A ceramic core for measuring the recrystallization tendency of the spoiler column structure in the inner cavity of a hollow blade and its use method

Abstract

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 and a method for using the same. The ceramic core comprises a ceramic core body and n rows of three-dimensional spoiler column forming units arranged in the ceramic core body. The n rows of three-dimensional spoiler column forming units constitute a hollow structure for forming spoiler columns of a casting. In the present invention, 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. This design allows different groups of spoiler column forming units in the same row to have different core thicknesses, so as to optimize the shrinkage matching between the ceramic core and the alloy melt by adjusting the thickness, reduce the plastic deformation of the blade cavity, improve the stress distribution in the blade cavity 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.

Description

Technical Field

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

[0002] Turbine blades are one of the most critical hot-end components of advanced aircraft engines. To further increase the temperature at the blade tip and optimize the engine's thrust-to-weight ratio, advanced gas turbine blades typically employ air cooling. Air-cooled hollow blade technology, film cooling, and multi-layer impingement cooling can effectively improve the hollow blade's thermal capacity in high-load, high-temperature environments, resulting in a higher thermal tolerance.

[0003] Therefore, to further improve the temperature-bearing capacity of single-crystal blades, the complexity and large-scale size of the air-cooling structure of single-crystal high-temperature alloy turbine blades have become an effective means and an inevitable trend to continue to improve the overall performance of key hot-end components of aircraft engines. However, as the complexity of the internal cavity structure of advanced turbine blades increases, the quality of the internal cavity needs to be more strictly controlled and guaranteed. Among them, the problem of internal cavity recrystallization has become one of the key technical difficulties in internal cavity quality. 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 in single-crystal high-temperature alloy components. Therefore, once recrystallization occurs in single-crystal components, their performance will be greatly reduced, which may lead to premature failure of the component.

[0004] As a key component in forming the inner cavity structure of a single-crystal hollow blade, the ceramic core hinders the alloy's solidification during solidification and shrinkage, easily causing minute plastic deformation within the blade cavity. This localized plastic deformation is in a metastable state, releasing the stored energy during heat treatment, triggering recrystallization on the blade's local surface.

[0005] Unlike recrystallization on the outer surface, the biggest difficulty in recrystallization of the inner cavity is that it is difficult to detect directly and the detection efficiency is low. In the actual production process, recrystallization of the inner cavity is very likely to occur at the point where the cross-sectional area changes suddenly, especially at the position of the spoiler column in 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 result in a long experimental cycle and easily cause a 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. 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, and m=4. That is, the structural 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 cell / the height difference between the bottom surface of the spoiler column forming cell located on the upper side and the top surface of the spoiler column forming cell located on the lower side in the adjacent spoiler columns in the same row. Figure 1 As shown, the length hollowing ratio = a / b. The length hollowing ratios of different rows of three-dimensional spoiler column forming units 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 left 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 different rows of three-dimensional spoiler column forming units 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 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 text).

[0016] Preferably, the transition fillet radius is in the range of 0.30-0.40 mm.

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

[0018] In the present invention, it is preferred that the thickness hollowing ratio of the three-dimensional spoiler column forming units of different groups in the same column increases or decreases along the Z axis. For example, the thickness hollowing ratio of the three-dimensional spoiler column forming units of different groups increases along the Z axis, specifically as follows Figure 2 As shown. Wherein, the thickness hollowing ratio = thickness of a single spoiler column forming a cell / thickness of the ceramic core body. Figure 2 As shown, the thickness-to-hollow ratio = e / f. The thickness-to-hollow 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 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 structure in the inner cavity of a hollow blade, comprising the following steps:

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

[0027] S2: After the wax film group is prepared into a shell, it is dewaxed, cast with a single crystal high-temperature alloy, and shelled 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 and visually observe the recrystallization condition.

[0030] Preferably, the vacuum heat treatment is: treating at 1300-1330° C. for 3-4 h; cooling to room temperature; treating at 1105-1160° C. for 3-5 h; treating at 820-890° C. for 30-35 h; and 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. The ceramic core comprises a ceramic core body and n rows of three-dimensional spoiler column forming units arranged in the ceramic core body. The n rows of three-dimensional spoiler column forming units constitute a hollow structure for forming spoiler columns of a casting. Each row of three-dimensional spoiler column forming units is divided into x groups, each group including 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 row increases or decreases along the Z axis. This design allows different groups of spoiler column forming units in the same row to have different core thicknesses, so that the shrinkage matching between the ceramic core and the alloy melt can be optimized by adjusting the thickness, reducing plastic deformation in the blade cavity, and improving the stress distribution in the blade cavity during shrinkage, thereby avoiding recrystallization during subsequent vacuum heat treatment and improving the physical and mechanical properties of the blade.

[0036] The optimized ceramic core provided by the present invention not only significantly improves blade quality but also avoids blade rejection due to recrystallization, effectively reducing production costs. Therefore, this design not only simplifies the process and reduces costs, but also has important practical applications for improving blade production efficiency and quality. 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 the ceramic core provided by the present invention. DETAILED DESCRIPTION

[0039] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts 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", "transverse", "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 accompanying 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 limiting 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 the indicated technical features. Therefore, 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 expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0043] Exemplary embodiments will be described in detail herein, examples of which are illustrated in the accompanying drawings. In the following description, when referring to the drawings, like numbers in different figures represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all possible embodiments consistent with the present invention. Rather, they are merely examples of methods and systems consistent with certain aspects of the present invention, as detailed in the appended claims.

[0044] Under current technology, alloy blades are typically manufactured using a special process that incorporates spoiler columns within the blade's internal cavity to improve heat dissipation and structural strength. However, during solidification, the shrinkage mismatch between the ceramic core and the alloy melt can cause slight plastic deformation within the blade cavity, leading to residual stress within the material. The presence of residual stress can trigger recrystallization during subsequent heat treatment, affecting the blade's physical and mechanical properties.

[0045] Based on this, the present invention provides a ceramic core for measuring the recrystallization tendency of the spoiler structure in the cavity of a hollow blade. The core comprises a ceramic core body and n rows of three-dimensional spoiler forming units disposed within the ceramic core body. The ceramic core body is a rectangular plate-like structure, and the n rows of three-dimensional spoiler forming units form a hollow structure for forming the spoilers of a casting.

[0046] It should be noted that the spoiler forming unit is derived from the actual data integration of the spoiler in the front cavity of an actual working blade, and is used to simulate the stress concentration of an 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, and each group includes m spoiler column forming cells.

[0048] wherein 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 diagram of the ceramic core is as follows: Figure 1 As shown, the hollow structure is composed of 4 rows, each row including 20 spoiler columns forming cells. It should be noted that the values ​​of n, x, and m can be reasonably taken within the above ranges, which are only for example and not for limitation.

[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] The length hollowing ratio is calculated as follows: the height of a single spoiler column forming cell / the height difference between the bottom surface of the spoiler column forming cell located on the upper side and the top surface of the spoiler column forming cell located on the lower side of adjacent spoiler columns in the same row. In the present invention, the length hollowing ratio ranges from 1:0.5 to 1:3.0, and specifically can be 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 left side 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, and specifically can be 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 columns forming cells can be divided into 5 groups, each with 4 spoiler columns forming cells (e.g. Figure 2 In the present invention, it is preferred that the thickness hollowing ratio of the three-dimensional spoiler column forming units of different groups in the same column increases or decreases along the Z axis. For example, the thickness hollowing ratio of the three-dimensional spoiler column forming units of different groups increases along the Z axis, specifically as follows Figure 2 shown.

[0055] The thickness-to-hollow ratio = the thickness of a single spoiler column forming cell / the thickness of the ceramic core body. The thickness-to-hollow ratio ranges from 8:20 to 8:60, and specifically can be 8:20, 8:30, 8:40, 8:50, 8:60, etc.

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

[0057] For ease of understanding, the specific 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), and (1-4) are set to: 1:0.8, 1:1.0, 1:1.2, and 1:1.4 in sequence.

[0058] For ease of understanding, the specific 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, and 8:70 in sequence.

[0060] After testing, it was found that the settings of the above-mentioned different length hollowing ratios, width hollowing ratios and thickness hollowing ratios do have an impact on the recrystallization problem of 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, it is preferred that the cross-section of the single spoiler column forming the cell is elliptical, such as Figure 2 At this time, the thickness of the single spoiler column forming the unit cell 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 cell is provided with different or identical transition fillet radii (such as Figure 1(1-5) in the figure) to introduce varying degrees of smooth transitions at different locations, thereby further improving the stress distribution of the subsequent single crystal alloy casting during shrinkage. 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 transition fillet radius are only for enumeration. 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 a ceramic core slurry into a ceramic core green body, followed by sintering. The ceramic core slurry comprises, by mass, 80-90% ceramic powder and 10-20% plasticizer, preferably 82-85% ceramic powder and 15-18% plasticizer.

[0066] The ceramic powder comprises, by mass, 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 comprises, by mass fraction, 65% to 99% paraffin wax, 1% to 20% polyethylene, and 0% to 15% organic additives, preferably 70% to 85% paraffin wax, 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 wax.

[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 wax films, and combining the wax films to obtain a wax film group;

[0070] S2: After the wax film group is prepared into a shell, it is dewaxed, cast with a single crystal high-temperature alloy, and shelled 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 and visually observe the recrystallization condition.

[0073] According to the present invention, the ceramic core is first pressed into wax films, 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-mentioned 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 5.5 MPa, injection time 7 s, holding time 40 s, mold closing pressure 4.0 MPa, mold temperature 35°C, and slurry temperature 100°C;

[0077] (2) The green ceramic core is then inserted into the kaolin filler in the calcination bowl so that the filler completely covers the ceramic core. The calcination bowl is placed in a calcination furnace. After the final calcination temperature reaches 1180°C, the ceramic core is transformed into a sintered state. After cooling to room temperature, the ceramic core is removed from the furnace to obtain 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 obtaining the ceramic core, 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 the 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 part wax mold with n rows of spoiler column forming units. The hollow structural part 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 mounted on a wax mold assembly device and a certain tilt angle is set to 0° to obtain the hollow structural component casting module. The wax mold assembly device is made of paraffin material and is used to support the hollow structural component wax mold.

[0081] Then, according to the present invention, a shell mold is prepared. The present invention does not particularly limit the shell mold preparation process, and the process can be performed using methods well known to those skilled in the art. In some embodiments of the present invention, the exterior of the hollow structural component casting module is preferably coated with a shell mold coating, which is dried and hardened to obtain a hollow structural component shell mold.

[0082] Then, according to the present invention, the hollow structural part shell obtained is dewaxed, and then cast with a single crystal high-temperature alloy and shelled to obtain a single crystal high-temperature alloy blank. 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 0-10% of the mass of the single crystal high-temperature alloy, preferably 2-5%. Studies have 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 load-bearing capacity and ability to resist plastic deformation at high temperatures; and can control the alloy's microstructure and optimize the alloy's mechanical properties by affecting the alloy's solidification process.

[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 and will not be described in detail here.

[0084] The single crystal superalloy blank is then subjected to vacuum heat treatment to obtain a single crystal superalloy casting. In some embodiments of the present invention, the vacuum heat treatment comprises: 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; and cooling to room temperature. Preferably, the treatment comprises 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; and cooling to room temperature.

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

[0086] In summary, the present invention proposes a unique ceramic core design. Specifically, this design incorporates multiple rows of spoiler-forming units, each row of which is further subdivided into different groups. The main difference between the different groups of spoiler-forming units lies in their varying core thicknesses, allowing for optimized shrinkage compatibility between the ceramic core and the molten alloy by adjusting the thickness. Furthermore, each row of spoilers has different or identical R angles (i.e., transition fillet radii) on both sides. This allows for varying degrees of smooth transitions at different locations, further improving stress distribution during shrinkage.

[0087] Furthermore, the process flow for using the ceramic core provided by the present invention can be simply summarized as the following steps: first, a wax pattern is pressed using a precision mold; then, the wax pattern 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 the necessary heat treatment to ensure that the material's microstructure reaches an optimal state. After completing the above series of processes, the spoiler column in the inner cavity of the hollow structural component is carefully inspected to assess 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 blade, 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 to prepare 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 commonly available commercial products.

[0090] Example 1

[0091] This embodiment provides a specially structured ceramic core for measuring the recrystallization tendency of the spoiler structure in the cavity of a hollow blade. The ceramic core has a length hollowing ratio of 1:0.8, 1:1.0, 1:1.2, and 1:1.4 for the four rows, and a width hollowing ratio of 1:1.0, 1:1.1, 1:1.2, and 1:1.3 for the four rows. Each row has 20 spoiler structures, and five different thickness hollowing ratios are set: 8:50, 8:55, 8:60, 8:65, and 8:70. 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 83 wt% of ceramic powder and 17 wt% of plasticizer; the ceramic powder is prepared by 86 wt% of quartz glass powder and 14 wt% of white corundum in proportion; the plasticizer is prepared by 91 wt% of paraffin wax, 4 wt% of polyethylene, and 5 wt% of beeswax in proportion.

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

[0094] Insert the green ceramic core into the kaolin filler in the calcination pot, so that the filler completely covers the ceramic core. Place the calcination pot in the roasting furnace, and after the final firing temperature of 1180℃, the ceramic core is transformed into a sintered state. It is then 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 press to obtain a hollow structural component wax mold with a four-row spoiler column structure;

[0096] The hollow structural member casting module is mounted on a wax mold assembly device at an inclination angle of 0° to obtain a hollow structural member 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 part shell, DD6 single crystal high temperature alloy is used to cast the hollow structural part shell, and the pulling direction is along the negative direction of the z-axis;

[0099] After casting, the hollow structural member is shelled to obtain a single crystal hollow structural member 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:

[0102] 3.5 h in a high temperature environment of 1300°C;

[0103] Cool to room temperature;

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

[0105] 32 h in a high temperature environment of 870°C;

[0106] 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 amount of spoiler columns with different hollow ratios and thickness

[0111]

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

[0113]

[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 production efficiency can be improved.

[0115] Example 2

[0116] This embodiment provides a specially structured ceramic core for measuring the recrystallization tendency of the spoiler structure in the cavity of a hollow blade. The ceramic core has a length hollowing ratio of 1:0.8, 1:1.0, 1:1.2, and 1:1.4 for the four rows, and a width hollowing ratio of 1:1.0, 1:1.1, 1:1.2, and 1:1.3 for the four rows. Each row has 20 spoiler structures, and five different thickness hollowing ratios are set: 8:50, 8:55, 8:60, 8:65, and 8:70. 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 83 wt% of ceramic powder and 17 wt% of plasticizer; the ceramic powder is prepared by 86 wt% of quartz glass powder and 14 wt% of white corundum in proportion; the plasticizer is prepared by 91 wt% of paraffin wax, 4 wt% of polyethylene, and 5 wt% of beeswax in proportion.

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

[0119] Insert the green ceramic core into the kaolin filler in the calcination pot, so that the filler completely covers the ceramic core. Place the calcination pot in the roasting furnace, and after the final firing temperature of 1180℃, the ceramic core is transformed into a sintered state. It is then 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 press 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. 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 interior of the hollow structural component shell, the hollow structural component shell is cast using DZ422 single crystal high temperature alloy, and the pulling direction is along the negative direction of the z-axis;

[0124] After casting, the hollow structural member is shelled to obtain a single crystal hollow structural member 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:

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

[0128] Cool to room temperature;

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

[0130] 32 h in a high temperature environment of 870°C;

[0131] 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 specially structured ceramic core for measuring the recrystallization tendency of the spoiler structure in the cavity of a hollow blade. The ceramic core has a length hollowing ratio of 1:0.8, 1:1.0, 1:1.2, and 1:1.4 for the four rows, and a width hollowing ratio of 1:1.0, 1:1.1, 1:1.2, and 1:1.3 for the four rows. Each row has 20 spoiler structures, and five different thickness hollowing ratios are set: 8:50, 8:55, 8:60, 8:65, and 8:70. 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 80 wt% ceramic powder and 20 wt% plasticizer; the ceramic powder is prepared in proportion by 86 wt% quartz glass powder and 14 wt% zirconium silicate; the plasticizer is prepared in proportion by 91 wt% paraffin wax, 4 wt% polyethylene, and 5 wt% beeswax.

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

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

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

[0141] Insert the green ceramic core into the kaolin filler in the calcination pot, so that the filler completely covers the ceramic core. Place the calcination pot in the roasting furnace, and after the final firing temperature of 1209℃, the ceramic core is transformed into a sintered state. It is then 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 press 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 a wax mold assembly device. The wax mold chassis size is 400 mm. Each wax mold assembly has a total of 12 wax molds. The wax mold group has an inclination angle of 3°. Four cores of W1, W2, and W3 are used to obtain a 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 casting, the hollow structural member is shelled to obtain a single crystal hollow structural member 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:

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

[0150] Cool to room temperature;

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

[0152] 34 h in a high temperature environment of 870°C;

[0153] 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 recrystallized 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 structure in the cavity of a hollow blade. The ceramic core has a length hollowing ratio of 1:0.8, 1:1.0, 1:1.2, and 1:1.4 for four rows, and a width hollowing ratio of 1:1.0, 1:1.1, 1:1.2, and 1:1.3 for four rows. Each row has 20 spoiler structures, and five different thickness hollowing ratios are set: 8:50, 8:55, 8:60, 8:65, and 8:70. 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 83 wt% of ceramic powder and 17 wt% of plasticizer; the ceramic powder is prepared by 86 wt% of quartz glass powder and 14 wt% of white corundum in proportion; the plasticizer is prepared by 91 wt% of paraffin wax, 4 wt% of polyethylene, and 5 wt% of beeswax in proportion.

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

[0160] Insert the green ceramic core into the kaolin filler in the calcination pot, so that the filler completely covers the ceramic core. Place the calcination pot in the roasting furnace, and after the final firing temperature of 1180℃, the ceramic core is transformed into a sintered state. It is then 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 press 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 a wax mold assembly device. The wax mold chassis size is 300 mm. Each group of wax molds has a total of 8 wax molds. 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 interior of the hollow structural component shell, the hollow structural component shell is cast using a CMSX-4 single crystal high-temperature alloy having a rhenium content of 2.0 wt%, 2.2 wt%, and 2.4 wt%, and the pulling direction is along the negative direction of the z-axis;

[0165] After casting, the hollow structural member is shelled to obtain a single crystal hollow structural member 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:

[0168] 3.5 h in a high temperature environment of 1300°C;

[0169] Cool to room temperature;

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

[0171] 32 h in a high temperature environment of 870°C;

[0172] 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 2.4 wt% rhenium added has the least amount of recrystallization, which can be further optimized.

[0176] The above description of the disclosed embodiments will enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one 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 is not limited to the embodiments shown herein but is to be construed in the widest manner 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 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; 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; 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 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 cell / the height difference between the bottom surface of the spoiler column forming cell located on the upper side and the top surface of the spoiler column forming cell located on the lower side in adjacent spoiler column forming cells in the same column; The width hollowing ratio=the width of a single spoiler column forming a cell / the width of the ceramic core body on the left 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 1:0.5~1:3.0, and the range of the width hollowing ratio is 1:1.0~1:5.

0.

3. The ceramic core for measuring the recrystallization tendency of the hollow blade inner cavity spoiler 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 size of the ellipse.

4. The ceramic core for measuring the recrystallization tendency of the hollow blade inner cavity spoiler structure according to claim 1 or 2, 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 hollow blade inner cavity spoiler structure according to claim 1 or 2, 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% quartz glass powder and 10-20% 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 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 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 mold, and combining the wax molds to obtain a wax mold set; S2: After the wax mold is shelled, the wax mold is dewaxed, and a single crystal high-temperature alloy is used for casting and shelling to obtain a single crystal high-temperature alloy blank; S3: vacuum heat treating 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 and visually observe the recrystallization condition.

8. The method of use according to claim 7, characterized in that: The vacuum heat treatment comprises the following steps: 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; and 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 nickel-based high temperature alloy, cobalt-based high temperature alloy or 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.

Images