Structure for improving metallurgical defects of integral casting turbine disc

Abstract

The utility model provides a structure for improving metallurgical defects of an integral casting turbine disc. The structure is mainly used for solving the problems of low dimensional accuracy and poor metallurgical quality when the integral casting turbine disc is manufactured by a traditional investment casting process. According to the structure, in the turbine disc wax mold design stage, the extension sections are additionally arranged at the blade tips of the fan blades, and the outer rings are additionally arranged outside the extension sections, so that the blades are prevented from deforming, the size precision is improved, and the problem of looseness of the blade tips is thoroughly solved. By means of the structure, the metallurgical effect and operation convenience of the integral casting turbine disc can be remarkably improved, and the structural strength and safety performance of the integral casting turbine disc are improved.

Description

Technical Field

[0001] The utility model relates to the field of integral casting turbine disk manufacturing, in particular to a structure for improving the metallurgical defects of integral casting turbine disks. Background Art

[0002] In the field of aerospace engine manufacturing, the manufacturing of integral casting turbine disks is a key link. The traditional investment casting process flow includes multiple stages such as wax pattern mold design, wax pattern pressing, wax pattern tree building, shell making, pouring, and post-processing. However, there are some significant problems in the actual application of this process.

[0003] Firstly, in terms of dimensions, during the manufacturing process of the traditional investment casting process, due to the long and thin blades, with the tip length of about 50 mm and the thickness of only about 3 mm, the sensitivity of the wax material to temperature causes the blades to be prone to warping and deformation during the wax pattern pressing and wax pattern tree building stages. At the same time, during the pouring stage, the shrinkage deformation during the cooling process further affects the shape and dimensional accuracy of the blades. These problems result in a large deviation in the runout value of the tip concentric circles measured with the central reference circle, and poor consistency in the shapes of each blade, seriously affecting the quality and service performance of the integral casting turbine disk.

[0004] Secondly, metallurgically, due to the long and thin tip part of the blade, the cooling rate at this position is relatively fast after the casting is poured, which is prone to poor feeding. Porosity problems are often found at the tip position during fluorescence inspection, which not only affects the structural strength of the turbine disk but also may pose safety hazards.

[0005] In summary, the traditional investment casting process faces problems of low dimensional accuracy and poor metallurgical quality when manufacturing integral casting turbine disks. Content of the Utility Model

[0006] The purpose of the utility model is to address the problems in the background art. A structure for improving the metallurgical defects of integral casting turbine disks aims to improve the consistency of the appearance sizing of the blades, reduce the runout deviation at the same concentric circle position of the blades, completely solve the porosity problem at the blade tips, and improve the pouring process to obtain better metallurgical effects.

[0007] To achieve the above purpose, the utility model provides a structure for improving the metallurgical defects of integral casting turbine disks. During the design stage of the turbine disk wax pattern mold, the mold structure includes a turbine center disk and a plurality of fan blades arranged around the turbine center disk. At the tip position of the fan blades, an extension section is added.

[0008] Preferably, the length of the extension section is 6 to 10 mm.

[0009] Furthermore, an outer ring is added outside the extension section.

[0010] Preferably, the thickness of the outer ring is 5 to 8 mm.

[0011] Furthermore, a fillet with a radius of R1 is adopted for the transition between the extension section and the outer ring.

[0012] Furthermore, a dividing line is provided on the fan blade. In the subsequent process stage, during the finishing of the casting blank, wire cutting is performed along the dividing line to obtain a complete metal casting.

[0013] The beneficial effects achieved by the present utility model are as follows: By introducing the outer ring design, the present utility model effectively prevents the irregular deformation of the ultra-thin blades and ensures a high degree of consistency in the sizing of each blade. At the same time, this method also effectively eliminates the torsional deformation of the blades and significantly improves the accuracy of positioning dimensions such as blade runout. The outer ring acts as a riser during the casting process, and the blades are fed through the extension section, thus effectively and thoroughly solving the problem of porosity at the blade tip. This not only enhances the structural strength of the turbine disk but also eliminates potential safety hazards. Since the outer ring can directly feed the blade tip through the extension section, the feeding channel is improved, the feeding distance is reduced, and the feeding becomes smoother. This improvement enables the pouring temperature to be optimized and reduced, thereby improving the overall metallurgical properties of the casting. Through the above process improvements, the casting blades are more stable during the manufacturing process, reducing the risk of the blade wax patterns being touched or damaged during the wax mold pressing and wax mold tree assembly stages, thus significantly enhancing the operational convenience. Description of the Drawings

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present utility model. For those skilled in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0015] Figure 1 is the step flow chart of the present utility model.

[0016] Figure 2 is the schematic diagram of the turbine disk with an outer ring attached to the present utility model.

[0017] Figure 3 is the schematic diagram of the turbine disk of the present utility model.

[0018] Figure 4 is the schematic diagram of the simulation result of the process Procast of the present utility model.

[0019] Among them, 1 - turbine center disk, 2 - fan blade, 3 - extension section, 4 - outer ring, 5 - dividing line. Detailed Embodiments

[0020] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative efforts fall within the protection scope of the present utility model. In addition, it should be understood that the specific implementation manners described herein are only used to illustrate and explain the present utility model, and are not used to limit the present utility model. In the present utility model, unless otherwise stated, the orientation terms such as "upper" and "lower" usually refer to the upper and lower in the actual use or working state of the device, specifically the drawing direction in the accompanying drawings; while "inner" and "outer" refer to the outline of the device. Embodiment

[0021] As Figures 1 to 4 shown, this embodiment provides a process method for improving the dimensions and metallurgical defects of an integrally cast turbine disk, and the specific steps are as follows:

[0022] The first step is the wax mold die design stage.

[0023] 1. Convert the drawing: First, the engineer needs to convert the part drawing into a casting drawing to ensure the consistency between the final casting and the original design. During the conversion process, the shrinkage rate of the metal during the casting process needs to be considered to ensure the dimensional accuracy of the final casting.

[0024] 2. Design the extension section 3 and the outer ring 4: At the tip positions of all the fan blades 2, an extension section 3 is added. It is usually set between 6 and 10 mm, and 8 mm is adopted in this embodiment. The design of this extension section 3 aims to facilitate the feeding of metal during the subsequent casting process, thereby solving the problem of porosity at the blade tips. At the same time, an outer ring 4 is added outside the extension section 3, and its thickness is controlled between 5 and 8 mm, and 6 mm is adopted in this embodiment. The design of the outer ring 4 not only enhances the integrity of the casting but also helps to reduce the deformation of the fan blades 2 during the casting process.

[0025] 3. Optimize the transition area: The connection between the extension section 3 and the outer ring 4 adopts an R1 rounded corner transition, which can reduce stress concentration and improve the structural strength and service life of the casting.

[0026] 4. Preset the dividing line 5: A dividing line 5 is preset on the fan blade 2 to facilitate the cutting operation in the subsequent process and ensure that the shape and size of the final casting meet the design requirements.

[0027] The second step is the wax mold pressing stage.

[0028] Use a metal mold to press out a complete and qualified wax mold model. The key to this stage is to ensure the accuracy and quality of the wax mold, laying a foundation for the subsequent casting process.

[0029] The third step is the stage of the wax pattern assembly tree.

[0030] The pressed wax pattern models are combined into a complete assembly including gating systems according to a specific process plan. In this step, the design of the outer ring 4 makes the assembly more stable, facilitating subsequent shell-making and pouring operations.

[0031] The fourth step is the stage of shell-making.

[0032] Several layers of ceramic shells are made around the wax pattern assembly to protect the assembly from being broken by the high-temperature molten metal during pouring. The production of the ceramic shells requires precise control of the thickness and uniformity of each layer to ensure the quality of the final casting.

[0033] The fifth step is the stage of pouring.

[0034] The ceramic shell is poured with metal to form a casting blank. In this stage, the molten metal compensates for the shrinkage of the fan blade 2 through the extension section 3, effectively solving the problem of tip porosity in traditional casting methods. At the same time, due to the improvement of the feeding channel and the reduction of the feeding distance, the pouring temperature can be optimized and reduced, thus improving the overall metallurgical properties of the casting.

[0035] The sixth step is the stage of post-processing.

[0036] 1. Casting finishing: The casting blank is subjected to finishing operations, including removing the gating systems, grinding burrs, etc., to ensure the surface quality and dimensional accuracy of the casting.

[0037] 2. Wire cutting: Wire cutting operations are carried out along the preset dividing line 5 to separate the casting from the assembly, obtaining a complete metal casting. This step requires precise control of the cutting position and depth to avoid unnecessary damage to the casting.

[0038] Through the detailed description of the above six steps, it can be seen that this process method has significant advantages in improving the dimensional accuracy and metallurgical quality of the integrally cast turbine disk. At the same time, this process also reduces the production cost and operation difficulty.

[0039] In this article, specific examples are used to elaborate on the principle and implementation mode of the present utility model. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the principle of the present utility model, several improvements and modifications can still be made to the present utility model, and these improvements and modifications also fall within the protection scope of the claims of the present utility model.

Claims

1. A structure for improving metallurgical defects of an integrally cast turbine disk, the mold structure comprising a turbine center disk (1) and a plurality of fan blades (2) arranged around the turbine center disk (1), characterized in that: An extension section (3) is added at the tip of the fan blade (2), and a dividing line (5) is provided on the fan blade (2).

2. The structure for improving metallurgical defects of integrally cast turbine disks according to claim 1, characterized in that: The extension section (3) has a length of 6 to 10 mm.

3. The structure for improving metallurgical defects of integrally cast turbine disks according to claim 1, characterized in that: An outer ring (4) is arranged outside the extension section (3).

4. The structure for improving metallurgical defects of integrally cast turbine disks according to claim 3, characterized in that: The thickness of the outer ring (4) is 5 to 8 mm.

5. The structure for improving metallurgical defects of integrally cast turbine disks according to claim 3, characterized in that: An R1 rounded transition is adopted between the extension section (3) and the outer ring (4).

Images