Large-size Ti2AlNb alloy sheet and preparation method thereof

Abstract

The invention relates to the technical field of alloy processing, in particular to a large-specification Ti2AlNb alloy sheet and a preparation method thereof. The preparation method comprises the following steps that (a) a Ti2AlNb alloy plate blank is subjected to one-fire rolling in the width direction and the length direction at the temperature of 1050-1100 DEG C, and an intermediate plate blank is obtained; the intermediate plate blank is subjected to annealing treatment at the temperature of 1000-1045 DEG C; (b) the intermediate plate blank subjected to annealing treatment is subjected to one-fire rolling in the width direction and the length direction at the temperature of 850-980 DEG C and then subjected to cladding rolling in the length direction; and then annealing treatment is carried out at the temperature of 800-950 DEG C. Through treatment of high-temperature reversing rolling, intermediate annealing, low-temperature reversing rolling, annealing after rolling and the like in sequence, the transverse and longitudinal deformation of the high-temperature reversing rolling and the low-temperature reversing rolling is regulated in a matched mode, the mechanical performance of the plate is guaranteed, and the transverse and longitudinal performance difference of the plate is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of alloy processing, in particular to a large-size Ti 2 AlNb alloy thin plate and preparation method thereof. Background Art

[0002] Ti 2 AlNb alloy is a titanium-aluminum intermetallic compound structural material. The alloy has the advantages of low density, good flame retardancy, high specific strength, high fracture toughness, and good high-temperature creep resistance. It can be used as a structural material for long-term service at 600-750°C or for short-term use at higher temperatures. It shows great application potential, especially in aerospace structural materials. It is of great significance to improve the thrust-to-weight ratio of aircraft, improve fuel efficiency, and high-temperature service performance.

[0003] With the rapid development of the aerospace industry, high-speed aircraft have put forward higher requirements on the load-bearing capacity and temperature resistance of thin-walled complex components such as wings and air inlets. At the same time, as the size of the aircraft increases, the size of the components also increases accordingly. Therefore, large-sized Ti 2 AlNb alloy plates have higher requirements. During high-speed flight, thin-walled components will be subjected to severe aerodynamic heat and aerodynamic coupling. When in service, components are often subjected to severe force / heat coupling in multiple directions. This requires the material to have low anisotropy and to ensure uniformity of structure and performance as much as possible. Ti prepared by conventional process 2 There are large differences in the transverse and longitudinal properties of AlNb alloy thin plates. Irregular deformation is prone to occur during the preparation of components, making it difficult to meet the dimensional accuracy requirements of the components.

[0004] In view of this, the present invention is proposed. Summary of the invention

[0005] The purpose of the present invention is to provide a large-size Ti 2 AlNb alloy thin plate and preparation method thereof, the preparation method of the present invention can obtain large-size Ti with low horizontal and vertical differences 2 AlNb alloy sheets have laid a good foundation for the preparation of large-size, thin-walled, complex structural parts in aerospace.

[0006] In order to achieve the above-mentioned object of the present invention, the first aspect of the present invention provides a large-size Ti 2 The method for preparing the AlNb alloy thin plate comprises the following steps:

[0007] (a) Ti 2The AlNb alloy slab is subjected to heat rolling at 1050-1100°C in the width direction and the length direction respectively to obtain an intermediate slab; the intermediate slab is subjected to annealing treatment at 1000-1045°C;

[0008] (b) the intermediate slab after annealing is subjected to heat rolling at 850-980°C in the width and length directions respectively, and then subjected to cladding rolling in the length direction; and then subjected to annealing at 800-935°C to obtain the Ti 2 AlNb alloy sheet.

[0009] In a specific embodiment of the present invention, in step (a), the deformation amount in the single-fire rolling along the width direction is 30% to 50%, and the deformation amount in the single-fire rolling along the length direction is 40% to 60%.

[0010] In a specific embodiment of the present invention, in step (b), the deformation amount in the single-fire rolling along the width direction is 35% to 75%, and the deformation amount in the single-fire rolling along the length direction is 10% to 45%.

[0011] In a specific embodiment of the present invention, the deformation amount of the cladding rolling is 30% to 90%.

[0012] In a specific embodiment of the present invention, in step (a), the annealing treatment time is 30 to 240 minutes.

[0013] In a specific embodiment of the present invention, in step (b), the annealing treatment time is 10 to 240 minutes.

[0014] In a specific embodiment of the present invention, the Ti 2 The thickness of the AlNb alloy slab is 100 to 200 mm.

[0015] In a specific embodiment of the present invention, the thickness of the intermediate slab is 12 to 40 mm.

[0016] In a specific embodiment of the present invention, in step (b), the intermediate slab after annealing is subjected to hot rolling at 850-980°C along the width and length directions respectively, and the thickness of the slab is 4-10 mm.

[0017] In a specific embodiment of the present invention, the Ti 2 The thickness of the AlNb alloy sheet is 1 to 2 mm.

[0018] The second aspect of the present invention provides a large-size Ti 2 Large-size Ti prepared by the preparation method of AlNb alloy thin plate 2 AlNb alloy sheet.

[0019] In a specific embodiment of the present invention, the large-size Ti 2 The tensile strength of the AlNb alloy sheet at room temperature of 23°C is ≥1000MPa, the yield strength is ≥850MPa, and the elongation is ≥6.0%; the tensile strength at high temperature of 650°C is ≥700MPa, the yield strength is ≥450MPa, and the elongation is ≥19.0%.

[0020] In a specific embodiment of the present invention, the large-size Ti 2 The ratio of the difference between the transverse and longitudinal tensile strength of the AlNb alloy thin plate at room temperature of 23°C to the transverse tensile strength is ≤5%, and the ratio of the difference between the transverse and longitudinal yield strength to the transverse yield strength at room temperature of 23°C is ≤5%; the ratio of the difference between the transverse and longitudinal tensile strength to the transverse tensile strength at a high temperature of 650°C is ≤6%, and the ratio of the difference between the transverse and longitudinal yield strength to the transverse yield strength at a high temperature of 650°C is ≤6%.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] (1) The large-size Ti of the present invention 2 The preparation method of AlNb alloy thin plate is sequentially processed by high temperature reversing rolling, intermediate annealing, low temperature reversing rolling and post-rolling annealing, and the transverse and longitudinal deformation of high temperature reversing rolling and low temperature reversing rolling are coordinated and regulated to ensure the mechanical properties of the plate and reduce the transverse and longitudinal performance differences of the plate;

[0023] (2) The preparation method of the present invention is suitable for large-sized Ti 2 Preparation of AlNb alloy sheets, and the large-size Ti 2 AlNb alloy thin plates not only have low transverse and longitudinal performance differences, but also have good room temperature and high temperature strength and plasticity, laying a good foundation for the subsequent preparation of aerospace thin-walled complex structural parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 A crystal orientation distribution diagram of the plate obtained in step (2) provided in Example 1 of the present invention;

[0026] Figure 2A crystal orientation distribution diagram of the plate obtained in step (3) provided in Example 1 of the present invention;

[0027] Figure 3 Ti prepared in Example 1 of the present invention 2 Longitudinal microstructure of AlNb alloy sheet;

[0028] Figure 4 Ti prepared in Example 1 of the present invention 2 Transverse microstructure of AlNb alloy sheet. DETAILED DESCRIPTION

[0029] The technical scheme of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and specific embodiments, but it will be understood by those skilled in the art that the following described embodiments are part of embodiments of the present invention, rather than all embodiments, and are only used to illustrate the present invention, and should not be considered as limiting the scope of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of the present invention. If specific conditions are not specified in the embodiments, they are carried out according to normal conditions or conditions recommended by the manufacturer. If the manufacturer is not specified in the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0030] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0031] Currently 2 In the preparation of AlNb alloy sheets, due to improper control of rolling process, Ti 2 AlNb alloy sheets have obvious transverse and longitudinal differences, which makes it difficult to meet the service requirements of thin-walled complex components in aerospace. The transverse and longitudinal deformation can be basically equalized through multiple reversal rolling, and the transverse and longitudinal performance differences can be appropriately improved. 2 The improvement of the transverse and longitudinal difference of AlNb alloy sheet cannot meet higher requirements, and the obtained Ti 2 The room temperature and high temperature performance of AlNb alloy sheets are relatively low, and Ti 2 The production efficiency of AlNb alloy thin plates is low.

[0032] Based on this, the first aspect of the present invention provides a large-size Ti 2 The method for preparing the AlNb alloy thin plate comprises the following steps:

[0033] (a) Ti 2 The AlNb alloy slab is subjected to heat rolling at 1050-1100°C in the width and length directions respectively to obtain an intermediate slab; the intermediate slab is subjected to annealing treatment at 1000-1045°C;

[0034] (b) The annealed intermediate slab is subjected to heat rolling at 850-980°C in the width and length directions respectively, and then cladding rolling is performed in the length direction; and then annealing is performed at 800-935°C to obtain Ti 2 AlNb alloy sheet.

[0035] The large-size Ti 2 The preparation method of AlNb alloy thin plate is carried out through high-temperature reversing rolling, intermediate annealing, low-temperature reversing rolling and post-rolling annealing in sequence, and the transverse and longitudinal deformation of high-temperature reversing rolling and low-temperature reversing rolling are coordinated and controlled, so as to ensure the mechanical properties of the plate and reduce the transverse and longitudinal performance differences of the plate.

[0036] Among them, first Ti 2 The AlNb alloy slab is subjected to one-time hot rolling in the width direction at a rolling temperature range of 1050-1100°C, and then another hot rolling in the length direction to obtain an intermediate slab. The rolling temperature at this stage can be 1050°C, 1060°C, 1070°C, 1080°C, 1090°C, 1100°C, or any two of them. At this rolling temperature, Ti 2 The hot deformation performance of AlNb alloy, combined with large deformation rolling, significantly improves the homogenization of grain structure, eliminates internal defects of the material, improves the strength and plasticity of the material, and effectively shortens the overall rolling cycle, improves the yield rate and production efficiency. And the study found that at this rolling temperature, combined with subsequent annealing at a certain temperature, while improving the degree of organizational homogenization, ensuring or even improving room temperature / high temperature strength and plasticity, the anisotropy of the plate is further reduced, and an intermediate slab without obvious preferential orientation is obtained. Among them, the annealing temperature can be 1000℃, 1010℃, 1020℃, 1030℃, 1040℃, 1045℃ or a range composed of any two of them.

[0037] After the intermediate slab is annealed, the intermediate slab is rolled once in the width direction within the rolling temperature range of 850-980°C, and then rolled once in the length direction, and then cladding rolling is performed in the length direction according to the target sheet size requirements. The rolling temperature at this stage can be 850°C, 880°C, 900°C, 920°C, 950°C, 980°C or any two of them. After high-temperature rolling and intermediate annealing, the rolling temperature is lowered to effectively refine the grain size of the sheet while ensuring low transverse and longitudinal differences, improve the mechanical properties of the sheet, and help improve room temperature and high temperature plasticity. After the above rolling, further annealing is performed, and the annealing temperature can be 800°C, 820°C, 850°C, 880°C, 900°C, 920°C, 935°C or any two of them.

[0038] In a specific embodiment of the present invention, in step (a), the annealing time is 30 to 240 min. For example, the annealing time can be 30 min, 60 min, 90 min, 120 min, 150 min, 180 min, 210 min, 240 min or a range consisting of any two thereof.

[0039] In a specific embodiment of the present invention, in step (b), the annealing time is 10 to 240 min. For example, the annealing time can be 10 min, 40 min, 90 min, 120 min, 150 min, 180 min, 240 min or a range consisting of any two thereof.

[0040] After the heat preservation of the above annealing treatment is completed, air cooling treatment is performed unless otherwise specified.

[0041] It should be noted that the “width direction” and “length direction” in the present invention are respectively the initial Ti 2 The width direction Y and the length direction X of the AlNb alloy slab are perpendicular to each other and are respectively 2 The thickness direction of the AlNb alloy slab is perpendicular to the Z direction.

[0042] In actual operation, rolling includes: rolling after heat preservation treatment at rolling temperature. The heat preservation time is determined according to the thickness of the slab, the heat preservation time of cold material is calculated as 0.5-0.8min / mm, and the heat preservation time of hot material is calculated as 0.2-0.4min / mm. The specific heat preservation time can be controlled within 10-240min.

[0043] In a specific embodiment of the present invention, in step (a), the deformation amount in the single-fire rolling along the width direction is 30% to 50%, and the deformation amount in the single-fire rolling along the length direction is 40% to 60%.

[0044] It should be noted that the calculation method of the deformation amount in the present invention is:

[0045] (Thickness of sheet material before deformation - thickness of sheet material after deformation) / thickness of sheet material before deformation × 100%.

[0046] For example, in different embodiments, in step (a), the deformation amount in the single-heat rolling along the width direction can be 30%, 35%, 40%, 45%, 50% or any two thereof; in the single-heat rolling along the length direction, the deformation amount can be 40%, 45%, 50%, 55%, 60% or any two thereof. The relatively high rolling temperature of step (a) combined with the above deformation amount helps to improve processing efficiency, low anisotropy and plate grain uniformity.

[0047] In a specific embodiment of the present invention, in step (b), the deformation amount in the single-fire rolling along the width direction is 35% to 75%, and the deformation amount in the single-fire rolling along the length direction is 10% to 45%.

[0048] For example, in different embodiments, in step (b), the deformation amount in the single hot rolling along the width direction can be 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75% or any two thereof; in the single hot rolling along the length direction, the deformation amount can be 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45% or any two thereof. The low rolling temperature of step (b) combined with the above deformation amount is helpful to both refine the grain size of the plate and ensure the quality of the plate.

[0049] In a specific embodiment of the present invention, in step (a), in the single-pass rolling along the width and length directions, the number of rolling passes of each pass is independently selected from 2 to 8 times.

[0050] In a specific embodiment of the present invention, in step (b), in the single-pass rolling along the width and length directions, the number of rolling passes of each pass is independently selected from 2 to 8 times.

[0051] In a specific embodiment of the present invention, the deformation amount of the cladding rolling is 30% to 90%, for example, it can be 30%, 40%, 50%, 60%, 70%, 80%, 90% or a range composed of any two thereof.

[0052] In actual operation, the slab can be divided into multiple equal parts and then coated and rolled. The specific number of equal parts is adjusted according to the size of the slab and the coating.

[0053] In a specific embodiment of the present invention, Ti 2 The thickness of the AlNb alloy slab is 100-200 mm, wherein the thickness can be 100 mm, 120 mm, 150 mm, 180 mm, 200 mm or a range consisting of any two thereof.

[0054] In a specific embodiment of the present invention, the thickness of the intermediate slab is 12 to 40 mm, for example, it can be 12 mm, 16 mm, 20 mm, 25 mm, 30 mm, 35 mm, 40 mm or a range consisting of any two of them.

[0055] In a specific embodiment of the present invention, in step (b), the intermediate slab after annealing is subjected to heat rolling at 850-980°C along the width and length directions respectively, and the thickness of the slab is 4-10 mm, for example, it can be 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm or a range consisting of any two of them.

[0056] In a specific embodiment of the present invention, Ti 2 The thickness of the AlNb alloy sheet is 1 to 2 mm. 2 The length of the AlNb alloy thin plate is greater than 1000 mm, and the width is greater than 800 mm.

[0057] In a specific embodiment of the present invention, Ti 2 AlNb alloy slab is mainly composed of Ti 2 AlNb alloy ingots are obtained by multi-fire forging. Among them, multi-fire forging includes: Ti 2 The AlNb alloy ingot was subjected to conventional three-upsetting and three-drawing at 1170℃, 1080℃, 1030℃ and 980℃ respectively, and then forged at 980℃ to form Ti 2 AlNb alloy slab.

[0058] The second aspect of the present invention provides a large-size Ti 2 Large-size Ti prepared by the preparation method of AlNb alloy thin plate 2 AlNb alloy sheet.

[0059] In a specific embodiment of the present invention, large-size Ti 2The tensile strength of the AlNb alloy sheet at room temperature of 23°C is ≥1000MPa, the yield strength is ≥850MPa, and the elongation is ≥6.0%; the tensile strength at high temperature of 650°C is ≥700MPa, the yield strength is ≥450MPa, and the elongation is ≥19.0%.

[0060] As in different embodiments, large-size Ti 2 The tensile strength of the AlNb alloy thin plate at room temperature of 23°C can be 1000MPa, 1050MPa, 1100MPa, 1150MPa, 1160MPa or a range consisting of any two thereof; the yield strength can be 850MPa, 900MPa, 1000MPa, 1050MPa, 1100MPa or a range consisting of any two thereof; the elongation can be 8.0%, 8.5%, 9%, 9.5%, 9.5%, 10.0% or a range consisting of any two thereof. The tensile strength under high temperature conditions of 650°C can be 750MPa, 760MPa, 770MPa, 780MPa, 790MPa, 800MPa or a range consisting of any two of them; the yield strength can be 620MPa, 630MPa, 640MPa, 650MPa or a range consisting of any two of them; the elongation can be 19.0%, 19.5%, 20%, 21%, 22%, 22.5% or a range consisting of any two of them.

[0061] In a specific embodiment of the present invention, large-size Ti 2 The ratio of the difference between the transverse and longitudinal tensile strength of the AlNb alloy sheet at room temperature of 23°C to the transverse tensile strength is ≤5%, preferably ≤3%, for example, it can be 5%, 4%, 3%, 2%, 1%, 0.5% or a range consisting of any two of them; the ratio of the difference between the transverse and longitudinal yield strength to the transverse yield strength at room temperature of 23°C is ≤5%, preferably ≤3%, for example, it can be 5%, 4%, 3%, 2%, 1%, 0.5% or a range consisting of any two of them; the ratio of the difference between the transverse and longitudinal tensile strength to the transverse tensile strength at a high temperature of 650°C is ≤6%, preferably ≤3%, for example, it can be 6%, 4%, 2%, 1%, 0.5% or a range consisting of any two of them; the ratio of the difference between the transverse and longitudinal yield strength to the transverse yield strength at a high temperature of 650°C is ≤6%, preferably ≤3%, for example, it can be 6%, 4%, 2%, 1%, 0.5% or a range consisting of any two of them.

[0062] Ti of the present invention 2 The AlNb alloy is described by taking the nominal composition of Ti-22Al-25Nb (at.%) as an example, but is not limited to this.

[0063] Example 1

[0064] This embodiment provides a large size Ti 2 The method for preparing the AlNb alloy thin plate comprises the following steps:

[0065] (1) Ti is obtained by vacuum consumable arc melting + vacuum shell melting combined melting process 2 AlNb alloy ingot, the ingot is subjected to three upsetting and three drawing at 1170℃, three upsetting and three drawing at 1080℃, three upsetting and three drawing at 1030℃, three upsetting and three drawing at 980℃, and then forged at 980℃ into a Ti alloy with a size of X×Y×Z=900mm×800mm×150mm 2 AlNb alloy slab.

[0066] (2) Ti obtained in step (1) 2 The AlNb alloy slab is kept at 1060°C for 120 min and then subjected to single-fire rolling along the Y direction (width direction) to obtain a slab with a size of X×Y×Z=900mm×1333mm×90mm; then the slab is returned to the furnace for 30 min of heating and subjected to single-fire rolling along the X direction (length direction) to obtain an intermediate slab with a size of X×Y×Z=2250mm×1333mm×36mm; wherein the deformation amount of single-fire rolling along the Y direction is 40%, and the deformation amount of single-fire rolling along the X direction is 60%; the single-fire rolling along the Y direction includes 7 passes, and the thickness reduction amount of each pass is 12mm, 11mm, 9mm, 8mm, 7mm, 7mm, and 6mm, respectively; the single-fire rolling along the X direction includes 6 passes, and the thickness reduction amount of each pass is 11mm, 10mm, 9mm, 9mm, 8mm, and 7mm, respectively.

[0067] (3) The intermediate slab obtained in step (2) is annealed and heat-insulated at 1040°C for 120 min, air-cooled, and then polished, trimmed and slit to obtain an annealed intermediate slab with a size of X×Y×Z=1000mm×1280mm×35mm.

[0068] (4) The intermediate slab after annealing in step (3) is kept at 930°C for 160 min, and then rolled in the Y direction (width direction) to obtain a plate with a size of X×Y×Z=1000mm×3200mm×14mm, and then polished, trimmed and cut to obtain a plate with a size of X×Y×Z=980mm×1500mm×13mm; then the plate is kept at 930°C for 30 min, and then rolled in the X direction (length direction) to obtain a plate with a size of X×Y×Z=1592mm×1500mm×8mm, and then polished, trimmed and cut to obtain two plates with a size of X×Y×Z=750mm×1500mm×7mm; then the two plates are stacked in a steel ladle jacket with a thickness of 54mm, and kept at 930°C for 120 min. After that, the plate with a size of X×Y×Z=2280mm×1500mm×2.3mm is obtained by rolling along the X direction (length direction); wherein, the deformation amount of the single-fire rolling along the Y direction is 60%, the deformation amount of the single-fire rolling along the X direction is 38%, and the deformation amount of the cladding rolling along the X direction is 67%; the single-fire rolling along the Y direction includes 8 passes, and the thickness reduction amount of each pass is 4mm, 3mm, 3mm, 3mm, 3mm, 2mm, 2mm, and 1mm respectively; the single-fire rolling along the X direction includes 6 passes, and the thickness reduction amount of each pass is 2mm, 1mm, 1mm, 1mm, 0.5mm, and 0.5mm; the cladding rolling along the X direction includes 6 passes, and the thickness reduction amount of each pass of the steel sleeve is 10mm, 8mm, 8mm, 6mm, 5mm, and 4mm.

[0069] (5) The plate obtained in step (4) was heat-treated at 850°C for 60 min, and then directly leveled by multi-roller, sanded, trimmed and pickled to obtain a Ti plate with a size of X×Y×Z=2000mm×1400mm×2mm. 2 AlNb alloy sheet.

[0070] Example 2

[0071] This example refers to the large-size Ti in Example 1. 2 The preparation method of AlNb alloy thin plate is different in that: in step (2), the rolling and holding temperature is 1100°C; in step (3), the annealing and holding temperature is 1045°C; in step (4), the rolling and holding temperature is 980°C; in step (5), the annealing and holding temperature is 935°C.

[0072] Example 3

[0073] This example refers to the large-size Ti in Example 1. 2The preparation method of AlNb alloy thin plate is different in that: in step (2), the rolling holding temperature is 1050°C; in step (3), the annealing holding temperature is 1000°C; in step (4), the rolling holding temperature is 850°C; in step (5), the annealing holding temperature is 800°C.

[0074] Comparative Example 1

[0075] Comparative Example 1: Large-sized Ti according to Example 1 2 The method for preparing the AlNb alloy thin plate is different in that: step (3) is different.

[0076] Step (3) of Comparative Example 1 is: grinding, trimming and cutting the intermediate slab obtained in step (2) to obtain an intermediate slab with a size of X×Y×Z=1000mm×1280mm×35mm.

[0077] Comparative Example 2

[0078] Comparative Example 2: Large-sized Ti according to Example 1 2 The method for preparing the AlNb alloy thin plate is different in that: step (3) is different.

[0079] Step (3) of Comparative Example 2 is: annealing and heat-insulating the intermediate slab obtained in step (2) at 980°C for 120 minutes, air-cooling, and then grinding, trimming and cutting to obtain an intermediate slab with a size of X×Y×Z=1000mm×1280mm×35mm.

[0080] Comparative Example 3

[0081] Comparative Example 3: Large-sized Ti according to Example 1 2 The method for preparing the AlNb alloy thin plate is different in that: step (3) is different.

[0082] Step (3) of Comparative Example 3 is: annealing and heat-insulating the intermediate slab obtained in step (2) at 1080°C for 120 minutes, air-cooling, and then grinding, trimming and cutting to obtain an intermediate slab with a size of X×Y×Z=1000mm×1280mm×35mm.

[0083] Comparative Example 4

[0084] Comparative Example 4: Large-sized Ti according to Example 1 2 The method for preparing the AlNb alloy thin plate is different in that: in step (2), the rolling and holding temperature is different.

[0085] In step (2) of comparative example 4, the rolling holding temperature is 1150°C.

[0086] Comparative Example 5

[0087] Comparative Example 5: Large-sized Ti according to Example 1 2 The method for preparing the AlNb alloy thin plate is different in that: in step (2), the rolling and holding temperature is different.

[0088] In step (2) of comparative example 5, the rolling holding temperature is 1000°C.

[0089] Comparative Example 6

[0090] Comparative Example 6: Large-sized Ti according to Example 1 2 The method for preparing the AlNb alloy thin plate is different in that: in step (4), the rolling and holding temperature is different.

[0091] In step (4) of Comparative Example 6, the rolling and holding temperature is 1000°C.

[0092] Comparative Example 7

[0093] Comparative Example 7: Large-sized Ti according to Example 1 2 The method for preparing the AlNb alloy thin plate is different in that: in step (4), the rolling and holding temperature is different.

[0094] In step (4) of Comparative Example 7, the rolling holding temperature is 830°C.

[0095] Comparative Example 8

[0096] Comparative Example 8: Large-sized Ti according to Example 1 2 The method for preparing the AlNb alloy thin plate is different in that: in step (5), the annealing and holding temperatures are different.

[0097] In step (5) of Comparative Example 8, the annealing temperature is 960°C.

[0098] Experimental example

[0099] Figure 1-2 The crystal orientation distribution diagrams of the plate obtained in step (2) and the plate obtained in step (3) of Example 1 of the present invention are shown in the figure. It can be seen from the figure that the high temperature reversing rolling of the present invention combined with a certain annealing treatment is conducive to obtaining a plate without obvious preferential orientation. Figure 3 Ti prepared in Example 1 of the present invention 2 Longitudinal cross-sectional microstructure of AlNb alloy sheet. Figure 4 Ti prepared in Example 1 of the present invention 2 Transverse cross-sectional microstructure of AlNb alloy sheet.

[0100] Further, Ti prepared in different embodiments and comparative examples 2 The mechanical properties of the AlNb alloy sheet were tested, and the test results are shown in Tables 1 and 2.

[0101] Table 1 Different Ti 2 Room temperature (23℃) mechanical properties test results of AlNb alloy thin plates

[0102]

[0103]

[0104] Table 2 Different Ti 2 High temperature (650℃) mechanical properties test results of AlNb alloy thin plate

[0105]

[0106] From the above test results, it can be seen that the Ti 2 The transverse and longitudinal mechanical properties of AlNb alloy sheets are basically the same at room temperature and high temperature, which can lay a good foundation for the subsequent forming of large-size aerospace thin-walled complex structural parts.

[0107] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements 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 method for preparing a large-sized Ti2AlNb alloy sheet, characterized in that: The steps include: (a) performing hot rolling of a Ti2AlNb alloy slab at 1050-1100° C. in width and length directions respectively to obtain an intermediate slab; and performing annealing treatment of the intermediate slab at 1000-1045° C.; (b) The intermediate slab after annealing is subjected to hot rolling at 850-980°C in the width and length directions respectively, and then subjected to cladding rolling in the length direction; and then subjected to annealing at 800-935°C to obtain the Ti2AlNb alloy sheet.

2. The preparation method according to claim 1, characterized in that: In step (a), the deformation amount in the single-fire rolling along the width direction is 30% to 50%, and the deformation amount in the single-fire rolling along the length direction is 40% to 60%.

3. The preparation method according to claim 1, characterized in that: In step (b), the deformation amount in the single-fire rolling along the width direction is 35% to 75%, and the deformation amount in the single-fire rolling along the length direction is 10% to 45%.

4. The preparation method according to claim 1, characterized in that: The deformation amount of the cladding rolling is 30% to 90%.

5. The preparation method according to claim 1, characterized in that: In step (a), the annealing treatment time is 30 to 240 minutes.

6. The preparation method according to claim 1, characterized in that: In step (b), the annealing treatment time is 10 to 240 minutes.

7. The preparation method according to claim 1, characterized in that: Having at least one of the following characteristics: (1) The thickness of the Ti2AlNb alloy slab is 100 to 200 mm; (2) The thickness of the intermediate slab is 12 to 40 mm; (3) In step (b), the intermediate slab after annealing is subjected to hot rolling at 850-980° C. in the width and length directions respectively, and the thickness of the slab is 4-10 mm; (4) The thickness of the Ti2AlNb alloy sheet is 1 to 2 mm.

8. Large-size Ti2AlNb alloy sheet, characterized in that: The method is prepared by the method according to any one of claims 1 to 7.

9. The large-sized Ti2AlNb alloy sheet according to claim 8, characterized in that: The large-size Ti2AlNb alloy sheet has a tensile strength of ≥1000MPa, a yield strength of ≥850MPa, and an elongation of ≥6.0% at room temperature of 23°C; and a tensile strength of ≥700MPa, a yield strength of ≥450MPa, and an elongation of ≥19.0% at a high temperature of 650°C.

10. The large-sized Ti2AlNb alloy sheet according to claim 8, characterized in that: The ratio of the difference between the transverse and longitudinal tensile strength of the large-size Ti2AlNb alloy sheet at room temperature of 23°C to the transverse tensile strength is ≤5%, and the ratio of the difference between the transverse and longitudinal yield strength to the transverse yield strength at room temperature of 23°C is ≤5%; the ratio of the difference between the transverse and longitudinal tensile strength to the transverse tensile strength at a high temperature of 650°C is ≤6%, and the ratio of the difference between the transverse and longitudinal yield strength to the transverse yield strength at a high temperature of 650°C is ≤6%.

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