Titanium-based material resistant to 700° c. and method for its preparation

Abstract

The application relates to the technical field of non-ferrous metal processing, in particular to a 700 DEG C-resistant titanium-based material and a preparation method thereof. The titanium-based material is composed of the following components and has the following mass percentage: 6.0-7.0% of aluminum, 1.0-4.5% of tin, 3.5-6.0% of zirconium, 0.5-1.0% of molybdenum, 0.5-1.5% of niobium, 0.2-0.5% of silicon, 0.2-0.7% of boron, 0.06-0.15% of carbon, and the balance of titanium, refractory metal and inevitable impurity elements. The 700 DEG C-resistant titanium-based material and the preparation method thereof aim to solve the problem of insufficient high-temperature performance of the titanium-based composite material.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of non-ferrous metal processing, in particular to a 700 DEG C-resistant titanium-based material and a preparation method thereof. BACKGROUND

[0002] The temperature requirement of some thermal structures in the field of aerospace reaches 650 DEG C or above. The service temperature of the currently mature high-temperature titanium alloy is 600 DEG C. The existing materials cannot meet the requirement of the aircraft for a service temperature of 650 DEG C or above. The research and development of new high-temperature structural materials has become a key problem to be solved.

[0003] Due to the large deformation resistance, narrow hot working window and difficulty in deformation of the high-temperature-resistant titanium alloy, the plasticity of the material decreases after the introduction of ceramic precipitates such as particles and whiskers with high brittleness, and cracking is prone to occur, which greatly increases the processing difficulty of the material and makes it more difficult to prepare wide sheets. The wide sheets of the reported 700 DEG C-resistant titanium-based material are less than 400 mm. For the large-size (width is greater than or equal to 800 mm, length is greater than or equal to 1500 mm, and thickness is 0.5-2 mm) sheet commonly used for thin-walled components, there is no related research report. The research and development of wide sheets of new 700-750 DEG C-resistant titanium-based material has become a difficult problem to be solved at present.

[0004] Therefore, the present application provides a 700 DEG C-resistant titanium-based material and a preparation method thereof. SUMMARY

[0005] (1) Technical problem to be solved

[0006] The present application provides a 700 DEG C-resistant titanium-based material and a preparation method thereof, which solves the technical problem of insufficient high-temperature performance of the titanium-based composite material.

[0007] (2) Technical scheme

[0008] The first aspect of the present application provides a 700 DEG C-resistant titanium-based material, the components and mass percentages of which are as follows: aluminum 6.0-7.0%, tin 1.0-4.5%, zirconium 3.5-6.0%, molybdenum 0.5-1.0%, niobium 0.5-1.5%, silicon 0.2-0.5%, boron 0.2-0.7%, carbon 0.06-0.15%, and the balance being titanium, refractory metal and unavoidable impurity elements.

[0009] Further, the sum of the mass percentages of the aluminum element and the tin element is less than 10.5%.

[0010] Further, the sum of the mass percentages of the molybdenum element and the niobium element is greater than 0.8%, and the sum of the mass percentages of the molybdenum element and the niobium element is less than or equal to 2.5%.

[0011] Further, the mass percentage of boron element is positively correlated with the sum of mass percentages of molybdenum element and niobium element, and is negatively correlated with the sum of mass percentages of aluminum element and tin element.

[0012] Further, the refractory metal includes at least one of tantalum and tungsten, and the mass percentage of the refractory metal is less than or equal to 3%.

[0013] The second aspect of the present application provides a preparation method of a 700℃-resistant titanium-based material, comprising the following steps:

[0014] Step 1: uniformly mixing raw materials of each element according to mass percentage, then pressing and welding into a smelting electrode, and preparing a titanium-based material ingot through multiple vacuum consumable electrode smelting;

[0015] Step 2: after coating a high-temperature-resistant and oxidation-resistant coating on the surface of the titanium-based material ingot, performing heat preservation treatment in a β+50℃-β+200℃ phase region, then performing multiple forging deformations, the deformation amount of each pass is 20-70%, and then air cooling to room temperature to obtain a titanium-based material forging blank with fine TiB precipitated phase and uniform distribution in all directions;

[0016] Step 3: performing surface grinding treatment on the titanium-based material forging blank, then coating an oxidation-resistant coating to obtain a titanium-based material plate blank;

[0017] Step 4: placing the titanium-based material plate blank in a heating furnace at β+20℃-β+200℃ for heating treatment and heat preservation, then rolling, and performing multiple pass deformations in the first pass, the deformation amount of each pass is 10-35%, and the pass deformation amount is 30-80%;

[0018] Step 5: performing heating treatment and heat preservation in a heating furnace at β+20℃-β+200℃, and then performing multiple pass deformations after reversing, the deformation amount of each pass is 20-40%, the pass deformation amount is 40-80%, and air cooling to room temperature after rolling deformation;

[0019] Step 6: repeating Step 5 for at least one pass deformation, then performing surface treatment on the blank, cutting and processing into a suitable size, covering the blank with a metal plate and sealing and welding;

[0020] Step 7: placing the blank after the covering treatment in a heating furnace at β+20℃-β+200℃ and heat preservation, and performing multiple pass deformations to obtain a semi-finished plate; wherein the deformation amount of each pass is 15-35%, and the final rolling temperature is higher than or equal to β-60℃;

[0021] Step 8: performing surface treatment on the semi-finished plate to obtain a 700℃-resistant titanium-based material plate.

[0022] Further, the heat preservation time in Step 2 is 3-10h.

[0023] Further, the holding time in step 4 is H x (1.0-2.0) min, H is the total thickness of the blank, and the unit is mm.

[0024] Further, the holding time in step 7 is H x (1.0-1.5) min, H is the total thickness of the blank, and the unit is mm.

[0025] Further, the last pass deformation in step 7 is less than the previous pass deformation and less than or equal to 25%.

[0026] Further, the plate obtained in step 8 has a matrix structure with a beta grain size of less than 100 μm, an internal nearly net basket-like lamellar structure, and a precipitate phase size of less than 80 μm.

[0027] (3) Beneficial effects

[0028] In summary, the present application improves the strength through the synergistic strengthening of TiB, alpha2 and silicide and other precipitates, moderately increases the beta stable element content to improve the plasticity, and controls the matrix structure to form a nearly net basket-like fine grain, thereby comprehensively improving the strength and plasticity, and achieving a good match of room temperature plasticity, high temperature strength and endurance performance. The beta single-phase region above is forged and rolled, the large heating and pass rolling deformation reduces the temperature drop, the final deformation temperature is strictly controlled, the pass deformation amount in the final forging and rolling heating is accurately controlled, the fine grain with a nearly net basket structure is obtained, the TiB phase is uniformly distributed, the (0.9-2 mm) x (800-1000 mm) x (1500-2000 mm) size titanium-based composite sheet is prepared, and the problem of wide width titanium-based material sheet rolling difficulty at 700 DEG C is solved. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0030] Figure 1 is a flowchart of a 700 DEG C titanium-based material and a preparation method thereof provided by the embodiments of the present application;

[0031] Figure 2 is a schematic diagram of the microstructure of a titanium-based material sheet prepared by the embodiment 1 of the present application;

[0032] Figure 3 is a schematic diagram of the microstructure of a titanium-based material sheet prepared by the comparative example 1 of the present application. DETAILED DESCRIPTION

[0033] The embodiments of the present application will be further described in details below with reference to the accompanying drawings and embodiments. The detailed description and drawings of the following embodiments are used to exemplarily illustrate the principles of the present application, but cannot be used to limit the scope of the present application, that is, the present application is not limited to the described embodiments.

[0034] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in details below with reference to the accompanying drawings and embodiments.

[0035] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "back", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship commonly used when the product of the present application is used, or the orientation or positional relationship commonly understood by those skilled in the art, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0036] Some existing 700℃-resistant titanium-based materials and their sheet preparation methods have the following problems: (1) the use temperature of the existing high-temperature-resistant titanium alloy material is limited, and it is difficult to improve the high-temperature performance. The addition of high-beta stabilizing elements to improve the high-temperature processing performance will significantly reduce the long-time durability, which is not conducive to the comprehensive performance of the material at high temperature; (2) the 700℃-resistant titanium-based composite material has many precipitated phases, which leads to large deformation resistance and narrow hot working window. The preparation of thin sheets is greatly affected by the rolling process such as temperature and deformation amount, and the rolling deformation is prone to cracking, making it difficult to prepare 700℃-resistant high-performance wide thin sheets.

[0037] The 700℃-resistant titanium-based material provided by the embodiments of the present application has the following components and mass percentages: aluminum 6.0% to 7.0%, tin 1.0% to 4.5%, zirconium 3.5% to 6.0%, molybdenum 0.5% to 1.0%, niobium 0.5% to 1.5%, silicon 0.2% to 0.5%, boron 0.2% to 0.7%, carbon 0.06% to 0.15%, and the balance being titanium, refractory metal and unavoidable impurity elements.

[0038] In the above embodiments, the strength is improved by the synergistic strengthening of multiple precipitated phases, and the content of beta stabilizing elements (i.e. molybdenum, niobium and refractory metal) is moderately increased to improve the plasticity of the titanium-based material.

[0039] As an optional implementation, the sum of the mass percentages of aluminum and tin is less than 10.5%. Among them, Al and Sn elements have a greater effect on improving high-temperature strength, and are also necessary conditions for forming α2 phase, but when the content is too high, it will also weaken the room temperature plasticity, in addition, B addition will also have a similar effect, considering the coordination and matching of both strength and room temperature plasticity, this range is selected.

[0040] As an optional implementation, the sum of the mass percentages of molybdenum and niobium is greater than 0.8%, and the sum of the mass percentages of molybdenum and niobium is less than or equal to 2.5%. Among them, Mo and Nb elements are helpful to improve the room temperature plasticity and processing performance of the material, but too much will reduce the high temperature durability, so this range is selected.

[0041] As an optional implementation, the sum of the mass percentages of molybdenum and niobium and the mass percentage of boron are positively correlated. Among them, TiB helps to improve the strength, but makes the hot working resistance larger, Mo and Nb help to improve the processing performance, by adjusting the two types of elements, the material can have reasonable processing performance while achieving good mechanical properties.

[0042] As an optional implementation, the refractory metal includes at least one of tantalum and tungsten, and the mass percentage is less than or equal to 3%. Among them, the addition of these two elements improves the high-temperature strength and room temperature plasticity, but since they are refractory alloy elements, too much addition will lead to uneven material composition and increased density. Therefore, it needs to be controlled within a certain range.

[0043] Figure 1 is a flowchart of a preparation method of a 700℃-resistant titanium-based material provided by an embodiment of the present application, as shown in the figure, the method can include the following steps: Figure 1

[0044] S100, uniformly mix the raw materials of each element according to the mass percentage, then press and weld into a melting electrode, and prepare a titanium-based material ingot by multiple vacuum consumable electrode melting.

[0045] Specifically, uniformly mix the raw materials of each alloy element according to the mass percentage in a mixer, then press and weld into a melting electrode, and prepare a titanium-based material ingot by three times of vacuum consumable electrode melting; the structure of the titanium-based material ingot is composed of α+β phase, α2 phase, TiB, silicide, etc.

[0046] S200, after coating a high-temperature oxidation-resistant coating on the surface of the titanium-based material ingot, heat treatment is carried out in the β+50℃-β+200℃ phase region, then multiple forging deformation is carried out, the deformation amount of each fire is 20-50%, and then air cooling is carried out to room temperature, to obtain a titanium-based material forging billet with fine precipitated phase and uniform distribution in all directions. ​

[0047] Specifically, the holding time in step S200 is 3-10 h, and then 6-9 forging deformations are performed. The temperature range is selected mainly in consideration of the fact that the material has large deformation resistance and is prone to cracking during deformation, and thus needs to be deformed at a high temperature to control deformation cracking, and also in consideration of the need for performance control, and thus the temperature cannot be too high to prevent the matrix from softening and being difficult to break the large-size TiB, and in order to ensure that the TiB phase can be broken well to obtain fine and uniform distribution and improve the deformation cracking, the temperature range is selected.

[0048] S300, surface polishing treatment is performed on the titanium-based material forging blank, and then an oxidation-resistant coating is coated to obtain a titanium-based material slab.

[0049] S400, the titanium-based material slab is placed in a heating furnace at a temperature of β+20℃-β+200℃ for heating treatment and holding, and then is rolled, and the first time is subjected to multi-pass deformation, and the deformation amount of each pass is 10-35%, and the deformation amount of the time is 30-80%.

[0050] Specifically, the holding time in step S400 is Hx(1.0-2.0) min, H is the total thickness of the blank, and the unit is mm, and then the blank is rolled on a hot rolling mill, and the first time is subjected to 2-8 pass deformation. The temperature range is selected mainly in consideration of the fact that the material has large deformation resistance and is prone to cracking during deformation, and thus needs to be deformed at a high temperature to control deformation cracking, and also in consideration of the need for performance control, and thus the temperature cannot be too high to prevent the β grains from being severely coarsened and to control the size and distribution of TiB, and thus the temperature range is selected.

[0051] S500, heating treatment and holding are performed in a heating furnace at a temperature of β+20℃-β+200℃, and then multi-pass deformation is performed after reversing, and the deformation amount of each pass is 20-40%, and the deformation amount of the time is 40-80%, and the rolled deformation is air-cooled to room temperature.

[0052] Specifically, the holding time in step S500 is Hx(1.0-2.0) min, and 2-10 pass deformations are performed after reversing, and the rolled deformation is air-cooled to room temperature, and the blank length is divided and adjusted according to the equipment conditions. The temperature range is selected mainly in consideration of the fact that the material has large deformation resistance and needs to be deformed at a high temperature to control deformation cracking, and also in consideration of the control of the size, distribution and matrix structure of TiB, and thus the temperature range is selected.

[0053] S600, at least one time deformation is repeated in step S500, and then the blank is surface treated, cut and processed into a suitable size, and the blank is covered with a metal plate and sealed.

[0054] Specifically, 1-4 time deformations are performed, and then the blank is surface treated to remove the oxide skin and other defects, cut and processed into a suitable size, and the blank is covered with a metal plate and sealed.

[0055] S700, placing the clad material after the coating treatment in a heating furnace at β+20℃-β+200℃ and holding, performing multi-pass deformation to obtain a semi-finished plate; wherein the deformation amount of each pass is 15-35%, and the final rolling temperature is higher than or equal to β-60℃.

[0056] Specifically, the holding time in step S700 is H x (1.0-1.5) min, H is the total thickness of the blank, and the unit is mm. 3-8 passes of deformation are performed, and the deformation amount of the last pass is less than that of the previous pass and less than or equal to 25%. Among them, the final rolling temperature should not be lower than β-60℃, to ensure that the matrix structure is near the basket structure, the grain size is below 100 μm, and the precipitated phase size is below 80 μm. The clad plate is removed to obtain a semi-finished thin plate with a width of more than 800 mm and a thickness of 0.9-3 mm. The temperature range of β+20℃-β+200℃ is mainly considered for the material deformation resistance, deformation cracking, and the need for performance control. The temperature cannot be too high to prevent grain growth and control TiB size and distribution, to ensure that fine β grains are obtained to improve room temperature plasticity, and fine and uniform TiB phases are formed; considering the processing performance and mechanical properties, this temperature range is selected.

[0057] The temperature range of β-60℃ is mainly selected to ensure the performance of the material. By controlling the final rolling temperature, the matrix forms fine β grains, the grain interior is near the basket-like lamellar structure, TiB is uniformly distributed, and the interface of TiB fragmentation is complete without micropores.

[0058] S800, surface treatment of the semi-finished plate to obtain a 700℃-resistant titanium-based material plate.

[0059] Specifically, the semi-finished plate air-cooled to room temperature is subjected to surface sanding, alkali and acid washing and other processing to obtain a 800mm-wide high-temperature-resistant titanium-based material plate with a thickness of 0.8-2.5mm.

[0060] In the above embodiment, β single-phase zone above forging and rolling deformation is adopted, large heating times and pass rolling deformation reduces temperature drop, and the final deformation temperature is strictly controlled. The deformation amount of the final forging and rolling pass is precisely controlled to obtain fine grains with a basket structure, realize the preparation of a (0.9-2mm) x (800-1000mm) x (1500-2000mm) size titanium-based composite thin plate, and solve the problem of wide high-temperature-resistant titanium-based material thin plate rolling.

[0061] The titanium-based composite sheet with a width of more than 800 mm is obtained by the above preparation method, the uniformity of the matrix structure state and the distribution of precipitated phase is improved by precisely controlling the forging and rolling heating times / deformation distribution, and the sheet has good room / high temperature performance.

[0062] In steps S400-S600, if there is no obvious crack on the surface of the slab within the heating times, short-time remelting and heat preservation treatment can be performed.

[0063] Example 1

[0064] (1) 200 kg of Ti-6.2Al-4.1Sn-4Zr-0.5Mo-1.0Nb-1.0Ta-0.7W-0.35Si-0.4B-0.11C raw materials are uniformly mixed in a mixer, then pressed into an electrode and welded into a melting electrode, and a titanium-based material ingot is prepared by three times of vacuum consumable electrode melting;

[0065] (2) After the surface of the ingot is processed and coated with a high-temperature resistant and oxidation resistant coating, heat preservation treatment is performed in the phase region at 1100-1150 °C, then 5-7 times of multi-directional forging deformation is performed, the first time is heat preserved for 4 h, the heat preservation time of the remaining times is 2-3 h, the deformation amount of each time is 20-70 %, and then air cooling is performed to room temperature, so that a forged blank with fine and uniformly distributed TiB precipitated phase is obtained;

[0066] (3) The surface of the titanium-based material ingot in step (2) is polished to obtain a titanium-based material slab with a thickness of 100 mm, and then an oxidation resistant coating is coated;

[0067] (4) The titanium-based material slab in step (3) is placed in a heating furnace at 1080-1200 °C and heat preserved for 120-140 min, then rolled on a hot rolling mill, 4-7 passes of deformation are performed in the first time, the pass deformation amount is 20-30 %, and the time deformation amount is 40-70 %;

[0068] (5) Then heat preserved for 50-70 min in a heating furnace at 1080-1200 °C, after reversing, 4-6 passes of deformation are performed, the pass deformation amount is 20-40 %, the time deformation amount is 55-75 %, and after rolling deformation, air cooling is performed to room temperature, the middle part is divided along the length direction and surface treatment is performed to remove the oxide skin and other defects, the blank is wrapped with a steel plate and sealed and welded;

[0069] (6) The wrapped blank is placed in a heating furnace at 1080-1200 °C and heat preserved for 40-60 min, 4-6 passes of deformation are performed, the pass deformation amount is 15-30 %, and the deformation amount of the last pass is 15-20 %; a 900 mm or more wide semi-finished sheet with a thickness of 1.2-1.5 mm is obtained, and after rolling, air cooling is performed to room temperature;

[0070] (7) the semi-finished plate obtained in step (6) is subjected to surface sanding, alkali and acid washing and other processing treatments to obtain a 900-1000 mm wide plate with a thickness of 0.9-1.1 mm.

[0071] The wide-width composite sheet obtained in the embodiment has a room temperature tensile strength of 1100 MPa and an elongation of 11%, a 700°C tensile strength of 610 MPa and an elongation of more than 20%, and a 700°C / 160 MPa endurance time of 290 h, and has good room temperature plasticity and high temperature performance matching.

[0072] Example 2

[0073] (1) 500 kg of Ti-6.1Al-3.9Sn-3.3Zr-0.5Mo-0.9Nb-0.5Ta-0.4Si-0.6B-0.06C raw materials are uniformly mixed in a mixer, then pressed into an electrode and welded into a melting electrode, and a titanium-based material ingot is prepared by three times of vacuum consumable electrode melting;

[0074] (2) after the surface of the ingot is processed and coated with a high-temperature resistant and oxidation resistant coating, the ingot is subjected to heat preservation treatment at 1150°C in a phase region, then subjected to 4-9 times of multi-directional forging deformation, the first time is heat preserved for 6-8 h, the heat preservation time of the remaining times is 3-5 h, the deformation amount of each time is 25-60%, and the ingot is air cooled to room temperature, so that a forged blank with fine and uniformly distributed TiB precipitated phases is obtained;

[0075] (3) the titanium-based material ingot in step (2) is subjected to surface grinding treatment to obtain a titanium-based material slab with a thickness of 150 mm, and the slab is sealed and welded with a steel plate;

[0076] (4) the titanium-based material slab in step (3) is placed in a heating furnace at 1080-1200°C and heat preserved for 270-300 min, then rolled on a hot rolling mill, the first time is subjected to 6-9 passes of deformation, the pass deformation amount is 10-30%, the time deformation amount is 60-75%, the rolled deformation is air cooled to room temperature, the middle part is divided along the length direction, then subjected to surface treatment and sealed and welded with a steel plate;

[0077] (5) heat preserved for 120-150 min in a heating furnace at 1080-1200°C, then subjected to 5-7 passes of deformation after reversing, the pass deformation amount is 20-40%, the time deformation amount is 50-70%, the rolled deformation is air cooled to room temperature, the middle part is divided along the length direction, then subjected to surface treatment and sealed and welded with a steel plate;

[0078] (6) then in 1080~1200℃ heating furnace for 80~100min, after reversing 4~6 pass deformation, pass deformation amount is 20~40%, fire deformation amount is 60~80%, after rolling deformation air cooling to room temperature, along the length direction middle split and carry on surface treatment to remove oxide skin and other defects, adopt steel plate to cover blank, and seal welding;

[0079] (7) the blanking treatment of the material is placed in a heating furnace at 1060~1150℃ for 70~90min, 4~6 pass deformation, pass deformation amount is 15~30%, the last pass deformation amount is less than 20%; get 900mm above wide semi-finished sheet of 1.5~1.7mm thickness, after rolling air cooling to room temperature;

[0080] (8) the semi-finished sheet air cooled to room temperature in step (7) is sanded, alkaline and acid washed and other processing treatment, get 900mm~1000mm wide sheet of 1.3~1.5mm thickness.

[0081] The wide composite sheet obtained by the embodiment has a room temperature tensile strength of 1050MPa or more, an elongation of 10% or more, a 700℃ tensile strength of 550MPa, an elongation of 15% or more, a 750℃ tensile strength of 450MPa, an elongation of 25% or more, and a 700℃ / 160MPa endurance time of 252h, and has good room temperature and high temperature performance matching.

[0082] Example 3

[0083] (1) 150kg of Ti-6.1Al-3.9Sn-3.3Zr-0.5Mo-0.9Nb-0.5Ta-0.4Si-0.6B-0.06C raw materials are uniformly mixed in a mixer, then pressed and welded into a melting electrode, and a titanium-based material ingot is prepared by three times of vacuum consumable electrode melting;

[0084] (2) after the surface of the ingot is processed and coated with a high-temperature resistant and oxidation resistant coating, it is subjected to a heat preservation treatment at 1100~1150℃ in a phase region for 2~5h, then subjected to 5~7 times of multi-directional forging deformation, each time with a deformation amount of 20~40%, and then air cooled to room temperature, to obtain a forged blank with fine TiB precipitated phase and uniform distribution in all directions;

[0085] (3) the titanium-based material ingot in step (2) is polished on the surface, then coated with an oxidation resistant coating, to obtain a titanium-based material slab with a thickness of 45mm;

[0086] (4) Put the titanium-based material slab in step (3) into a heating furnace at 1080-1200 °C and keep for 60-90 min, then roll on a hot rolling mill, 2-3 passes deformation, pass deformation 15-20%, then put into a heating furnace at 1100-1150 °C and keep for 5 min, after reversing, 2-3 passes deformation, pass deformation 20-30%, total deformation 50-60%;

[0087] (5) Put the titanium-based material slab in step (4) into a heating furnace at 1080-1200 °C and keep for 20-30 min, then roll on a hot rolling mill, 2-3 passes deformation, pass deformation 25-35%, then put into a heating furnace at 1080-1200 °C and keep for 5 min, after reversing, 2-3 passes deformation, pass deformation 20-30%, total deformation 60-70%;

[0088] (6) Put the clad-treated blank into a heating furnace at 1080-1200 °C and keep for 40-60 min, 4-6 passes deformation, pass deformation 15-30%, the last pass deformation less than 20%; get 900 mm wide semi-finished thin plate of 1.0-1.3 mm in thickness, after rolling, air cooling to room temperature;

[0089] (7) Surface sanding, alkali and acid washing and other processing of the semi-finished plate cooled to room temperature in step (6) to get 900-1000 mm wide plate of 0.9-1.1 mm in thickness.

[0090] The wide-width composite thin plate obtained by the embodiment has a room temperature tensile strength of 1020 MPa or more, an elongation of 8%, a 700 °C tensile strength of 600 MPa, an elongation of 20% or more, and a 700 °C / 160 MPa endurance time of 200 h, and has good room temperature and high temperature performance matching.

[0091] Example 4

[0092] The embodiment is the same as example 1 except that the raw material composition is Ti-7Al-2Sn-5Zr-1.0Mo-1.0Nb-1.0Ta-0.5W-0.3Si-0.3B-0.06C.

[0093] The wide-width composite thin plate obtained by the embodiment has a room temperature tensile strength of 1000 MPa or more, an elongation of 8% or more, a 700 °C tensile strength of 600 MPa, and an elongation of 15% or more, and has good room temperature and high temperature performance matching.

[0094] Example 5

[0095] The present embodiment is consistent with other embodiments of embodiment 1, except that the raw material composition is: Ti-6.5Al-3Sn-4Zr-0.5Mo-1.0Nb-0.5Ta-0.35Si-0.5B-0.08C.

[0096] The wide-width composite sheet obtained by the present embodiment has a tensile strength of 1000 MPa and an elongation of 8% at room temperature, a tensile strength of 600 MPa and an elongation of more than 15% at 700°C, and has good room-temperature and high-temperature performance matching.

[0097] Comparative Example 1 Comparative Example 2

[0098] The difference between the present embodiment and embodiment 1 is that the slab rolling temperature in steps (4)-(6) is 1050°C and the pass deformation is 20-40%, and other aspects are consistent with embodiment 1.

[0099] The wide-width composite sheet obtained by the present embodiment has a near-bimodal structure with a large amount of equiaxed alpha phase, a tensile strength of 1200 MPa and an elongation of 4-7% at room temperature, a tensile strength of 450-550 MPa and an elongation of more than 15% at 700°C, and a 700°C / 160MPa endurance time of less than 10h.

[0100] It should be noted that each of the embodiments in the specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other. Each embodiment mainly describes the differences from other embodiments. The present application is not limited to the specific steps and structures described above and shown in the drawings. Moreover, for the sake of brevity, detailed descriptions of known methods and techniques are omitted.

[0101] The above is only an embodiment of the present application, and is not limited to the present application. The present application can have various modifications and changes for those skilled in the art without departing from the scope of the present application. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application shall be included in the scope of the claims of the present application.

Claims

1. A method for preparing a titanium-based material resistant to 700℃, characterized in that, The 700℃ resistant titanium-based material comprises the following components and mass percentages: aluminum 6.0%–7.0%, tin 1.0%–4.5%, zirconium 3.5%–6.0%, molybdenum 0.5%–1.0%, niobium 0.5%–1.5%, silicon 0.2%–0.5%, boron 0.2%–0.7%, carbon 0.06%–0.15%, with the balance being titanium, refractory metals, and unavoidable impurity elements; the method includes the following steps: Step 1: Mix the raw materials of each element in a uniform mass percentage, then press and weld them into a melting electrode, and prepare a titanium-based material ingot through multiple vacuum consumable electrode melting processes. Step 2: After applying a high-temperature resistant and anti-oxidation coating to the surface of the titanium-based material ingot, heat treatment is carried out in the β+50℃~β+200℃ phase region, followed by multi-fire forging deformation, with a deformation amount of 20~70% per fire, and then air-cooled to room temperature to obtain a titanium-based material forging ingot with fine and uniformly distributed TiB precipitates. Step 3: Grind the surface of the titanium-based material forging blank, and then coat it with an anti-oxidation coating to obtain a titanium-based material slab. Step 4: The titanium-based material slab is placed in a heating furnace at β+20℃~β+200℃ for heat treatment and held at that temperature, and then rolled. The first heat treatment involves multiple deformation passes, with each pass involving 10-35% deformation and the total deformation per heat treatment being 30-80%. Step 5: Heat and hold the product in a furnace at β+20℃~β+200℃, then perform multiple deformation passes after reversal. The deformation amount in each pass is 20~40%, and the deformation amount in each pass is 40~80%. After rolling deformation, air cool to room temperature. Step 6: Repeat step 5 for at least one heat deformation, then perform surface treatment on the billet, cut it into appropriate sizes, cover the billet with metal sheet and seal it with welding. Step 7: Place the coated billet in a heating furnace at β+20℃~β+200℃ and keep it at that temperature for multiple passes of deformation to obtain a semi-finished sheet; wherein the deformation amount of each pass is 15~35%, and the final rolling temperature is higher than or equal to β-60℃. Step 8: Perform surface treatment on the semi-finished sheet to obtain a titanium-based material sheet resistant to 700℃, with dimensions of (0.9~2mm)×(800~1000mm)×(1500~2000mm); The sum of the mass percentages of aluminum and tin is less than 10.5%, the sum of the mass percentages of molybdenum and niobium is greater than 0.8%, and the sum of the mass percentages of molybdenum and niobium is less than or equal to 2.5%. The refractory metal is at least one of tantalum and tungsten, and its mass percentage is less than or equal to 3%.

2. The preparation method according to claim 1, characterized in that, The heat preservation time in step 2 is 3 to 10 hours.

3. The preparation method according to claim 1, characterized in that, The heat preservation time in step 4 is H×(1.0~2.0)min, where H is the total thickness of the billet in mm.

4. The preparation method according to claim 1, characterized in that, The microstructure of the plate obtained in step 8 is characterized by β grains with a size of less than 100 μm in the matrix, a near-basket-like lamellar structure inside, and precipitated phases with a size of less than 80 μm.

5. The preparation method according to any one of claims 1-4, characterized in that, The deformation amount in the last pass in step 7 is less than the deformation amount in the previous pass and is less than or equal to 25%.

6. The preparation method according to claim 1, characterized in that, The mass percentage of boron is positively correlated with the sum of the mass percentages of molybdenum and niobium, while the mass percentage of boron is negatively correlated with the sum of the mass percentages of aluminum and tin.

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