Mold shell structure for preparing large-size single crystal casting by seed crystal method

Abstract

The utility model discloses a mould shell structure for preparing a large-size single crystal casting by a seed crystal method, which comprises a base plate, a casting cavity, a middle column tube and a pouring cup, the middle column tube is arranged at the center of the base plate, the pouring cup is arranged at the top of the middle column tube, and the casting cavity is arranged in the middle of the middle column tube. The lower end of the casting cavity is communicated with a corresponding seed crystal cavity on the base plate through a connecting transition section, the upper end of the casting cavity is communicated with the pouring cup through a connecting pouring gate, a seed crystal is mounted in the seed crystal cavity in a matched manner, and the lower end of the seed crystal is flush with the lower surface of the base plate; and the upper end of the connecting transition section penetrates through the seed crystal cavity and is inserted into the inner cavity of the connecting transition section. According to the utility model, the connection transition section of the casting cavity and the seed crystal cavity is optimized and enlarged, when the seed crystal is stuffed into the seed crystal cavity, the top end of the seed crystal can be inserted into the connection transition section for heat preservation and heating, the seed crystal can be fully fused and deformed at high temperature, and an oxide film can be effectively crushed; therefore, the welding of the casting and the seed crystal and the seeding of the seed crystal are realized.

Description

Technical Field

[0001] This invention belongs to the field of single crystal casting technology, and particularly relates to a seed crystal method for preparing large-size single crystal casting mold shell structures. Background Technology

[0002] Traditional seed crystal introduction involves reserving a seed crystal segment of a certain height below the casting, typically 50mm or more. The casting is then connected above the seed crystal to achieve seed crystal introduction. This method requires the seed crystal to reach a certain height and have a certain degree of superheat. The molten metal in the seed crystal segment must also have good fluidity to break the oxide film when the alloy is poured, thus achieving effective seed crystal introduction. For large-sized single-crystal blade castings, the height of the seed crystal segment (which becomes the seed crystal cavity after shelling and dewaxing) is limited to about 30mm due to the height of the wax pattern assembly. Under these conditions, insufficient superheat of the seed crystal and poor fluidity of the molten metal often result in poor welding with the casting, leading to seed crystal introduction failure. Summary of the Invention

[0003] The main purpose of this invention is to provide a seed crystal method for preparing large-size single-crystal casting mold shell structure. By optimizing and enlarging the connection transition section between the casting cavity and the seed crystal cavity, when the seed crystal is inserted into the seed crystal cavity, the top of the seed crystal can be inserted into the connection transition section for heat preservation and heating. The seed crystal can be fully melted and deformed at high temperature, and the oxide film can be effectively broken, thereby realizing the welding of the casting and the seed crystal and the seed crystal introduction.

[0004] Therefore, this utility model provides a seed crystal method for preparing large-size single crystal casting mold shell structure, including a base, a casting cavity, a central column tube, and a pouring cup. The central column tube is installed in the center of the base, and the pouring cup is installed on the top of the central column tube. The lower end of the casting cavity is connected to the corresponding seed crystal cavity on the base through a connecting transition section, and the upper end is connected to the pouring cup through a connecting gating. A seed crystal is matched and installed in the seed crystal cavity. The lower end of the seed crystal is flush with the lower surface of the base, and the upper end passes through the seed crystal cavity and is inserted into the inner cavity of the connecting transition section.

[0005] Specifically, multiple casting cavities are evenly arranged around the central column tube on the chassis. The chassis is provided with multiple seed crystal cavities that correspond one-to-one with each of the casting cavities. Each casting cavity is connected to the pouring cup through an independent connecting runner.

[0006] Specifically, the connecting transition section is a cone shape that is larger at the top and smaller at the bottom.

[0007] Specifically, the inner bottom of the pouring cup is sealed by a plug.

[0008] Compared with the prior art, the present invention has the following beneficial effects:

[0009] The connection transition section between the casting cavity and the seed crystal cavity was optimized and improved by increasing its size to ensure that the seed crystal in the lower seed crystal cavity can be inserted into the connection transition section without interference. In this way, although the height of the seed crystal cavity is limited by the height of the wax mold assembly, a longer seed crystal can still be inserted into the transition section. This allows the seed crystal to fully melt and deform at high temperatures during the mold shell insulation stage, effectively breaking down the oxide film and achieving welding between the casting and the seed crystal, as well as seed crystal introduction. Attached Figure Description

[0010] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0011] Figure 1 This is a schematic diagram of the mold shell structure for preparing large-size single-crystal castings using the seed crystal method provided in this embodiment of the utility model;

[0012] Figure 2 This is a schematic diagram of the seed crystal insertion into the seed crystal cavity provided in an embodiment of this utility model;

[0013] The components are: 1. base; 2. casting cavity; 3. central column tube; 4. pouring cup; 5. connecting transition section; 6. connecting runner; 7. seed crystal cavity; 8. seed crystal. Detailed Implementation

[0014] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0015] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", 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 this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0016] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0017] See Figure 1 and Figure 2 This invention discloses a mold shell structure for preparing large-size single-crystal castings using the seed crystal method. The mold shell structure includes a base plate 1, a casting cavity 2, a central column tube 3, and a pouring cup 4. The central column tube 3 is vertically mounted in the center of the base plate 1, while the pouring cup 4 is located at the top of the central column tube 3. The lower end of the casting cavity 2 is connected to the seed crystal cavity 7 on the base plate 1 via a connecting transition section 5, and the upper end is connected to the pouring cup 4 via a connecting runner 6. A seed crystal 8 is fitted inside the seed crystal cavity 7; the lower end of the seed crystal 8 is flush with the lower surface of the base plate 1, and the upper end passes through the seed crystal cavity 7 and is inserted into the inner cavity of the connecting transition section 5.

[0018] In this embodiment, the connection transition section 5 between the casting cavity 2 and the seed crystal cavity 7 has been optimized and improved. By increasing the size of the connection transition section 5, it is ensured that the seed crystal in the seed crystal cavity 7 can be inserted into the connection transition section 5 without obstruction. Although the height of the seed crystal cavity 7 is limited by the wax mold module (approximately 30mm in this embodiment), this design allows for the use of longer seed crystals (50-60mm) inserted into the connection transition section 5. During the mold shell heat preservation stage, the seed crystal can fully melt and deform at high temperature, and its oxide film is effectively broken, thereby achieving the welding of the casting and the seed crystal and the seed crystal introduction.

[0019] like Figure 1As shown, in actual production, the casting cavities 2 are evenly arranged around the central column tube 3 on the base plate 1. The base plate 1 is provided with multiple seed crystal cavities 7 that correspond one-to-one with each casting cavity 2. Each casting cavity 2 is connected to the pouring cup 4 through an independent connecting runner 6. This design allows multiple castings to be obtained in one pour, thereby improving production efficiency.

[0020] Specifically, to ensure that the grains can grow smoothly into the casting along the connecting transition section 5 without generating impurities, the connecting transition section 5 is designed as a tapered structure that is larger at the top and smaller at the bottom. To prevent the molten metal in the pouring cup 4 from entering the central column tube 3, a plug (not shown in the figure) is provided at the bottom of the pouring cup 4 to seal the connection between the pouring cup 4 and the central column tube 3.

[0021] Unless otherwise stated, if any of the technical solutions disclosed in this utility model discloses a numerical range, then the disclosed numerical range is a preferred numerical range. Anyone skilled in the art should understand that the preferred numerical range is merely one among many feasible numerical values ​​that has a more obvious or representative technical effect. Because there are many numerical values, it is impossible to list them all. Therefore, this utility model discloses only some numerical values ​​to illustrate the technical solutions of the invention. Furthermore, the numerical values ​​listed above should not constitute a limitation on the scope of protection of this invention.

[0022] Meanwhile, if the present invention discloses or relates to mutually fixedly connected parts or structural components, then unless otherwise stated, the fixed connection can be understood as: a detachable fixed connection (e.g., using bolts or screws), or a non-detachable fixed connection (e.g., riveting, welding). Of course, mutually fixed connections can also be replaced by an integral structure (e.g., manufactured by casting) (except where it is obviously impossible to use an integral forming process).

[0023] Furthermore, unless otherwise stated, the terms used to indicate positional relationships or shapes in any of the technical solutions disclosed in this utility model include states or shapes that are similar to, analogous to, or close to those states or shapes. Any component provided by this utility model can be assembled from multiple individual components or can be a single component manufactured using a one-piece molding process.

[0024] The above embodiments are merely illustrative examples to clearly illustrate the present invention, and are not intended to limit the implementation. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all embodiments here. However, obvious variations or modifications derived therefrom are still within the protection scope of this invention.

Claims

1. A seed crystal method for preparing large-size single-crystal casting mold shell structures, characterized in that: The system includes a base (1), a casting cavity (2), a central column (3), and a pouring cup (4). The central column (3) is installed in the center of the base (1), and the pouring cup (4) is installed on the top of the central column (3). The lower end of the casting cavity (2) is connected to the corresponding seed crystal cavity (7) on the base (1) through a connecting transition section (5), and the upper end is connected to the pouring cup (4) through a connecting gating channel (6). A seed crystal (8) is installed in the seed crystal cavity (7). The lower end of the seed crystal (8) is flush with the lower surface of the base (1), and the upper end passes through the seed crystal cavity (7) and is inserted into the inner cavity of the connecting transition section (5).

2. The seed crystal method for preparing large-size single-crystal casting mold shell structures according to claim 1, characterized in that: The casting cavities (2) are evenly arranged around the central column tube (3) on the base plate (1). The base plate (1) is provided with multiple seed crystal cavities (7) that correspond one-to-one with each of the casting cavities (2). Each casting cavity (2) is connected to the pouring cup (4) through an independent connecting gating channel (6).

3. The seed crystal method for preparing large-size single-crystal casting mold shell structures according to claim 1 or 2, characterized in that: The connecting transition section (5) is a cone shape that is larger at the top and smaller at the bottom.

4. The seed crystal method for preparing large-size single-crystal casting mold shell structures according to claim 1 or 2, characterized in that: The inner bottom of the pouring cup (4) is sealed by a plug.

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