Titanium alloy hollow blade blank, hollow blade forming method and hollow blade
By opening inner and lower grooves on the hollow blade blank and adding deformation isolation and transition sections, the problem of difficult control of hollow blade wall thickness was solved, the wall thickness was effectively controlled, the finished product qualification rate and production efficiency were improved, and the cost was reduced.
Patent Information
- Application Number
- CN202511766167.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-27
- Publication Date
- 2026-03-06
AI Technical Summary
After the hollow blades are diffused together, it is difficult to control the wall thickness, which leads to increased production cycle and cost, and low finished product qualification rate.
Inner and lower grooves are made on the hollow blade blank, and deformation isolation section and transition section are added. The deformation section absorbs the horizontal deformation, and the transition section isolates the deformation, thereby controlling the wall thickness and optimizing the diffusion connection process.
Effective control of hollow blade wall thickness improves finished product qualification rate, reduces production costs, shortens production cycle, and enhances production efficiency and mechanical properties.
Smart Images
Figure CN121611513A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of aero-engine technology, specifically to a titanium alloy hollow blade blank, a hollow blade forming method, and a hollow blade. Background Technology
[0002] The weight of an aircraft engine directly affects its thrust-to-weight ratio and fuel economy. To reduce the weight of aircraft engines, the blades are designed as hollow structures.
[0003] Currently, due to the influence of the diffusion bonding method, controlling the cavity and wall thickness dimensions after diffusion bonding has become a major challenge in the manufacturing of hollow blades. During the processing, wall thickness control requires continuous alignment by combining ultrasonic thickness measurement, which increases the production cycle and production cost.
[0004] During diffusion bonding, pressure is typically applied to the entire surface of the part. Due to the superplastic forming process involved in diffusion bonding, the dimensions of the part decrease along the pressure loading direction and increase perpendicular to the pressure loading direction. This results in the cavity size decreasing along the pressure loading direction while the wall thickness increases, causing the cavity size and wall thickness to exceed tolerance requirements. Consequently, the hollow blade cannot meet the usage requirements, leading to both cost waste and extended production cycle. Summary of the Invention
[0005] The purpose of this invention is to provide a titanium alloy hollow blade blank, a hollow blade forming method, and a hollow blade, thereby solving the technical problem that the wall thickness of hollow blades is difficult to control.
[0006] The solution of the present invention to the above-mentioned technical problems is as follows: A hollow blade blank includes a blank body, the blank body including a blade blank area and a diffusion connection area around the blade blank area, a lower groove is formed on the upper surface of the blade blank area, and an inner groove is formed on the lower surface of the blade blank area according to the shape of the hollow blade cavity, the blade blank is between the bottom of the lower groove and the top of the inner groove, and the inner groove is directly opposite the lower groove.
[0007] Furthermore, the thickness of the blade blank is greater than the target thickness of the hollow blade.
[0008] Further defined, the blade blank includes a thickened reinforcing section and a deformable isolation section, the deformable isolation section is located on the periphery of the thickened reinforcing section, and the thickened reinforcing section is connected to the diffusion connection region through the deformable isolation section; The thickness of the thickened reinforcing section is greater than the thickness of the deformable isolation section.
[0009] Further defined, the deformable isolation section includes a deformable section and a transition section, wherein the transition section is located between the deformable section and the thickened reinforcement section; The thickness of the deformed section is D1 = P + 0.25 mm; when P < 2.5 mm, the thickness of the thickened and reinforced section is D2 = 2.5 mm; when P ≥ 2.5 mm, the thickness of the thickened and reinforced section is D2 = P + 0.25 mm; where P is the target thickness of the hollow blade. Furthermore, the width of the deformed segment is equal to the width of the transition segment.
[0010] Furthermore, the diffusion connection area is provided with multiple positioning holes.
[0011] A method for forming hollow blades includes the following steps: S1. Two hollow blade blanks are obtained by forging titanium alloy bars according to the material and size of the hollow blades. S2. After fastening and positioning the two hollow blade blanks, assemble and connect them. S3. Diffusion connection is performed on the two hollow blade blanks after assembly and connection. S4. The two hollow blade blanks that have completed the diffusion connection are precision machined to obtain hollow blades.
[0012] Further specifying, in step S1, the forging temperature of the hollow blade blank is (T β -50)℃±10℃, heat preservation time T=aH; where, T β denoted as the phase transformation point of the titanium alloy bar, α as the thermal insulation coefficient, which ranges from 1.1 to 2 min / mm, and H as the thickness of the diffusion bonding zone in the hollow blade blank.
[0013] Further specifying, in step S3, the temperature for diffusion bonding is (T β -40℃±10℃, heat preservation time is 170~185min.
[0014] A hollow blade is prepared by the hollow blade forming method described above.
[0015] The beneficial effects of this invention are as follows: 1. This invention creates an internal groove on an existing hollow blade blank to form the internal cavity structure of the hollow blade. Simultaneously, a lower groove is created at the top of the hollow blade blank, directly opposite the internal groove. This prevents external pressure from directly acting on the upper part of the internal groove during subsequent diffusion bonding, thus avoiding deformation caused by vertical compression of the internal groove. This reduces the impact of diffusion bonding on the thickness of the blade blank, ensuring the finished quality of the hollow blade, improving the pass rate, reducing costs, increasing production efficiency, and meeting production needs.
[0016] 2. This invention provides a deformation section and a transition section around the thickened and reinforced section. The deformation section absorbs the deformation caused by the horizontal compression of the peripheral diffusion connection area and the deformation caused by thermal expansion and contraction, thereby further reducing the deformation impact on the thickened and reinforced section. At the same time, the transition section further isolates the deformation, thus achieving effective control of the hollow blade wall thickness. Attached Figure Description
[0017] Figure 1 This is a top view of the hollow blade blank of the present invention; Figure 2 for Figure 1 Cross-sectional view along the AA direction; Figure 3 This is a flowchart illustrating the hollow blade forming method of the present invention.
[0018] In the figure, 10-the billet body; 20-the lower groove; 30-the inner groove; 40-the blade billet; 41-the thickened and reinforced section; 42-the deformed section; 43-the transition section; 50-the diffusion connection zone. Detailed Implementation
[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.
[0020] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.
[0021] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.
[0022] In the description of the embodiments of the present invention, it should be noted that if terms such as "upper," "lower," "horizontal," or "inner" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use, they are only for the convenience of describing the present invention and simplifying the description, and do not 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 the present invention. Furthermore, terms such as "first" and "second" are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.
[0023] Example 1 refer to Figure 1 and Figure 2 The present invention provides a hollow blade blank, including a blank body 10, the blank body 10 including a blade blank area and a diffusion connection area 50. The blade blank area is usually located in the middle of the blank body 10 and serves as the forming area of the hollow blade. The diffusion connection area 50 is located on the periphery of the blade blank area and is used to bear pressure to realize the diffusion connection of two hollow blade blanks during the diffusion connection process.
[0024] Among them, the lower surface of the blade blank area is provided with matching inner grooves 30 according to the upper or lower half of the hollow blade cavity shape. After diffusion connection, the two interlocking inner grooves 30 constitute the cavity structure inside the hollow blade.
[0025] A lower groove 20 is provided on the upper surface of the blade blank area. The lower groove 20 is located directly above the inner groove 30 to avoid applying pressure to the inner groove 30 in the vertical direction when applying pressure to the surface of the blank body 10 for diffusion connection. The depth of the lower groove 20 is at least 2 mm, preferably 2.5 mm.
[0026] The portion of the blank body 10 between the bottom of the lower groove 20 and the top of the inner groove 30 is the blade blank 40, which is the position of the upper / lower wall thickness of the hollow blade in the later stage. Preferably, the thickness of the blade blank 40 is greater than the target thickness P of the hollow blade to improve its structural strength and reduce deformation. During the diffusion connection process, since the inner groove 30 is not subjected to force in the vertical direction, it will not directly apply vertical pressure to the blade blank 40, thereby avoiding deformation of the blade blank 40 during the diffusion connection process, ensuring effective control of the hollow blade wall thickness, improving the qualification rate of subsequent processing and production, reducing costs by about 50%, and increasing production capacity.
[0027] Meanwhile, since a lower groove 20 is opened on the blank body 10, the pressure and heat preservation time during the diffusion connection process can be reduced, thereby reducing the diffusion connection process time and the total diffusion connection process time, thus improving the efficiency of diffusion connection. The machining process does not require repeated alignment, shortening the production cycle, and ensuring the comprehensive performance of the diffusion connection joint, especially the plasticity index in the mechanical properties is greatly improved.
[0028] To further explain, the blade blank 40 includes a thickened reinforcing section 41 and a deformed isolation section. The deformed isolation section is located around the thickened reinforcing section 41, and the thickened reinforcing section 41 is connected to the diffusion connection region 50 through the deformed isolation section. The thickness of the thickened reinforcing section 41 is greater than the thickness of the deformed isolation section.
[0029] Because the diffusion connection zone undergoes slight deformation in the horizontal direction due to vertical pressure during the diffusion connection process, in order to avoid the force in this direction compressing the thickened reinforcing section 41 and causing deformation during the diffusion connection process, it is preferable to add a deformation isolation section between the diffusion connection zone and the thickened reinforcing section and reduce the thickness of the deformation isolation section. This allows the deformation of the peripheral diffusion connection zone 50 to be absorbed by the deformation isolation section, further ensuring effective control of the wall thickness of the hollow blade body and further improving the pass rate of the hollow blade.
[0030] To further explain, the deformable isolation section includes a deformable section 42 and a transition section 43, with the transition section 43 located between the deformable section 42 and the thickened and reinforced section 41.
[0031] Specifically, the thickness of the deformed section 42 is D1 = P + 0.25 mm; when P < 2.5 mm, the thickness of the thickened and reinforced section 41 is D2 = 2.5 mm, that is, the thickness of the thickened and reinforced section 41 is at least 2.5 mm and a machining allowance needs to be reserved; when P ≥ 2.5 mm, the thickness of the thickened and reinforced section 41 is D2 = P + 0.25 mm, that is, at this time, the thickness of the thickened and reinforced section 41 only needs to reserve a machining allowance of 0.25 mm; where P is the target thickness of the hollow blade; the thickness of the transition section 43 smoothly transitions from D1 to D2.
[0032] Preferably, the width of the deformed section 42 is equal to the width of the transition section 43, for example, both are 1.5mm wide.
[0033] Example 2 Based on the hollow blade blank provided in Example 1, this example provides a hollow blade forming method, including the following steps: S1. Two hollow blade blanks are obtained by forging titanium alloy bars according to the material and size of the hollow blades. The forging temperature of the hollow blade blank is T. β -50℃±10℃, heat preservation time T=aH; where Tβ denoted as the phase transformation point of the titanium alloy bar, α as the thermal insulation coefficient, with a value ranging from 1.1 to 2 min / mm, and H as the thickness of the diffusion bonding zone 50 in the hollow blade blank.
[0034] S2. After fastening and positioning the two hollow blade blanks, assemble and connect them. S3. Diffusion connection is performed on the two hollow blade blanks after assembly and connection. The temperature of the diffusion connection is T. β -40℃±10℃, heat preservation time is 170~185min.
[0035] S4. The two hollow blade blanks that have completed the diffusion connection are precision machined to obtain hollow blades.
[0036] The hollow blades prepared by the hollow blade forming method provided in this embodiment have a wall thickness range of 1.04mm to 1.21mm, which meets the tolerance requirement of 1mm to 1.25mm. Since the current hollow blade wall thickness range is 1.23mm to 1.65mm, the production qualification rate is greatly improved.
[0037] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the scope of the invention. No reference numerals in the claims should be construed as limiting the scope of the claims.
[0038] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that can be understood by those skilled in the art. The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.
[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.
Claims
1. A hollow blade blank, characterized in that, The blank body (10) comprises a blade blank area and a diffusion connection area (50) on the periphery of the blade blank area, an upper surface of the blade blank area is provided with a lower groove (20), a lower surface of the blade blank area is provided with an inner groove (30) according to the shape of the inner cavity of the hollow blade, and the blade blank (40) is arranged between the bottom of the lower groove (20) and the top of the inner groove (30).
2. Hollow blade blank according to claim 1, characterized in that The thickness of the blade blank (40) is greater than the target thickness of the hollow blade.
3. Hollow blade blank according to claim 2, characterized in that The blade blank (40) comprises a thickened reinforcing section (41) and a deformation isolation section, the deformation isolation section is arranged on the periphery of the thickened reinforcing section (41), and the thickened reinforcing section (41) is connected with the diffusion connection area (50) through the deformation isolation section. The thickness of the thickened reinforcing section (41) is greater than the thickness of the deformation isolation section.
4. Hollow blade blank according to claim 3, characterized in that The deformation isolation section comprises a deformation section (42) and a transition section (43), and the transition section (43) is arranged between the deformation section (42) and the thickened reinforcing section (41). The thickness D1 of the deformation section (42) is P+0.25mm, the thickness D2 of the thickened reinforcing section (41) is 2.5mm when P<2.5mm, and the thickness D2 of the thickened reinforcing section (41) is P+0.25mm when P≥2.5mm, wherein P is the target thickness of the hollow blade.
5. Hollow blade blank according to claim 4, characterized in that The width of the deformation section (42) is equal to the width of the transition section (43).
6. Hollow blade blank according to claim 5, characterized in that A plurality of positioning holes are arranged on the diffusion connection area (50).
7. A method of forming a hollow blade, characterized by The method comprises the following steps: S1, titanium alloy bars are forged to obtain two hollow blade blanks according to the material and size of the hollow blade; S2, the two hollow blade blanks are positioned and connected after being buckled; S3, the two hollow blade blanks after being connected are subjected to diffusion connection; S4, the two hollow blade blanks after being subjected to diffusion connection are subjected to finishing processing to obtain a hollow blade.
8. The hollow vane forming method according to claim 7, wherein The hollow blade blank is forged at a forming temperature (T β -50) °C ± 10 °C for a holding time T = aH; wherein T β is the phase transition point of the titanium alloy bar, a is a holding coefficient, the holding coefficient has a value range of 1.1-2 min / mm, and H is the thickness of the diffusion connection area (50) in the hollow blade blank.
9. The hollow vane forming method according to claim 8, wherein The temperature of the diffusion connection in the step S3 is (T β -40) °C ± 10 °C, and the holding time is 170-185 min.
10. A hollow blade, characterized by The hollow blade is prepared by the method of claim 9.