the transition fillet radius are only for enumeration, and other point values ​​within the numerical range are applicable. To avoid complexity, they will not be described one by one here.

[0064] In some embodiments of the present invention, the transition fillet radii (abbreviated as "R angle") on both sides of the ceramic core are set to 0.30 mm and 0.35 mm respectively.

[0065] In the present invention, the ceramic core is formed by hot pressing ceramic core slurry into a ceramic core green body and then sintering. The ceramic core slurry comprises, by mass fraction, 80-90% ceramic powder and 10-20% plasticizer; preferably 82-85% ceramic powder and 15-18% plasticizer.

[0066] The ceramic powder comprises, by mass fraction, 80-90% quartz glass powder and 10-20% mineralizer, preferably 82-85% quartz glass powder and 15-18% mineralizer. The mineralizer is selected from any one or more of mullite, white corundum, zircon sand or cristobalite, preferably mullite.

[0067] The plasticizer includes, by mass fraction, 65% to 99% paraffin, 1% to 20% polyethylene, and 0% to 15% organic additives, preferably 70% to 85% paraffin, 2% to 15% polyethylene, and 2% to 10% organic additives. The organic additives are selected from any one or more of beeswax, resin or paraffin.

[0068] The present invention also provides a method for using the ceramic core for measuring the recrystallization tendency of the spoiler column structure in the inner cavity of a hollow blade, which comprises the following steps:

[0069] S1: pressing the ceramic core into a wax film, and combining the wax films to obtain a wax film group;

[0070] S2: After the wax film group is subjected to shell preparation, the wax is removed, and a single crystal high temperature alloy is used for casting and shell removal to obtain a single crystal high temperature alloy blank;

[0071] S3: performing vacuum heat treatment on the single crystal high temperature alloy blank to obtain a single crystal high temperature alloy casting;

[0072] S4: Dissect the single crystal high temperature alloy casting along the Z-axis direction and visually observe the recrystallization condition.

[0073] According to the present invention, the ceramic core is first pressed into a wax film, and the wax films are combined to obtain a wax film group.

[0074] First, a ceramic core is prepared. For example, in some embodiments of the present invention, the ceramic core is prepared according to the following method:

[0075] (1) preparing a slurry that meets the above raw material ratio requirements, and obtaining a ceramic core green body by hot pressing;

[0076] The pressing parameters of the hot pressing method are: injection pressure 5.5MPa, injection time 7s, holding time 40s, mold closing pressure 4.0MPa, mold temperature 35°C, slurry temperature 100°C;

[0077] (2) Then insert the green ceramic core into the kaolin filler in the calcining pot, so that the filler completely covers the ceramic core. The calcining pot is placed in a calcining furnace, and after the final calcination temperature is 1180°C, the ceramic core is transformed into a sintered state, and is taken out of the furnace after cooling to room temperature, thereby obtaining a ceramic core.

[0078] It should be noted that the specific parameters involved in the above-mentioned ceramic core preparation process can be adjusted within a reasonable range.

[0079] In the present invention, after the ceramic core is obtained, wax film pressing is performed. The present invention has no special restrictions on the operation of wax film pressing, and it can be performed according to means familiar to those skilled in the art. In some embodiments of the present invention, the ceramic core is placed in a mold, and wax is injected and formed by a wax press to obtain a hollow structural component wax mold having n rows of spoiler column forming units. The hollow structural component wax mold includes: a wax mold and a ceramic core, wherein the wax mold is a paraffin material, which covers and fills the surface of the ceramic core and the hollow hole position, but does not cover the positioning ends on both sides of the core.

[0080] Then the hollow structural component casting module is installed on the wax model assembly device, and a certain inclination angle is set to 0° to obtain the hollow structural component casting module. The wax model assembly device is made of paraffin material and is used to support the hollow structural component wax model.

[0081] Then, according to the present invention, a shell mold is prepared. The present invention has no particular restrictions on the operation of shell mold preparation, and it can be carried out according to means familiar to those skilled in the art. In some embodiments of the present invention, preferably, the outer surface of the hollow structural part casting module is coated with a shell mold coating, and after drying and hardening, a hollow structural part shell mold can be obtained.

[0082] Then, according to the present invention, after the obtained hollow structural part shell is dewaxed, a single crystal high temperature alloy is used for casting and shelling to obtain a single crystal high temperature alloy blank. Wherein, the single crystal high temperature alloy is selected from any one or more of a nickel-based high temperature alloy, a cobalt-based high temperature alloy or an iron-based high temperature alloy. In the present invention, the single crystal high temperature alloy includes rhenium, and the rhenium accounts for 0 to 10% of the mass of the single crystal high temperature alloy, preferably 2 to 5%. According to research, it is found that the introduction of a small amount of metallic rhenium can improve the high temperature strength and creep properties of the alloy, enhance the alloy's bearing capacity and ability to resist plastic deformation at high temperatures; it can control the microstructure of the alloy and optimize the mechanical properties of the alloy by affecting the solidification process of the alloy.

[0083] The specific operations of dewaxing, pouring and shelling can be carried out according to technical means well known to those skilled in the art, which will not be described in detail here.

[0084] Then, the single crystal high temperature alloy blank is subjected to vacuum heat treatment to obtain a single crystal high temperature alloy casting. In some embodiments of the present invention, the vacuum heat treatment is: treating at 1300-1330°C for 3-4 hours; cooling to room temperature; treating at 1105-1160°C for 3-5 hours; cooling to room temperature; treating at 820-890°C for 30-35 hours; cooling to room temperature. Preferably, treating at 1300-1320°C for 3-3.5 hours; cooling to room temperature; treating at 1105-1160°C for 3-4 hours; treating at 820-860°C for 30-34 hours; cooling to room temperature.

[0085] After obtaining the single crystal high temperature alloy casting, it is preferably subjected to mechanical processing and cutting, and then dissected along the Z-axis direction and visually inspected to observe the recrystallization. The mechanical processing includes: removing excess metal on the surface of the blank by wire cutting and grinding.

[0086] In summary, the present invention proposes a special ceramic core design. Specifically, the design sets a plurality of rows of spoiler column forming units on the ceramic core, and each row of spoiler column forming units is further subdivided into different groups. The main difference between different groups of spoiler column forming units is that they have different core thicknesses, so as to optimize the shrinkage matching between the ceramic core and the alloy melt by adjusting the thickness. In addition, different or the same R angles (i.e., transition fillet radius) are respectively set on both sides of each row of spoiler columns, so that different degrees of smooth transition can be introduced at different positions, further improving the stress distribution during the shrinkage process.

[0087] Furthermore, the process flow of using the ceramic core provided by the present invention can be simply summarized as the following steps: first, the wax mold is pressed using a precision mold; then, the wax mold is coated to form a shell; then, the wax is melted and discharged at high temperature, leaving a hollow ceramic core; then, a single crystal high-temperature alloy melt is injected into the hollow core for casting; finally, the casting is subjected to necessary heat treatment to ensure that the microstructure of the material reaches the optimal state. After completing the above series of processes, the spoiler column in the inner cavity of the hollow structural part is inspected in detail to evaluate its degree of recrystallization.

[0088] Based on the experimental research of this application, researchers can further optimize the inclination angle of the wax mold, the hollowing ratio of the spoiler column, and the design of the R angle to find the best combination. Such optimization can not only significantly improve the quality of the blades, but also avoid the problem of blade scrapping due to recrystallization, thereby effectively reducing production costs. Therefore, the ceramic core provided by the present invention is not only simple in preparation process and low in cost, but also has important practical application significance for improving the production efficiency and quality of blades.

[0089] In order to further illustrate the present invention, the following examples are provided for detailed description. The experimental raw materials used in the following examples of the present invention are all common commercially available products.

[0090] Example 1

[0091] This embodiment provides a special structure ceramic core for measuring the recrystallization tendency of the spoiler column structure in the inner cavity of a hollow blade. The ceramic core is set with a length hollowing ratio of 1:0.8, 1:1.0, 1:1.2, and 1:1.4 for four columns, and a width hollowing ratio of 1:1.0, 1:1.1, 1:1.2, and 1:1.3 for four columns. Each column is provided with 20 spoiler column structures, and five different thickness hollowing ratios are set, and the thickness ratios are 8:50, 8:55, 8:60, 8:65, and 8:70, respectively. The R angles on both sides of the ceramic core are set to 0.30 mm and 0.35 mm, respectively.

[0092] The ceramic core slurry ratio is 83wt% of ceramic powder and 17wt% of plasticizer; the ceramic powder is prepared by 86wt% of quartz glass powder and 14wt% of white corundum; the plasticizer is prepared by 91wt% of paraffin, 4wt% of polyethylene and 5wt% of beeswax.

[0093] The pressing parameters of the hot pressing method are: injection pressure 5.5MPa, injection time 7s, holding time 40s, mold closing pressure 4.0MPa, mold temperature 35°C, slurry temperature 100°C, and a ceramic core blank is obtained.

[0094] Insert the green ceramic core into the kaolin filler in the calcining pot, so that the filler completely covers the ceramic core. Put the calcining pot into the roasting furnace, and after the final firing temperature of 1180℃, the ceramic core is transformed into a sintered state, and is taken out of the furnace after cooling to room temperature.

[0095] Placing the ceramic core in a mold, injecting wax and molding with a wax injection machine to obtain a hollow structural component wax mold with a four-row spoiler column structure;

[0096] The hollow structural component casting module is installed on the wax mold assembly device with an inclination angle of 0° to obtain the hollow structural component casting module;

[0097] The outer surface of the hollow structural component casting module is coated with a shell coating, and after drying and hardening, a hollow structural component shell is obtained;

[0098] After dewaxing the interior of the hollow structural component shell, the hollow structural component shell is cast using DD6 single crystal high temperature alloy, and the pulling direction is along the negative direction of the z-axis;

[0099] After pouring, the hollow structural component is shelled to obtain a single crystal hollow structural component blank;

[0100] Performing vacuum heat treatment on the blank;

[0101] The vacuum heat treatment comprises subjecting the blank to vacuum heat treatment in the following steps in sequence:

[0102] 3.5h in 1300℃ high temperature environment;

[0103] Cool to room temperature;

[0104] In a high temperature environment of 1120℃ for 3h;

[0105] In a high temperature environment of 870℃ for 32h;

[0106] Allow to cool to room temperature.

[0107] Mechanically processing the blank to obtain a complete single crystal hollow structural part;

[0108] The single crystal hollow structural member is cut to inspect the recrystallization condition of the inner cavity.

[0109] The test results are shown in Table 1 and Table 2:

[0110] Table 1 Recrystallization quantity of spoiler columns with different hollow ratios at different thicknesses

[0111]

[0112] Table 2 Recrystallization quantity of spoiler columns with different hollowing ratios

[0113] Width hollow ratio 1:1.0 1:1.1 1:1.2 1:1.3 Recrystallization amount 9 / 20 11 / 20 3 / 20 5 / 20

[0114] Based on this, the design of various parameters of the single-crystal high-vortex hollow blade spoiler column can be guided, the optimal hollowing ratio can be designed, the subsequent annealing process can be reduced, the heat treatment cycle can be shortened, and the production efficiency can be improved.

[0115] Example 2

[0116] This embodiment provides a special structure ceramic core for measuring the recrystallization tendency of the spoiler column structure in the inner cavity of a hollow blade. The ceramic core is set with a length hollowing ratio of 1:0.8, 1:1.0, 1:1.2, and 1:1.4 for four columns, and a width hollowing ratio of 1:1.0, 1:1.1, 1:1.2, and 1:1.3 for four columns. Each column is provided with 20 spoiler column structures, and five different thickness hollowing ratios are set, and the thickness ratios are 8:50, 8:55, 8:60, 8:65, and 8:70, respectively. The R angles on both sides of the ceramic core are set to 0.30 mm and 0.35 mm, respectively.

[0117] The ceramic core slurry ratio is 83wt% of ceramic powder and 17wt% of plasticizer; the ceramic powder is prepared by 86wt% of quartz glass powder and 14wt% of white corundum; the plasticizer is prepared by 91wt% of paraffin, 4wt% of polyethylene and 5wt% of beeswax.

[0118] The pressing parameters of the hot pressing method are: injection pressure 5.5MPa, injection time 7s, holding time 40s, mold closing pressure 4.0MPa, mold temperature 35℃, and slurry temperature 100℃.

[0119] Insert the green ceramic core into the kaolin filler in the calcining pot, so that the filler completely covers the ceramic core. Put the calcining pot into the roasting furnace, and after the final firing temperature of 1180℃, the ceramic core is transformed into a sintered state, and is taken out of the furnace after cooling to room temperature.

[0120] Placing the ceramic core in a mold, injecting wax and molding with a wax injection machine to obtain a hollow structural component wax mold with a four-row spoiler column structure;

[0121] The hollow structural part casting module is installed on the wax mold assembly device, the wax mold chassis size is 300 mm, each wax mold group has 8 wax molds, and the 8 wax molds are respectively set at inclination angles of 3°, 5°, 7°, and 9° to obtain the hollow structural part casting module;

[0122] The outer surface of the hollow structural component casting module is coated with a shell coating, and after drying and hardening, a hollow structural component shell is obtained;

[0123] After dewaxing the inside of the hollow structural component shell, the hollow structural component shell is cast using a DZ422 single crystal high temperature alloy, and the pulling direction is along the negative direction of the z-axis;

[0124] After pouring, the hollow structural component is shelled to obtain a single crystal hollow structural component blank;

[0125] Performing vacuum heat treatment on the blank;

[0126] The vacuum heat treatment comprises subjecting the blank to vacuum heat treatment in the following steps in sequence:

[0127] 4h in a high temperature environment of 1308℃;

[0128] Cool to room temperature;

[0129] In a high temperature environment of 1120℃ for 3h;

[0130] In a high temperature environment of 870℃ for 32h;

[0131] Allow to cool to room temperature.

[0132] Mechanically processing the blank to obtain a complete single crystal hollow structural part;

[0133] The single crystal hollow structural member is cut to inspect the recrystallization condition of the inner cavity.

[0134] According to statistics, no recrystallization occurred in the inner cavity of castings with inclination angles of 3°, 5° and 7°. Therefore, in actual blade production, the recommended wax mold inclination angles are 3°, 5° and 7°.

[0135] Example 3

[0136] This embodiment provides a special structure ceramic core for measuring the recrystallization tendency of the spoiler column structure in the inner cavity of a hollow blade. The ceramic core is set with a length hollowing ratio of 1:0.8, 1:1.0, 1:1.2, and 1:1.4 for four columns, and a width hollowing ratio of 1:1.0, 1:1.1, 1:1.2, and 1:1.3 for four columns. Each column is provided with 20 spoiler column structures, and five different thickness hollowing ratios are set, and the thickness ratios are 8:50, 8:55, 8:60, 8:65, and 8:70, respectively. The R angles on both sides of the ceramic core are set to 0.30 mm and 0.35 mm, respectively.

[0137] The ceramic core slurry W1 has a ratio of 80wt% ceramic powder and 20wt% plasticizer; the ceramic powder is prepared by 86wt% quartz glass powder and 14wt% zirconium silicate in proportion; the plasticizer is prepared by 91wt% paraffin, 4wt% polyethylene and 5wt% beeswax in proportion.

[0138] The ratio of ceramic core slurry W2 is 85wt% ceramic powder and 15wt% plasticizer; the ceramic powder is prepared in proportion by 86wt% quartz glass powder and 14wt% zirconium silicate; the plasticizer is prepared in proportion by 91wt% paraffin, 4wt% polyethylene and 5wt% beeswax.

[0139] The ceramic core slurry W3 has a ratio of 90wt% ceramic powder and 10wt% plasticizer; the ceramic powder is prepared in proportion by 86wt% quartz glass powder and 14wt% zirconium silicate; the plasticizer is prepared in proportion by 91wt% paraffin, 4wt% polyethylene and 5wt% beeswax.

[0140] The pressing parameters of the hot pressing method are: injection pressure 5.5MPa, injection time 7s, holding time 40s, mold closing pressure 4.0MPa, mold temperature 35℃, and slurry temperature 100℃.

[0141] Insert the green ceramic core into the kaolin filler in the calcining pot, so that the filler completely covers the ceramic core. Put the calcining pot into the roasting furnace, and after the final firing temperature of 1209℃, the ceramic core is transformed into a sintered state, and is taken out of the furnace after cooling to room temperature.

[0142] Placing the ceramic core in a mold, injecting wax and molding with a wax injection machine to obtain a hollow structural component wax mold with a four-row spoiler column structure;

[0143] The hollow structural part casting module is installed on the wax mold assembly device, the wax mold chassis size is 400 mm, each wax mold assembly has 12 wax molds, the wax mold group has an inclination angle of 3°, and 4 cores of W1, W2, and W3 are used to obtain the hollow structural part casting module;

[0144] The outer surface of the hollow structural component casting module is coated with a shell coating, and after drying and hardening, a hollow structural component shell is obtained;

[0145] After dewaxing the interior of the hollow structural part shell, the hollow structural part shell is cast using CMSX-4 single crystal high temperature alloy;

[0146] After pouring, the hollow structural component is shelled to obtain a single crystal hollow structural component blank;

[0147] Performing vacuum heat treatment on the blank;

[0148] The vacuum heat treatment comprises subjecting the blank to vacuum heat treatment in the following steps in sequence:

[0149] In a high temperature environment of 1304℃ for 4h;

[0150] Cool to room temperature;

[0151] 4h in a high temperature environment of 1120℃;

[0152] In a high temperature environment of 870℃ for 34h;

[0153] Allow to cool to room temperature.

[0154] Mechanically processing the blank to obtain a complete single crystal hollow structural part;

[0155] The single crystal hollow structural parts were cut to examine the recrystallization of the inner cavity. According to statistics, the number of recrystallizations of the spoiler columns in the W1 sample was the least, indicating that the single crystal blades prepared using the W1 ceramic core have a lower tendency to recrystallize.

[0156] Example 4

[0157] This embodiment provides a ceramic core for measuring the recrystallization tendency of the spoiler column structure in the inner cavity of a hollow blade. The ceramic core is set with a length hollowing ratio of 1:0.8, 1:1.0, 1:1.2, and 1:1.4 for four columns, and a width hollowing ratio of 1:1.0, 1:1.1, 1:1.2, and 1:1.3 for four columns. Each column is provided with 20 spoiler column structures, and five different thickness hollowing ratios are set, and the thickness ratios are 8:50, 8:55, 8:60, 8:65, and 8:70, respectively. The R angles on both sides of the ceramic core are set to 0.30 mm and 0.35 mm, respectively.

[0158] The ceramic core slurry ratio is 83wt% of ceramic powder and 17wt% of plasticizer; the ceramic powder is prepared by 86wt% of quartz glass powder and 14wt% of white corundum; the plasticizer is prepared by 91wt% of paraffin, 4wt% of polyethylene and 5wt% of beeswax.

[0159] The pressing parameters of the hot pressing method are: injection pressure 5.5MPa, injection time 7s, holding time 40s, mold closing pressure 4.0MPa, mold temperature 35℃, and slurry temperature 100℃.

[0160] Insert the green ceramic core into the kaolin filler in the calcining pot, so that the filler completely covers the ceramic core. Put the calcining pot into the roasting furnace, and after the final firing temperature of 1180℃, the ceramic core is transformed into a sintered state, and is taken out of the furnace after cooling to room temperature.

[0161] Placing the ceramic core in a mold, injecting wax and molding with a wax injection machine to obtain a hollow structural component wax mold with a four-row spoiler column structure;

[0162] The hollow structural part casting mold is installed on the wax mold assembly device, the wax mold chassis size is 300 mm, each group of wax molds has 8 wax molds, and three groups are prepared to obtain the hollow structural part casting mold;

[0163] The outer surface of the hollow structural component casting module is coated with a shell coating, and after drying and hardening, a hollow structural component shell is obtained;

[0164] After dewaxing the inside of the hollow structural part shell, pouring the hollow structural part shell with CMSX-4 single crystal high temperature alloy having rhenium content of 2.0wt%, 2.2wt%, and 2.4wt%, and pulling in the negative direction of the z-axis;

[0165] After pouring, the hollow structural component is shelled to obtain a single crystal hollow structural component blank;

[0166] Performing vacuum heat treatment on the blank;

[0167] The vacuum heat treatment comprises subjecting the blank to vacuum heat treatment in the following steps in sequence:

[0168] 3.5h in 1300℃ high temperature environment;

[0169] Cool to room temperature;

[0170] In a high temperature environment of 1120℃ for 3h;

[0171] In a high temperature environment of 870℃ for 32h;

[0172] Allow to cool to room temperature.

[0173] Mechanically processing the blank to obtain a complete single crystal hollow structural part;

[0174] The single crystal hollow structural member is cut to inspect the recrystallization condition of the inner cavity.

[0175] According to statistics, the alloy spoiler column with 2.4wt% rhenium added has the least amount of recrystallization, and further optimization experiments can be carried out.

[0176] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A ceramic core for measuring the recrystallization tendency of the spoiler column structure in the inner cavity of a hollow blade, characterized in that: It comprises a ceramic core body and n rows of three-dimensional spoiler column forming units arranged in the ceramic core body, wherein the n rows of three-dimensional spoiler column forming units constitute a hollow structure and are used to form spoiler columns of a casting; Each column of three-dimensional spoiler column forming units is divided into x groups, each group includes m spoiler column forming cells; The n is any integer from 2 to 6, the x is any integer from 3 to 6, and the m is any integer from 4 to 10; The thickness hollowing ratio of different groups of three-dimensional spoiler column forming units in the same row increases or decreases along the Z axis; The thickness hollowing ratio = the thickness of a single spoiler column forming a cell / the thickness of the ceramic core body; The thickness-to-hollow ratio ranges from 8:20 to 8:

60.

2. The ceramic core for measuring the recrystallization tendency of the hollow blade inner cavity spoiler column structure according to claim 1, characterized in that: The length hollowing ratio and width hollowing ratio of the three-dimensional spoiler column forming units in each column are the same, and the length hollowing ratio and width hollowing ratio of the three-dimensional spoiler column forming units in different columns are different; The length hollowing ratio = the height of a single spoiler column forming a cell / (the height difference between adjacent spoiler column forming cells in the same row); The width hollowing ratio = the width of a single spoiler column forming a cell / the width of the ceramic core body on the right side of the two sides of the single spoiler column forming a cell on the x-axis; The range of the length hollowing ratio is 1:0.5 to 1:3.0, and the range of the width hollowing ratio is 1:1.0 to 1:5.

0.

3. The ceramic core for measuring the recrystallization tendency of the hollow blade inner cavity spoiler column structure according to claim 1 or 2, characterized in that: The cross-section of the unit cell formed by the single spoiler column is in the shape of an ellipse; The thickness of the unit cell formed by the single spoiler column is equal to the minor axis dimension of the ellipse.

4. The ceramic core for measuring the recrystallization tendency of the hollow blade inner cavity spoiler column structure according to any one of claims 1 to 3, characterized in that: The single spoiler column forming cell is provided with different or same transition fillet radii on both sides in the x-axis direction; The transition fillet radius ranges from 0.30 to 0.40 mm.

5. The ceramic core for measuring the recrystallization tendency of the spoiler column structure in the inner cavity of a hollow blade according to any one of claims 1 to 4, characterized in that: The raw materials for preparing the ceramic core include, by mass fraction, 80-90% ceramic powder and 10-20% plasticizer; The ceramic powder comprises, by mass fraction, 80-90% of quartz glass powder and 10-20% of mineralizer; The plasticizer comprises, by mass fraction, 65% to 99% paraffin, 1% to 20% polyethylene, and 0% to 15% organic additives; The organic additive is selected from any one or more of beeswax, resin or paraffin.

6. The ceramic core for measuring the recrystallization tendency of the hollow blade inner cavity spoiler column structure according to claim 5, characterized in that: The mineralizer is selected from any one or more of mullite, white corundum, zircon sand or cristobalite.

7. A method for using a ceramic core for measuring the recrystallization tendency of a hollow blade inner cavity spoiler column structure, characterized in that: The following steps are involved: S1: pressing the ceramic core according to any one of claims 1 to 6 into a wax film, and combining the wax films to obtain a wax film group; S2: After the wax film group is subjected to shell preparation, the wax is removed, and a single crystal high temperature alloy is used for casting and shell removal to obtain a single crystal high temperature alloy blank; S3: performing vacuum heat treatment on the single crystal high temperature alloy blank to obtain a single crystal high temperature alloy casting; S4: Dissect the single crystal high temperature alloy casting along the Z-axis direction and visually observe the recrystallization condition.

8. The method of use according to claim 7, characterized in that: The vacuum heat treatment is as follows: treating at 1300-1330° C. for 3-4 hours; cooling to room temperature; treating at 1105-1160° C. for 3-5 hours; treating at 820-890° C. for 30-35 hours; cooling to room temperature.

9. The method of use according to claim 7 or 8, characterized in that: The single crystal high temperature alloy is selected from any one or more of a nickel-based high temperature alloy, a cobalt-based high temperature alloy or an iron-based high temperature alloy.

10. The method of use according to claim 9, characterized in that: The single crystal high temperature alloy includes rhenium; The rhenium accounts for 0% to 10% of the mass of the single crystal high temperature alloy.

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