A processing method for high-performance and high-precision titanium alloy sheets

Abstract

The present invention relates to the technical field of processing and manufacturing medical titanium alloy plates, and specifically to a processing method for high-performance and high-precision titanium alloy plates. The chemical composition and mass percentage of the titanium alloy are as follows: Al is 5.9% - 6.4%, V is 3.9% - 4.4%, Fe is 0.15 - 0.22%, O is 0.09 - 0.13%, B is 0.002 - 0.05%, C ≤ 0.05%, H ≤ 0.005%, N ≤ 0.01%, and the balance is Ti; First, a thick slab with suitable dimensions is prepared through three times of vacuum consumable melting and forging processes; Then, a 10-mm thick slab with suitable dimensions is rolled in the single-phase region and the two-phase region, followed by water quenching after heat preservation in the two-phase region, and then the thin plate is rolled asynchronously in the two-phase region. Subsequently, it is straightened by a creep straightening furnace, and then sandblasted, pickled, and vacuum annealed to prepare the finished titanium alloy plate. The present invention can prepare titanium alloy plates with fine grain size, excellent performance, low flatness, and uniform thickness, meeting the requirements of the high-end medical device field for titanium alloy plates.

Description

Technical Field

[0001] The present invention relates to the technical field of processing and manufacturing of medical titanium alloy plates, and specifically to a processing method for high-performance and high-precision titanium alloy plates. Background Art

[0002] Titanium alloys have the advantages of high specific strength, good high-temperature performance, good fatigue resistance, excellent corrosion resistance, good biocompatibility, non-magnetic, non-toxic, etc., and are widely used in the field of medical devices. Ti-6Al-4V ELI alloy plates are widely used in medical devices such as bone plates, curved plates, and splints. However, there are various problems with the titanium alloy plates provided on the market, such as coarse microstructure, large performance deviation, excessive flatness resulting in low thickness accuracy, etc., which seriously affect the localization of titanium alloy plates and titanium alloy medical devices, leading to long-term dependence on imports for high-end plates and medical devices. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a processing method for high-performance and high-precision titanium alloy plates, to break through the key technologies existing in the manufacturing and processing of titanium alloy plates, and to realize the processing technology of titanium alloy plates. Through the present invention, various index requirements of medical titanium alloy plates can be met.

[0004] The technical solution adopted by the present invention is as follows:

[0005] A processing method for high-performance and high-precision titanium alloy plates, the chemical composition and mass percentage of the titanium alloy are: Al is 5.9% - 6.4%, V is 3.9% - 4.4%, Fe is 0.15 - 0.22%, O is 0.09 - 0.13%, B is 0.002 - 0.05%, C ≤ 0.05%, H ≤ 0.005%, N ≤ 0.01%, and the balance is Ti;

[0006] The preparation method of the high-performance and high-precision titanium alloy plates, this method includes the following steps:

[0007] Step 1: Prepare a titanium alloy ingot by vacuum consumable triple melting;

[0008] Step 2: Forge a thick slab in the single-phase region using a quick forging machine and machine the surface;

[0009] Step 3: Perform single-phase region rolling on the machined thick slab;

[0010] Step 4: Perform two-phase region rolling on the slab;

[0011] Step 5: Heat the slab to the single-phase region for heat treatment and then water quench;

[0012] Step 6: Perform warm rolling on the water-quenched slab;

[0013] Step 7: Perform creep straightening on the warm-rolled slab.

[0014] Step 8: Perform sanding on the slab blank after creep straightening.

[0015] Step 9: Polish the sanded sheet; thus, qualified sheets are prepared.

[0016] For the processing method of the high-performance and high-precision titanium alloy sheet, in Step 1, it is required to use titanium sponge, metal Al, intermediate alloy AlV, metal Fe, compound TiB2, and compound TiO2, mix materials according to the alloy composition, and perform triple vacuum consumable melting to obtain a titanium alloy ingot.

[0017] For the processing method of the high-performance and high-precision titanium alloy sheet, in Step 2, it is required to perform cogging forging at 1050°C - 1150°C, control the holding time within 2 - 5 hours, and process the ingot into a sheet with a thickness of 80 mm - 120 mm; then use a planer or milling machine to remove the surface oxidation, and process the slab blank into a slab blank with regular chamfer dimensions, and the surface roughness Ra value ≤ 3.2 μm.

[0018] For the processing method of the high-performance and high-precision titanium alloy sheet, in Step 3, it is required to perform rolling at 960°C - 1000°C, control the holding time within 2 - 3 hours, and process the slab blank into a sheet with a thickness of 40 mm - 60 mm, then remove the surface scale and oxygen-rich layer, and the surface roughness Ra value ≤ 3.2 μm.

[0019] For the processing method of the high-performance and high-precision titanium alloy sheet, in Step 4, at 890 - 940°C, hold for 1 - 2 hours, and process the slab blank into a sheet with a thickness of 10 mm - 15 mm.

[0020] For the processing method of the high-performance and high-precision titanium alloy sheet, the heat treatment in Step 5 is: heat the slab blank to 970 - 1000°C, hold for 0.5 - 1 hour, then perform water quenching, remove the surface scale and oxygen-rich layer, and the surface roughness Ra value ≤ 3.2 μm.

[0021] For the processing method of the high-performance and high-precision titanium alloy sheet, in Step 6, perform asynchronous rolling on the heat-treated slab blank at 780 - 860°C, control the holding time within 1 - 2 hours, and reverse the direction 1 - 3 times to roll the slab blank into a slab blank with the target size.

[0022] For the processing method of the high-performance and high-precision titanium alloy sheet, in Step 7, perform creep straightening on the rolled slab blank, the processing temperature is 660 - 740°C, hold for 1 - 2 hours, then cool in the furnace, and the flatness ≤ 1 mm / m.

[0023] In the processing method of the high-performance and high-precision titanium alloy plate, in step eight, the slab after creep straightening and flattening is subjected to sanding treatment.

[0024] In the processing method of the high-performance and high-precision titanium alloy plate, in step nine, the sanded slab is polished to prepare a qualified plate.

[0025] The design concept of the present invention is as follows:

[0026] First, in view of the performance requirements of medical titanium alloy plates and the requirement of grain refinement, on the basis of the Ti-6Al-4VELI alloy composition, a trace amount of B element is added. Due to the extremely low solubility of the B element in the α-phase and β-phase and its presence at the solidification front during melting, it can effectively inhibit the growth of grain size. Second, the "β-phase region and α+β-phase region rolling" process is adopted. The basket rolling formed by the slender α-phase formed during β-phase region rolling is greatly broken during the subsequent α+β-phase region rolling, making the slab structure in the process fine. Third, through heat treatment and water quenching in the β-phase region, a finer α′ martensite phase is formed inside the slab. As it is held in the α+β-phase region, the α′ martensite transforms into needle-shaped or rod-shaped α-phase, and rolling deformation causes dynamic recrystallization, thus effectively refining the grain size. Fourth, a creep straightening furnace is used for straightening, which not only achieves a lower flatness of the slab but also conducts finished product annealing, and can control the residual stress within 30 MPa. Fifth, the present invention uses sanding treatment to clean the oxide layer and oxygen-rich layer on the slab surface, eliminating the acid and alkali washing required for the preparation of conventional titanium alloy plates and greatly reducing environmental pollution.

[0027] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0028] 1. On the basis of meeting the Ti-6Al-4V ELI alloy composition, the present invention adds a trace amount of B element. Due to the extremely low solubility of the B element in the α-phase and β-phase and its often existing as a single element at the grain boundary and phase boundary, it can effectively inhibit the growth of grain size and phase size, effectively refining the grain size and phase size of the alloy material.

[0029] 2. The present invention adopts the process of "single-phase region rolling - two-phase region rolling - single-phase region heat treatment - two-phase region rolling". By using the needle-shaped or rod-shaped α-phase formed by high-temperature treatment and cooling, through shear deformation and dynamic recrystallization, the α-phase grain size is effectively reduced, thus effectively refining the microstructure of the material.

[0030] 3. The present invention uses a creep straightening furnace for slab straightening, which not only achieves a high flatness of the slab and meets the strict requirements of the plate shape and size, but also conducts finished product annealing of the plate to ensure that the mechanical properties of the plate meet the standard requirements.

[0031] 4. The present invention uses sanding and polishing to treat the surface oxide layer and oxygen-rich layer, eliminating the surface treatment process of titanium alloy plates such as acid and alkali washing, greatly reducing environmental pollution. In addition, this process avoids excessive hydrogen introduced by acid and alkali washing, and there is no need for vacuum heat treatment, which greatly improves production efficiency and reduces production costs.

[0032] 5. The present invention obtains high-performance and high-precision titanium alloy plates, and the performance index ranges are as follows: tensile strength R m =1070~1200MPa, yield strength R p0.2 =970~1100MPa, which is about 200~300MPa higher than the value specified in GB / T 13810-2017 standard; elongation A≥15%, 5% higher than the standard; section shrinkage Z≥40%, 20% higher than the standard; plate unevenness ≤1mm / m, 2mm / m lower than the standard; thickness deviation ≤0.2mm, 0.1~0.3mm lower than the standard. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is the microstructure of the 8.0 mm titanium alloy plate prepared in Example 1.

[0034] Figure 2 This is the microstructure of the 6.0 mm titanium alloy plate prepared in Example 2.

[0035] Figure 3 This is the microstructure of the 5.0 mm titanium alloy plate prepared in Example 3.

[0036] Figure 4 This is the microstructure of the 4.0 mm titanium alloy plate prepared in Example 4. DETAILED DESCRIPTION

[0037] The present invention is further described in detail below through examples and drawings.

[0038] Example 1

[0039] In this embodiment, the chemical composition of the titanium alloy is as follows by mass percentage: Al element 6.13%, V element 4.15%, Fe element 0.18%, O element 0.11%, B element 0.0034%, C element 0.012%, H element 0.0008%, N element 0.0089%, and the remainder is Ti.

[0040] In this embodiment, the preparation method of the high-performance and high-precision titanium alloy plate is as follows:

[0041] Step 1: Use sponge titanium, metal Al, master alloy AlV, metal Fe, elemental B, and compound TiO2, prepare materials according to the alloy components, and perform vacuum self-smelting three times to obtain an ingot with stable and uniform composition;

[0042] Step 2: Perform cogging forging at 1130°C, hold for 4 hours, and process the ingot to 110 mm; then use a milling machine to remove the surface oxide layer and oxygen-rich layer, and process the slab into a slab with chamfers and dimensional specifications, with a surface roughness Ra value of 3.2 μm;

[0043] Step 3: Roll the slab at 970°C, hold for 3 hours, and process the slab into a 60-mm thick plate, then remove the surface scale and oxygen-rich layer, with a surface roughness Ra value of 3.2 μm;

[0044] Step 4: Perform further rolling at 900°C, hold for 2 hours, and process the slab to 15 mm, then remove the surface scale and oxygen-rich layer, with a surface roughness Ra value of 3.2 μm;

[0045] Step 5: Heat the slab to 970°C, hold for 30 min, then water quench to room temperature, remove the surface scale and oxygen-rich layer, with a surface roughness Ra value of 3.2 μm;

[0046] Step 6: Asynchronously roll the heat-treated slab at 780°C, hold for 1 hour, reverse the direction once in the middle, and roll the slab to 9 mm;

[0047] Step 7: Place the rolled slab into a creep straightening furnace, with a straightening temperature of 660°C, hold for 1 hour, then cool in the furnace, with a flatness ≤ 1 mm / m;

[0048] Step 8: Sand the straightened slab, and control the plate size to 8.1 mm;

[0049] Step 9: Polish the sanded slab to prepare a finished 8.0-mm thick titanium alloy plate. Its microstructure is shown in Figure 1 , the mechanical properties are shown in Table 1, the flatness is 0.9 mm / m, and the thickness deviation is 0 - 0.20 mm.

[0050] Table 1 Test Results of the Mechanical Properties of the 8.0-mm Titanium Alloy Plate Prepared in Example 1

[0051] Sample number <![CDATA[R m / MPa]]> <![CDATA[R p0.2 / MPa]]> A / ％ Z / ％ Specimen 1 1095 976 16.5 47 Specimen 2 1091 988 18.0 44

[0052] From Figure 1 and Table 1, it can be seen that the titanium alloy plate prepared by the present invention has a fine and uniform microstructure, excellent mechanical properties, and high flatness, and can meet the technical requirements of medical titanium alloy plates.

[0053] Example 2

[0054] In this embodiment, the chemical composition of the titanium alloy is as follows by mass percentage: Al element 6.33%, V element 4.21%, Fe element 0.21%, O element 0.12%, B element 0.017%, C element 0.022%, H element 0.0005%, N element 0.0079%, and the remainder is Ti.

[0055] In this embodiment, the preparation method of the high-performance and high-precision titanium alloy plate is as follows:

[0056] Step 1: Use sponge titanium, metal Al, master alloy AlV, metal Fe, elemental B, and compound TiO2, prepare materials according to the alloy components, and perform vacuum self-smelting three times to obtain an ingot with stable and uniform composition;

[0057] Step 2: Forging at 1050°C for 3 hours, and processing the ingot to 100 mm; then using a milling machine to remove the surface oxide layer and oxygen-rich layer, and processing the slab into a slab with chamfers and size specifications, with a surface roughness Ra value of 3.2 μm;

[0058] Step 3: Roll the slab at 990°C for 2 hours, process the slab into a 50mm thick plate, then remove the surface oxide scale and oxygen-rich layer, and the surface roughness Ra value is 3.2μm;

[0059] Step 4: further rolling at 890°C for 1 hour to process the slab to 12 mm;

[0060] Step 5: Heat the slab to 1000°C, keep it warm for 1 hour, then quench it with water to room temperature, remove the surface oxide scale and oxygen-rich layer, and the surface roughness Ra value is 3.2μm;

[0061] Step 6: Asynchronously roll the heat-treated slab at 800°C for 2 hours, change direction twice in the middle, and roll the slab to 7 mm;

[0062] Step 7: Place the rolled slab into a creep straightening furnace at a straightening temperature of 700°C for 1.5 hours, then cool the furnace, and the unevenness is ≤1mm / m;

[0063] Step 8: Sand the flattened slab to control the size of the slab to 6.1 mm;

[0064] Step 9: Polish the sanded slab to produce a 6.0 mm finished titanium alloy sheet. Figure 2 The mechanical properties are shown in Table 2. The roughness is 0.8 mm / m and the thickness deviation is 0 to 0.17 mm.

[0065] Table 2 Mechanical properties test results of 6.0 mm titanium alloy plate prepared in Example 2

[0066] Sample number <![CDATA[R m / MPa]]> <![CDATA[R p0.2 / MPa]]> A / ％ Z / ％ Specimen 1 1124 1006 17.5 45 Specimen 2 1137 1023 16.0 43

[0067] from Figure 2 It can be seen from Table 2 that the titanium alloy plate prepared by the present invention has a fine and uniform microstructure, excellent mechanical properties, high flatness, and can meet the technical requirements of medical titanium alloy plates.

[0068] Example 3

[0069] In this embodiment, the chemical composition of the titanium alloy is as follows by mass percentage: Al element 5.97%, V element 4.07%, Fe element 0.15%, O element 0.105%, B element 0.032%, C element 0.026%, H element 0.0011%, N element 0.0094%, and the remainder is Ti.

[0070] In this embodiment, the preparation method of the high-performance and high-precision titanium alloy plate is as follows:

[0071] Step 1: Use sponge titanium, metal Al, master alloy AlV, metal Fe, elemental B, and compound TiO2, prepare materials according to the alloy components, and perform vacuum self-smelting three times to obtain an ingot with stable and uniform composition;

[0072] Step 2: Forging at 1100°C for 2.5 hours, and processing the ingot to 90 mm; then using a milling machine to remove the surface oxide layer and oxygen-rich layer, and processing the slab into a slab with chamfers and size specifications, with a surface roughness Ra value of 3.2 μm;

[0073] Step 3: Roll the slab at 980°C for 2.5 hours, process the slab into a 40mm thick plate, then remove the surface oxide scale and oxygen-rich layer, and the surface roughness Ra value is 3.2μm;

[0074] Step 4: further rolling at 930°C for 1.2 hours to process the slab to 10 mm;

[0075] Step 5: Heat the slab to 990°C, keep it warm for 45 minutes, then quench it with water to room temperature, remove the surface oxide scale and oxygen-rich layer, and the surface roughness Ra value is 3.2 μm;

[0076] Step 6: Asynchronously roll the heat-treated slab at 820°C for 1.5 hours, change direction twice in the middle, and roll the slab to 6 mm;

[0077] Step 7: Place the rolled slab into a creep straightening furnace at a straightening temperature of 720°C for 1.5 hours, then cool the furnace, and the unevenness is ≤1mm / m;

[0078] Step 8: Sand the leveled slab, and control the size of the plate to 5.1 mm;

[0079] Step 9: Polish the sanded slab to prepare a finished titanium alloy plate with a thickness of 5.0 mm. The micro-structure is shown in Figure 3 , the mechanical properties are shown in Table 3, the flatness is 0.6 mm / m, and the thickness deviation is 0 - 0.15 mm.

[0080] Table 3 Test Results of Mechanical Properties of 5.0 mm Titanium Alloy Plate Prepared in Example 3

[0081] Sample number <![CDATA[R m / MPa]]> <![CDATA[R p0.2 / MPa]]> A / ％ Z / ％ Specimen 1 1157 1036 18.5 48 Specimen 2 1160 1045 17.5 46

[0082] From Figure 3 and Table 3, it can be seen that the titanium alloy plate prepared by the present invention has a fine and uniform micro-structure, excellent mechanical properties, high flatness, and can meet the technical requirements of medical titanium alloy plates.

[0083] Example 4

[0084] In this example, the chemical composition of the titanium alloy by mass percentage is: 6.25% of Al element, 3.96% of V element, 0.22% of Fe element, 0.12% of O element, 0.041% of B element, 0.0065% of C element, 0.0012% of H element, 0.017% of N element, and the balance is Ti.

[0085] In this example, the preparation method of the high-performance and high-precision titanium alloy plate is as follows:

[0086] Step 1: Use sponge titanium, metallic Al, intermediate alloy AlV, metallic Fe, elemental B, and compound TiO2 to charge according to the alloy composition, and perform vacuum consumable triple melting to obtain an ingot with stable and uniform composition;

[0087] Step 2: Perform cogging forging at 1080 °C for 2 hours to process the ingot to 80 mm; then use a milling machine to remove the surface oxide layer and oxygen-rich layer, and process the slab into a slab with chamfers and dimensional specifications, with a surface roughness Ra value of 3.2 μm;

[0088] Step 3: Perform slab rolling at 1000 °C for 2 hours to process the slab into a 40 mm thick plate, then remove the surface oxide scale and oxygen-rich layer, and the surface roughness Ra value is 3.2 μm;

[0089] Step 4: Perform further rolling at 930 °C for 2 hours to process the slab into 9 mm;

[0090] Step 5: Heat the slab to 970 °C, hold for 45 min, then water quench to room temperature, remove the surface scale and oxygen-rich layer, and the surface roughness Ra value is 3.2 μm;

[0091] Step 6: Asynchronously roll the heat-treated slab at 850 °C, hold for 1 hour, reverse the direction 3 times in the middle, and roll the slab to 5 mm;

[0092] Step 7: Place the rolled slab into a creep straightening furnace, the straightening temperature is 730 °C, hold for 1.5 hours, then cool in the furnace, and the flatness ≤ 1 mm / m;

[0093] Step 8: Sand the straightened slab, and control the sheet size to 4.1 mm;

[0094] Step 9: Polish the sanded slab to prepare a finished titanium alloy sheet with a thickness of 4.0 mm. The micro-structure is shown in Figure 4 , the mechanical properties are shown in Table 4, the flatness is 0.5 mm / m, and the thickness deviation is 0 - 0.14 mm.

[0095] Table 4 Test results of the mechanical properties of the 4.0 mm titanium alloy sheet prepared in Example 4

[0096] Sample number <![CDATA[R m / MPa]]> <![CDATA[R p0.2 / MPa]]> A / ％ Specimen 1 1189 1076 17.5 Specimen 2 1182 1081 19.0

[0097] From Figure 4 and Table 4, it can be seen that the titanium alloy sheet prepared by the present invention has a fine and uniform micro-structure, excellent mechanical properties, and high flatness, and can meet the technical requirements of medical titanium alloy sheets.

[0098] The results of the examples show that the present invention proposes a processing method for high-performance and high-precision titanium alloy sheets. By using the principle that element B has extremely low solubility in titanium alloys and often exists as a single-element at grain boundaries and phase boundaries, which can effectively inhibit the growth of grain size and phase size. On the basis of meeting the composition of Ti-6Al-4V ELI alloy, a trace amount of element B is added. In addition, the process of "single-phase zone rolling - two-phase zone rolling - single-phase zone heat treatment - two-phase zone rolling" is adopted. By using the acicular or rod-shaped α phase formed by cooling during high-temperature treatment, through shear deformation and dynamic recrystallization, the grain size of the α phase is effectively reduced, thereby effectively refining the microstructure of the material. Third, a creep straightening furnace is used for slab straightening, which not only achieves high flatness of the slab and meets the evolution requirements of the sheet shape and size, but also performs finished annealing of the sheet to ensure that the mechanical properties of the sheet meet the standard requirements. Finally, the surface oxide layer and oxygen-rich layer are treated by sanding and polishing, eliminating the surface treatment process of acid and alkali washing for this kind of titanium alloy sheet, greatly reducing environmental pollution. In addition, this process avoids excessive hydrogen introduced by acid and alkali washing, so there is no need for vacuum heat treatment, greatly improving production efficiency and reducing production costs. Therefore, through the present invention, titanium alloy sheets with fine and uniform microstructures, excellent properties and high flatness that meet the requirements of the medical field can be produced.

[0099] The above are only the preferred embodiments of the present invention and do not impose any limitations on the present invention. Any simple modifications, changes and equivalent variations made to the above embodiments according to the technical essence of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. A processing method for high-performance and high-precision titanium alloy sheets, characterized in that, The chemical composition and mass percentage of the titanium alloy are as follows: Al is 5.9% - 6.4%, V is 3.9% - 4.4%, Fe is 0.15 - 0.22%, O is 0.09 - 0.13%, B is 0.002 - 0.05%, C ≤ 0.05%, H ≤ 0.005%, N ≤ 0.01%, and the balance is Ti; The preparation method of the high-performance and high-precision titanium alloy sheet, which comprises the following steps: Step 1: Prepare a titanium alloy ingot by triple vacuum consumable melting; Step 2: Forge a thick slab in the single-phase region using a quick forging machine and machine the surface; Step 3: Roll the machined thick slab in the single-phase region; Step 4: Roll the slab in the two-phase region; Step 5: Heat the slab to the single-phase region for heat treatment and then water quench; Step 6: Warm roll the water-quenched slab; Step 7: Perform creep straightening on the warm-rolled slab; Step 8: Sand the slab blank after creep straightening; Step 9: Polish the sanded sheet to prepare a qualified sheet; In Step 3, it is required to roll at 960°C - 1000°C, control the holding time within 2 - 3 hours, process the slab into a 40mm - 60mm thick sheet, then remove the surface oxide scale and oxygen-rich layer, and the surface roughness Ra value ≤ 3.2μm; In Step 4, at 890 - 940°C, hold for 1 - 2 hours, and process the slab into a 10mm - 15mm thick sheet; The heat treatment in Step 5 is: heat the slab to 970 - 1000°C, hold for 0.5 - 1 hour, then water quench, remove the surface oxide scale and oxygen-rich layer, and the surface roughness Ra value ≤ 3.2μm; In Step 6, the heat-treated slab is asynchronously rolled at 780 - 860°C, control the holding time within 1 - 2 hours, and reverse the direction 1 - 3 times to roll the slab into the target-sized slab.

2. The processing method of the high-performance and high-precision titanium alloy sheet according to claim 1, characterized in that, In Step 1, it is required to use titanium sponge, metallic Al, intermediate alloy AlV, metallic Fe, compound TiB₂, and compound TiO₂, proportion the materials according to the alloy composition, and obtain the titanium alloy ingot by triple vacuum consumable melting.

3. The processing method of the high-performance and high-precision titanium alloy sheet according to claim 1, characterized in that, In Step 2, it is required to perform cogging forging at 1050°C - 1150°C, control the holding time within 2 - 5 hours, and process the ingot into an 80mm - 120mm thick sheet; then use a planer or milling machine to remove the surface oxidation and process the slab into a slab with regular chamfered dimensions, and the surface roughness Ra value ≤ 3.2μm.

4. The processing method of the high-performance and high-precision titanium alloy sheet according to claim 1, characterized in that, In Step 7, perform creep straightening on the rolled slab, the processing temperature is 660 - 740°C, hold for 1 - 2 hours, then furnace cool, and the flatness ≤ 1mm / m.

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