An ordered phase reinforced titanium alloy sheet, its preparation method and application

Abstract

This application discloses an ordered phase-strengthened titanium alloy sheet, its preparation method, and its application. The method involves cyclically upsetting and flattening a homogenized titanium alloy ingot to obtain a forged slab; coating the surface of the forged slab and heating it to 1000-1050°C, then cross-rolling it along its length and width to obtain a first intermediate slab; coating the surface of the first intermediate slab and heating it to 950-980°C, then cross-rolling it along its length and width to obtain a second intermediate slab; cladding the second intermediate slab and heating it to 920-950°C, then cladding it along its length; finally, surface treating the rolled sheet to remove oxide scale and grind it smooth to obtain the titanium alloy sheet. This application achieves this by using staged temperature gradient rolling, cross-rolling to control texture, cladding rolling to improve deformation uniformity, and multi-pass intermittent stress-relief annealing to eliminate stress concentration, ultimately obtaining a titanium alloy sheet with uniform microstructure, no obvious cracks, and excellent room temperature / high temperature performance.

Description

Technical Field

[0001] This application belongs to the field of alloy processing technology, specifically relating to an ordered phase-strengthened titanium alloy thin plate, its preparation method, and its application. Background Technology

[0002] The high thrust-to-weight ratio engines in aerospace applications urgently require lightweight, high-temperature resistant structural materials. Ti-Al-Sn ordered phase reinforced titanium alloys can be used for extended periods above 750℃, making them a key material for breaking through the upper limit of the service temperature of titanium alloys. However, Ti-Al-Sn alloys have inherently high room temperature brittleness and high deformation resistance, making them prone to cracking and shape loss during thin-plate rolling. Existing processes struggle to balance microstructure, shape, and high-temperature performance.

[0003] Currently, high-temperature titanium alloys have evolved from near-α-type alloys such as Ti60 and Ti65, which operate at 600-650℃, to Ti-Al intermetallic compounds operating at 650-700℃. Further development has led to the creation of novel ordered-phase reinforced titanium alloys based on the Ti-Al-Sn system, which exhibit even higher phase transformation temperatures and superior thermal stability. Ti-Al-Sn alloys, with ordered phases as the dominant ordered phase, exhibit high room-temperature brittleness and high deformation resistance, making them highly susceptible to cracking during rolling. Simultaneously, the large aspect ratio of thin-plate rolling results in rapid heat loss, significant temperature differences between the core and surface, and concentrated thermal stress at the edges, easily leading to edge cracks, surface microcracks, and shape loss. Existing processes cannot simultaneously guarantee the uniformity of microstructure, shape accuracy, and high-temperature service performance of thin plates, making it difficult to meet the application requirements of aerospace equipment. Summary of the Invention

[0004] This application addresses the technical problem that Ti-Al-Sn ordered phase reinforced titanium alloy thin plates with large aspect ratios are prone to cracking during rolling, and that existing processes cannot simultaneously ensure microstructure uniformity, plate shape accuracy, and long-term service performance at high temperatures of 700°C and above. It provides an ordered phase reinforced titanium alloy thin plate, its preparation method, and its application.

[0005] To achieve the above objectives, this application adopts the following technical solution: This application provides a method for preparing ordered phase-strengthened titanium alloy thin plates, comprising the following steps: S1, the homogenized titanium alloy ingot is subjected to cyclic upsetting and flattening to obtain a forged slab with a thickness of 100~150mm. S2, after coating the surface of the forged slab, heat it to 1000~1050℃ and cross-roll it along the length and width directions to obtain the first intermediate slab; S3, after coating the surface of the first intermediate slab, heat it to 950~980℃, and then cross-roll it along the length and width directions to obtain the second intermediate slab; S4. After the second intermediate slab is coated, it is heated to 920~950℃ and rolled along the length direction; then it is held at 920~950℃ for 2~4 hours to obtain the titanium alloy sheet.

[0006] Furthermore, in S2, the cumulative deformation along the length direction is 40%~50%, the cumulative deformation along the width direction is 30%~40%, and the deformation per pass is 5%~10%. During the rolling process, after every 2~3 passes of rolling, the temperature is raised to 950~1000℃ and held for 1~4 hours, then raised to 1000~1050℃ and held for 10~30 minutes before rolling.

[0007] Furthermore, in S3, the cumulative deformation along the length and width directions is 30%~40% each, and the deformation per pass is 5%~10%; during the rolling process, after every 2~3 passes of rolling, the temperature is raised to 880~920℃ and held for 1~4 hours, then raised to 950~980℃ and held for 10-30 minutes before rolling.

[0008] Furthermore, the coating is a silicate glass coating with a thickness of 30~50μm.

[0009] Furthermore, the coating process specifically involves coating the surface of the second intermediate slab with a soft steel layer, the thickness of which is 50% to 80% of the thickness of the second intermediate slab.

[0010] Furthermore, in S4, the cumulative deformation along the length direction of the cladding rolling is 40%~60%, and the deformation per pass is 5%~10%. During the rolling process, after every 2~3 passes of rolling, the temperature is raised to 880~920℃ and held for 1~4 hours, then raised to 920~950℃ and held for 10-30 minutes before rolling.

[0011] This application also provides an ordered phase reinforced titanium alloy sheet, which is prepared according to the above-mentioned ordered phase reinforced titanium alloy sheet preparation method. The composition of the titanium alloy by mass percentage includes: Al: 5%~10%, Sn: 5%~20%, neutral elements and β-stabilizing elements total ≤10%, and the balance is Ti and unavoidable impurities. The ordered phases dispersed in the matrix of the titanium alloy include one or both of the Ti8AlSn phase and the Ti4AlSn2 phase.

[0012] Furthermore, the ordered phase is coherent or semi-coherent with the matrix.

[0013] Furthermore, the titanium alloy sheet has a tensile strength ≥1190MPa and an elongation ≥5.5%; at 700℃, the tensile strength ≥635MPa and the elongation ≥20%.

[0014] This application also provides an application of the above-mentioned ordered phase-reinforced titanium alloy sheet, which is used in high-temperature structural components of aerospace engines.

[0015] Compared with the prior art, this application has the following beneficial effects: This application employs a gradient temperature design involving high-temperature cross-rolling at 1000~1050℃, medium-temperature cross-rolling at 950~980℃, and cladding rolling. This design induces partial dissolution or spheroidization of the ordered phase in the alloy, significantly increasing the proportion of the matrix phase. This effectively reduces deformation resistance and avoids rolling cracks caused by stress concentration. Simultaneously, by employing a near-isothermal rolling process after every 2~3 rolling passes, coupled with a small deformation design for each pass, multiple stress-relief annealing processes eliminate the matrix fragmentation effect caused by the continuous distribution of the ordered phase. This achieves uniform refinement of the sheet microstructure and a synergistic improvement in overall performance. Furthermore, the combination of cross-rolling and cladding rolling effectively improves the anisotropy of the sheet and enhances surface quality, demonstrating promising prospects for industrialization.

[0016] The ordered phase reinforced titanium alloy sheet provided in this application, through the design and preparation method of titanium alloy composition ratio, forms one or two ordered phases of Ti8AlSn and Ti4AlSn2 dispersedly distributed in the matrix. Compared with existing similar titanium alloy products, the ordered phase has excellent thermodynamic stability, and can maintain a small size after long-term exposure at temperatures of 700℃ and above, and is coherent / semi-coherent with the matrix, effectively pinning grain boundaries and dislocations. At room temperature, the tensile strength of the titanium alloy sheet is ≥1190MPa and the elongation is ≥5.5%; at 700℃, the tensile strength is ≥635MPa and the elongation is ≥20%. It simultaneously takes into account high strength and good plasticity, and solves the technical problem that existing titanium alloys cannot simultaneously meet the requirements of high strength at room temperature and high temperature stability above 700℃, thus meeting the requirements of high-end equipment for high-temperature structural materials.

[0017] This application applies ordered phase reinforced titanium alloy thin plates to high-temperature structural components of aerospace engines. It utilizes the core performance advantages of maintaining high strength, high plasticity and good microstructure stability at temperatures of 700℃ and above to solve the pain points of insufficient high-temperature strength, easy creep deformation and short service life of existing high-temperature structural components for aerospace engines. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 The microstructure of the titanium alloy sheet prepared in Example 1 of this application; Figure 2 The microstructure of the titanium alloy sheet prepared in Example 2 of this application; Figure 3 The microstructure of the titanium alloy sheet prepared in Example 3 of this application; Figure 4 This is a diffraction analysis diagram of the titanium alloy sheet prepared in Example 1 of this application. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] With the rapid development of aerospace technology, the demand for lightweight, high-temperature resistant structural materials for high thrust-to-weight ratio aero engines is becoming increasingly urgent. Ti-Al-Sn titanium alloys, with their high-temperature stable ordered phases, can serve for extended periods above 700°C, making them a key material for overcoming the service temperature bottleneck of traditional titanium alloys.

[0022] However, these alloys, with ordered intermetallic compounds as the main ordered phase, exhibit high intrinsic room-temperature brittleness and strong deformation resistance, making them highly susceptible to cracking during rolling. Furthermore, thin-plate rolling is characterized by large aspect ratios and high surface areas, leading to rapid heat loss, significant core-to-surface temperature differences, and concentrated thermal stress at the edges, which easily result in edge cracks, surface microcracks, and shape loss. Existing processes struggle to simultaneously achieve uniform microstructure, shape accuracy, and high-temperature performance in thin plates, severely limiting the application of these alloys in high-temperature aerospace structural components.

[0023] Based on this, this application provides a method for preparing ordered phase-strengthened titanium alloy thin plates, comprising the following steps: S1, the homogenized titanium alloy ingot is subjected to cyclic upsetting and flattening to obtain a forged slab with a thickness of 100~150mm. S2, after coating the surface of the forged slab, heat it to 1000~1050℃ and cross-roll it along the length and width directions to obtain the first intermediate slab; S3, after coating the surface of the first intermediate slab, heat it to 950~980℃, and then cross-roll it along the length and width directions to obtain the second intermediate slab; S4. After the second intermediate slab is coated, it is heated to 950~980℃ and rolled along the length direction; then it is held at 920~950℃ for 2~4h to obtain the titanium alloy sheet.

[0024] This application employs cyclic upsetting and flattening to avoid rolling cracks caused by uneven microstructure. Subsequently, large-deformation cross-rolling is performed in a temperature range above the dissolution temperature of the ordered phase, promoting the re-dissolution of some ordered phases to increase the proportion of the matrix phase, significantly reducing deformation resistance, and improving the anisotropy of the sheet, thus reducing differences in transverse and longitudinal properties. Next, medium-temperature cross-rolling is performed in the temperature range where the ordered phase partially dissolves, reducing deformation resistance while retaining some fine ordered phases as nucleation sites, creating conditions for the subsequent uniform precipitation of the ordered phase. Finally, mild steel cladding rolling is used to effectively alleviate thermal stress concentration at the edges of the sheet to prevent edge cracking, while utilizing the low thermal conductivity of mild steel to slow heat loss and improve temperature uniformity during the rolling process.

[0025] In some specific embodiments of this application, in step S2, the cumulative deformation along the length direction is 40%~50%, the cumulative deformation along the width direction is 30%~40%, and the deformation per pass is 5%~10%. During the rolling process, after every 2~3 passes, the temperature is raised to 950~1000℃ and held for 1~4 hours, then raised to 1000~1050℃ and held for 10~30 minutes before rolling, achieving near-isothermal rolling. This step ensures the uniformity of the initial deformation, effectively breaks up the coarse structure in the cast state, and lays the foundation for subsequent microstructure control.

[0026] In some specific embodiments of this application, in step S3, the cumulative deformation along the length and width directions is 30%~40% each, and the deformation per pass is 5%~10%. During the rolling process, after every 2~3 passes, the temperature is raised to 880~920℃ and held for 1~4 hours, then raised to 950~980℃ and held for 10~30 minutes before rolling again, achieving near-isothermal rolling. This step further refines the grain structure, regulates the distribution of the ordered phase, and improves the uniformity of the plate's properties.

[0027] In some specific embodiments of this application, the coating is a silicate glass coating with a thickness of 30-50 μm. The coating protects the surface of the slab, effectively preventing high-temperature oxidation during rolling, significantly improving the surface quality of the slab, and reducing the workload of subsequent surface treatment.

[0028] In some specific embodiments of this application, the coating process specifically involves coating the surface of the second intermediate slab with a soft steel layer, the thickness of which is 50% to 80% of the thickness of the second intermediate slab. Coating the sheet effectively reduces surface friction and cracking risks during the rolling process, improves the uniformity of deformation, and enables a larger cumulative deformation.

[0029] In some specific embodiments of this application, in step S4, the cumulative deformation along the length direction of the cladding rolling is 40%~60%, and the deformation per pass is 5%~10%. During the rolling process, the temperature is ≥900℃. Specifically, after every 2~3 passes of rolling, the temperature is raised to 880~920℃ and held for 1~4 hours, then raised to 920~950℃ and held for 10~30 minutes to achieve near-isothermal rolling. This step achieves large deformation rolling while ensuring that the sheet does not crack, thus producing a titanium alloy thin sheet that meets the requirements.

[0030] In some specific embodiments of this application, the rolled sheet is leveled, then sandblasted to remove the surface oxide scale, and then acid-cleaned and surface-polished to obtain a titanium alloy sheet.

[0031] This application describes the preparation method of ordered phase-strengthened titanium alloy thin plates to obtain an ordered phase-strengthened titanium alloy thin plate. The titanium alloy composition, by mass percentage, is: Al: 5%~10%, Sn: 5%~20%, with a total of ≤10% neutral elements and β-stabilizing elements, and the balance being Ti and unavoidable impurities. The neutral element is Zr, and the β-stabilizing element is one or more of W, Nb, and Mo. The ordered phase dispersed in the matrix of the titanium alloy includes one or both of Ti8AlSn phase and Ti4AlSn2 phase, with the ordered phase accounting for 5%~20% of the volume.

[0032] In some specific embodiments of this application, the ordered phase is coherent or semi-coherent with the matrix.

[0033] In some specific embodiments of this application, at room temperature, the tensile strength of the titanium alloy sheet is ≥1190MPa and the elongation is ≥5.5%; at 700℃, the tensile strength is ≥635MPa and the elongation is ≥20%. The difference between the transverse and longitudinal tensile strengths of the titanium alloy sheet is ≤20MPa and the difference in elongation is ≤2%.

[0034] The ordered phase-strengthened titanium alloy sheet obtained in this application can be used in high-temperature structural components of aerospace engines.

[0035] The present application will be further described in detail below with reference to specific embodiments and accompanying drawings. The specific embodiments described below are only used to further illustrate the present application and are not intended to limit the scope of protection of the present application.

[0036] Unless otherwise defined, all terms used below shall be interpreted in accordance with their meaning as commonly understood by those skilled in the art. Unless otherwise specified, all raw materials, reagents, instruments, and equipment used in this application may be obtained commercially or prepared by existing methods.

[0037] Example 1 The selected titanium alloy ingot has dimensions of 150mm × 500mm × 800mm. The titanium alloy composition, by mass percentage, is: Sn 11.5%, Al 6.5%, W 2.5%, Ta 1.0%, Si 0.4%, with the balance being Ti and unavoidable impurities. The specific implementation steps are as follows: Step 1: After the titanium alloy ingot is opened, it undergoes 4 upsetting and drawing cycles and 4 flattening and forming cycles to obtain a forged slab with a thickness of 120mm. Step 2: Apply a coating to the surface of the forged slab with a coating thickness of 30 μm; heat to 1050℃ and hold for 6 hours; after exiting the furnace, roll along the length and width directions (intersecting), with a cumulative deformation of 50% in the length direction and 40% in the width direction, at a rolling speed of 60 mm / s, and a single-pass deformation not exceeding 10%; after every 2-3 rolling passes, heat to 1000℃ and hold for 2 hours, then heat to 1050℃ and hold for 30 minutes before rolling again; finally, after rolling, grind, slit, and air-cool to room temperature to obtain the first intermediate slab; Step 3: Apply a coating to the surface of the first intermediate slab with a coating thickness of 30 μm; heat to 980℃ and hold for 4 hours; after exiting the furnace, perform cross rolling along the length and width directions, with a cumulative deformation of 40% in each direction and a rolling speed of 40 mm / s, with a single pass deformation not exceeding 10%; after every 2-3 passes of rolling, heat to 920℃ and hold for 2 hours, then heat to 980℃ and hold for 30 minutes before rolling again; finally, after rolling, grind, slit, and air-cool to room temperature to obtain the second intermediate slab; Step 4: Cover the surface of the second intermediate slab with a soft steel layer, the thickness of which is 50% of the thickness of the second intermediate slab. Heat to 950℃ and hold for 4 hours. After exiting the furnace, roll lengthwise with a cumulative deformation of 50% at a rolling speed of 30 mm / s. The deformation per pass should not exceed 10%. After every 2-3 passes of rolling, heat to 900℃ and hold for 2 hours, then heat to 950℃ and hold for 30 minutes before rolling again. Finally, after rolling, grind, slit, and air-cool to room temperature. Step 5: The rolled sheet from Step 4 is kept at 950℃ for 2 hours. After the heat treatment, it is leveled and then sandblasted to remove the surface oxide scale. After that, acid cleaning and surface grinding are performed to obtain a finished titanium alloy sheet with a thickness of 6mm.

[0038] Characterization results: After grinding, polishing, and etching, the microstructure of the heat-treated sheet was characterized. Figure 1 It can be seen that the titanium alloy sheet has a bimodal structure, with no obvious banded structure, a primary α phase content of 13%, a size of 8 μm, and no obvious defects; from Figure 4As can be seen from the table, the titanium alloy sheet prepared in this embodiment has an ordered Ti8AlSn phase. Its tensile properties were tested, and at room temperature, the tensile strength was not less than 1210 MPa and the elongation was not less than 5.5%; at 700℃, the tensile strength was not less than 630 MPa and the elongation was not less than 26%; the difference between transverse and longitudinal strength did not exceed 15 MPa, and the difference in elongation did not exceed 1.5%; specific test results are shown in Table 1.

[0039] Table 1. Room temperature and high temperature tensile properties of Example 1

[0040] Example 2 The selected titanium alloy ingot has dimensions of 150mm × 500mm × 800mm. The titanium alloy composition, by mass percentage, is: Sn 10.5%, Al 6.5%, W 2.0%, Ta 1.0%, Si 0.4%, with the balance being Ti and unavoidable impurities. The specific implementation steps are as follows: Step 1: After the billet is opened, the ingot is subjected to 4 upsetting and drawing cycles and 4 flattening and forming cycles to obtain a slab with a thickness of 100mm. Step 2: Apply a coating to the surface of the forged slab with a coating thickness of 50 μm; heat to 1030℃ and hold for 6 hours; after exiting the furnace, roll along the length and width directions (intersecting), with a cumulative deformation of 45% in the length direction and 35% in the width direction, at a rolling speed of 55 mm / s, and a single-pass deformation not exceeding 10%; after every 2-3 rolling passes, heat to 980℃ and hold for 2 hours, then raise the temperature to 1030℃ and hold for 30 minutes before rolling again; finally, after rolling, grind, slit, and air-cool to room temperature to obtain the first intermediate slab; Step 3: Apply a coating to the surface of the first intermediate slab with a coating thickness of 50 μm; heat to 960℃ and hold for 4 hours; after exiting the furnace, perform cross rolling along the length and width directions, with a cumulative deformation of 35% in each direction, a rolling speed of 40 mm / s, and a single-pass deformation of no more than 10%; after every 2 to 3 rolling passes, heat to 900℃ and hold for 2 hours, then heat to 960℃ and hold for 30 minutes before rolling again; finally, after rolling, grind, slit, and air-cool to room temperature to obtain the second intermediate slab; Step 4: Cover the surface of the second intermediate slab with a soft steel layer, the thickness of which is 60% of the thickness of the second intermediate slab. Heat to 930℃ and hold for 4 hours. After exiting the furnace, roll lengthwise with a cumulative deformation of 60% at a rolling speed of 30 mm / s. The deformation per pass should not exceed 10%. After every 2-3 passes of rolling, heat to 900℃ and hold for 2 hours, then heat to 930℃ and hold for 20 minutes before rolling again. Finally, after rolling, grind, slit, and air-cool to room temperature. Step 5: The rolled sheet from Step 4 is kept at 950℃ for 2 hours. After the heat treatment, it is leveled and then sandblasted to remove the surface oxide scale. After that, acid cleaning and surface grinding are performed to obtain a finished titanium alloy sheet with a thickness of 6mm.

[0041] Characterization results: After grinding, polishing, and etching, the microstructure of the heat-treated sheet was characterized. Figure 2 As can be seen from the table, the titanium alloy sheet prepared in this embodiment has a dual-state structure, with no obvious elongation of grains along the rolling direction, no obvious banded structure, a primary α phase content of 12%, a size of about 9 μm, and no obvious defects. Its tensile properties were tested, and at room temperature, the tensile strength was not less than 1190 MPa and the elongation was not less than 6.5%; at 700℃, the tensile strength was not less than 635 MPa and the elongation was not less than 24%; the difference between transverse and longitudinal strength did not exceed 20 MPa and the difference in elongation did not exceed 2%. The specific test results are shown in Table 2.

[0042] Table 2. Room temperature and high temperature tensile properties of Example 2

[0043] Example 3 The selected titanium alloy ingot has dimensions of 150mm × 500mm × 800mm. The titanium alloy composition, by mass percentage, is: Sn 11.5%, Al 6.5%, W 1.5%, Ta 1.0%, Si 0.4%, with the balance being Ti and unavoidable impurities. The specific implementation steps are as follows: Step 1: After the billet is opened, the ingot is subjected to 4 upsetting and drawing cycles and 4 flattening and forming cycles to obtain a slab with a thickness of 100mm. Step 2: Apply a coating to the surface of the forged slab with a coating thickness of 50 μm; heat to 1000℃ and hold for 6 hours; after exiting the furnace, roll along the length and width directions (intersecting), with a cumulative deformation of 40% in the length direction and 30% in the width direction, at a rolling speed of 50 mm / s, and a single-pass deformation not exceeding 10%; after every 2-3 rolling passes, heat to 950℃ and hold for 2 hours, then raise the temperature to 1000℃ and hold for 30 minutes before rolling again; finally, after rolling, grind, slit, and air-cool to room temperature to obtain the first intermediate slab; Step 3: Apply a coating to the surface of the first intermediate slab with a coating thickness of 50 μm; heat to 950℃ and hold for 4 hours; after exiting the furnace, perform cross rolling along the length and width directions, with a cumulative deformation of 30% in each direction and a rolling speed of 30 mm / s, with a single pass deformation not exceeding 10%; after every 2-3 passes of rolling, heat to 880℃ and hold for 2 hours, then raise the temperature to 950℃ and hold for 30 minutes before rolling again; finally, after rolling, grind, slit, and air-cool to room temperature to obtain the second intermediate slab; Step 4: Cover the surface of the second intermediate slab with a soft steel layer, the thickness of which is 50% of the thickness of the second intermediate slab. Heat to 920℃ and hold for 4 hours. After exiting the furnace, roll lengthwise with a cumulative deformation of 70% at a rolling speed of 25 mm / s. The deformation per pass should not exceed 10%. After every 2-3 passes of rolling, heat to 850℃ and hold for 2 hours, then heat to 920℃ and hold for 10 minutes before rolling again. Finally, after rolling, grind, slit, and air-cool to room temperature. Step 5: The rolled sheet from Step 4 is kept at 950℃ for 2 hours. After the heat treatment, it is leveled and then sandblasted to remove the surface oxide scale. After that, acid cleaning and surface grinding are performed to obtain a finished titanium alloy sheet with a thickness of 6mm.

[0044] Characterization results: After grinding, polishing, and etching, the microstructure of the heat-treated samples was characterized. Figure 3 As can be seen from the table, the titanium alloy sheet prepared in this embodiment has a bimodal structure with no obvious banded structure. The primary α phase content is about 10%, the size is about 8 μm, and there are no obvious defects. The tensile properties were tested. At room temperature, the tensile strength is not less than 1190 MPa and the elongation is not less than 6%. At 700℃, the tensile strength is not less than 650 MPa and the elongation is not less than 23.5%. The difference between transverse and longitudinal strength is not more than 15 MPa and the difference in elongation is not more than 1%. The specific test results are shown in Table 3.

[0045] Table 3. Room temperature and high temperature tensile properties of Example 3

[0046] The embodiments described above are merely preferred embodiments of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various improvements and substitutions without departing from the technical principles of this application, and these improvements and substitutions should also be considered within the scope of protection of this application. Therefore, the scope of protection of this patent application should be determined by the scope of the claims.

Claims

1. A method for preparing ordered phase-reinforced titanium alloy thin plates, characterized in that, Includes the following steps: S1, the homogenized titanium alloy ingot is subjected to cyclic upsetting and flattening to obtain a forged slab with a thickness of 100~150mm. S2, after coating the surface of the forged slab, heat it to 1000~1050℃ and cross-roll it along the length and width directions to obtain the first intermediate slab; S3, after coating the surface of the first intermediate slab, heat it to 950~980℃, and then cross-roll it along the length and width directions to obtain the second intermediate slab; S4, after the second intermediate slab is coated, it is heated to 920~950℃ and rolled along the length direction; The titanium alloy sheet was then held at 920-950℃ for 2-4 hours to obtain the sheet.

2. The method for preparing ordered phase-strengthened titanium alloy thin plates according to claim 1, characterized in that, In S2, the cumulative deformation along the length direction is 40%~50%, the cumulative deformation along the width direction is 30%~40%, and the deformation per pass is 5%~10%. During the rolling process, after every 2~3 passes, the temperature is raised to 950~1000℃ and held for 1~4 hours, then raised to 1000~1050℃ and held for 10~30 minutes before rolling.

3. The method for preparing ordered phase-strengthened titanium alloy thin plates according to claim 1, characterized in that, In S3, the cumulative deformation along the length and width directions is 30%~40% each, and the deformation per pass is 5%~10%. During the rolling process, after every 2~3 passes, the temperature is raised to 880~920℃ and held for 1~4 hours, then raised to 950~980℃ and held for 10-30 minutes before rolling.

4. The method for preparing ordered phase-strengthened titanium alloy thin plates according to claim 1, characterized in that, The coating is a silicate glass coating with a thickness of 30~50μm.

5. The method for preparing ordered phase-strengthened titanium alloy thin plates according to claim 1, characterized in that, The coating process specifically involves coating the surface of the second intermediate slab with a soft steel layer, the thickness of which is 50% to 80% of the thickness of the second intermediate slab.

6. The method for preparing ordered phase-strengthened titanium alloy thin plates according to claim 1, characterized in that, In S4, the cumulative deformation along the length direction of the cladding rolling is 40%~60%, and the deformation per pass is 5%~10%. During the rolling process, after every 2~3 passes, the temperature is raised to 880~920℃ and held for 1~4 hours, then raised to 920~950℃ and held for 10-30 minutes before rolling.

7. A titanium alloy thin sheet reinforced by an ordered phase, characterized in that, The titanium alloy sheet is prepared by the method of preparing ordered phase-strengthened titanium alloy sheet according to any one of claims 1-6. The composition of the titanium alloy by mass percentage includes: Al: 5%~10%, Sn: 5%~20%, neutral elements and β-stabilizing elements total ≤10%, and the balance is Ti and unavoidable impurities. The ordered phases dispersed in the matrix of the titanium alloy include one or both of the Ti8AlSn phase and the Ti4AlSn2 phase.

8. The ordered phase-strengthened titanium alloy sheet according to claim 7, characterized in that, The ordered phase is coherent or semi-coherent with the matrix.

9. The ordered phase-strengthened titanium alloy sheet according to claim 7, characterized in that, At room temperature, the titanium alloy sheet has a tensile strength ≥1190MPa and an elongation ≥5.5%; at 700℃, the tensile strength ≥635MPa and the elongation ≥20%.

10. An application of an ordered phase-strengthened titanium alloy sheet according to any one of claims 7-9, characterized in that, The titanium alloy sheet is used in high-temperature structural components of aerospace engines.

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