TiAl alloy shaped blank pack rolling method by imitating asynchronous rolling and TiAl alloy plate

Abstract

A kind of TiAl alloy shaped blank package rolling method of imitating asynchronous rolling and TiAl alloy plate, the method comprises the following steps: preparing TiAl alloy shaped blank; The prepared TiAl alloy shaped blank is placed in the recess of corresponding stainless steel package, a composite isolation layer is filled between the TiAl alloy shaped blank and the outer layer stainless steel package, and welding is carried out, to obtain the TiAl alloy package blank of imitating asynchronous rolling;The obtained TiAl alloy package blank of imitating asynchronous rolling is placed in high temperature furnace, heated to 1100-1350 DEG C, and kept for 0.5-5h, then package rolling is carried out along the specified direction, and after every two passes, it is returned to the furnace and kept for 5-30min, after rolling, the rolled TiAl alloy package plate is placed in vacuum furnace for stress relief annealing;And the package shell on the rolled TiAl alloy package plate is removed by wire cutting method, to obtain TiAl alloy plate with deformation≥90%.The application also provides TiAl alloy plate prepared by the method.

Description

A method for cladding and rolling TiAl alloy shaped billets in the form of asynchronous rolling and TiAl alloy plates Technical Field

[0001] This invention relates to the processing and preparation technology of TiAl intermetallic compounds, and in particular to a method for rolling TiAl alloy shaped billets in a manner similar to asynchronous rolling, and TiAl alloy plates. Background Technology

[0002] TiAl intermetallic compounds (hereinafter referred to as TiAl alloys) possess characteristics such as low density, high specific strength, and excellent oxidation resistance, making them one of the promising structural materials to replace Ni-based superalloys. Especially in the temperature range of 600–800℃, they exhibit better service performance than Ni-based and Ti-based superalloys, showing broad prospects for high-temperature structural components in the aerospace and automotive industries. However, despite their promising commercial applications, their plastic forming ability is poor, requiring high-temperature forming above 1100℃, and they face the risk of cracking. To reduce the temperature drop during rolling and ensure good high-temperature plasticity, a cladding rolling method is generally adopted, in which a stainless steel shell is wrapped around the TiAl alloy billet. During rolling, the stainless steel shell isolates the TiAl alloy billet from the outside air, reducing temperature drop and preventing oxidation of the TiAl alloy billet.

[0003] Asynchronous rolling, as a rolling method with different surface linear velocities of the upper and lower rolls, has advantages such as low rolling force, strong thinning capability, and good shape control. During asynchronous rolling, the asymmetry of the rolling state of the upper and lower rolls causes severe additional shear deformation inside the rolled material, thereby improving the uniformity of the rolled material along the thickness direction and enhancing its comprehensive mechanical properties. Studies have shown that asynchronous rolling is a method that can be used to generate large plastic deformation and has been successfully applied to the preparation of nanocrystals and ultrafine grains (see "Microstructure and Mechanical Properties of Industrial Pure Titanium by Asynchronous Rolling", Li Zhiming et al., Shanghai Nonferrous Metals, 2011; and "Superplastic behavior of an ultrafine-grained Mg-13Zn-1.55Y alloy with a high volume fraction of icosahedral phases prepared by high-ratio differential speed rolling[J]. Kwak et al. Journal of Materials Science & Technology, 2017), etc.

[0004] For the rolling deformation of TiAl alloy, due to the presence of the external cladding, the shear force of asynchronous rolling acts directly on the stainless steel cladding and cannot be transmitted to the TiAl alloy slab inside the cladding. Therefore, it is impossible to directly perform asynchronous rolling on TiAl alloy to improve its formability. There is no publicly available record of asynchronous rolling of TiAl alloy in the prior art. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a method for rolling TiAl alloy shaped billets in a manner similar to asynchronous rolling, and a TiAl alloy plate, in order to address the above-mentioned deficiencies of the prior art.

[0006] To achieve the above objectives, the present invention provides a method for shrouding TiAl alloy shaped billets in a manner similar to asynchronous rolling, comprising the following steps:

[0007] S100, Preparation of TiAl alloy shaped billets;

[0008] S200. Assemble the irregular billet sleeve. Place the prepared TiAl alloy irregular billet in the groove of the corresponding stainless steel sleeve. Fill the space between the TiAl alloy irregular billet and the outer stainless steel sleeve with a composite isolation layer and weld them together to obtain a TiAl alloy sleeve billet that is simulated by asynchronous rolling.

[0009] S300, heat preservation and cladding rolling: The obtained simulated asynchronous rolling TiAl alloy clad billet is placed in a high-temperature furnace and heated to 1100-1350℃, held for 0.5-5 hours, and then clad rolling is performed along a specified direction. After every two passes, it is returned to the furnace for heat preservation for 5-30 minutes. The rolled TiAl alloy clad plate is then placed in a vacuum furnace for stress-relief annealing; and

[0010] S400. The machining process of the rolled TiAl alloy cladding plate involves removing the outer cladding shell from the rolled TiAl alloy cladding plate using a wire cutting method to obtain a TiAl alloy plate with a deformation amount ≥90%.

[0011] The above-mentioned method for shrouding TiAl alloy shaped billets using simulated asynchronous rolling, wherein step S100 further includes:

[0012] S101. TiAl alloy ingots are obtained by vacuum consumable arc melting.

[0013] S102. TiAl alloy forging discs are obtained by isothermal forging, and TiAl alloy shaped billets are obtained by wire electrical discharge machining; and

[0014] S103. Polish the surface of the TiAl alloy shaped billet.

[0015] In the above-mentioned method for shrouding TiAl alloy shaped billets using simulated asynchronous rolling, the isothermal forging temperature in step S102 is 1100℃~1350℃, the total deformation is 70%~80%, and the deformation rate is 0.1~1s. -1 .

[0016] The above-mentioned method for rolling TiAl alloy shaped billets in a simulated asynchronous rolling manner, wherein, by atomic percentage, the TiAl alloy composition of the TiAl alloy shaped billet includes: Al 40%–48%, Nb 0%–5%, Mo 0%–1.5%, V 0%–9%, ​​Y 0%–1%, B 0%–1%, C 0%–1%, and the balance being Ti.

[0017] The above-mentioned method for shrouding TiAl alloy shaped billets in simulated asynchronous rolling, wherein the TiAl alloy shaped billet is a straight parallelepiped or an isosceles trapezoid, and the included angle θ in the straight parallelepiped or isosceles trapezoid is 30 to 60°.

[0018] The above-mentioned method for cladding and rolling TiAl alloy shaped billets in the form of simulated asynchronous rolling, wherein the composite isolation layer is a layer of thermal insulation cotton material doped with boron nitride, and the thickness of the composite isolation layer is 2.5 mm; and vacuum electron beam welding is used for welding.

[0019] The above-described method for shrouding TiAl alloy shaped billets in a simulated asynchronous rolling process includes two specified directions: RD1 and RD2, which are along the length of the TiAl alloy shaped billet. The RD2 direction is opposite to the RD1 direction, with odd-numbered passes along the RD1 direction and even-numbered passes along the RD2 direction.

[0020] In the above-mentioned method for cladding rolling of TiAl alloy shaped billets in simulated asynchronous rolling, in step S300, during cladding rolling along the specified direction, the deformation amount of the first two passes is 25% to 30%, and the rolling speed is 0.8 m / s to 1 m / s; the deformation amount of the last two passes is 5% to 8%, and the rolling speed is 0.3 m / s to 0.5 m / s; the deformation amount of the intermediate passes is 10% to 20%, and the rolling speed is 0.5 m / s to 1 m / s.

[0021] In the above-mentioned method for rolling TiAl alloy shaped billets in the form of asynchronous rolling, in step S300, the rolled TiAl alloy cladding plate is placed in a vacuum furnace and held at 900℃~1100℃ for 36h~48h, then cooled in the furnace and subjected to stress-relief annealing.

[0022] To better achieve the above objectives, the present invention also provides a TiAl alloy sheet prepared by the above-mentioned simulated asynchronous rolling method for shaped TiAl alloy billets, wherein the internal microstructure of the TiAl alloy sheet includes fine equiaxed γ phase, β phase and / or γ / α2 lamellae, and fine shear bands and twin structures are visible under a transmission electron microscope.

[0023] The technical effects of this invention are as follows:

[0024] This invention introduces shear force into TiAl alloy billets, improving the traditional rectangular shape of TiAl alloy billets. Combined with optimized rolling process, specific structures such as shear bands and twins are introduced into the microstructure of TiAl alloy, reducing rolling force and rolling passes, thereby saving energy. At the same time, it improves the high-temperature plasticity of TiAl alloy, realizing the production of large-scale, high-volume fine-grained TiAl alloys.

[0025] Compared to traditional rectangular TiAl alloy cladding rolling, this invention introduces shear force into the TiAl alloy rolling process by improving the TiAl alloy billet morphology. This differs from traditional asynchronous rolling, which applies shear force by changing the roll speed or roll diameter. Simultaneously, by altering the TiAl alloy billet morphology, the shear force can penetrate the cladding and act directly on the TiAl alloy billet. On one hand, this reduces rolling force, lightens the mill load, and lowers equipment requirements; on the other hand, it increases the deformation per pass of the TiAl alloy, thereby reducing the number of rolling passes, improving production efficiency, and saving energy. Furthermore, due to the presence of shear force, fine shear bands and twinned structures appear in the internal microstructure of the irregularly shaped TiAl alloy billet after rolling deformation. This special microstructure improves the high-temperature deformation capability of the TiAl alloy, resulting in a fine, uniform microstructure with good ductility, enabling the preparation of large-size, thin-dimension TiAl alloy plates.

[0026] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the present invention. Attached Figure Description

[0027] Figure 1 is a schematic diagram of a straight parallelepiped TiAl alloy irregular billet structure according to an embodiment of the present invention;

[0028] Figure 2 is a schematic diagram of an isosceles trapezoidal TiAl alloy irregular billet structure according to an embodiment of the present invention;

[0029] Figure 3A is a scanning electron microscope image of the microstructure of the TiAl alloy thin plate prepared in Example 1 of the present invention;

[0030] Figure 3B is a transmission electron microscope image of the TiAl alloy thin plate prepared in Example 1 of the present invention.

[0031] Figure 4A is a scanning electron microscope image of the microstructure of the TiAl alloy thin plate prepared in Example 2 of the present invention;

[0032] Figure 4B is a transmission electron microscope image of the TiAl alloy thin plate prepared in Example 2 of the present invention.

[0033] Figure 5A is a scanning electron microscope image of the microstructure of the TiAl alloy thin plate prepared in Example 3 of the present invention.

[0034] Figure 5B is a transmission electron microscope (TEM) image of the TiAl alloy thin plate prepared in Example 3 of this invention. Detailed Implementation

[0035] The structural and working principles of the present invention will be described in detail below with reference to the accompanying drawings:

[0036] The present invention provides a method for rolling TiAl alloy shaped billets in a manner similar to asynchronous rolling. The method mainly includes: preparing TiAl alloy shaped billets that differ from traditional cuboids; placing the TiAl alloy shaped billet into a stainless steel cladding groove; placing a composite isolation layer on the contact surface between the stainless steel cladding and the TiAl alloy; performing a sealing weld to obtain a clad slab; holding the slab in a heating furnace to homogenize the microstructure; subsequently performing multi-pass hot rolling and stress-relief annealing; mechanically trimming the edges to remove the outer cladding shell, thereby obtaining a high-quality TiAl alloy rolled plate.

[0037] The method for producing TiAl alloy shaped billets using a simulated asynchronous rolling process includes the following steps:

[0038] Step S100: Prepare TiAl alloy shaped billet; wherein, by atomic percentage, the TiAl alloy composition of the TiAl alloy shaped billet includes: Al 40%–48%, Nb 0%–5%, Mo 0%–1.5%, V 0%–9%, ​​Y 0%–1%, B 0%–1%, C 0%–1%, with the balance being Ti; the TiAl alloy shaped billet is preferably a right parallelepiped or an isosceles trapezoid (see Figures 1 and 2), and the included angle θ in the right parallelepiped or isosceles trapezoid is preferably 30–60°;

[0039] Step S200: Assemble the irregularly shaped billet sleeve. Place the prepared TiAl alloy irregularly shaped billet into the groove of the corresponding stainless steel sleeve. Fill the space between the TiAl alloy irregularly shaped billet and the outer stainless steel sleeve with a composite isolation layer and weld them together to obtain a TiAl alloy sleeve billet with simulated asynchronous rolling. The composite isolation layer is preferably a layer of thermal insulation cotton material doped with boron nitride. The thermal insulation cotton can play a role in heat insulation and reducing temperature drop, while the boron nitride reagent can isolate the stainless steel and TiAl alloy plate to avoid metallurgical bonding. The thickness of the composite isolation layer is preferably 2.5 mm. Vacuum electron beam welding is preferably used for welding.

[0040] Step S300, heat preservation and cladding rolling: The obtained simulated asynchronous rolling TiAl alloy cladding billet is placed in a high-temperature furnace and heated to 1100-1350℃, held for 0.5-5 hours, and then cladding rolling is performed along a specified direction. After every two passes, it is returned to the furnace for heat preservation for 5-30 minutes. The rolled TiAl alloy cladding plate is then placed in a vacuum furnace for stress-relief annealing. The specified direction includes RD1 and RD2 directions along the length of the TiAl alloy shaped billet. The RD2 direction is opposite to the RD1 direction. Odd-numbered passes are along the RD1 direction, and even-numbered passes are along the RD2 direction. Specific-direction rolling allows for continuous application of shear force in a designated direction during deformation. During cladding rolling along the designated direction, the deformation amount in the first two passes is preferably 25%–30%, and the rolling speed is preferably 0.8 m / s–1 m / s; the deformation amount in the last two passes is preferably 5%–8%, and the rolling speed is preferably 0.3 m / s–0.5 m / s; the deformation amount in the intermediate passes is preferably 10%–20%, and the rolling speed is preferably 0.5 m / s–1 m / s. The large deformation in the first two passes introduces shear bands and twin structures, and refines the grains; the intermediate passes achieve thinning of the TiAl alloy billet; the last two passes primarily correct the plate shape. After rolling, stress-relief annealing is performed by placing the rolled TiAl alloy clad plate in a vacuum furnace and holding it at 900℃–1100℃ for 36h–48h, followed by furnace cooling for stress-relief annealing.

[0041] Step S400: The rolling TiAl alloy cladding plate is machined by wire cutting to remove the outer cladding shell from the rolling TiAl alloy cladding plate, resulting in a TiAl alloy plate with a deformation of ≥90%.

[0042] Step S100 further includes:

[0043] Step S101: Obtain TiAl alloy ingots by vacuum consumable arc melting;

[0044] Step S102: Obtain a TiAl alloy forging disc by isothermal forging, and obtain a TiAl alloy irregularly shaped billet that differs from the traditional cuboid shape using wire electrical discharge machining; wherein the isothermal forging temperature is preferably 1100℃~1350℃, the total deformation is preferably 70%~80%, and the deformation rate is preferably 0.1~1s. -1 ; and step S103, polishing the surface of the TiAl alloy shaped billet with a grinding machine.

[0045] This invention also provides TiAl alloy sheets prepared using the above-described simulated asynchronous rolling method for shaped TiAl alloy billets. The specific preparation process of the TiAl alloy sheets of this invention is illustrated below.

[0046] Example 1

[0047] The TiAl alloy sheet in this embodiment is prepared using a simulated asynchronous rolling method for TiAl alloy shaped billets, including the following steps:

[0048] Step S100: Preparation of TiAl alloy shaped billet: TiAl alloy ingots are obtained by vacuum arc melting with nominal composition of Ti-43Al-9V-0.3Y-0.1B-0.1C (atomic ratio). TiAl alloy forging is obtained by isothermal forging at 1300℃. Straight parallelepiped TiAl alloy shaped billet is obtained by wire electrical discharge machining, wherein the included angle θ in the hexahedron is 45°. The surface of the straight parallelepiped TiAl alloy shaped billet is polished by a grinding machine.

[0049] Step S200: Assemble the irregular billet sleeve: Place the straight parallelepiped TiAl alloy irregular billet in the groove of the corresponding stainless steel sleeve, fill the gap between the straight parallelepiped TiAl alloy irregular billet and the outer stainless steel sleeve with a 2.5mm composite isolation layer, and then perform vacuum electron beam welding to obtain the TiAl alloy sleeve billet with simulated asynchronous rolling.

[0050] Step S300, heat preservation and cladding rolling: The simulated asynchronous rolled TiAl alloy cladding billet is placed in a high-temperature furnace, heated to 1200℃, held for 3 hours, and then hot rolled. Odd-numbered passes are along the RD1 direction, and even-numbered passes are along the RD2 direction. The deformation amount of the first two passes is 30%, and the rolling speed is 1 m / s; the deformation amount of the last two passes is 5%, and the rolling speed is 0.3 m / s; the deformation amount of the intermediate passes is 10%, and the rolling speed is 0.5 m / s. After rolling, it is placed in a vacuum furnace and held at 1000℃ for 48 hours, then cooled in the furnace for stress-relief annealing.

[0051] Step S400: Machining of the rolled slab: The cladding on the simulated asynchronous rolled TiAl alloy cladding slab after stress-relief annealing is removed by wire cutting. The cladding is automatically removed, resulting in a 1.5mm thick TiAl alloy shaped slab with good surface quality. Its internal microstructure consists of fine equiaxed γ phase, β phase and γ / α2 lamellars. Fine shear bands and twin structures can be observed under a transmission electron microscope, as shown in Figures 3A and 3B.

[0052] Example 2

[0053] The TiAl alloy sheet in this embodiment is prepared using a simulated asynchronous rolling method for TiAl alloy shaped billets, including the following steps:

[0054] Step S100: Preparation of TiAl alloy shaped billet: TiAl alloy ingot is obtained by vacuum arc melting with nominal composition of Ti-43Al-9V-0.2Y (atomic ratio). TiAl alloy forging is obtained by isothermal forging at 1300℃. Straight parallelepiped TiAl alloy shaped billet is obtained by wire electrical discharge machining with included angle θ of 60°. The surface of the billet is polished by grinding machine.

[0055] Step S200: Assemble the irregular billet sleeve: Place the straight parallelepiped TiAl alloy irregular billet in the groove of the corresponding stainless steel sleeve, fill the gap between the straight parallelepiped TiAl alloy irregular billet and the outer stainless steel sleeve with a 2.5mm composite isolation layer, and then perform vacuum electron beam welding to obtain a TiAl alloy sleeve billet that is simulated by asynchronous rolling.

[0056] Step S300, heat preservation and cladding rolling: The simulated asynchronous rolled TiAl alloy cladding billet is placed in a high-temperature furnace, heated to 1150℃, held for 2 hours, and then hot rolled. Odd-numbered passes are along the RD1 direction, and even-numbered passes are along the RD2 direction. The deformation amount of the first two passes is 25%, and the rolling speed is 1 m / s; the deformation amount of the last two passes is 5%, and the rolling speed is 0.3 m / s; the deformation amount of the intermediate passes is 15%, and the rolling speed is 0.5 m / s. After rolling, it is placed in a vacuum furnace and held at 1000℃ for 48 hours, then cooled in the furnace for stress-relief annealing.

[0057] Step S400: Machining of the rolled slab: The cladding on the simulated asynchronous rolled TiAl alloy cladding slab after stress-relief annealing is removed by wire cutting. The cladding is completely removed automatically, resulting in a 1.2mm thick TiAl alloy shaped slab with good surface quality. Its internal microstructure consists of fine equiaxed β phase and γ / α2 lamellae. At the same time, fine shear bands and twin structures can be observed under transmission electron microscopy, as shown in Figures 4A and 4B.

[0058] Example 3

[0059] The TiAl alloy sheet in this embodiment is prepared using a simulated asynchronous rolling method for TiAl alloy shaped billets, including the following steps:

[0060] Step S100: Preparation of TiAl alloy shaped billet: TiAl alloy ingots are obtained by vacuum arc melting with nominal composition of Ti-44Al-4Nb-1.2Mo-0.1B-0.1Y (atomic ratio). TiAl alloy forging is obtained by isothermal forging at 1300℃. Isosceles trapezoidal TiAl alloy shaped billet is obtained by electrical discharge wire cutting with included angle θ of 45°. The surface of the billet is polished by grinding machine.

[0061] Step S200: Assemble the irregular billet sleeve: Place the isosceles trapezoidal TiAl alloy irregular billet in the groove of the corresponding stainless steel sleeve, fill the gap between the isosceles trapezoidal TiAl alloy irregular billet and the outer stainless steel sleeve with a 2.5mm composite isolation layer, and then perform vacuum electron beam welding to obtain the TiAl alloy sleeve billet with simulated asynchronous rolling.

[0062] Step S300, heat preservation and cladding rolling: The simulated asynchronous rolled TiAl alloy cladding billet is placed in a high-temperature furnace, heated to 1350℃, held for 2 hours, and then hot rolled. Odd-numbered passes are along the RD1 direction, and even-numbered passes are along the RD2 direction. The deformation amount of the first two passes is 25%, and the rolling speed is 1 m / s; the deformation amount of the last two passes is 5%, and the rolling speed is 0.3 m / s; the deformation amount of the intermediate passes is 10%, and the rolling speed is 0.5 m / s. After rolling, it is placed in a vacuum furnace and held at 1000℃ for 48 hours, then cooled in the furnace for stress-relief annealing.

[0063] Step S400: Machining of the rolled slab: The cladding on the simulated asynchronous rolled TiAl alloy cladding slab after stress-relief annealing is removed by wire cutting. The cladding is completely removed automatically, resulting in a 1.4 mm thick TiAl alloy shaped slab with good surface quality. Its internal microstructure consists of fine equiaxed γ phase, β phase and γ / α2 lamellars. At the same time, fine shear bands and twin structures can be observed under transmission electron microscopy, as shown in Figures 5A and 5B.

[0064] This invention prepares TiAl alloy shaped billets with specific morphologies and introduces shear deformation during the TiAl alloy rolling process to achieve a simulated asynchronous rolling effect. This effectively reduces rolling force, increases rolling strain, improves production efficiency, and avoids cracking of the sheet during rolling. The process is simple and stable. Furthermore, by controlling process parameters such as holding time, rolling temperature, rolling speed, deformation per pass, and post-rolling stress-relief annealing temperature, a TiAl alloy microstructure with fine shear bands and twinned structure characteristics is obtained, thereby improving the plastic deformation capacity of the TiAl alloy.

[0065] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the appended claims.

Claims

1. A method for shrouding TiAl alloy shaped billets in a simulated asynchronous rolling process, characterized in that, The process includes the following steps: S100, preparing a TiAl alloy shaped billet, wherein the TiAl alloy shaped billet is a right parallelepiped or an isosceles trapezoid, and the included angle θ in the right parallelepiped or isosceles trapezoid is 30~60°; S200, assembling the shaped billet sheath, placing the prepared TiAl alloy shaped billet in the groove of the corresponding stainless steel sheath, filling the space between the TiAl alloy shaped billet and the outer stainless steel sheath with a composite isolation layer, and welding them together to obtain a simulated asynchronous rolling TiAl alloy sheathed billet; S300, heat preservation and sheath rolling, placing the obtained simulated asynchronous rolling TiAl alloy sheathed billet in a high-temperature furnace, heating it to 1100~1350 ℃, holding it for 0.5~5 h, and then rolling it in a specified direction, returning it to the furnace for heat preservation for 5~30 h after every two passes. After rolling, the rolled TiAl alloy cladding sheet is placed in a vacuum furnace for stress-relief annealing; and in step S400, the rolled TiAl alloy cladding sheet is machined by wire cutting to remove the outer shell of the cladding sheet, resulting in a TiAl alloy sheet with a deformation of ≥90%. The internal microstructure of the TiAl alloy sheet includes fine equiaxed γ phase, β phase and / or γ / α2 lamellae, and fine shear bands and twin structures are visible under a transmission electron microscope; wherein, the specified direction includes the RD1 direction and the RD2 direction along the length direction of the TiAl alloy shaped billet, the RD2 direction is opposite to the RD1 direction, odd-numbered passes are along the RD1 direction, and even-numbered passes are along the RD2 direction, so as to continuously apply shear force in the specified direction during deformation; in step S300, during cladding rolling along the specified direction, the deformation of the first two passes is 25%~30%, and the rolling speed is 0.8m / s. ~1m / s; the deformation of the last two passes is 5%~8%, and the rolling speed is 0.3 m / s ~0.5 m / s; the deformation of the intermediate passes is 10%~20%, and the rolling speed is 0.5 m / s ~1m / s.

2. The method for shrouding TiAl alloy shaped billets using simulated asynchronous rolling according to claim 1, characterized in that, Step S100 further includes: S101, obtaining TiAl alloy ingots by vacuum arc melting; S102, obtaining TiAl alloy forging cakes by isothermal forging, and obtaining TiAl alloy shaped billets by electrical discharge wire cutting; and S103, polishing the surface of the TiAl alloy shaped billets.

3. The method for shrouding TiAl alloy shaped billets in simulated asynchronous rolling according to claim 2, characterized in that, The isothermal forging temperature in step S102 is 1100 ℃~1350 ℃, the total deformation is 70%~80%, and the deformation rate is 0.1~1 s. -1 .

4. The method for shrouding TiAl alloy shaped billets in simulated asynchronous rolling according to claim 1, 2, or 3, characterized in that, The TiAl alloy composition of the TiAl alloy shaped billet, by atomic percentage, includes: Al 40%~48%, Nb 0%~5%, Mo 0%~1.5%, V 0%~9%, Y 0%~1%, B 0%~1%, C 0%~1%, and the balance being Ti.

5. The method for shrouding TiAl alloy shaped billets in simulated asynchronous rolling according to claim 1, 2, or 3, characterized in that, The composite isolation layer is a layer of thermal insulation cotton material doped with boron nitride, and the thickness of the composite isolation layer is 2.5 mm; and it is welded by vacuum electron beam welding.

6. The method for shrouding TiAl alloy shaped billets in simulated asynchronous rolling according to claim 1, 2, or 3, characterized in that, In step S300, the rolled TiAl alloy cladding plate is placed in a vacuum furnace and held at 900 ℃~1100 ℃ for 36 h~48 h, then cooled in the furnace for stress-relief annealing.

7. A TiAl alloy sheet prepared by the simulated asynchronous rolling method for forming TiAl alloy shaped billets as described in any one of claims 1-6.

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