A single crystal blade die-casting shell for a gas turbine and a preparation method thereof

Abstract

A single crystal blade mold shell for a gas turbine and a preparation method thereof, wherein the single crystal blade mold shell for the gas turbine includes: a main body portion, and the main body portion includes a mold shell transition section; several bottom support portions connected to the side wall of the main body portion, and the top height of the bottom support portion is greater than the top height of the mold shell transition section within a preset range. The strength is enhanced through the bottom support portion, so that the structure of the single crystal blade mold shell for the gas turbine is relatively stable, and better strength can be maintained during the processes of combining the wax mold and making the shell. During the subsequent single crystal blade growth process, the influence of the bottom support portion on the temperature field during the single crystal growth of the single crystal blade for the gas turbine is small, and the uniformity of the overall temperature field where the main body portion is located can be effectively improved, thereby improving the quality and yield of the single crystal blade product.

Description

Technical Field

[0001] The present invention relates to the technical field of manufacturing single crystal blades for gas turbines, and particularly to a mold shell for a gas turbine single crystal blade and a preparation method thereof. Background Art

[0002] A gas turbine is a major power equipment integrating many high-end technologies such as design, materials, manufacturing, etc., and is known as a pearl on the crown of manufacturing. It centrally reflects the comprehensive level of a country's scientific and technological development in multiple disciplines and engineering fields such as energy power, materials metallurgy, mechanical manufacturing, and automatic control. Heavy-duty gas turbines are widely used in fields such as power generation, mechanical drive, and ship power, and are essential major industrial equipment for national development.

[0003] The working temperature of the key hot-end component - the single crystal blade of the high-pressure turbine in a gas turbine is relatively high, and it is usually prepared by a directional solidification process single crystal growth process. However, with the increase in the size of the single crystal blade of a heavy-duty gas turbine and the complexity of its structure, the initial wax mold size and weight during its preparation process also increase accordingly. The complex wax mold structure and large size make it difficult to prepare the mold shell, and usually multiple wax support structures need to be added to prevent the wax mold from deforming and breaking. However, like the wax mold, the wax support structure also needs to go through the process of coating and shell making, and the finally formed support part of the mold shell is likely to cause non-uniform temperature field and the appearance of transverse temperature gradient, which will lead to the appearance of defects such as equiaxed crystals, shrinkage cavities, and freckles in the blade, significantly reducing the qualification rate of the blade. Therefore, how to prepare a mold shell for a large-size and complex-structure gas turbine single crystal blade is a problem that must be solved in the actual production of gas turbine blades. Summary of the Invention

[0004] The technical problem solved by the present invention is to provide a mold shell for a gas turbine single crystal blade and a preparation method thereof, ensuring that the gas turbine blade has sufficient strength during the wax mold combination and shell making processes, and at the same time being able to avoid the negative impact of excessive support structures on the temperature uniformity during the growth process of the single crystal blade, thereby improving the quality and yield of the single crystal blade product.

[0005] To solve the above problems, the present invention provides a mold shell for a gas turbine single crystal blade, including: a main body part, the main body part including a mold shell transition section; several bottom support parts connected to the side wall of the main body part, the top height of the bottom support part being greater than the top height of the mold shell transition section within a preset range.

[0006] Optionally, the preset range is 20 mm to 50 mm.

[0007] Optionally, the main body part further includes: a mold shell crystal starting section, a mold shell crystal selecting section connected to the mold shell crystal starting section, the mold shell transition section being connected to the mold shell crystal selecting section, a mold shell blade connected to the mold shell transition section, and a mold shell pouring cup connected to the mold shell blade.

[0008] Optionally, the bottom support part includes: a bottom solid support column and a mold shell layer coated on the surface of the bottom solid support column.

[0009] Optionally, the number of the bottom solid support columns is one or more, and the diameter of the bottom solid support columns is 5 mm to 10 mm.

[0010] Optionally, the material of the bottom solid support column is alumina with a mass percentage content greater than 99%.

[0011] Correspondingly, the technical solution of the present invention also provides a method for preparing a single crystal blade mold shell of a gas turbine, including: preparing a blade wax mold; inserting a plurality of additional support columns and a plurality of bottom solid support columns on the side wall of the blade wax mold, the height of the additional support columns being greater than the height of the bottom solid support columns, the material of the additional support columns being the same as the material of the blade wax mold, and the material of the bottom solid support columns being different from the material of the blade wax mold; coating a mold shell slurry on the surfaces of the blade wax mold, the additional support columns and the bottom solid support columns to form a blade mold shell green body; after forming the blade mold shell green body, removing the blade wax mold; after removing the blade wax mold, sintering the blade mold shell green body to form an initial single crystal blade mold shell of a gas turbine, the initial single crystal blade mold shell of a gas turbine including a main body part corresponding to the blade wax mold, an additional support part corresponding to the additional support columns, and a bottom support part corresponding to the bottom solid support columns; cutting off the additional support part along the surface of the main body part; filling the holes exposed on the surface of the main body part after cutting off the additional support part, and drying at room temperature to form the single crystal blade mold shell of a gas turbine.

[0012] Optionally, the blade wax mold includes: a wax mold starting crystal section, a wax mold crystal selection section connected to the wax mold starting crystal section, a wax mold transition section connected to the wax mold crystal selection section, a wax mold blade connected to the wax mold transition section, and a wax mold pouring cup connected to the wax mold blade.

[0013] Optionally, before forming the blade mold shell green body, it further includes: providing a chassis, a plurality of additional support columns and a plurality of bottom solid support columns being located on the chassis, and the plurality of additional support columns and the plurality of bottom solid support columns being connected to the chassis.

[0014] Optionally, during the process of coating the mold shell slurry on the surfaces of the blade wax mold, the additional support columns and the bottom solid support columns, it further includes: coating the mold shell slurry on the surface of the chassis.

[0015] Optionally, before sintering the green body of the blade mold shell, it further includes: removing the chassis and the mold shell slurry adhered to the lower surface and side surface of the chassis, and retaining the mold shell slurry on the upper surface of the chassis connected to the additional support columns and the bottom solid support columns.

[0016] Optionally, the material of the chassis includes: aluminum alloy, engineering plastic or wax material.

[0017] Optionally, the diameter of the additional support column is 20 mm to 50 mm, and the height of the additional support column is 2 / 3 to 4 / 5 of the height of the blade wax mold.

[0018] Optionally, the process for preparing the blade wax mold includes an injection molding process; the process parameters of the injection molding process include: a wax temperature of 65 °C to 80 °C, an injection pressure of 2 MPa to 9 MPa, an injection time of 10 s to 60 s, and a holding pressure time of 10 s to 30 s.

[0019] Optionally, the process for removing the blade wax mold includes a steam removal process; the process parameters of the steam removal process include: a steam temperature of 150 °C to 170 °C, a pressure of 3 to 7 standard atmospheres, and a time of 1 minute to 5 minutes.

[0020] Optionally, the process parameters of the sintering treatment include: a roasting temperature of 850 °C to 1050 °C and a holding time of 3 hours to 6 hours.

[0021] Optionally, the method for filling the holes exposed on the surface of the main body after removing the additional support part includes: filling the holes with refractory cement or a mixed paste of mold shell slurry and powder; then drying the filled refractory cement or the mixed paste of mold shell slurry and powder at room temperature, and the drying time is greater than 24 hours.

[0022] Compared with the prior art, the technical solution of the present invention has the following advantages:

[0023] In the single crystal blade mold shell of the gas turbine of the technical solution of the present invention, it includes a main body part and a plurality of bottom support parts connected to the side wall of the main body part. Through the support provided by the bottom support parts, the structure of the single crystal blade mold shell of the gas turbine is relatively stable, and it can maintain good strength during the process of combining the wax mold and making the shell. During the subsequent single crystal blade growth process, the bottom support parts have little influence on the temperature field during the single crystal growth of the single crystal blade of the gas turbine, and can effectively improve the uniformity of the overall temperature field where the main body part is located, thereby improving the quality and yield of the single crystal blade product. Description of the Drawings

[0024] Figure 1It is a schematic structural diagram of a single-crystal blade mold shell of a gas turbine engine in an embodiment of the present invention;

[0025] Figure 2 It is a schematic cross-sectional structural diagram of the bottom support part of a single-crystal blade mold shell of a gas turbine engine in an embodiment of the present invention;

[0026] Figure 3 It is a schematic flow diagram of a preparation method of a single-crystal blade mold shell of a gas turbine engine in an embodiment of the present invention;

[0027] Figures 4 to 7 and Figure 1 It is a schematic structural diagram of each step of a preparation method of a single-crystal blade mold shell of a gas turbine engine in an embodiment of the present invention. Detailed implementation manners

[0028] For the convenience of understanding the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings. Typical embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided so that the disclosure of the present invention will be thorough and comprehensive.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0030] Figure 1 It is a schematic structural diagram of a single-crystal blade mold shell of a gas turbine engine in an embodiment of the present invention.

[0031] Please refer to Figure 1 , including: a main body part 601, the main body part 601 includes a mold shell transition section (not labeled); several bottom support parts 602 connected to the side wall of the main body part 601, and the top height of the bottom support part 602 is greater than the top height of the mold shell transition section within a preset range.

[0032] By providing support through the bottom support part 602, the structure of the single-crystal blade mold shell of the gas turbine engine is relatively stable, and good strength can be maintained during the process of combining the wax mold and making the shell. During the subsequent single-crystal blade growth process, since the single-crystal blade mold shell of the gas turbine engine only includes the main body part 601 and several bottom support parts 602 connected to the side wall of the main body part 601, the influence of the bottom support part 602 on the temperature field during the single-crystal growth of the single-crystal blade of the gas turbine engine is small, and the uniformity of the overall temperature field where the main body part 601 is located can be effectively improved, thereby improving the quality and yield of the single-crystal blade product.

[0033] The preset range is 20 millimeters to 50 millimeters.

[0034] In this embodiment, the preset range is 20 millimeters.

[0035] In other embodiments, the preset range is 30 millimeters

[0036] In other embodiments, the preset range is 50 millimeters.

[0037] In this embodiment, the main body portion 601 further includes: a mold shell seeding section, a mold shell crystal selection section connected to the mold shell seeding section, a mold shell transition section connected to the mold shell crystal selection section, a mold shell blade connected to the mold shell transition section, and a mold shell pouring cup (not labeled) connected to the mold shell blade.

[0038] Please refer to Figure 2 , in this embodiment, the bottom support portion 602 includes: a bottom solid support column 30, and a mold shell layer 70 covering the surface of the bottom solid support column 30.

[0039] The diameter of the bottom solid support column 30 is 5 millimeters to 10 millimeters.

[0040] In this embodiment, the diameter of the bottom solid support column 30 is 5 millimeters.

[0041] In other embodiments, the diameter of the bottom solid support column is 10 millimeters.

[0042] The number of the bottom solid support columns 30 is one or more.

[0043] In this embodiment, the number of the bottom solid support columns 30 is 4.

[0044] In other embodiments, the number of the bottom solid support columns is 6.

[0045] In other embodiments, the number of the bottom solid support columns is 8.

[0046] In this embodiment, the material of the bottom solid support column 30 is alumina with a mass percentage content greater than 99%.

[0047] Correspondingly, an embodiment of the present invention also provides a method for preparing a single crystal blade mold shell of a gas turbine.

[0048] Figure 3 It is a schematic flow chart of a method for preparing a single crystal blade mold shell of an embodiment of the present invention.

[0049] Step S101, prepare a blade wax mold;

[0050] Step S102: inserting a plurality of additional support columns and a plurality of bottom solid support columns into the side walls of the blade wax model, wherein the height of the additional support columns is greater than that of the bottom solid support columns, the material of the additional support columns is the same as that of the blade wax model, and the material of the bottom solid support columns is different from that of the blade wax model;

[0051] Step S103, coating the surfaces of the blade wax mold, the additional support columns, and the bottom solid support columns with mold shell slurry to form a blade mold shell blank;

[0052] Step S104, after the blade shell blank is formed, removing the blade wax mold;

[0053] Step S105, after removing the blade wax mold, sintering the blade mold blank to form an initial single crystal gas turbine blade mold, wherein the initial single crystal gas turbine blade mold includes a main body corresponding to the blade wax mold, an additional support portion corresponding to the additional support column, and a bottom support portion corresponding to the bottom solid support column;

[0054] Step S106, cutting off the additional support portion along the surface of the main body;

[0055] Step S107 , filling the holes exposed on the surface of the main body after the additional support portion is cut away, and drying at room temperature to form the combustion turbine single crystal blade mold.

[0056] The following will describe in detail each step of the method for preparing the combined core with reference to the accompanying drawings.

[0057] Figures 4 to 7 ,as well as Figure 1 It is a structural schematic diagram of each step of a method for preparing a single crystal blade mold for a gas turbine in an embodiment of the present invention.

[0058] Please refer to Figure 4 , prepare a blade wax model 10.

[0059] In this embodiment, the blade wax mold 10 includes: a wax mold crystallization section 101, a wax mold crystal selection section 102 connected to the wax mold crystallization section 101, a wax mold transition section 103 connected to the wax mold crystal selection section 102, a wax mold blade 104 connected to the wax mold transition section 103, and a wax mold pouring cup 105 connected to the wax mold blade 104.

[0060] In this embodiment, the process for preparing the blade wax mold 10 adopts an injection molding process.

[0061] The process parameters of the injection molding process include: the wax temperature is 65 °C to 80 °C, the injection pressure is 2 MPa to 9 MPa, the injection time is 10 s to 60 s, and the holding pressure time is 10 s to 30 s.

[0062] In this embodiment, the process parameters of the injection molding process include: the wax temperature is 65 °C, the injection pressure is 3 MPa, the injection time is 60 s, and the holding pressure time is 30 s.

[0063] In other embodiments, the process parameters of the injection molding process include: the wax temperature is 68 °C, the injection pressure is 5 MPa, the injection time is 30 s, and the holding pressure time is 30 s.

[0064] In other embodiments, the process parameters of the injection molding process include: the wax temperature is 70 °C, the injection pressure is 4 MPa, the injection time is 30 s, and the holding pressure time is 10 s.

[0065] In other embodiments, the process parameters of the injection molding process include: the wax temperature is 68 °C, the injection pressure is 7 MPa, the injection time is 10 s, and the holding pressure time is 10 s.

[0066] Please refer to Figure 5 , several additional support columns 20 and several bottom solid support columns 30 are inserted into the side wall of the blade wax mold 10. The height of the additional support column 20 is greater than the height of the bottom solid support column 30. The material of the additional support column 20 is the same as that of the blade wax mold 10, and the material of the bottom solid support column 30 is different from that of the blade wax mold 10.

[0067] In this embodiment, the method of inserting several additional support columns 20 and several bottom solid support columns 30 into the side wall of the blade wax mold 10 includes: inserting several additional support columns 20 and several bottom solid support columns 30 into the side wall of the blade wax mold 10; bonding and fixing the additional support column 20 and the bottom solid support column 30 to the blade wax mold 10 with wax.

[0068] In this embodiment, the material of the bottom solid support column 30 is alumina with a mass percentage content greater than 99%.

[0069] The diameter of the additional support column 20 is 20 mm to 50 mm, and the height of the additional support column 20 is 2 / 3 to 4 / 5 of the height of the blade wax mold 10.

[0070] In this embodiment, the diameter of the additional support column 20 is 20 mm, and the height of the additional support column 20 is 4 / 5 of the height of the blade wax mold 10.

[0071] In other embodiments, the diameter of the additional support column is 30 mm, and the height of the additional support column is 2 / 3 of the height of the blade wax mold.

[0072] In other embodiments, the diameter of the additional support column is 50 mm, and the height of the additional support column is 2 / 3 of the height of the blade wax mold.

[0073] In other embodiments, the diameter of the additional support column is 50 mm, and the height of the additional support column is 4 / 5 of the height of the blade wax mold.

[0074] In this embodiment, please continue to refer to Figure 5 , further comprising: providing a chassis 40, a plurality of additional support columns 20 and a plurality of bottom solid support columns 30 are located on the chassis 40, and the plurality of additional support columns 20 and the plurality of bottom solid support columns 30 are connected to the chassis 40.

[0075] By providing the chassis 40, the bottoms of the blade wax mold 10, the plurality of additional support columns 20 and the plurality of bottom solid support columns 30 are located on the same horizontal plane, so that during the subsequent single crystal blade growth process, the combustion engine single crystal blade mold shell can be placed relatively stably on a water-cooled copper plate (not shown) of a single crystal furnace device having the same shape as the chassis 40.

[0076] In this embodiment, the material of the chassis 40 is aluminum alloy; in other embodiments, the material of the chassis can also be engineering plastic or wax material.

[0077] Please refer to Figure 6 , on the surfaces of the blade wax mold 10, the additional support columns 20 and the bottom solid support columns 30, a mold shell slurry is coated to form a blade mold shell green body 50.

[0078] In this embodiment, during the process of coating the mold shell slurry on the surfaces of the blade wax mold 10, the additional support columns 20 and the bottom solid support columns 30, it further comprises: coating the mold shell slurry on the surface of the chassis 40.

[0079] In this embodiment, the mold shell slurry uses 320-mesh powder and silica sol solution, the first layer of sand spraying is 80-mesh sand, the second layer of sand spraying is 60-mesh sand, the third layer of sand spraying is 32-mesh sand, the fourth to seventh layers of sand spraying are 24-mesh sand, and the final sealing slurry layer uses a surface coating; the powder uses alumina powder, and the sand spraying material is alumina sand.

[0080] The mass ratio of the powder to the silica sol solution is 3:1 to 3.5:1.

[0081] In this embodiment, the mass ratio of the powder to the silica sol solution is 3:1.

[0082] In other embodiments, the mass ratio of the powder material to the silica sol solution is 3.2:1.

[0083] In other embodiments, the mass ratio of the powder material to the silica sol solution is 3.5:1.

[0084] In this embodiment, please continue to refer to Figure 6 , further comprising: removing the mold shell slurry adhered to the lower surface and side surfaces of the chassis 40, and retaining the mold shell slurry on the upper surface of the chassis 40 that is connected to the additional support columns 20 and the bottom solid support columns 30.

[0085] Since the chassis 40 is not the structure that needs to be finally retained in the single crystal blade mold shell of the gas turbine. Therefore, the chassis 40 can be relatively easily removed before sintering the green body 50 of the blade mold shell.

[0086] Since after sintering the green body 50 of the blade mold shell, the hardness of the mold shell slurry is very high, and it will be very difficult to remove the chassis 40 at this time.

[0087] The thickness of the mold shell slurry on the upper surface of the chassis 40 that is connected to the additional support columns 20 and the bottom solid support columns 30 is 8 mm to 10 mm.

[0088] In this embodiment, the thickness of the mold shell slurry on the upper surface of the chassis 40 that is connected to the additional support columns 20 and the bottom solid support columns 30 is 8 mm.

[0089] In other embodiments, the thickness of the mold shell slurry on the upper surface of the chassis that is connected to the additional support columns and the bottom solid support columns 30 is 9 mm.

[0090] In other embodiments, the thickness of the mold shell slurry on the upper surface of the chassis that is connected to the additional support columns and the bottom solid support columns 30 is 10 mm.

[0091] Please refer to Figure 7 , after forming the green body 50 of the blade mold shell, the blade wax mold 10 is removed.

[0092] In this embodiment, during the process of removing the blade wax mold 10, the additional support columns 20 are also removed simultaneously.

[0093] In this embodiment, the process of removing the blade wax mold 10 adopts a steam removal process.

[0094] The process parameters of the steam removal process include: the steam temperature is 150 °C to 170 °C, the pressure is 3 standard atmospheres to 7 standard atmospheres, and the time is 1 minute to 5 minutes.

[0095] In this embodiment, the process parameters of the steam removal process include: the steam temperature is 170 degrees Celsius, the pressure is 6 standard atmospheres, and the time is 1 minute.

[0096] In other embodiments, the process parameters of the steam removal process include: the steam temperature is 160 degrees Celsius, the pressure is 6 standard atmospheres, and the time is 2 minutes.

[0097] In other embodiments, the process parameters of the steam removal process include: the steam temperature is 150 degrees Celsius, the pressure is 7 standard atmospheres, and the time is 2 minutes.

[0098] Please continue to refer to Figure 1 , after removing the blade wax mold 10, the green body of the blade mold shell 50 is sintered to form an initial single-crystal blade mold shell 60 for a gas turbine. The initial single-crystal blade mold shell 60 for a gas turbine includes a main body portion 601 corresponding to the blade wax mold 10, an additional support portion (not shown) corresponding to the additional support column 20, and a bottom support portion 602 corresponding to the bottom solid support column 30.

[0099] The process parameters of the sintering process include: the roasting temperature is 850 degrees Celsius to 1050 degrees Celsius, and the holding time is 3 hours to 6 hours.

[0100] In this embodiment, the process parameters of the sintering process include: the roasting temperature is 1050 degrees Celsius, the holding time is 3 hours, and the initial single-crystal blade mold shell for a gas turbine is cleaned after the furnace is cooled.

[0101] In other embodiments, the process parameters of the sintering process include: the roasting temperature is 850 degrees Celsius, the holding time is 4 hours, and the initial single-crystal blade mold shell for a gas turbine is cleaned after the furnace is cooled.

[0102] In other embodiments, the process parameters of the sintering process include: the roasting temperature is 850 degrees Celsius, the holding time is 6 hours, and the initial single-crystal blade mold shell for a gas turbine is cleaned after the furnace is cooled.

[0103] Please continue to refer to Figure 1 , the additional support portion is cut off along the surface of the main body portion 601.

[0104] After the additional support portion is cut off, during the subsequent single-crystal blade growth process, the temperature field of the bottom support portion has less influence on the single-crystal growth of the single-crystal blade for a gas turbine, which can effectively improve the uniformity of the overall temperature field where the main body portion is located, and further improve the quality and yield of the single-crystal blade product.

[0105] Please continue to refer to Figure 1, filling the hole exposed on the surface of the main body part after removing the additional support part to form the combustion engine single crystal blade mold shell.

[0106] In this embodiment, the purpose of filling the hole exposed on the surface of the main body part after removing the additional support part is to ensure the sealing performance of the finally formed combustion engine single crystal blade mold shell.

[0107] In this embodiment, the method for filling the hole exposed on the surface of the main body part after removing the additional support part includes: filling the hole with refractory cement; drying the refractory cement at room temperature, and the drying time is greater than 24 hours.

[0108] In other embodiments, the hole can also be filled with a mixed paste of mold shell slurry and powder, and the ratio of the mold shell slurry to the powder is 8:1 to 10:1; then the mixed paste of the mold shell slurry and the powder is dried at room temperature, and the drying time is greater than 24 hours.

[0109] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention should be subject to the scope defined by the claims.

Claims

1. A preparation method of a single crystal blade die shell for a gas turbine, characterized in that, Including: Preparing a blade wax mold; Inserting a plurality of additional support columns and a plurality of bottom solid support columns into the side wall of the blade wax mold. The height of the additional support columns is greater than that of the bottom solid support columns. The material of the additional support columns is the same as that of the blade wax mold, and the material of the bottom solid support columns is different from that of the blade wax mold. The height of the additional support columns is 2 / 3 to 4 / 5 of the height of the blade wax mold; Coating a mold shell slurry on the surfaces of the blade wax mold, the additional support columns and the bottom solid support columns to form a blade mold shell green body; After forming the blade mold shell green body, removing the blade wax mold; After removing the blade wax mold, performing a sintering treatment on the blade mold shell green body to form an initial gas turbine single crystal blade mold shell. The initial gas turbine single crystal blade mold shell includes a main body portion corresponding to the blade wax mold, an additional support portion corresponding to the additional support columns, and a bottom support portion corresponding to the bottom solid support columns; Cutting off the additional support portion along the surface of the main body portion; Filling the holes exposed on the surface of the main body portion after cutting off the additional support portion, and drying at room temperature to form the gas turbine single crystal blade mold shell.

2. The preparation method of the single crystal blade die shell of the gas turbine as described in claim 1, wherein The blade wax mold includes: a wax mold crystal starting section, a wax mold crystal selecting section connected to the wax mold crystal starting section, a wax mold transition section connected to the wax mold crystal selecting section, a wax mold blade connected to the wax mold transition section, and a wax mold pouring cup connected to the wax mold blade.

3. The preparation method of the single crystal blade die shell of the gas turbine as described in claim 1, wherein Before forming the blade mold shell green body, it further includes: providing a chassis, and a plurality of additional support columns and a plurality of bottom solid support columns are located on the chassis, and the plurality of additional support columns and the plurality of bottom solid support columns are connected to the chassis.

4. The preparation method of the single crystal blade die shell of a gas turbine according to claim 3, characterized in that, During the process of coating the mold shell slurry on the surfaces of the blade wax mold, the additional support columns and the bottom solid support columns, it further includes: coating the mold shell slurry on the surface of the chassis.

5. The preparation method of the single crystal blade die shell of a gas turbine according to claim 4, characterized in that, Before performing the sintering treatment on the blade mold shell green body, it further includes: removing the chassis and the mold shell slurry adhered to the lower surface and side surface of the chassis, and retaining the mold shell slurry connected to the additional support columns and the bottom solid support columns on the upper surface of the chassis.

6. The preparation method of the single crystal blade die shell of the gas turbine according to claim 3, wherein, The material of the chassis includes: aluminum alloy, engineering plastic or wax material.

7. The preparation method of the single crystal blade die shell of the gas turbine as described in claim 1, characterized in that, The diameter of the additional support columns is 20 mm to 50 mm.

8. The preparation method of the single crystal blade die shell of a gas turbine according to claim 1, characterized in that The process for preparing the blade wax mold includes an injection molding process; the process parameters of the injection molding process include: the wax material temperature is 65 °C to 80 °C, the injection pressure is 2 MPa to 9 MPa, the injection time is 10 s to 60 s, and the holding pressure time is 10 s to 30 s.

9. The preparation method of the single crystal blade die shell of a gas turbine according to claim 1, characterized in that, The process for removing the blade wax mold includes a steam removal process; the process parameters of the steam removal process include: the steam temperature is 150 °C to 170 °C, the pressure is 3 standard atmospheres to 7 standard atmospheres, and the time is 1 minute to 5 minutes.

10. The preparation method of the single crystal blade die shell of a gas turbine as described in claim 1, characterized in that, The process parameters of the sintering treatment include: the roasting temperature is 850 °C to 1050 °C, and the holding time is 3 hours to 6 hours.

11. The preparation method of the single crystal blade die shell of a gas turbine as described in claim 1, characterized in that, The method for filling the holes exposed on the surface of the main body after removing the additional support part includes: filling the holes with a refractory cement or a mixed paste of a formwork slurry and powder; then drying the filled refractory cement or the mixed paste of the formwork slurry and powder at room temperature, and the drying time is greater than 24 hours.

12. A single-crystal blade mold shell of a gas turbine formed by using the preparation method according to any one of claims 1 to 11, characterized in that, Comprising: A main body part, which includes a formwork transition section; Several bottom support parts connected to the side wall of the main body part, and the top height of the bottom support part is greater than the top height of the formwork transition section within a preset range.

13. The single-crystal blade die-casting shell of a gas turbine according to claim 12, wherein, The preset range is 20 mm to 50 mm.

14. The single crystal blade die-casting shell of a gas turbine as described in claim 12, characterized in that, The main body part further includes: a formwork nucleation section, a formwork crystal selection section connected to the formwork nucleation section, a formwork transition section connected to the formwork crystal selection section, a formwork blade connected to the formwork transition section, and a formwork pouring cup connected to the formwork blade.

15. The single crystal blade die shell of a gas turbine according to claim 12, characterized in that, The bottom support part includes: a bottom solid support column and a formwork layer covering the surface of the bottom solid support column.

16. The single crystal blade die shell of a gas turbine according to claim 15, wherein, The number of the bottom solid support columns is one or more, and the diameter of the bottom solid support column is 5 mm to 10 mm.

17. The single crystal blade die shell of a gas turbine as described in claim 15, characterized in that, The material of the bottom solid support column is made of alumina with a mass percentage content greater than 99%.

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