A large aspect ratio titanium-aluminum alloy billet apparatus and method

Abstract

The application provides a large height-diameter ratio titanium-aluminum alloy blank manufacturing device and method. The method comprises the following steps: S10, designing a blank: designing a forging according to a target titanium-aluminum alloy blade; the forging comprises a blade root part, a blade body part and a blade crown part; presetting the shape and size of the blank according to the forging; S20, obtaining a forming die and a raw material: preparing the forming die according to the preset shape and size of the blank in step S10, and selecting a bar; S30, adopting the forming die to perform upsetting forming on the bar to obtain the blank; and performing hot working on the blank to obtain a target titanium-aluminum alloy blade forging. The large height-diameter ratio titanium-aluminum alloy blank manufacturing method and device can solve the problems of blank instability of a large height-diameter ratio metal bar and high mold cost caused by titanium-aluminum alloy isothermal forming, realize non-isothermal forming of a large height-diameter ratio titanium-aluminum alloy special-shaped part, improve material utilization, reduce waste of titanium-aluminum alloy material, and effectively reduce the machining cost of the blade.

Description

Technical Field

[0001] This invention relates to the field of accessory preparation technology in the high-end manufacturing equipment industry, and in particular to a titanium-aluminum alloy billet preparation device and method with a large aspect ratio. Background Technology

[0002] Titanium-aluminum alloy, as a novel high-strength, lightweight, and high-temperature resistant material, has shown great application potential in the manufacture of high-temperature components such as aerospace engines due to its excellent specific strength and superior high-temperature performance. It can partially or completely replace traditional high-density nickel-based and iron-based materials, and is widely used in fields such as aero-engine turbine blades and high-performance automotive engine turbocharger impellers.

[0003] However, the inherent brittleness of titanium-aluminum alloys poses a significant challenge to their hot forming. This material is prone to cracking and fracture during conventional hot working, greatly limiting the application of traditional hot working techniques. To overcome the material's brittleness and achieve plastic deformation, titanium-aluminum alloys typically require isothermal forming at extremely high temperatures, generally ranging from 1000 to 1400°C. This high-temperature environment places stringent requirements on mold materials; ordinary mold steels cannot withstand such high temperatures. Therefore, expensive nickel-based superalloys and molybdenum-based alloys are often used as mold materials, further increasing processing costs.

[0004] For parts with complex geometries, such as Figure 1 The engine blade shown has a thinner and longer blade body with a smaller cross-sectional area, while the crown and root sections are thicker and shorter with a larger cross-sectional area. This structural characteristic results in the required blank material having a dumbbell-shaped profile, larger at both ends and smaller in the middle (e.g., Figure 2 (As shown), and the height-to-diameter ratio of the billet is greater than 4, making it highly susceptible to instability during forming. Currently, the common practice is to directly machine or machine metal bars of equal diameter into specific shapes before forging. This method not only leads to low material utilization but also significantly increases machining costs due to complex post-processing steps.

[0005] Furthermore, while high-temperature isothermal forming solves the problem of material brittleness, it places extremely high demands on equipment and molds under high-temperature conditions. The use of expensive high-temperature alloys also contributes to the high overall processing costs. Additionally, the special properties of the materials result in a long processing cycle, impacting production efficiency.

[0006] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0007] In view of this, the present invention proposes a billet-making device and method for titanium-aluminum alloy with large aspect ratio to solve the problem of instability in billet-making of metal bars with large aspect ratio, realize non-isothermal forming of titanium-aluminum alloy irregular parts with large aspect ratio, improve material utilization, reduce waste of titanium-aluminum alloy materials, effectively reduce the machining cost of blades, and at the same time, the non-isothermal forming method can avoid the extensive use of high-temperature alloys as mold materials, thus reducing costs.

[0008] The technical solution of this invention is implemented as follows:

[0009] In a first aspect, the present invention provides a billet-making device for titanium-aluminum alloy with a large aspect ratio, comprising a bar stock, a forming die, a collar, a pressure rod, a base heating furnace, and a base; the bar stock is pre-treated with lubrication and then nested in the forming die; the forming die is nested in the collar; the bar stock, the forming die, and the collar form an integral whole, namely an upsetting assembly;

[0010] The base heating furnace surrounds and connects the base and the pressure rod, and is used to heat the base and the pressure rod. The base and the pressure rod are arranged opposite to each other to form a preheating and heat preservation system.

[0011] The upsetting assembly is placed in the base to fix and support the upsetting assembly; the pressure bar is used to apply pressure to the bar stock to complete the upsetting process.

[0012] In this invention, the collar can be made of a high-temperature alloy with high strength and thermal stability at 1000-1400℃, preferably a nickel-based high-temperature alloy; the base is made of mold steel.

[0013] Based on the above technical solutions, preferably, the forming mold is a ceramic mold; the collar is selected from nickel-based alloy K403 or nickel-based alloy N403; the pressure rod is made of nickel-based alloy or ceramic material; the base is made of mold steel H13; the outer diameter of the forming mold is 2-3 times the diameter of the bar stock, and the minimum diameter of the through hole of the forming mold is equivalent to the diameter of the bar stock.

[0014] Based on the above technical solutions, preferably, the base is not completely placed into the base heating furnace, which facilitates external air cooling and creates a certain temperature gradient in the base, thereby providing support and compressive stress enhancement for the internal upsetting components.

[0015] Based on the above technical solutions, preferably, the upsetting component, the pressure rod, and the base all need to be heat-insulated; the heat-insulating temperature of the upsetting component is 1000-1400℃, and the time is 30-120 minutes; the heat-insulating temperature of the pressure rod and the base is 500-800℃, and the time is 1-5 hours.

[0016] Secondly, the present invention provides a method for preparing titanium-aluminum alloy billets with a large aspect ratio based on the aforementioned device, characterized by comprising the following steps:

[0017] S10, Design billet:

[0018] Forgings are designed based on the target titanium-aluminum alloy blades; the forgings include a blade root, a blade body, and a blade crown; the shape and size of the blank are preset according to the forgings;

[0019] S20. Obtain forming mold and raw materials: Prepare forming mold according to the preset shape and size of the blank described in step S10, and select bar stock;

[0020] S30. The bar stock is upsetting using the forming mold to obtain a billet;

[0021] The blank is hot-processed to obtain the target titanium-aluminum alloy blade forging.

[0022] Based on the above technical solution, preferably, in step S20, the selection of bar stock includes:

[0023] Based on the shape and size of the billet described in step S10, a bar stock with a height-to-diameter ratio greater than 4 is selected as the raw material; the bar stock includes a first end, a middle part, and a second end.

[0024] The first and second ends of the bar stock are heated, kept warm, and upset, respectively, without deformation in the middle, to obtain a billet.

[0025] More preferably, the bar stock needs to undergo a lubrication pretreatment before upsetting, and the lubrication pretreatment involves coating the bar stock with a glass lubricant; the coating thickness of the glass lubricant is 1-2 mm.

[0026] More preferably, the upsetting speed is 1 to 10 mm / s.

[0027] Based on the above technical solution, preferably, in step S30, the upsetting forming adopts a non-isothermal forging forming method; the upsetting forming temperature is 1000-1400℃; after the upsetting forming is completed, the height-to-diameter ratio H / D of the forging is less than 2.5.

[0028] Based on the above technical solutions, preferably, the target titanium-aluminum alloy blade is TiAlXZ;

[0029] Wherein, X is at least one of the elements Nb, Mo, Cr, Ta, V, and Mn; and Z is at least one of the elements Fe, C, N, O, B, and Si.

[0030] The atomic percentage of Al is 43%-48%, that of X is 0%-8%, and that of Z is 0%-1%.

[0031] Thirdly, the present invention provides a titanium-aluminum alloy blade prepared by the above-described blanking method.

[0032] The apparatus and method for preparing titanium-aluminum alloy billets with a large aspect ratio provided by the present invention have the following advantages over the prior art:

[0033] 1. In this invention, high-quality ceramic with high compressive strength at high temperatures is used as the forming mold, and a reasonably designed cavity is used to reduce the height-to-diameter ratio of the deformed titanium-aluminum alloy portion, thus avoiding instability. A high-strength, thermally stable high-temperature alloy collar is used to apply compressive stress to the forming mold, enhancing its compressive strength and preventing cracking and failure. The base is made of mold steel, which has a relatively low insulation temperature, providing support and compressive stress enhancement for the internal collar and mold. Furthermore, only the forming mold needs to be replaced between several upsetting passes. In addition, this invention avoids using a single high-temperature alloy or ceramic material. Structurally, it uses high-quality mold steel as the base, ceramic as the forming mold, and a high-temperature alloy as the supporting collar, forming a composite structure that effectively reduces mold costs.

[0034] 2. The device and method for making titanium-aluminum alloy billets with large aspect ratios of the present invention can solve the problems of instability in the billet making of large aspect ratio metal bars and high mold costs caused by isothermal forming of titanium-aluminum alloys. It can realize non-isothermal forming of titanium-aluminum alloy irregular parts with large aspect ratios, improve material utilization, reduce waste of titanium-aluminum alloy materials, and effectively reduce the machining cost of blades. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 This is a schematic diagram of the titanium-aluminum alloy blade irregular part mentioned in the background art;

[0037] Figure 2 This is a schematic diagram of the dumbbell-shaped irregular part blank mentioned in the background art;

[0038] Figure 3This is a schematic diagram of the forming mold of the present invention; in the figure, (a) is a schematic diagram of a first-pass upsetting forming mold; (b) is a schematic diagram of a second-pass upsetting forming mold; 1 is a bar stock, 21 is the first set of forming molds; 1' is a first-pass upsetting forming blank, 22 is the second set of forming molds;

[0039] Figure 4 This is a schematic diagram of a single upsetting process according to the present invention; in the figure, (a) is the upsetting assembly; (b) is the preheating and heat preservation system; and (c) is the upsetting device.

[0040] Figure 5 This is a schematic diagram of the two-pass upsetting process of the present invention; in the figure, (a) is the upsetting assembly; (b) is the preheating and heat preservation system; and (c) is the upsetting device.

[0041] Figures 3-5 In the diagram, 1 is the bar stock, 2 is the forming die, 3 is the collar, 4 is the pressure rod, 5 is the base heating furnace, and 6 is the base.

[0042] Figure 6 The figure shows a schematic diagram of the billet of the present invention. In the figure, (a) is a schematic diagram of a billet formed by one upsetting step; and (b) is a schematic diagram of a billet formed by two upsetting steps. Detailed Implementation

[0043] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0044] like Figure 1 As shown, for leaves with special shapes, the leaf blade is thinner and longer with a smaller cross-sectional area, while the crown and root are thicker, shorter, and have a larger cross-sectional area. This results in the required shape of the blank, such as... Figure 2 As shown, this is a dumbbell-shaped irregular part, wider at both ends and narrower in the middle; and the height-to-diameter ratio of the billet is greater than 4, making it highly susceptible to instability during forming. Currently, it is generally formed by direct machining or by machining metal bars of the same diameter into a specific shape before forging, resulting in low material utilization and high machining costs. Furthermore, isothermal forming requires high temperatures, mostly in the range of 1000-1400℃, placing more stringent demands on mold performance. Conventional mold steels cannot be used; instead, expensive nickel-based high-temperature alloys and molybdenum-based alloys are often used, further increasing processing costs.

[0045] To solve the above problems, a high aspect ratio titanium-aluminum alloy billet forming device is provided, comprising a bar stock 1, a forming die 2, a collar 3, a pressure rod 4, a base heating furnace 5, and a base 6; the bar stock 1 is pre-treated with lubrication and then nested in the forming die 2; the forming die 2 is nested within the collar 3; the bar stock 1, the forming die 2, and the collar 3 form an integral unit, namely an upsetting assembly, as shown below. Figure 4 As shown in (a);

[0046] The base heating furnace 5 surrounds and connects the base 6 and the pressure rod 4, and is used to heat the base 6 and the pressure rod 4. The base 6 and the pressure rod 4 are arranged opposite to each other to form a preheating and heat preservation system. Figure 4 As shown in (b);

[0047] The upsetting assembly is placed in the base 6 to fix and support the upsetting assembly; the pressure rod 4 is used to apply pressure to the upsetting assembly to complete the upsetting process.

[0048] In a specific embodiment of the present invention, at least two sets of forming molds 2 are designed. One end of the first set of forming molds 21 has a groove, the shape and size of which are determined according to the following... Figure 2 The shape and dimensions of one end of the dumbbell-shaped blank shown are designed according to the specifications; one end of the second forming mold 22 that contacts the collar 3 has a groove that is exactly similar in shape and size to the first forming mold 21, and the other end is designed according to the specifications shown. Figure 2 The shape and dimensions of the other end of the dumbbell-shaped blank shown are designed as needed.

[0049] In a specific embodiment of the present invention, the height-to-diameter ratio of the bar stock 1 is greater than 4; the pressure bar 4 is made of nickel-based high-temperature alloy or ceramic; the base 6 is made of mold steel, preferably high-quality hot-work mold steel such as H13; and the base 6 is not completely placed in the base heating furnace 5, and its exterior is air-cooled for heat dissipation, so the base 6 as a whole has a certain temperature gradient, which can provide support and compressive stress enhancement for the internal collar 3 and forming mold 2; the forming mold 2 is made of high-quality ceramic mold; the collar 3 is selected from high-temperature alloys that have high strength and thermal stability at 1000-1400℃, preferably nickel-based high-temperature alloys such as K403 and N403.

[0050] In a specific embodiment of the present invention, the outer diameter of the forming mold 2 is 2-3 times the diameter of the bar stock 1; the minimum diameter of the through hole of the forming mold 2 is equivalent to the diameter of the bar stock 1, that is, the minimum inner diameter of the second forming mold 22 is equal to the diameter of the bar stock 1.

[0051] In a specific embodiment of the present invention, the pressure bar 4 is connected to a press and is used to apply pressure to the bar stock 1 to complete the upsetting process.

[0052] Furthermore, the present invention also provides a method for preparing titanium-aluminum alloy billets with a large aspect ratio, characterized by comprising the following steps:

[0053] S10, Design billet:

[0054] Forgings are designed based on the target titanium-aluminum alloy blades; the forgings include a blade root, a blade body, and a blade crown; the shape and size of the blank are preset according to the forgings;

[0055] S20. Obtain forming mold 2 and raw materials: Prepare forming mold 2 according to the preset shape and size of the blank described in step S10, and select bar stock 1;

[0056] S30. The forming mold 2 is used to upset the bar stock 1 to obtain a billet;

[0057] The blank is hot-processed to obtain the target titanium-aluminum alloy blade forging.

[0058] In a specific embodiment of the present invention, the target titanium-aluminum alloy blade can be of any shape. The present invention uses... Figure 1 Taking the blade with a complex geometry as an example, the preset shape and size of the forging are determined.

[0059] In a specific embodiment of the present invention, S20, the selection of bar stock 1 includes:

[0060] Based on the shape and size of the billet described in step S10, a bar stock 1 with a height-to-diameter ratio greater than 4 is selected as the raw material; the bar stock 1 includes a first end, a middle part, and a second end.

[0061] The first and second ends of the bar stock 1 are heated, kept warm, and upset, respectively, without deformation in the middle, to obtain a billet.

[0062] In a specific embodiment of the present invention, the bar stock 1 needs to be lubricated before upsetting. The lubricating pretreatment is to coat the bar stock 1 with a commercially available glass lubricant. The coating thickness of the glass lubricant is 1-2 mm.

[0063] In a specific embodiment of the present invention, in step S30, the method of upsetting the bar stock 1 using the forming mold 2 to obtain the billet is as follows: the forging is performed using a non-isothermal forging process, that is, the temperature of the billet and the temperature of the mold are not the same. The non-isothermal forging process is as follows: the temperature of the bar stock 1 or the billet is 1000-1400℃, the temperature of the mold is 500-800℃, and the upsetting speed is 1-10mm / s.

[0064] In a specific embodiment of the present invention, the upsetting component, the pressure rod, and the base need to be heat-insulated; the heat-insulating temperature of the upsetting component is 1000-1400℃, and the time is 30-120 minutes; the heat-insulating temperature of the pressure rod and the base is 500-800℃, and the time is 1-5 hours.

[0065] In this invention, after the heat preservation is completed, the base heating furnace 5 is turned off, and the heat preservation upsetting component is quickly transferred to the base 6 for one-end upsetting. The forming speed is 1-10 mm / s. After upsetting, the first blank is taken out and cooled. Glass lubricant is applied to the first blank again and placed in the second set of forming molds 22 with the undeformed end of the bar 1 facing upward. The second set of forming molds 22 containing the bar 1 is nested in the collar 3 for secondary heat preservation and upsetting to obtain the required blank.

[0066] The forging method of titanium-aluminum alloy engine blades provided in this disclosure will be further explained below with reference to specific embodiments.

[0067] Example 1

[0068] This embodiment uses the titanium-aluminum alloy Ti-47Al-2Cr-2Nb-0.5C as an example.

[0069] S10. Obtain the billet:

[0070] Forgings are designed based on the target titanium-aluminum alloy blades; the forgings include a blade root, a blade body, and a blade crown;

[0071] According to the preset blank shape and size of the forging;

[0072] S20. Obtain forming mold 2 and raw materials: According to the preset shape and size of the blank described in step S10, prepare two sets of forming mold 2 and select bar stock 1;

[0073] S30, Upsetting: The raw material is bar stock 1. Bar stock 1 is coated with glass lubricant and placed in... Figure 3 In the first set of forming molds 21 shown in (a), the bar stock 1, forming mold 21 and collar 3 are nested in sequence to form the following structure: Figure 4 (a) The upsetting assembly is placed in a heating furnace and held at 1300℃ for 60 minutes; simultaneously, the pressure rod 4 and the base 6 are held at 600℃ for 4 hours under the action of the base heating furnace 5. Figure 4 (b) As shown; after the heat preservation is completed, the base heating furnace 5 is turned off and removed, and the upsetting component is quickly transferred to the base 6 for one-end upsetting forming at a forming speed of 1 mm / s, as shown. Figure 4 As shown in (c); after cooling, remove it to obtain the following result: Figure 6(a) shows a schematic diagram of a single-stage upsetting billet, where the height-to-diameter ratio H1 / D1 of the single-stage upsetting billet is less than 2.5; after coating the single-stage upsetting billet with glass lubricant, it is placed as shown in the diagram. Figure 3 (b) The second molding die 22 is shown, with the unformed end facing upwards, and then nested into the collar 3 to form a shape as shown. Figure 5 (a) The upsetting assembly is placed in a heating furnace and held at 1300℃ for 60 minutes; simultaneously, the pressure rod 4 and the base 6 are held at 600℃ for 4 hours under the action of the base heating furnace 5. Figure 5 (b) As shown; after the heat preservation is completed, the base heating furnace 5 is turned off and removed, and the upsetting component is quickly transferred to the base 6 for upsetting the other end, with a forming speed of 1 mm / s, as shown. Figure 5 As shown in (c); after cooling, remove it to obtain the following result. Figure 6 (b) shows a schematic diagram of a two-pass upsetting billet, and the height-to-diameter ratio H2 / D2 of the two-pass upsetting billet is less than 2.5.

[0074] After two rounds of upsetting are completed, a forging is obtained, and the forging is then machined to obtain the target titanium-aluminum alloy blade.

[0075] Example 2

[0076] This embodiment uses the titanium-aluminum alloy Ti-45Al-8Nb as an example.

[0077] S10. Obtain the billet:

[0078] Forgings are designed based on the target titanium-aluminum alloy blades; the forgings include a blade root, a blade body, and a blade crown;

[0079] According to the preset blank shape and size of the forging;

[0080] S20. Obtain forming mold 2 and raw materials: According to the preset shape and size of the blank described in step S10, prepare two sets of forming mold 2 and select bar stock 1;

[0081] S30. Upsetting: Prepare a billet according to the preset shape and dimensions of the forging described in step S10. The raw material is bar stock 1. Coat bar stock 1 with glass lubricant and place it in... Figure 3 (a) In the first set of forming molds 21 shown, the bar stock 1, the first set of forming molds 21 and the collar 3 are nested in sequence to form the following structure: Figure 4 (a) The upsetting assembly is placed in a heating furnace and held at 1000℃ for 120 minutes; simultaneously, the pressure rod 4 and the base 6 are held at 500℃ for 5 hours under the action of the base heating furnace 5. Figure 4(b) As shown; after the heat preservation is completed, the base heating furnace 5 is turned off and removed, and the upsetting component is quickly transferred to the base 6 for one-end upsetting forming at a forming speed of 4mm / s, as shown. Figure 4 As shown in (c); after cooling, remove it to obtain the following result. Figure 6 (a) shows a schematic diagram of a single-stage upsetting billet, where the height-to-diameter ratio H1 / D1 of the single-stage upsetting billet is less than 2.5; after coating the single-stage upsetting billet with glass lubricant, it is placed as shown in the diagram. Figure 3 (b) In the second molding die 22 shown, with the unformed end facing upwards, it is arranged within the nested collar 3 as follows. Figure 5 (a) The upsetting assembly is placed in a heating furnace and held at 1200℃ for 80 minutes; simultaneously, the pressure rod 4 and the base 6 are held at 600℃ for 2 hours under the action of the base heating furnace 5. Figure 5 (b) As shown; after the heat preservation is completed, the base heating furnace 5 is turned off and removed, and the upsetting component is quickly transferred to the base 6 for upsetting the other end, with a forming speed of 4mm / s, as shown. Figure 5 As shown in (c); after cooling, remove it to obtain the following result. Figure 6 (b) shows a schematic diagram of a two-pass upsetting billet, and the height-to-diameter ratio H2 / D2 of the two-pass upsetting billet is less than 2.5.

[0082] After two rounds of upsetting are completed, the final billet is obtained. The billet is then hot-worked to obtain the target titanium-aluminum alloy blade forging.

[0083] Example 3

[0084] This embodiment uses the titanium-aluminum alloy Ti-46Al-2Cr-2Nb-C as an example.

[0085] S10. Obtain the billet:

[0086] Forgings are designed based on the target titanium-aluminum alloy blades; the forgings include a blade root, a blade body, and a blade crown;

[0087] According to the preset blank shape and size of the forging;

[0088] S20. Obtain forming mold 2 and raw materials: According to the preset shape and size of the blank described in step S10, prepare two sets of forming mold 2 and select bar stock 1;

[0089] S30. Upsetting: Prepare a billet according to the preset shape and dimensions of the forging described in step S10. The raw material is bar stock 1. Coat bar stock 1 with glass lubricant and place it in... Figure 3 (a) In the first set of forming molds 21 shown, the bar stock 1, the first set of forming molds 21 and the collar 3 are nested in sequence to form the following structure: Figure 4(a) The upsetting assembly is placed in a heating furnace and held at 1400℃ for 30 minutes; simultaneously, the pressure rod 4 and the base 6 are held at 800℃ for 1 hour under the action of the base heating furnace 5. Figure 4 (b) As shown; after the heat preservation is completed, the base heating furnace 5 is turned off and removed, and the upsetting component is quickly transferred to the base 6 for one-end upsetting forming at a forming speed of 6 mm / s, as shown. Figure 4 As shown in (c); after cooling, remove it to obtain the following result. Figure 6 (a) shows a schematic diagram of a single-stage upsetting billet, where the height-to-diameter ratio H1 / D1 of the single-stage upsetting billet is less than 2.5; after coating the single-stage upsetting billet with glass lubricant, it is placed as shown in the diagram. Figure 3 (b) In the second molding die 22 shown, with the unformed end facing upwards, it is arranged within the nested collar 3 as follows. Figure 5 (a) The upsetting assembly is placed in a heating furnace and held at 1400℃ for 30 minutes; simultaneously, the pressure rod 4 and the base 6 are held at 800℃ for 1 hour under the action of the base heating furnace 5. Figure 5 (b) As shown; after the heat preservation is completed, the base heating furnace 5 is turned off and removed, and the upsetting component is quickly transferred to the base 6 for upsetting the other end, with a forming speed of 6 mm / s, as shown. Figure 5 As shown in (c); after cooling, remove it to obtain the following result. Figure 6 (b) shows a schematic diagram of a two-pass upsetting billet, and the height-to-diameter ratio H2 / D2 of the two-pass upsetting billet is less than 2.5.

[0090] After two rounds of upsetting are completed, the final billet is obtained. The billet is then hot-worked to obtain the target titanium-aluminum alloy blade forging.

[0091] Comparative Example 1

[0092] The difference between this comparative example and Example 1 is that the bar stock is processed by machining. Due to the special shape of the blade, machining a bar stock that completely covers the shape of the blade part would result in a very large machining allowance in the blade body and extremely low material utilization.

[0093] Comparative Example 2

[0094] The difference between this comparative example and Example 1 is that: the blade is forged after being machined into a specific shape using metal bars of equal diameter. Due to the special shape of the blade, the cross-sectional area of ​​the blade body is much smaller than that of the blade ends. Using bars of equal diameter for machining would result in a very large machining allowance in the blade body, leading to extremely low material utilization.

[0095] It should be noted that although the steps of the upsetting method for high aspect ratio titanium-aluminum alloys in this disclosure are described in a specific order in the accompanying drawings, this does not require or imply that the steps must be performed in that specific order, or that all the steps shown must be performed to achieve the desired result. Additional or alternative steps may be omitted, multiple steps may be combined into one step, and / or a step may be broken down into multiple steps.

[0096] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a titanium-aluminum alloy billet using a high aspect ratio billet preparation apparatus, characterized in that, The billet preparation device includes a bar stock (1), a forming mold (2), a collar (3), a pressure rod (4), a base heating furnace (5), and a base (6); the bar stock (1) is pre-lubricated and then nested in the forming mold (2); the forming mold (2) is nested in the collar (3); the bar stock (1), the forming mold (2), and the collar (3) form a whole, namely, an upsetting assembly; The base heating furnace (5) surrounds and connects the base (6) and the pressure rod (4) for heating the base (6) and the pressure rod (4), and the base (6) and the pressure rod (4) are arranged opposite to each other to form a preheating and heat preservation system; The upsetting assembly is placed in the base (6), which is used to fix and support the upsetting assembly; the pressure bar (4) is used to apply pressure to the bar stock (1) to complete the upsetting process; The forming mold (2) is a ceramic mold; the collar (3) is made of nickel-based alloy material; the base (6) is made of mold steel; The upsetting assembly, the pressure bar (4), and the base (6) need to be heat-insulated; the heat-insulating temperature of the upsetting assembly is 1000-1400℃, and the time is 30-120min; the heat-insulating temperature of the pressure bar (4) and the base (6) is 500-800℃, and the time is 1-5h; the pressure bar (4) is made of nickel-based alloy or ceramic material; the outer diameter of the forming mold (2) is 2-3 times the diameter of the bar stock (1), and the minimum diameter of the through hole of the forming mold (2) is equivalent to the diameter of the bar stock (1); The billet preparation method of the high aspect ratio titanium-aluminum alloy billet preparation apparatus includes the following steps: S10. Designing the blank: Designing the forging based on the target titanium-aluminum alloy blade; the forging includes the blade root, blade body, and blade crown; the shape and size of the blank are preset according to the forging. S20. Obtain forming mold (2) and raw materials: Prepare forming mold (2) according to the preset shape and size of the blank described in step S10, and select bar stock (1). S30. The forming mold (2) is used to upset the bar stock (1) to obtain a billet; The blank is hot-worked to obtain the target titanium-aluminum alloy blade forging; In step S20, selecting the bar stock (1) includes: According to the shape and size of the billet described in step S10, a bar stock (1) with a height-to-diameter ratio greater than 4 is selected as the raw material; the bar stock (1) includes a first end, a middle part and a second end; the first end and the second end of the bar stock (1) are heated and upsetting respectively, and the middle part is not deformed, so as to obtain the billet; In step S30, the upsetting process is performed using a non-isothermal forging method; the upsetting temperature is 1000-1400℃; after the upsetting process is completed, the height-to-diameter ratio H / D of the forging is less than 2.

5.

2. The billet-making method of the billet-making apparatus according to claim 1, characterized in that, Before upsetting the bar stock (1), a lubrication pretreatment is required. The lubrication pretreatment involves coating the bar stock (1) with a glass lubricant. The coating thickness of the glass lubricant is 1-2 mm.

3. The billet-making method of the billet-making apparatus according to claim 2, characterized in that, The upsetting speed is 1~10mm / s.

4. The billet-making method of the billet-making apparatus according to claim 1, characterized in that, The target titanium-aluminum alloy blade is TiAlXZ; Wherein, X is at least one of the elements Nb, Mo, Cr, Ta, V, and Mn; and Z is at least one of the elements Fe, C, N, O, B, and Si. The atomic percentage of Al is 43%-48%, that of X is 0%-8%, and that of Z is 0%-1%.

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