A method for preparing large-size crystal flowers on the surface of a titanium plate

Abstract

This invention provides a method for preparing large-sized crystal flowers on the surface of a titanium plate, wherein the titanium plate has a titanium content ≥99wt% and a titanium phase transformation temperature T. β =880~890℃, the preparation process involves sequentially degreasing and removing the oxide film from the surface of the titanium plate, followed by placing it in a heat treatment furnace at a vacuum degree ≤1.0×10 ‑2 Under the condition of Pa, at T β Gradient cyclic heat treatment is performed at ~1200℃ and 500~700℃. After the gradient cyclic heat treatment is completed, the plate is cooled to below 250℃ before being removed from the furnace, resulting in a titanium plate with large-sized crystal flowers on the surface. The gradient cyclic heat treatment first involves heating to T... β Hold at ~1200℃ for 15-60 minutes, then cool down to 500-700℃ and hold for 10-30 minutes, then raise the temperature to T. β The temperature is maintained at ~1200℃ for 15-60 minutes, then cooled to 500-700℃ and maintained for 10-30 minutes. This heating-holding and cooling-holding cycle is repeated continuously. One heating-holding and cooling-holding cycle is defined as one cycle. Experiments show that the more cycles, the larger the grain size on the surface of the prepared titanium plate. Therefore, it is convenient to prepare grains of different sizes on the surface of titanium plates as needed.

Description

Technical Field

[0001] This invention belongs to the field of surface treatment technology for titanium plates and titanium products, and relates to a method for preparing crystal flowers on the surface of titanium plates. Background Technology

[0002] Research and practice have been conducted on the preparation of flake-like crystals on the surface of titanium plates or titanium products. CN202210367037.2 discloses a method for preparing a pure titanium sheet with a flake-like crystal structure on its surface. This method involves subjecting the pure titanium sheet raw material to a first heating and holding step and a second heating and holding step under vacuum conditions, followed by rapid air-cooling quenching, to obtain a pure titanium sheet with a flake-like crystal structure on its surface. The first heating and holding temperature is 550℃~650℃, and the time is 1h~3h, the purpose of which is to homogenize the grains; the second heating and holding temperature is T... β ~950℃(T) β =833℃~890℃), for a time greater than 2.5h and less than or equal to 3.5h, the purpose of which is to allow the grains to regrow. Although this method produces scaly crystal flowers on the surface of pure titanium thin plates, the size of the prepared crystal flowers is small, only greater than 3mm and less than or equal to 8mm, and the first and second holding times are both relatively long.

[0003] CN201710494148.9 discloses a method for processing crystalline patterns on titanium products, comprising the following steps: First, the titanium product is heat-treated under vacuum conditions, specifically, the titanium product is heated from room temperature to 1000℃~1200℃ and held at that temperature for 1h~2h under vacuum for 1h~3h, then argon gas is introduced, and the titanium product is cooled to 20℃~60℃ for 3h~5h; Second, the heat-treated titanium product is polished; Third, the polished titanium product is acid-washed to obtain a titanium product with crystalline patterns. The crystal pattern prepared by this method is smaller, not exceeding 5mm. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for preparing large-sized crystal flowers on the surface of a titanium plate, so as to prepare larger crystal flowers on the surface of the titanium plate and facilitate the control of the size of the crystal flowers, thereby meeting the needs of society.

[0005] The method for preparing large-size crystal flowers on the surface of a titanium plate according to the present invention has a titanium content ≥99wt% and a titanium phase transformation temperature T. β =880℃~890℃, the preparation process involves sequentially degreasing and removing the oxide film from the surface of the titanium plate before placing it in a heat treatment furnace at a vacuum degree ≤1.0×10 -2 Under the condition of Pa, at T βGradient cyclic heat treatment is performed at ~1200℃ and 500℃~700℃. After the gradient cyclic heat treatment is completed, the plate is cooled to below 250℃ before being removed from the furnace, resulting in a titanium plate with large-sized crystal flowers on the surface. The gradient cyclic heat treatment first involves heating to T... β Hold at ~1200℃ for 15-60 minutes, then cool down to 500℃-700℃ and hold for 10-30 minutes, then raise the temperature to T. β The temperature is maintained at ~1200℃ for 15-60 minutes, then cooled to 500℃-700℃ and maintained for 10-30 minutes. This heating-holding and cooling-holding process is repeated continuously. One heating-holding and cooling-holding cycle is defined as one cycle. Experiments show that the more cycles, the larger the size of the crystal flowers prepared on the surface of the titanium plate (see examples).

[0006] In the above method for preparing large-sized flowers on the surface of titanium plates, the gradient cyclic heat treatment is performed at least twice, and in the last cycle, at T... β After the heat preservation at ~1200℃ is completed, it is preferable to directly reduce the temperature to below 250℃ before unloading.

[0007] In the above method for preparing large-sized crystal flowers on the surface of a titanium plate, the heating rate during the gradient cyclic heat treatment is 10–60 °C / min, and the cooling rate is 10–30 °C / min.

[0008] The above-mentioned method for preparing large-sized crystal flowers on the surface of titanium plates involves immersing the titanium plate in a sodium dodecylbenzenesulfonate solution with a mass concentration of 5% to 50%, wiping off the oil stains on the surface of the titanium plate, rinsing it with tap water, and then drying it.

[0009] The above-mentioned method for preparing large-sized crystal flowers on the surface of titanium plates involves removing the oxide film from the surface of the titanium plates by immersing the degreased titanium plates in a hydrofluoric acid solution with a mass concentration of 8-12% for pickling. The pickling time is controlled to expose the silvery-white metallic luster on the surface of the titanium plates (the pickling time is usually 30s-300s). After pickling, the titanium plates are quickly rinsed with tap water to remove any residual acid and then dried.

[0010] Mechanism analysis: When titanium plates are held at or above the titanium phase transformation temperature, an α-phase to β-phase transformation occurs. However, due to the pinning effect of the hot erosion grooves (see...), the transformation is not complete. Figure 1 ,about Figure 1The concept of "pinning effect of hot erosion grooves" originates from *Fundamentals of Materials Science*, edited by Liu Zhi'en, Northwestern Polytechnical University Press, 2013, 4th edition, pp. 272-273. In heat treatment processes where the titanium phase transformation temperature is reached or higher, and the grains on the titanium plate surface are held at this temperature once, regardless of whether the heat treatment temperature or time increases, it becomes difficult for the grains to continue growing beyond a certain size. The inventors of this application have confirmed this through experiments (four titanium plates with dimensions of 0.5×50×100mm were degreased and deoxide-removed, and then subjected to a vacuum of 9.9×10⁻⁶ mm). -3 Titanium plates were obtained by holding at 882℃, 950℃, 1050℃, and 1150℃ for 1 hour at Pa, and then cooling to 100℃. The macroscopic morphology of their surfaces is as follows. Figure 2 As shown, from Figure 2 It can be seen that the macroscopic morphology of the four titanium plates is not significantly different, with average grain sizes of approximately 0.79 mm, 0.81 mm, 0.80 mm, and 0.82 mm, respectively. Two titanium plates with dimensions of 0.5 × 50 × 100 mm were subjected to degreasing and oxide film removal treatments, and then subjected to a vacuum of 9.9 × 10⁻⁶ mm. -3 The titanium plates obtained by holding at 1050℃ for 1 hour and 4 hours under Pa conditions, and then cooling to 100℃, have the following macroscopic morphology: Figure 3 As shown, from Figure 3 It can be seen that the macroscopic morphology of the two titanium plates is not significantly different, with average grain sizes of approximately 0.83 mm and 0.81 mm, respectively. This explains why the methods described in CN202210367037.2 and CN201710494148.9 produce smaller grain sizes on the surface of titanium plates or titanium products. In the method described in this invention, when the titanium plate is held at or above the titanium phase transformation temperature, an α-phase → β-phase transformation occurs. When the temperature is lowered from or above the titanium phase transformation temperature to a certain temperature below the titanium phase transformation temperature and held, lamellar α-phases with different orientations precipitate along the β-phase grain boundaries during the transformation of the β-phase into the α-phase. Therefore, during the gradient cyclic heat treatment process, α-phase → β-phase and β-phase → α-phase phase transformations continuously occur, resulting in atomic misalignment. Under the action of atomic misalignment, a large amount of subgrain boundary energy is imparted to the grains of the titanium plate. (The scanning electron microscope image obtained by polishing the titanium plate obtained by the method described in Example 1 of this invention with sandpaper, polishing it to a mirror finish with SiO2 suspension, removing stress with a vibratory polishing machine, and then collecting signals with an electron backscatter diffractometer is shown in the figure.) Figure 5 ,from Figure 5 It can be seen that a large number of subgrain boundaries are present. New thermal erosion grooves will form at these higher-energy subgrain boundaries, disrupting the pinning effect of the original thermal erosion grooves, and under the influence of a large number of subgrain boundary energies, promoting high temperatures (T). β The growth of β-phase grains in titanium plates at temperatures above T0, and the growth of these larger β-phase grains upon cooling to T0 βDuring the heat treatment at the following temperatures, a transformation from β phase to α phase occurs, and lamellar α phase clusters with different orientations will still precipitate along the grain boundaries, thus forming larger crystal flowers.

[0011] This invention also found through experiments that the pinning effect of hot erosion grooves is related to the thickness of the titanium plate. The thinner the titanium plate, the stronger the pinning effect of the hot erosion grooves, and the smaller the limiting size of the grains obtained on the surface of the titanium plate. (TA1 titanium plates with specifications of 0.5×50×100mm, 1.2×50×100mm, and 4×40×40mm were degreased and deoxide-removed, and then subjected to a vacuum of 9.9×10⁻⁶ mm.) -3 The titanium plate obtained by holding at 1050℃ for 1 hour under Pa conditions, and then cooling to 100℃, has the following macroscopic morphology: Figure 4 As shown, from Figure 4 It can be seen that the TA1 titanium plate with a thickness of 0.5 mm has the smallest grain size, with an average grain size of approximately 0.83 mm. The TA1 titanium plate with a thickness of 4 mm has the largest grain size, with an average grain size of approximately 4.41 mm. The TA1 titanium plate with a thickness of 1.2 mm has a grain size in between, with an average grain size of approximately 2.01 mm.

[0012] The method described in this invention is applicable not only to titanium plates, but also to the preparation of large-sized crystal flowers on the surface of titanium products.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] 1. This invention provides a technical solution with a different technical concept for preparing large-sized crystal flowers on the surface of titanium plates. Using the method described in this invention, crystal flowers with a size of about 48 mm were obtained (see Example 3).

[0015] 2. The method described in this invention can control the size of the crystal flowers on the surface of the titanium plate by the number of heat treatment cycles, thus making it easy to prepare crystal flowers of different sizes on the surface of the titanium plate as needed.

[0016] 3. The method described in this invention is simple in process and uses conventional equipment, which is conducive to large-scale production and thus beneficial to industrial application. Attached Figure Description

[0017] Figure 1 This is a diagram illustrating the mechanism of the hot erosion groove pinning effect.

[0018] Figure 2 These are optical photographs of a TA1 titanium plate with dimensions of 0.5×50×100mm, after being held at 882℃, 950℃, 1050℃ and 1150℃ for 1 hour (one holding time) and then cooled.

[0019] Figure 3These are optical photographs of a TA1 titanium plate with dimensions of 0.5×50×100mm, after being heated at 1050℃ for 1 hour and 4 hours (one heating cycle) and then cooled.

[0020] Figure 4 These are optical photographs of TA1 titanium plates with thicknesses of 0.5 mm, 1.2 mm, and 4 mm, after being held at 1050℃ for 1 hour (one holding time) and then cooled.

[0021] Figure 5 This is a scanning electron microscope image of the titanium plate obtained in Example 1 of the present invention. In the image, the white curved strips are subgrain boundaries.

[0022] Figure 6 This is an optical photograph of the crystal flowers prepared on the surface of a titanium plate in Embodiment 1 of the present invention.

[0023] Figure 7 This is an optical photograph of the crystal flowers prepared on the surface of a titanium plate in Embodiment 2 of the present invention.

[0024] Figure 8 This is an optical photograph of the crystal flowers prepared on the surface of a titanium plate in Embodiment 3 of the present invention.

[0025] Figure 9 This is an optical photograph of the crystal flowers prepared on the surface of a titanium plate in Embodiment 4 of the present invention.

[0026] Figure 10 This is an optical photograph of the crystal flowers prepared on the surface of a titanium plate in Embodiment 5 of the present invention.

[0027] Figure 11 This is an optical photograph of the crystal flowers prepared on the surface of a titanium plate in Embodiment 6 of the present invention. Detailed Implementation

[0028] The method for preparing large-size flowers on the surface of a titanium plate according to the present invention will be further described below through embodiments and in conjunction with the accompanying drawings. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0029] In the following examples, the titanium plate is a TA1 titanium plate with dimensions of 0.5×50×100mm and a titanium content of ≥99wt%; it is heated using a vacuum heat treatment furnace. All raw materials were purchased from the market.

[0030] Example 1

[0031] The process steps in this embodiment are as follows:

[0032] (1) Degreasing and oxide film removal treatment of titanium plates

[0033] The titanium plate was immersed in a 15% sodium dodecylbenzene sulfonate solution. After wiping off the oil stains on the surface of the titanium plate with a velvet cloth, it was rinsed with tap water and dried at 60°C. Then, the degreased titanium plate was placed in a 10% hydrofluoric acid solution for pickling for 100 seconds to remove the oxide film on the surface of the titanium plate, exposing a silvery-white metallic luster. After pickling, the titanium plate was quickly rinsed with tap water to remove any residual acid and dried at 60°C.

[0034] (2) Gradient cyclic heat treatment of titanium plates

[0035] The titanium plate after oxide film removal is placed in a heat treatment furnace, and the vacuum degree inside the furnace is controlled at 8.9 × 10⁻⁶. -3 Pa, the furnace temperature is increased from room temperature to 1050℃ at a heating rate of 17℃ / min and held for 30min, then the temperature is decreased to 700℃ at a cooling rate of 23℃ / min and held for 15min; then the temperature is increased from 700℃ to 1050℃ at a heating rate of 17℃ / min and held for 30min, then the temperature is decreased to 200℃ at a cooling rate of 27℃ / min and removed to cool naturally at room temperature.

[0036] After the above two gradient cycle heat treatments, the crystal flowers prepared on the surface of the TA1 titanium plate in this embodiment are as follows: Figure 6 As shown, from Figure 6 It can be seen that the macroscopic grain morphology is clear and the average grain size is about 8.99 mm.

[0037] Example 2

[0038] The process steps in this embodiment are as follows:

[0039] (1) Degreasing and oxide film removal treatment of titanium plates

[0040] The titanium plate was immersed in a 15% sodium dodecylbenzene sulfonate solution. After wiping off the oil stains on the surface of the titanium plate with a velvet cloth, it was rinsed with tap water and dried at 60°C. Then, the degreased titanium plate was placed in a 10% hydrofluoric acid solution for pickling for 100 seconds to remove the oxide film on the surface of the titanium plate, exposing a silvery-white metallic luster. After pickling, the titanium plate was quickly rinsed with tap water to remove any residual acid and dried at 60°C.

[0041] (2) Gradient cyclic heat treatment of titanium plates

[0042] The titanium plate, after oxide film removal treatment, is placed in a heat treatment furnace, and the vacuum degree inside the furnace is controlled at 7.9 × 10⁻⁶. -3Pa, the furnace temperature is increased from room temperature to 1050℃ at a heating rate of 17℃ / min and held for 30 min, then the temperature is decreased to 650℃ at a cooling rate of 27℃ / min and held for 15 min; then the temperature is increased from 650℃ to 1050℃ at a heating rate of 13℃ / min and held for 30 min, then the temperature is decreased to 650℃ at a cooling rate of 27℃ / min and held for 15 min; then the temperature is increased from 650℃ to 1050℃ at a heating rate of 13℃ / min and held for 30 min, then the temperature is decreased to 180℃ at a cooling rate of 27℃ / min and removed to cool naturally at room temperature.

[0043] After the above three gradient cycle heat treatments, the crystal flowers prepared on the surface of the TA1 titanium plate in this embodiment are as follows: Figure 7 As shown, from Figure 7 It can be seen that the macroscopic grain morphology is clear and the average grain size is about 22.04 mm.

[0044] Example 3

[0045] The process steps in this embodiment are as follows:

[0046] (1) Degreasing and oxide film removal treatment of titanium plates

[0047] The titanium plate was immersed in a 15% sodium dodecylbenzene sulfonate solution. After wiping off the oil stains on the surface of the titanium plate with a velvet cloth, it was rinsed with tap water and dried at 60°C. Then, the degreased titanium plate was placed in a 10% hydrofluoric acid solution for pickling for 100 seconds to remove the oxide film on the surface of the titanium plate, exposing a silvery-white metallic luster. After pickling, the titanium plate was quickly rinsed with tap water to remove any residual acid and dried at 60°C.

[0048] (2) Gradient cyclic heat treatment of titanium plates

[0049] The titanium plate, after oxide film removal treatment, is placed in a heat treatment furnace, and the vacuum degree inside the furnace is controlled at 8.3 × 10⁻⁶. -3 Pa: The furnace temperature is increased from room temperature to 1050℃ at a heating rate of 17℃ / min and held for 30 min, then decreased to 650℃ at a cooling rate of 27℃ / min and held for 15 min; then increased to 1050℃ at a heating rate of 13℃ / min and held for 30 min, then decreased to 650℃ at a cooling rate of 27℃ / min and held for 15 min; then increased to 1050℃ at a heating rate of 13℃ / min and held for 30 min, then decreased to 650℃ at a cooling rate of 27℃ / min and held for 15 min; then increased to 1050℃ at a heating rate of 13℃ / min and held for 30 min, then decreased to 650℃ at a cooling rate of 27℃ / min and held for 15 min; then increased to 1050℃ at a heating rate of 13℃ / min and held for 30 min, then decreased to 180℃ at a cooling rate of 27℃ / min and removed to allow to cool naturally at room temperature.

[0050] After the above four gradient cycle heat treatments, the crystal flowers prepared on the surface of the TA1 titanium plate in this embodiment are as follows: Figure 8 As shown, from Figure 8 It can be seen that the macroscopic grain morphology is clear and the average grain size is about 48.16 mm.

[0051] Example 4

[0052] The process steps in this embodiment are as follows:

[0053] (1) Degreasing and oxide film removal treatment of titanium plates

[0054] The titanium plate was immersed in a 15% sodium dodecylbenzene sulfonate solution. After wiping off the oil stains on the surface of the titanium plate with a velvet cloth, it was rinsed with tap water and dried at 60°C. Then, the degreased titanium plate was placed in a 10% hydrofluoric acid solution for pickling for 100 seconds to remove the oxide film on the surface of the titanium plate, exposing a silvery-white metallic luster. After pickling, the titanium plate was quickly rinsed with tap water to remove any residual acid and dried at 60°C.

[0055] (2) Gradient cyclic heat treatment of titanium plates

[0056] The titanium plate, after oxide film removal treatment, is placed in a heat treatment furnace, and the vacuum degree inside the furnace is controlled at 1.0 × 10⁻⁶. -2 Pa, the furnace temperature is increased from room temperature to 1150℃ at a heating rate of 16℃ / min and held for 30min, then the temperature is decreased to 700℃ at a cooling rate of 22.5℃ / min and held for 15min; then the temperature is increased from 700℃ to 1150℃ at a heating rate of 11℃ / min and held for 30min, then the temperature is decreased to 150℃ at a cooling rate of 18℃ / min and removed to cool naturally at room temperature.

[0057] After the above two gradient cycle heat treatments, the crystal flowers prepared on the surface of the TA1 titanium plate in this embodiment are as follows: Figure 9 As shown, from Figure 9 It can be seen that the macroscopic grain morphology is clear and the average grain size is about 13.84 mm.

[0058] Example 5

[0059] The process steps in this embodiment are as follows:

[0060] (1) Degreasing and oxide film removal treatment of titanium plates

[0061] The titanium plate was immersed in a 15% sodium dodecylbenzene sulfonate solution. After wiping off the oil stains on the surface of the titanium plate with a velvet cloth, it was rinsed with tap water and dried at 60°C. Then, the degreased titanium plate was placed in a 10% hydrofluoric acid solution for pickling for 100 seconds to remove the oxide film on the surface of the titanium plate, exposing a silvery-white metallic luster. After pickling, the titanium plate was quickly rinsed with tap water to remove any residual acid and dried at 60°C.

[0062] (2) Gradient cyclic heat treatment of titanium plates

[0063] The titanium plate, after oxide film removal treatment, is placed in a heat treatment furnace, and the vacuum degree inside the furnace is controlled at 9.3 × 10⁻⁶. -3 Pa, the furnace temperature is increased from room temperature to 882℃ at a heating rate of 17℃ / min and held for 30min, then the temperature is decreased to 500℃ at a cooling rate of 19℃ / min and held for 15min; then the temperature is increased from 500℃ to 882℃ at a heating rate of 15℃ / min and held for 60min, then the temperature is decreased to 150℃ at a cooling rate of 21℃ / min and removed to cool naturally at room temperature.

[0064] After the above two gradient cycle heat treatments, the crystal flowers prepared on the surface of the TA1 titanium plate in this embodiment are as follows: Figure 10 As shown, from Figure 10 It can be seen that the macroscopic grain morphology is clear and the average grain size is about 5.59 mm.

[0065] Example 6

[0066] The process steps in this embodiment are as follows:

[0067] (1) Degreasing and oxide film removal treatment of titanium plates

[0068] The titanium plate was immersed in a 15% sodium dodecylbenzene sulfonate solution. After wiping off the oil stains on the surface of the titanium plate with a velvet cloth, it was rinsed with tap water and dried at 60°C. Then, the degreased titanium plate was placed in a 10% hydrofluoric acid solution for 60 seconds to pickle the oxide film on the surface of the titanium plate, exposing a silvery-white metallic luster. After pickling, the titanium plate was quickly rinsed with tap water to remove any residual acid and dried at 60°C.

[0069] (2) Gradient cyclic heat treatment of titanium plates

[0070] The titanium plate after oxide film removal is placed in a heat treatment furnace, and the vacuum degree inside the furnace is controlled at 6.8 × 10⁻⁶. -3Pa, the furnace temperature is increased from room temperature to 950℃ at a heating rate of 15℃ / min and held for 60min, then the temperature is decreased to 600℃ at a cooling rate of 16℃ / min and held for 15min; then the temperature is increased from 600℃ to 950℃ at a heating rate of 15℃ / min and held for 60min, then the temperature is decreased to 150℃ at a cooling rate of 10℃ / min and removed to cool naturally at room temperature.

[0071] After the above two gradient cycle heat treatments, the crystal flowers prepared on the surface of the TA1 titanium plate in this embodiment are as follows: Figure 11 As shown, from Figure 11 It can be seen that the macroscopic grain morphology is clear and the average grain size is about 13.91 mm.

Claims

1. A method for preparing large-size crystal flowers on the surface of a titanium plate, the titanium content of the titanium plate being ≥ 99 wt%, the titanium phase transition temperature T β = 880℃ ~ 890℃, characterized in that The preparation process is that the titanium plate surface is sequentially subjected to oil removal and oxide film removal treatment, and then is placed into a heat treatment furnace, and is subjected to gradient cycle heat treatment at T -2 Pa, and is cooled to below 250 DEG C to be discharged from the furnace, so that the titanium plate with large-size crystal flowers on the surface is obtained. β The gradient cycle heat treatment is that the temperature is first increased to T β ~1200 DEG C, is maintained for 15 min to 60 min, is then decreased to 500 DEG C to 700 DEG C, is maintained for 10 min to 30 min, is then increased to T β ~1200 DEG C again, is maintained for 15 min to 60 min, is then decreased to 500 DEG C to 700 DEG C, is maintained for 10 min to 30 min, and the above-mentioned temperature increasing-maintaining, temperature decreasing-maintaining is repeatedly performed, the cycle number of the gradient cycle heat treatment is at least two times, and after the temperature maintaining at T β ~1200 DEG C in the last cycle, the temperature is directly decreased to below 250 DEG C to be discharged from the furnace.

2. The method of claim 1, wherein the titanium plate is heated to a temperature of 800- 1000°C. During gradient cyclic heat treatment, the heating rate is 10 ~ 60℃ / min and the cooling rate is 10 ~ 30℃ / min.

3. The method of claim 1 or 2, wherein The degreasing treatment of titanium plate surface involves immersing the titanium plate in a sodium dodecylbenzene sulfonate solution with a mass concentration of 5%~50%, wiping off the oil stains on the titanium plate surface, rinsing with tap water, and then drying.

4. The method of claim 1 or 2, wherein The process of removing the oxide film from the surface of titanium plates involves immersing the degreased titanium plates in a hydrofluoric acid solution with a mass concentration of 8-12% for pickling. The pickling time is controlled until the surface of the titanium plates reveals a silvery-white metallic luster. After pickling, the titanium plates are quickly rinsed with tap water to remove any residual acid and then dried.

5. The method for preparing large-size flowers on the surface of a titanium plate according to claim 3, characterized in that... The process of removing the oxide film from the surface of titanium plates involves immersing the degreased titanium plates in a hydrofluoric acid solution with a mass concentration of 8-12% for pickling. The pickling time is controlled until the surface of the titanium plates reveals a silvery-white metallic luster. After pickling, the titanium plates are quickly rinsed with tap water to remove any residual acid and then dried.

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