Titanium alloy casting process for casting a titanium alloy casting with an aspect ratio greater than 15 and titanium alloy casting

Abstract

This application relates to a titanium alloy casting process for titanium alloy castings with an aspect ratio greater than 15, and the titanium alloy casting itself. The investment casting process includes: creating a wax model of the casting using a casting mold; creating a wax model of the connector using a connector mold; arranging multiple wax models of the casting circumferentially and connecting them through multiple wax models of the connector, with the multiple wax models of the connector arranged at intervals along the length direction of the casting wax models; preparing a shell on the casting wax models and the connector wax models; and then sequentially performing baking and melting of wax, pouring, cleaning, and cutting to obtain the titanium alloy casting. This application reduces the deformation of long titanium alloy rod structures for aero-engines during the investment casting process and improves the quality of the titanium alloy casting.

Description

Technical Field

[0001] This application relates to the field of investment casting technology, and in particular to an investment casting process for titanium alloy castings with an aspect ratio greater than 15 and titanium alloy castings. Background Technology

[0002] The application of titanium alloys in the aerospace industry is divided into aircraft structural titanium alloys and engine structural titanium alloys. Aero-engine titanium alloy castings have diverse structures, with long rod structures being one type. Castings are metal parts obtained through various casting methods, namely, pouring molten metal into a pre-prepared mold using methods such as pouring, injection, suction, or other casting techniques, followed by cooling and subsequent processing such as grinding, to obtain an object with a specific shape, size, and performance. However, current aero-engine titanium alloy long rod structures are prone to twisting deformation during investment casting, especially long rod structures with a large length-to-diameter ratio, which exhibit severe deformation. Summary of the Invention

[0003] In order to reduce the deformation of titanium alloy long rod structures in aero-engines during the investment casting process and improve the quality of titanium alloy castings, this application provides an investment casting process for titanium alloy castings with an aspect ratio greater than 15 and titanium alloy castings.

[0004] According to one aspect of the present invention, a process for investment casting of titanium alloy castings with an aspect ratio greater than 15 is provided, comprising: preparing a casting wax model using a casting mold; preparing a connector wax model using a connector mold; arranging a plurality of the casting wax models circumferentially and connecting them through the plurality of connector wax models, wherein the plurality of connector wax models are spaced apart along the length direction of the casting wax models; preparing a shell on the casting wax models and the connector wax models; and then sequentially performing baking and melting wax, pouring, cleaning, and cutting separation to obtain a titanium alloy casting.

[0005] By using the investment casting process for titanium alloy castings with a length-to-diameter ratio greater than 15 in this technical solution, the connection of multiple multi-layer connector wax patterns to multiple casting wax patterns strengthens the radial and axial stiffness of the casting wax patterns and enhances their resistance to deformation. This reduces the deformation of the titanium alloy long rod structure of aero-engines during the investment casting process and improves the quality of titanium alloy castings.

[0006] In addition, the investment casting process for titanium alloy castings with an aspect ratio greater than 15 according to this application may also have the following additional technical features:

[0007] In some embodiments of the present invention, the connecting wax model includes a plurality of connecting rods, the number of which is equal to the number of casting wax models. The plurality of connecting rods are arranged circumferentially and connected together, and the outer circumferential ends of the plurality of connecting rods are connected to the plurality of casting wax models one by one.

[0008] In some embodiments of the present invention, the casting wax model includes a main rod body, and the diameter ratio of the connecting rod to the diameter of the main rod body is 0.7 to 1.3:1;

[0009] Preferably, the diameter ratio of the connecting rod to the main rod is 0.85 to 1.15:1.

[0010] In some embodiments of the present invention, a ring plate wax model is provided at each end of the plurality of casting wax models. The ring plate wax model is made by using a ring plate mold. The ring plate wax model and the plurality of casting wax models are arranged coaxially in a circle and connected to the plurality of casting wax models.

[0011] In some embodiments of the present invention, the ring width of the ring plate wax mold is greater than the diameter of the main rod.

[0012] In some embodiments of the present invention, the casting wax model further includes a plate connected to one end of the main rod, the diameter of the plate being larger than the diameter of the main rod, and the ring width of the ring plate wax model located at the end of the plate being larger than the diameter of the plate.

[0013] In some embodiments of the present invention, a column is arranged and connected between the plate and the ring plate wax mold at intervals, and the diameter of the column is smaller than the diameter of the plate.

[0014] In some embodiments of the present invention, the pouring port is located on one side of the annular plate wax mold with the plate body.

[0015] In some embodiments of the present invention, the casting wax molds are arranged in a circumferential pattern of 3 to 5.

[0016] According to another aspect of the present invention, a titanium alloy casting with an aspect ratio greater than 15 is provided, wherein the titanium alloy casting is produced by investment casting using the above-described investment casting process for titanium alloy castings with an aspect ratio greater than 15. Attached Figure Description

[0017] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0018] Figure 1 This is a schematic diagram of the structure of the wax model of the casting according to the embodiments of this application;

[0019] Figure 2 This is a schematic diagram of the structure of the connecting wax model connecting the casting wax model to the connector according to the embodiment of this application;

[0020] Figure 3This is a schematic diagram of the structure of the ring plate wax model connecting the casting wax model according to the embodiment of this application.

[0021] The labels in the attached drawings represent the following: 1. Casting wax model; 11. Main rod body; 12. Plate body; 13. Reinforcing rib; 14. Drilled boss; 15. Connecting column; 16. Block body; 2. Connecting wax model; 21. Connecting rod; 3. Ring plate wax model; 31. Column body. Detailed Implementation

[0022] It should be understood that the described embodiments are merely some, not all, of the embodiments in this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0023] In the following description, when referring to the accompanying drawings, the same numbers in different drawings denote the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0024] In the description of this application, it should be understood that the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances. Furthermore, in the description of this application, unless otherwise stated, "multiple" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship.

[0025] The following is in conjunction with the appendix Figure 1-3 The investment casting process for titanium alloy castings with an aspect ratio greater than 15 and the titanium alloy castings provided in the embodiments of this application are described.

[0026] This application discloses a gold casting process for titanium alloy castings with an aspect ratio greater than 15. The gold casting process includes the following steps:

[0027] Based on the shape and size of the titanium alloy castings and the number of titanium alloy castings to be cast in a single operation, design and manufacture casting molds, connector molds, and ring plate molds.

[0028] Use casting molds, connector molds, and ring plate molds to make casting wax model 1, connector wax model 2, and ring plate wax model 3 respectively;

[0029] Multiple casting wax models 1 are arranged in a circle and connected by multiple connecting wax models 2, with the multiple connecting wax models 2 spaced apart along the length of the casting wax models 1.

[0030] Two ring-plate wax molds 3 are selected and placed at both ends of multiple casting wax molds 1 respectively. The ring-plate wax molds 3 and the multiple casting wax molds 1 are arranged coaxially and connected to the multiple casting wax molds 1.

[0031] A mold shell is prepared on the wax mold 1 of the casting, the wax mold 2 of the connector, and the wax mold 3 of the ring plate. Then, the wax is baked, melted, poured, cleaned, and cut and separated in sequence to obtain the titanium alloy casting.

[0032] By using the investment casting process in this technical solution, the multi-layer connector wax pattern 2 connects multiple casting wax patterns 1, and with the fixing of the ring plate wax patterns 3 at both ends of the casting wax pattern 1, the radial and axial stiffness of the casting wax pattern 1 is strengthened, the ability to resist deformation is enhanced, the deformation of the aero-engine titanium alloy long rod structure in the investment casting process is reduced, and the quality of the titanium alloy casting is improved.

[0033] The preparation of the mold shell, baking the molten wax, pouring, cleaning and cutting separation can be carried out using conventional investment casting processes for titanium alloy castings, which are known technologies and will not be described in detail here.

[0034] In some embodiments of the present invention, such as Figure 1 As shown, the casting wax model 1 includes a main rod 11 and a plate 12 connected to one end of the main rod 11. The diameter of the plate 12 is larger than the diameter of the main rod 11. Multiple reinforcing ribs 13 are formed between the plate 12 and the main rod 11. Several perforated bosses 14 are distributed along the axial direction on the main rod 11. Several connecting columns 15 and blocks 16 are connected along the axial direction on the side of the main rod 11 away from the perforated bosses 14.

[0035] Specifically, in other embodiments, depending on the titanium alloy casting, the casting wax model 1 may also be a long rod structure including a main rod 11 and other components connected to the main rod 11. The investment casting process of the present invention is applicable to titanium alloy castings with a long rod structure having a length-to-diameter ratio of the main rod 11 greater than 15.

[0036] In some embodiments of the present invention, such as Figure 2 and Figure 3 As shown, the connecting wax model 2 includes multiple connecting rods 21, the number of which is equal to the number of casting wax models 1. The multiple connecting rods 21 are arranged circumferentially and connected together, with the outer ends of each connecting rod 21 corresponding to one of the casting wax models 1. Specifically, in this embodiment, the multiple casting wax models 1 are evenly arranged circumferentially, and the outer ends of each connecting rod 21 are correspondingly connected to the blocks 16 of the multiple casting wax models 1. A heated welding torch can be used for this connection.

[0037] In some embodiments of the present invention, such as Figure 2 and Figure 3 As shown, the diameter ratio of the connecting rod 21 to the main rod 11 is 0.7 to 1.3:1; preferably, the ratio is 0.85 to 1.15:1. Through the design of the dimensions of the connecting rod 21, especially its diameter, the radial and axial reinforcement of the casting wax model 1 by the connecting rod 21 is ensured. The length of the connecting rod 21 is appropriately adjusted according to the number of titanium alloy castings produced in a single molding process; for example, the length of the connecting rod 21 can be set to be approximately equal to the length of the connecting column 15.

[0038] In some embodiments of the present invention, such as Figure 3 As shown, the ring width of the ring plate wax pattern 3 is greater than the diameter of the main rod 11, and the ring width of the ring plate wax pattern 3 at the end of the plate 12 is greater than the diameter of the plate 12. Furthermore, the ring width of the ring plate wax pattern 3 does not exceed twice the diameter of the main rod 11 or twice the diameter of the plate 12. Through the design of the dimensions of the ring plate wax pattern 3, the radial and axial reinforcement of the casting wax pattern 1 by the ring plate wax pattern 3 is ensured.

[0039] In some embodiments of the present invention, such as Figure 3 As shown, a column 31 is arranged and connected between the plate 12 and the ring plate wax model 3 at intervals. The diameter of the column 31 is smaller than the diameter of the plate 12. The column 31 connects the plate 12 and the ring plate wax model 3, which facilitates cutting and separation after casting and cleaning to obtain individual titanium alloy castings, and reduces casting deformation caused by the shrinkage of the ring.

[0040] In some embodiments of the present invention, such as Figure 3 As shown, the pouring gate is located on one side of the annular wax mold 3 with plate 12. The forming system is designed in the thick part of the casting, and the size of the forming system should be appropriate to reduce the deformation of the casting caused by the shrinkage of the forming system.

[0041] In some embodiments of the present invention, such as Figure 2 and Figure 3 As shown, there are 3 to 5 casting wax models 1 arranged circumferentially. Specifically, in this embodiment, there can be 3, 4 or 5 casting wax models 1 arranged circumferentially. The arrangement can be adjusted according to the space radiating around the casting wax model 1, so as to increase the number of titanium alloy castings that can be formed in a single casting while ensuring the quality of the titanium alloy casting.

[0042] The investment casting process in this application will be further described below with reference to specific embodiments.

[0043] Example 1:

[0044] Preparation of the titanium alloy casting of main rod 11 with a height of 190mm and a diameter of 12mm.

[0045] The number of titanium alloy castings produced in a single casting is four, and the casting mold is as follows: Figure 1 It is designed and manufactured according to the shape and size of the titanium alloy casting; the connecting wax model 2 formed by the connecting part mold is a cross shape formed by four connecting rods 21, and the diameter of the connecting rods 21 is 10mm; the ring plate mold is divided into two types, one with a ring width greater than the diameter of the main rod 11 by 2mm, and the other with a ring width greater than the diameter of the plate 12 by 2mm.

[0046] Four casting wax models 1, three connecting wax models 2, and two ring plate wax models 3 with different ring widths were made using casting molds, connector molds, and two types of ring plate molds.

[0047] Four casting wax models 1 are arranged in a circle and connected by three connecting wax models 2. The three connecting wax models 2 are arranged at intervals along the length of the casting wax models 1.

[0048] Two ring-plate wax molds 3 are respectively placed at both ends of four casting wax molds 1. The ring-plate wax molds 3 and the four casting wax molds 1 are arranged coaxially and connected to multiple casting wax molds 1.

[0049] A mold shell is prepared on the wax mold 1 of the casting, the wax mold 2 of the connector, and the wax mold 3 of the ring plate. Then, the wax is baked, melted, poured, cleaned, and cut and separated in sequence to obtain the titanium alloy casting.

[0050] Example 2:

[0051] Preparation of the titanium alloy casting of main rod 11 with a height of 190mm and a diameter of 12mm.

[0052] The number of titanium alloy castings produced in a single casting is four, and the casting mold is as follows: Figure 1 It is designed and manufactured according to the shape and size of the titanium alloy casting; the connecting wax model 2 formed by the connecting part mold is a cross shape formed by four connecting rods 21, and the diameter of the connecting rods 21 is 12mm; the ring plate mold is divided into two types, one with a ring width greater than the diameter of the main rod 11 by 4mm, and the other with a ring width greater than the diameter of the plate 12 by 4mm.

[0053] Four casting wax models 1, three connecting wax models 2, and two ring plate wax models 3 with different ring widths were made using casting molds, connector molds, and two types of ring plate molds.

[0054] Four casting wax models 1 are arranged in a circle and connected by three connecting wax models 2. The three connecting wax models 2 are arranged at intervals along the length of the casting wax models 1.

[0055] Two ring-plate wax molds 3 are respectively placed at both ends of four casting wax molds 1. The ring-plate wax molds 3 and the four casting wax molds 1 are arranged coaxially and connected to multiple casting wax molds 1.

[0056] A mold shell is prepared on the wax mold 1 of the casting, the wax mold 2 of the connector, and the wax mold 3 of the ring plate. Then, the wax is baked, melted, poured, cleaned, and cut and separated in sequence to obtain the titanium alloy casting.

[0057] Example 3:

[0058] Preparation of the titanium alloy casting of main rod 11 with a height of 190mm and a diameter of 12mm.

[0059] The number of titanium alloy castings produced in a single casting is four, and the casting mold is as follows: Figure 1 It is designed and manufactured according to the shape and size of the titanium alloy casting; the connecting wax model 2 formed by the connecting part mold is a cross shape formed by four connecting rods 21, and the diameter of the connecting rods 21 is 14mm; the ring plate mold is divided into two types, one with a ring width greater than the diameter of the main rod 11 by 6mm, and the other with a ring width greater than the diameter of the plate 12 by 6mm.

[0060] Four casting wax models 1, three connecting wax models 2, and two ring plate wax models 3 with different ring widths were made using casting molds, connector molds, and two types of ring plate molds.

[0061] Four casting wax models 1 are arranged in a circle and connected by three connecting wax models 2. The three connecting wax models 2 are arranged at intervals along the length of the casting wax models 1.

[0062] Two ring-plate wax molds 3 are respectively placed at both ends of four casting wax molds 1. The ring-plate wax molds 3 and the four casting wax molds 1 are arranged coaxially and connected to multiple casting wax molds 1.

[0063] A mold shell is prepared on the wax mold 1 of the casting, the wax mold 2 of the connector, and the wax mold 3 of the ring plate. Then, the wax is baked, melted, poured, cleaned, and cut and separated in sequence to obtain the titanium alloy casting.

[0064] Blue light scanning fitting inspection was performed on the titanium alloy castings obtained in Examples 1-3. The blue light scanning fitting inspection showed that the surface profile of all surfaces of the titanium alloy castings obtained in Examples 1-3 met the tolerance requirement of ±0.30mm. The investment casting process of this invention can overcome the problem of easy twisting and deformation of traditional long-rod structure titanium alloy castings during investment casting. By further reinforcing the number of titanium alloy castings formed in a single process, the size, shape, and number of welds on the connecting wax pattern 2, and the ring plate wax pattern 3, long-rod structure titanium alloy castings with high surface profile requirements can be obtained.

[0065] This embodiment also proposes a titanium alloy casting with an aspect ratio greater than 15, which is produced by investment casting using the aforementioned investment casting process for titanium alloy castings with an aspect ratio greater than 15. The specific beneficial effects of this titanium alloy casting with an aspect ratio greater than 15 compared to current titanium alloy castings are the same as described above, and will not be repeated here.

[0066] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A process for investment casting of titanium alloy castings with an aspect ratio greater than 15, characterized in that, include: A casting wax model is made by using a casting mold, the casting wax model including a main rod and a plate connected to one end of the main rod; A connector wax model is made by using a connector mold. The connector wax model includes multiple connecting rods, the number of which is equal to the number of casting wax models. The diameter ratio of the connecting rod to the diameter of the main rod is 0.7 to 1.3:

1. Multiple casting wax models are arranged circumferentially and connected by multiple connector wax models. Multiple connecting rods of each connector wax model are arranged circumferentially and connected together. The outer ends of the multiple connecting rods are connected to the multiple casting wax models one by one. The multiple connector wax models are arranged at intervals along the length direction of the casting wax models. At each end of the plurality of casting wax models, a ring plate wax model is respectively set. The ring plate wax model is made by the ring plate mold. The ring plate wax model and the plurality of casting wax models are arranged coaxially and connected to the plurality of casting wax models. The plate body and the ring plate wax model are spaced apart and connected by a column. The diameter of the column is smaller than the diameter of the plate body. A mold shell is prepared on the wax mold of the casting, the wax mold of the connector, and the wax mold of the ring plate. Then, the wax is baked, melted, poured, cleaned, and cut and separated in sequence to obtain the titanium alloy casting.

2. The investment casting process for titanium alloy castings with an aspect ratio greater than 15 according to claim 1, characterized in that, The diameter ratio of the connecting rod to the main rod is 0.85 to 1.15:

1.

3. The investment casting process for titanium alloy castings with an aspect ratio greater than 15 according to claim 1, characterized in that, The ring width of the ring plate wax mold is greater than the diameter of the main rod.

4. The investment casting process for titanium alloy castings with an aspect ratio greater than 15 according to claim 3, characterized in that, The diameter of the plate is greater than the diameter of the main rod, and the ring width of the ring plate wax mold located at the end of the plate is greater than the diameter of the plate.

5. The investment casting process for titanium alloy castings with an aspect ratio greater than 15 according to claim 4, characterized in that, The pouring port is located on one side of the annular plate wax mold containing the plate.

6. The investment casting process for titanium alloy castings with an aspect ratio greater than 15 according to any one of claims 1-5, characterized in that, The wax molds for the casting are arranged in a circumference of 3 to 5.

7. A titanium alloy casting with an aspect ratio greater than 15, wherein the titanium alloy casting is produced by investment casting using the investment casting process for titanium alloy castings with an aspect ratio greater than 15 as described in any one of claims 1-6.

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