Test method for researching mixed crystals on single crystal blade partition plate platform and blade model

Abstract

The invention provides a test method for researching mixed crystals on a single crystal blade partition plate platform and a blade model, and relates to the technical field of aero-engine blades. Firstly, the blade model is designed, and the blade model comprises two parallel model outer plates and a model partition plate located between the two model outer plates; the distance between the two model outer plates is equal to the maximum width of an actual blade simulated by the blade model; then a blade model is manufactured through a casting technology; (3) analyzing the platform mixed crystal growth condition of the model partition plate; complex structures such as air film holes and turbulent flow columns in an actual blade are omitted, meanwhile, an arc-shaped actual outer plate in the actual blade is simplified into a parallel model outer plate, the modeling process of a blade model and the design forming process of a casting mold are remarkably simplified, the modeling and casting cost is reduced, and the test efficiency is improved; blade models of different partition plate structures can be obtained more easily, and the growth condition of mixed crystals on the partition plate platform of the inner cavity of the blade can be further analyzed.

Description

Technical Field

[0001] The invention relates to the technical field of aero-engine blades, and in particular to a test method for studying miscellaneous crystals on a single-crystal blade partition platform and a blade model. Background Art

[0002] The thrust-to-weight ratio of an aircraft engine is directly related to its turbine inlet temperature. As modern aircraft demand higher thrust-to-weight ratios, the turbine inlet temperature of the engine is also getting higher. In order to improve the cooling efficiency and mechanical properties of turbine blades at extremely high temperatures, the structure of turbine blades tends to be thinner and more complex. In order to improve the cooling performance of the blades, baffles are designed in the blade cavity to increase the heat dissipation area of ​​the blades.

[0003] Traditionally, aircraft engine blades are formed by welding, but the welds produced by welding seriously affect the high temperature performance and mechanical properties of the blades at high temperatures. Casting can avoid the appearance of welds, so casting is becoming more and more common in the manufacture of aircraft engine blades. However, in the actual casting process, the inventors found that it is very easy for stray crystals to appear at the internal partition of the blade. The appearance of stray crystals destroys the single crystal integrity of the blade and greatly reduces the high temperature performance and mechanical properties of the blade.

[0004] In the technology known to the inventor, the situation of the impurity crystals in the blade is usually analyzed after the blade is cast, so as to further improve the blade structure and reduce the occurrence of impurity crystals. However, the blade structure is complex, and the design, manufacture and casting process of the casting mold are relatively cumbersome and costly. Therefore, it is necessary to design a simple test method to study the impurity crystal problem of the partition platform in the single crystal blade. Summary of the invention

[0005] The purpose of the present invention is to provide a test method and blade model for single crystal blade partition platform impurities to solve the problems existing in the prior art, significantly simplify the modeling process of the blade model and the design and molding process of the casting mold, reduce the modeling and casting costs, improve the test efficiency, and facilitate the analysis of the growth of impurities on the blade inner cavity partition platform.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] An experimental method for studying the miscellaneous crystals of a single crystal blade partition platform comprises the following steps:

[0008] 1) Designing a blade model: the blade model comprises two parallel model outer plates and a model partition between the two model outer plates, wherein the two ends of the model partition are respectively connected to the two model outer plates; the spacing between the two model outer plates is equal to the maximum width of the actual blade simulated by the blade model; 2) obtaining the blade model in step 1) according to the casting process of the actual blade; 3) analyzing the growth of platform impurity crystals on the model partition.

[0009] As an implementation manner, in step 1), a plurality of the model partitions are arranged between the two model outer plates.

[0010] As an implementation manner, in step 1), the angles between the plurality of model partitions and the model outer plates are different.

[0011] As an implementation manner, in step 1), the blade model includes a plurality of groups of model baffle groups, and the model baffle groups include a plurality of model baffles having different angles with the model outer plate.

[0012] As an embodiment, in step 1), the blade model includes a bottom enlarged end, and the bottom enlarged end is in a conical shape with a cross-sectional size gradually decreasing from top to bottom, and the top end of the bottom enlarged end is connected to the bottom ends of the two model partitions.

[0013] As an embodiment, in step 1), the blade model also includes a top enlarged end, and the top enlarged end is in a conical shape with a cross-sectional size gradually increasing from top to bottom, and the bottom end of the top enlarged end is connected to the top ends of the two model partitions.

[0014] As one embodiment, the casting process in step 2) adopts a lost wax casting process.

[0015] The present invention also provides a blade model for studying the miscellaneous crystals of the single crystal blade partition platform, and the blade model is obtained by steps 1) and 2) in the above-mentioned experimental method for studying the miscellaneous crystals of the single crystal blade partition platform.

[0016] Compared with the prior art, the present invention has the following technical effects:

[0017] During the blade model design stage, the test method of the present invention omits complex structures such as air film holes and spoiler columns in the actual blade, and simplifies the actual arc-shaped outer panels in the actual blade into parallel model outer panels, which significantly simplifies the modeling process of the blade model and the design and molding process of the casting mold, reduces the modeling and casting costs, improves the test efficiency, and is more conducive to obtaining blade models with different partition structures, so as to further analyze the growth of impure crystals on the blade inner cavity partition platform. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0019] Figure 1 It is a structural schematic diagram of a blade model according to an embodiment of the present invention;

[0020] Figure 2 for Figure 1 A front view of

[0021] Figure 3 for Figure 1 Left view of

[0022] Figure 4 It is a schematic diagram of the matching structure between the seed crystal and the blade model during the casting process;

[0023] Figure 5 is a schematic diagram of the cross-sectional structure of an existing blade;

[0024] Description of reference numerals:

[0025] 1. Model outer plate; 2. Model partition; 3. Bottom enlarged end; 4. Top enlarged end; 5. Seed crystal; 6. Actual outer plate; 7. Actual partition. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in 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.

[0027] The purpose of the present invention is to provide a test method and blade model for single crystal blade partition platform impurities to solve the problems existing in the prior art, significantly simplify the modeling process of the blade model and the design and molding process of the casting mold, reduce the modeling and casting costs, improve the test efficiency, and facilitate the analysis of the growth of impurities on the blade inner cavity partition platform.

[0028] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] During the research, it was found that as the size of the partition increases, the tendency of the partition to produce impurities increases. If there are multiple partitions in the inner cavity of the blade, if the partition at the widest position of the blade (the width of the volume here and in the following refers to the thickness direction of the blade) does not produce impurities, then the partitions at other positions will not produce impurities. The blade is usually curved, and the outer plates on both sides are arc-shaped. The maximum width of the blade can be determined in the following way: generate a figure with the same cross-sectional shape as the blade, and the figure has two arcs corresponding to the outer plates on both sides of the blade; make tangents to the two arcs, each arc corresponds to countless tangents, and divide the countless tangents corresponding to the two arcs into a first group of tangents and a second group of tangents; the first group of tangents and the second group of tangents have several pairs of parallel tangents, and the maximum distance between the two parallel tangents is the maximum width of the blade. At the same time, the study also found that the growth of impurities on the partition has little to do with the structures such as the air film holes and spoiler columns in the blade. Based on the above conclusions, the inventors simplified the curvature of the blade and complex structures such as air film holes and spoiler columns; at the same time, a blade with a partition only at the widest position of the blade was used as a model for research.

[0030] Embodiment 1:

[0031] An experimental method for studying the miscellaneous crystals of a single crystal blade partition platform comprises the following steps:

[0032] 1) Design blade model: The blade model includes two parallel model outer plates 1 and a model partition 2 located between the two model outer plates 1. The two ends of the model partition 2 are connected to the two model outer plates 1. The distance between the two model outer plates 1 is equal to the maximum width of the actual blade being simulated. Among them, the model outer plate 1 and the model partition 2 are equivalent to the actual outer plate 6 and the actual partition 7 in the actual blade, respectively. Figure 1 to Figure 4 shown.

[0033] 2) The blade model in step 1) is manufactured according to the actual blade casting process.

[0034] 3) Analyze the growth of platform impurity crystals on the model partition 2.

[0035] Therefore, in the blade model design stage, the experimental method in this embodiment omits complex structures such as air film holes and spoiler columns in the actual blade, and simplifies the actual arc-shaped outer panel 6 in the actual blade into a parallel model outer panel 1, which significantly simplifies the modeling process of the blade model and the design and molding process of the casting mold, reduces the modeling and casting costs, improves the experimental efficiency, and is more conducive to obtaining blade models with different partition structures, so as to further analyze the growth of impurity crystals on the blade inner cavity partition platform.

[0036] The mold used in the casting process of step 2) in this embodiment can be obtained by 3D printing. The casting process can adopt a lost wax casting process. The specific casting process is well known to those skilled in the art, and this embodiment will not be described in detail.

[0037] In order to improve the test efficiency, in step 1), a plurality of model partitions 2 are arranged between the two model outer plates 1. As an embodiment, the plurality of model partitions 2 are parallel to each other, in other words, the angle between each model partition 2 and the model outer plate 1 is the same. This method can increase the number of model partitions 2 at a certain angle, and can better analyze the growth of platform impurities of the model partition 2 at this angle to improve the test accuracy. As another embodiment, in step 1), the angles between the plurality of model partitions 2 and the model outer plate 1 are different. This method can study the growth of platform impurities of the model partition 2 at different angles relative to the model partition 2, so as to obtain a better angle setting range between the model partition 2 and the model outer plate 1. As an embodiment, in step 1), the blade model includes a plurality of groups of model partitions 2, and the model partition 2 groups include a plurality of model partitions 2 with different angles to the model outer plate 1. This method covers the setting features and advantages of the above two methods.

[0038] As an embodiment, in step 1), the blade model includes a bottom enlarged end 3, the bottom enlarged end 3 is in a tapered shape with a gradually decreasing cross-sectional size from top to bottom, and the top of the bottom enlarged end 3 is connected to the bottom ends of the two model partitions 2. Correspondingly, the mold used for casting is also provided with a casting cavity corresponding to the shape of the bottom enlarged end 3. During casting, the seed crystal 5 is placed at the bottom of the mold, and the seed crystal 5 is used to control the growth of the crystal during the solidification process. The tapered cavity corresponding to the bottom enlarged end 3 can realize the transition from the cavity corresponding to the two model outer plates 1 to the seed crystal 5.

[0039] As an embodiment, in step 1), the blade model further includes a top enlarged end 4, which is in a tapered shape with a gradually increasing cross-sectional size from top to bottom, and the bottom end of the top enlarged end 4 is connected to the top ends of the two model partitions 2. Correspondingly, the mold used for casting is also provided with a casting cavity corresponding to the shape of the top enlarged end 4. The tapered cavity corresponding to the top enlarged end 4 can realize the transition between the mold casting port and the cavity corresponding to the two model outer plates 1.

[0040] There may be an equal-diameter transition section between the bottom enlarged end 3 , the top enlarged end 4 and the model outer plate 1 .

[0041] Embodiment 2:

[0042] like Figure 1 to Figure 4 As shown, this embodiment provides a blade model for studying the miscellaneous crystals of the single crystal blade partition platform, and the blade model is obtained by steps 1) and 2) in the experimental method for studying the miscellaneous crystals of the single crystal blade partition platform in Example 1.

[0043] Adaptive changes made according to actual needs are all within the protection scope of the present invention.

[0044] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. An experimental method for studying the miscellaneous crystals of a single crystal blade partition platform, characterized in that: The following steps are involved: 1) Designing a blade model: the blade model comprises two parallel model outer plates and a model partition plate located between the two model outer plates, wherein two ends of the model partition plate are respectively connected to the two model outer plates; and the spacing between the two model outer plates is equal to the maximum width of the actual blade simulated by the blade model; 2) producing the blade model in step 1) according to the casting process of the actual blade; 3) Analyze the growth of platform impurity crystals of the model partition.

2. The experimental method for studying the miscellaneous crystals of the single crystal blade partition platform according to claim 1 is characterized in that: In step 1), a plurality of the model partitions are arranged between the two model outer plates.

3. The experimental method for studying the miscellaneous crystals of the single crystal blade partition platform according to claim 2 is characterized in that: In step 1), the angles between the plurality of model partitions and the model outer plates are different.

4. The experimental method for studying the miscellaneous crystals of the single crystal blade partition platform according to claim 1 is characterized in that: In step 1), the blade model includes a plurality of groups of model baffle groups, and the model baffle groups include a plurality of model baffles having different angles with the model outer plate.

5. The test method for studying the miscellaneous crystals of the single crystal blade partition platform according to claim 1 is characterized in that: In step 1), the blade model includes a bottom enlarged end, and the bottom enlarged end is in a conical shape with a cross-sectional size gradually decreasing from top to bottom, and the top end of the bottom enlarged end is connected to the bottom ends of the two model partitions.

6. The test method for studying the miscellaneous crystals of the single crystal blade partition platform according to claim 1 is characterized in that: In step 1), the blade model also includes a top enlarged end, which is in a conical shape with a cross-sectional size gradually increasing from top to bottom, and the bottom end of the top enlarged end is connected to the top ends of the two model partitions.

7. The test method for studying the miscellaneous crystals of the single crystal blade partition platform according to claim 1 is characterized in that: The casting process in step 2) adopts lost wax casting process.

8. A blade model for studying single crystal blade partition platform impurities, characterized in that: The blade model is made by steps 1) and 2) of the test method for studying single crystal blade partition platform miscellaneous crystals as described in any one of claims 1 to 7.

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