Super-corrosion-resistant titanium alloy wire and preparation method thereof

Abstract

The application discloses a kind of super corrosion-resistant titanium alloy wire and preparation method thereof, and is related to metal coating technical field.The application specifically includes the following steps:S1: titanium alloy bar is sequentially pretreated, multi-pass drawing, heat treatment, fine drawing, secondary heat treatment, finishing, detection, winding, and titanium alloy wire base material is obtained;S2: titanium alloy wire base material is pretreated, and pretreated titanium alloy wire base material is obtained;S3: corrosion-resistant coating is uniformly sprayed on pretreated titanium alloy wire base material, heat treatment is carried out, corrosion-resistant coating layer is formed, and super corrosion-resistant titanium alloy wire is obtained.The corrosion-resistant coating is obtained by mixing the following weight fractions of raw material components: modified polyether ether ketone 100 parts, polyimide 5 parts to 15 parts, polyetherimide 15 parts to 25 parts, graphite 5 parts to 15 parts, leveling agent 1 part to 3 parts, ultraviolet absorber 0.8 parts to 1.2 parts, and antioxidant 0.5 parts to 1 part.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of metal coating, in particular to a super-corrosion-resistant titanium alloy wire and a preparation method thereof. BACKGROUND

[0002] Titanium alloy has been widely used in aerospace, ocean engineering, biomedical, chemical equipment and other high-end fields due to its high specific strength, excellent biocompatibility and non-magnetic characteristics. In the field of aerospace, titanium alloy wire is used to manufacture engine fasteners and fuselage framework connectors, and its corrosion resistance directly affects the service safety of aircraft. In ocean engineering, titanium alloy wire is used as a marine platform cable and underwater instrument connector, which needs to withstand the corrosion of high-salinity seawater for a long time. In the biomedical field, titanium alloy wire is used for orthopedic implants and dental restorations, which need to maintain stable corrosion resistance and biocompatibility in a body fluid environment.

[0003] However, the existing titanium alloy wire still has performance short boards in extreme corrosion environments: in marine environments or strong acid and alkali media containing high concentrations of Cl - , ordinary pure titanium and conventional titanium alloys such as TC4 are prone to pitting corrosion and crevice corrosion, leading to degradation of mechanical properties and even early failure. In high-temperature and high-pressure corrosion environments, the oxide film is prone to peeling, losing its protective effect. At the same time, traditional titanium alloy wire is prepared by the process of "melting and ingot casting-forging and breaking down-multi-pass rolling-drawing", which has problems such as composition segregation and uneven structure, further leading to fluctuations in the corrosion resistance of titanium alloy wire.

[0004] To improve corrosion resistance, existing technologies often use surface coating, anodic oxidation and other post-processing techniques, but the surface treatment layer is easily damaged and quickly fails during processing or service.

[0005] Therefore, the present application provides a super-corrosion-resistant titanium alloy wire to ensure the long-term stable corrosion resistance of titanium alloy wire, thereby meeting the harsh service requirements in related fields, which is of great significance. SUMMARY

[0006] The present application aims to provide a super-corrosion-resistant titanium alloy wire and a preparation method thereof to solve the problems raised in the background.

[0007] To solve the above technical problems, the present application provides the following technical solutions:

[0008] A preparation method of a super-corrosion-resistant titanium alloy wire, comprising the following steps:

[0009] S1: titanium alloy bar is sequentially pretreated, multi-pass drawn, once heat treated, fine drawn, twice heat treated, finished, detected and wound to obtain a titanium alloy wire base material;

[0010] S2: the titanium alloy wire substrate is pretreated to obtain a pretreated titanium alloy wire substrate;

[0011] S3: uniformly spraying the corrosion-resistant coating on the pretreated titanium alloy wire substrate, and performing heat treatment to form a corrosion-resistant coating layer, thereby obtaining the super-corrosion-resistant titanium alloy wire.

[0012] Further, in S1, the pretreatment comprises, in sequence, skin turning, alkali washing, acid washing, and water washing;

[0013] The skin turning has a turning depth of ≥0.3 mm;

[0014] The alkali washing comprises: after the skin turning, washing the titanium alloy bar with an alkali washing solution at 80-100°C for 10-20 min to complete the alkali washing; the alkali washing solution comprises the following components at the following concentrations: 80-120 g / L sodium hydroxide and 50-80 g / L sodium nitrate, and water is used as the solvent;

[0015] The acid washing comprises: after the alkali washing, washing the titanium alloy bar with an acid washing solution at room temperature for 3-8 min to complete the acid washing; the acid washing solution comprises the following components at the following concentrations: 50-80 mL / L hydrofluoric acid and 150-200 mL / L nitric acid, and water is used as the solvent;

[0016] The water washing comprises: after the acid washing, washing the titanium alloy bar with flowing water at room temperature for 5-10 min, and vacuum drying to complete the water washing.

[0017] Further, the process parameters of the multi-pass drawing are as follows: a single-pass diameter reduction rate of 10-15%, a drawing speed of 10-30 m / min, a die cone angle of 8-12°, and a total deformation amount controlled to be 60-70%;

[0018] The process parameters of the fine drawing are as follows: a dimensional accuracy of ±0.003 mm for titanium alloy wire substrates with a diameter of 0.1-1 mm, a dimensional accuracy of ±0.01 mm for titanium alloy wire substrates with a diameter of 1-6 mm, and a total deformation amount controlled to be ≤90%;

[0019] A lubricant needs to be coated before the multi-pass drawing and the fine drawing;

[0020] Further, the first heat treatment is annealing, and the process parameters of the annealing are as follows: an annealing temperature of 700-750°C, an annealing time of 30-60 min, and air cooling to room temperature;

[0021] If the titanium alloy bar is an α alloy, the secondary heat treatment is an annealing treatment, and its process parameters are: annealing temperature of 700℃~800℃, annealing time of 30min~60min, and air cooling to room temperature;

[0022] If the titanium alloy bar is an α+β alloy or a β alloy, the secondary heat treatment is solution treatment and aging treatment, and the process parameters are: solution treatment temperature is 880℃~950℃, water quenching; aging treatment temperature is 450℃~500℃, holding for 6h~12h, and air cooling to room temperature.

[0023] Furthermore, the finishing process involves polishing to a surface roughness Ra ≤ 0.4 μm.

[0024] Furthermore, in S2, the pretreatment includes cleaning and activation.

[0025] The cleaning process involves cleaning the titanium alloy wire substrate with a neutral degreasing agent at 40℃~60℃ for 10min~20min; then cleaning the titanium alloy wire substrate with running water at room temperature for 5min~10min, followed by vacuum drying to complete the cleaning process.

[0026] The activation treatment is as follows: the titanium alloy wire substrate is activated by plasma technology to obtain a pretreated titanium alloy wire substrate; the process parameters of plasma technology are: Ar / O2 (1:1) mixed gas flow rate is 100mL / min~200mL / min; gas pressure is 5Pa~10Pa; discharge power is 100W~150W; plasma treatment time is 2min~4min.

[0027] Furthermore, the modified polyetheretherketone is prepared as follows:

[0028] (1) Under nitrogen protection, polyether ether ketone and sodium borohydride were added to dimethyl sulfoxide, stirred and heated to 115℃~125℃ for 8h~12h, the reaction was stopped, excess ice water was added to the reaction solution, the precipitate was precipitated, and after separation and purification, the hydroxyl content was determined by acid-base titration to obtain hydroxylated polyether ether ketone with a hydroxyl content of 1.5wt%~3wt%;

[0029] (2) Under nitrogen protection, 2,4-dihydroxybenzophenone, 2-bromo-N-(bromoethyl)ethylamine and tetrabutylammonium bromide were added to a 50wt% sodium hydroxide aqueous solution, stirred and mixed evenly, and reacted at 55℃~65℃ for 4h~12h. The reaction was then stopped and the mixture was set aside for later use.

[0030] (3) Add hydroxylated polyether ether ketone to N,N-dimethylformamide, stir and heat to 55℃~65℃, dissolve to obtain hydroxylated polyether ether ketone solution; slowly add hydroxylated polyether ether ketone solution to (2), continue stirring at 55℃~65℃ for 4h~12h, stop the reaction, add excess ice water to the reaction solution, precipitate out, and after separation and purification, obtain benzophenone-polyether ether ketone;

[0031] (4) Under nitrogen protection, benzophenone-polyether ether ketone, isocyanate-based silane coupling agent and dibutyltin dilaurate were added to N,N-dimethylformamide, stirred and heated to 70℃~85℃ for 1h~6h, the product was collected by vacuum distillation, washed with water and ground into powder of 20μm~30μm, the powder was then placed in 75wt% ethanol aqueous solution and soaked for 30min~60min, and then vacuum dried to obtain modified polyether ether ketone.

[0032] Furthermore, the ratio of the amounts of polyetheretherketone, sodium borohydride, and dimethyl sulfoxide added is 1g:(0.1~0.2)g:10mL.

[0033] Furthermore, the molar ratio of the amounts of 2,4-dihydroxybenzophenone, 2-bromo-N-(bromoethyl)ethylamine, and tetrabutylammonium bromide is 1:1:0.01; the ratio of the amount of sodium hydroxide aqueous solution added to the weight of the solute is 1 mL:1 g.

[0034] Furthermore, the amount of hydroxylated polyether ether ketone added is 5 times the weight of 2,4-dihydroxybenzophenone added.

[0035] Furthermore, the ratio of the amounts of benzophenone-polyetheretherketone, isocyanate-based silane coupling agent, dibutyltin dilaurate, and N,N-dimethylformamide is 1g:(0.1~0.2)g:(0.005~0.01)g:10mL.

[0036] Furthermore, the isocyanate-based silane coupling agent is any one of 3-isocyanate-propyltrimethoxysilane and 3-isocyanate-propyltriethoxysilane.

[0037] Furthermore, the corrosion-resistant coating is obtained by mixing the following raw material components in parts by weight: 100 parts modified polyether ether ketone, 5 to 15 parts polyimide, 15 to 25 parts polyether imide, 5 to 15 parts graphite, 1 to 3 parts leveling agent, 0.8 to 1.2 parts ultraviolet absorber, and 0.5 to 1 part antioxidant.

[0038] Furthermore, the particle size of each raw material component of the corrosion-resistant coating is 20μm~30μm.

[0039] Furthermore, the spraying is electrostatic spraying, and its process parameters are: spraying voltage of 60kV~90kV and spraying thickness of 50μm~100μm.

[0040] Furthermore, the parameters of the heat treatment are: holding temperature of 340℃~370℃, holding time of 15min~30min, and air cooling to room temperature.

[0041] Furthermore, the super corrosion-resistant titanium alloy wire prepared by the aforementioned method is a super corrosion-resistant titanium alloy wire.

[0042] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0043] (1) In this invention, the titanium alloy rods are first pretreated by peeling, alkaline washing, and acid washing to remove the surface defect layer, oil stains, and oxide scale, providing a clean surface for subsequent drawing. To avoid damage during the drawing process, a multi-pass drawing process is adopted to control the drawing parameters and balance drawing efficiency and quality. After drawing, annealing is performed to eliminate drawing defects. Then, after precision drawing, heat treatment, and finishing, a high-quality titanium alloy wire substrate is obtained. Compared with the traditional "melting and casting ingot - forging and billet opening - multi-pass rolling - wire drawing" process, the adjusted drawing process of this invention can better eliminate stress defects generated during the drawing process, resulting in better and more stable comprehensive performance of the processed titanium alloy wire substrate.

[0044] (2) After cleaning the titanium alloy wire substrate, it is then activated. The activation treatment can introduce oxygen-containing functional groups into the titanium alloy wire substrate, which can form a strong bond with the subsequent corrosion-resistant coating, thereby reducing the risk of corrosion-resistant layer peeling and delamination, and extending the corrosion resistance life of the titanium alloy wire substrate.

[0045] (3) In this invention, polyetheretherketone is first hydroxylated, and its hydroxyl content is ensured to be 1.5~3wt%. On the one hand, the polyetheretherketone is effectively hydroxylated, which facilitates the subsequent grafting of sufficient benzophenone structure onto the polyetheretherketone. On the other hand, it can effectively avoid the low degree of hydroxylation, which leads to insufficient modification of polyetheretherketone. It can also avoid the high degree of hydroxylation, which leads to the deterioration of the physical properties of polyetheretherketone and the risk of crosslinking, which is not conducive to subsequent spray coating. Then, the hydroxyl group at the para position of 2,4-dihydroxybenzophenone undergoes a nucleophilic substitution reaction with 2-bromo-N-(bromoethyl)ethylamine. By controlling the molar ratio of the two, an intermediate product retaining one bromine is prepared. Then, it undergoes a nucleophilic substitution reaction with hydroxylated polyetheretherketone. Due to the control of the hydroxyl content of hydroxylated polyetheretherketone mentioned above, benzophenone-polyetheretherketone grafted with sufficient benzophenone structure is finally prepared. Subsequently, the residual hydroxyl groups and remaining imino groups of benzophenone-polyetheretherketone (PEEEK) and the isocyanate groups of 3-isocyanatopropyltriethoxysilane are reacted, followed by immersion in an aqueous ethanol solution for hydrolysis, to prepare modified PEEK. The modified PEEK contains a large number of benzophenone structures and silane segments. The benzophenone structure effectively improves the poor UV resistance of PEEK, thereby ensuring the weather resistance of the corrosion-resistant coating layer and endowing the titanium alloy wire with long-term effective corrosion resistance. The silane segments, in conjunction with the initial activation treatment of the titanium alloy wire substrate, greatly ensure the adhesion between the corrosion-resistant coating layer and the titanium alloy substrate.

[0046] (4) The modified polyether ether ketone, polyimide, polyetherimide, graphite, leveling agent, ultraviolet absorber, and antioxidant are mixed evenly to obtain a corrosion-resistant coating. Polyimide and graphite are added to the corrosion-resistant coating to synergistically modify polyether ether ketone and enhance the corrosion resistance of the coating. Considering that polyether ether ketone itself has high rigidity, the further introduction of polyimide and graphite, two high-rigidity materials, will make the film layer formed easily cracked due to external impact or defects in the film formation process. Therefore, in this invention, polyetherimide is further added to replace most of the polyimide. Although its corrosion resistance is not as good as that of polyimide, it contains ether bonds, which can enhance the flexibility of the film layer molecules and help to obtain a corrosion-resistant coating layer with better overall quality. The subsequent addition of relevant additives, such as leveling agent, ultraviolet absorber, and antioxidant, further improves the quality and related properties of the corrosion-resistant coating layer.

[0047] In summary, this invention achieves a comprehensive preparation of an ultra-corrosion-resistant titanium alloy wire through the synergistic effect of adjusting the drawing process of the titanium rod, activating the titanium alloy wire substrate, and applying a corrosion-resistant coating layer. Furthermore, the corrosion-resistant coating layer on the ultra-corrosion-resistant titanium alloy wire exhibits good weather resistance and adhesion, thus providing long-term and effective protection for the titanium alloy wire. Detailed Implementation

[0048] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0049] It should be noted that the following quantities are by weight, and there are no special restrictions on the suppliers of all raw materials involved in this invention. Exemplary examples include:

[0050] In the following embodiments, the titanium alloy rod is of grade Ti6Al4V ELI and has a diameter of 9 mm;

[0051] Polyetheretherketone (PEEK), 99% pure, product number JSPL-PEEK-001, purchased from Jiangsu Puli New Materials Co., Ltd.

[0052] 2,4-Dihydroxybenzophenone, purity 99%; 2-bromo-N-(bromoethyl)ethylamine, purity 99%; 3-isocyanatopropyltriethoxysilane, purity 99%; leveling agent BYK-333; UV absorber UV-531; antioxidant 1010; graphite, purity 99%; all purchased from Shanghai Maclean Reagent Co., Ltd.

[0053] Polyimide, 99% purity, item number 62929-02-6, purchased from Hubei Yongkuo Technology Co., Ltd.

[0054] Polyetherimide, 99% purity, catalog number 700193, purchased from Merck Reagents Ltd.; other raw materials were commercially available; each serving is 10g.

[0055] Preliminary preparations:

[0056] 1. Alkaline washing solution: The alkaline washing solution consists of the following components at the following concentrations: 100g / L sodium hydroxide, 65g / L sodium nitrate, and water as the solvent;

[0057] 2. Pickling solution: The pickling solution consists of the following components at the following concentrations: 65 mL / L hydrofluoric acid, 175 mL / L nitric acid, and water as the solvent.

[0058] Example 1: A method for preparing an ultra-corrosion-resistant titanium alloy wire:

[0059] S1: Titanium alloy bars are sequentially pretreated, drawn in multiple passes, heat treated once, fine drawn, heat treated twice, finished, inspected, and wound to obtain titanium alloy wire substrate;

[0060] Pretreatment: Ti6Al4V ELI titanium alloy bars with a diameter of 9mm were peeled and turned to a depth of 0.3mm; then, the titanium alloy bars were cleaned with an alkaline solution at 90℃ for 15 minutes to complete the alkaline cleaning treatment; then, the titanium alloy bars were cleaned with an acid pickling solution at room temperature for 5 minutes to complete the acid pickling treatment; finally, the titanium alloy bars were cleaned with running water at room temperature for 10 minutes and vacuum dried at 80℃ to complete the water washing treatment.

[0061] Multi-pass drawing: A 5μm thick layer of calcium stearate is uniformly coated on the pretreated titanium alloy bar, and multi-pass drawing is performed. The process parameters are: single-pass diameter reduction rate of 12%, drawing speed of 20m / min, die cone angle of 10°, and total deformation controlled at 65%.

[0062] First heat treatment: The titanium alloy wire obtained by multiple drawing processes is heated to 725℃, held for 45 minutes, and then air-cooled to room temperature;

[0063] Precision drawing: A 5μm thick layer of calcium stearate is uniformly coated on the titanium alloy wire after heat treatment, and then precision drawn into a titanium alloy wire with a diameter of 3mm, with the tolerance controlled within ±0.01mm.

[0064] Secondary heat treatment: The titanium alloy wire obtained by precision drawing is heated to 900℃, water quenched, then heated to 475℃, held for 9 hours, and air cooled to room temperature;

[0065] Finishing: Polish the secondary treated titanium alloy wire to Ra=0.39±0.01μm;

[0066] S2: The titanium alloy wire substrate is pretreated to obtain the pretreated titanium alloy wire substrate;

[0067] Pretreatment: The titanium alloy wire substrate was immersed in 5wt% CT-213A neutral degreasing agent at 50℃ for 15 min; then, it was cleaned with running water at room temperature for 10 min, and vacuum dried at 80℃ to complete the cleaning process; next, the titanium alloy wire substrate was activated by plasma technology to obtain pretreated titanium alloy wire substrate; the process parameters of plasma technology were: Ar / O2 (1:1) mixed gas flow rate of 150 mL / min; gas pressure of 8 Pa; discharge power of 125 W; plasma treatment time of 3 min;

[0068] S3: The corrosion-resistant coating is evenly sprayed onto the pretreated titanium alloy wire substrate, and after heat treatment, a corrosion-resistant coating layer is formed to obtain an ultra-corrosion-resistant titanium alloy wire.

[0069] Preparation of modified polyether ether ketone: (1) Under nitrogen protection, 110 parts of polyether ether ketone and 16.5 parts of sodium borohydride were added to 11 L of dimethyl sulfoxide, stirred and heated to 120 °C for 10 h, the reaction was stopped, excess ice water was added to the reaction solution, the precipitate was precipitated, and after separation and purification, 2 g of the product was taken and its hydroxyl content was determined by acid-base titration to obtain hydroxylated polyether ether ketone with a hydroxyl content of 2.56 wt%; (2) Under nitrogen protection, 1 mol of 2,4-dihydroxybenzophenone, 1 mol of 2-bromo-N-(bromoethyl)ethylamine and 0.01 mol of tetrabutylammonium bromide were added to 767 mL of 50 wt% sodium hydroxide aqueous solution, stirred and mixed evenly, and stirred at 60 °C for 8 h, the reaction was stopped and the product was set aside; (3) 107 parts of hydroxylated polyether ether ketone were added to 214 parts of N, In N-dimethylformamide, the mixture was stirred and heated to 60°C to dissolve and obtain a hydroxylated polyether ether ketone solution. The hydroxylated polyether ether ketone solution was slowly added to (2), and the mixture was stirred and reacted at 60°C for 8 hours. The reaction was then stopped, and excess ice water was added to the reaction solution to precipitate the precipitate. After separation and purification, benzophenone-polyether ether ketone was obtained. (4) Under nitrogen protection, 100 parts of benzophenone-polyether ether ketone, 15 parts of 3-isocyanate-propyltriethoxysilane, and 0.75 parts of dibutyltin dilaurate were added to 10L of N,N-dimethylformamide. The mixture was stirred and heated to 75°C for 4 hours. The product was collected by vacuum distillation, washed with deionized water, and ground into a 25μm powder. The powder was then placed in a 75wt% ethanol aqueous solution and soaked for 45 minutes. After vacuum drying, the modified polyether ether ketone was obtained.

[0070] Preparation of corrosion-resistant coating: Mix 100 parts of modified polyether ether ketone, 10 parts of polyimide, 20 parts of polyether imide, 10 parts of graphite, 2 parts of leveling agent BYK-333, 1 part of ultraviolet absorber UV-531, and 0.75 parts of antioxidant 1010 evenly to obtain corrosion-resistant coating.

[0071] Spraying: The corrosion-resistant coating is uniformly sprayed onto the pretreated titanium alloy wire substrate using electrostatic spraying. The spraying parameters are: spraying voltage of 75kV and spraying thickness of 75μm.

[0072] Heat treatment: The pretreated titanium alloy wire substrate coated with corrosion-resistant paint is heated to 355℃, held for 20 minutes, and then air-cooled to room temperature to form a corrosion-resistant coating layer, thus obtaining ultra-corrosion-resistant titanium alloy wire.

[0073] Example 2: Example 2 is based on Example 1, but with adjustments made to the raw material composition of the corrosion-resistant coating, while other processes remain unchanged. Specifically:

[0074] Preparation of corrosion-resistant coating: Mix 100 parts of modified polyether ether ketone, 5 parts of polyimide, 15 parts of polyether imide, 5 parts of graphite, 2 parts of leveling agent BYK-333, 1 part of ultraviolet absorber UV-531, and 0.75 parts of antioxidant 1010 evenly to obtain corrosion-resistant coating.

[0075] Example 3: Example 3 is based on Example 1, but with adjustments made to the raw material composition of the corrosion-resistant coating, while keeping other processes unchanged. Specifically:

[0076] Preparation of corrosion-resistant coating: Mix 100 parts of modified polyether ether ketone, 15 parts of polyimide, 25 parts of polyether imide, 15 parts of graphite, 2 parts of leveling agent BYK-333, 1 part of ultraviolet absorber UV-531, and 0.75 parts of antioxidant evenly to obtain corrosion-resistant coating.

[0077] The following is a control experiment based on Example 1, with comparative examples 1 to 5, as detailed below:

[0078] Comparative Example 1: Comparative Example 1 is based on Example 1, with the following adjustments: the titanium alloy wire substrate is obtained only through multiple drawing passes, without any intermediate heat treatment, while other processes remain unchanged, as follows:

[0079] S1: Pretreatment: The titanium alloy bar with grade Ti6Al4V ELI and φ of 9mm was peeled and turned to a depth of 0.3mm; then, it was cleaned with alkaline solution at 90℃ for 15min to complete the alkaline cleaning treatment; then, it was cleaned with acid pickling solution at room temperature for 5min to complete the acid pickling treatment; finally, it was cleaned with running water at room temperature for 10min and vacuum dried at 80℃ to complete the water washing treatment.

[0080] Multi-pass drawing: A 5μm thick layer of calcium stearate is uniformly coated on the pretreated titanium alloy bar, and multi-pass drawing is performed. The process parameters are: single-pass diameter reduction rate of 12%, drawing speed of 20m / min, die cone angle of 10°, and titanium alloy wire with φ of 3mm is obtained by drawing, with tolerance controlled within ±0.01mm.

[0081] Heat treatment: The titanium alloy wire obtained by multiple drawing passes is heated to 900℃, water quenched, then heated to 475℃, held for 9 hours, and air cooled to room temperature.

[0082] Finishing: Polish the titanium alloy wire after secondary treatment to Ra=0.39±0.01μm.

[0083] Comparative Example 2: Comparative Example 2 is based on Example 1, with the following adjustment: the titanium alloy wire substrate is not activated, while other processes remain unchanged. Specifically:

[0084] S2: The titanium alloy wire substrate is pretreated to obtain the pretreated titanium alloy wire substrate;

[0085] Pretreatment: The titanium alloy wire substrate was immersed in 5wt% CT-213A neutral degreasing agent at 50℃ for 15 minutes; then, the titanium alloy wire substrate was cleaned with running water at room temperature for 10 minutes, and vacuum dried at 80℃ to complete the cleaning process.

[0086] Comparative Example 3: Comparative Example 3 is based on Example 1, with the following adjustment: no modification treatment is performed on polyetheretherketone, while other processes remain unchanged. Specifically:

[0087] Preparation of corrosion-resistant coating: Mix 100 parts of polyetheretherketone, 10 parts of polyimide, 20 parts of polyetherimide, 10 parts of graphite, 2 parts of leveling agent BYK-333, 1 part of ultraviolet absorber UV-531, and 0.75 parts of antioxidant 1010 evenly to obtain corrosion-resistant coating.

[0088] Comparative Example 4: Comparative Example 4 is based on Example 1, with the following adjustment: polyetherimide is not used to replace polyimide, while other processes remain unchanged. Specifically:

[0089] Preparation of corrosion-resistant coating: Mix 100 parts of modified polyether ether ketone, 30 parts of polyimide, 10 parts of graphite, 2 parts of leveling agent BYK-333, 1 part of ultraviolet absorber UV-531, and 0.75 parts of antioxidant 1010 evenly to obtain corrosion-resistant coating.

[0090] Comparative Example 5: Comparative Example 5 is based on Example 1, with the following adjustment: benzophenone-polyetheretherketone is used as the raw material for the corrosion-resistant coating, while other processes remain unchanged. Specifically:

[0091] Preparation of corrosion-resistant coating: Mix 100 parts of benzophenone-polyetheretherketone, 10 parts of polyimide, 20 parts of polyetherimide, 10 parts of graphite, 2 parts of leveling agent BYK-333, 1 part of ultraviolet absorber UV-531, and 0.75 parts of antioxidant 1010 evenly to obtain corrosion-resistant coating.

[0092] Performance testing: Tensile properties were tested on the titanium alloy wire substrates prepared in Example 1 and Comparative Example 1; adhesion, corrosion resistance, and UV resistance were tested on the ultra-corrosion-resistant titanium alloy wires prepared in Examples 1-3 and Comparative Examples 2-5. The specific test methods are as follows:

[0093] (1) Tensile property test: Tensile property test was conducted using a universal testing machine at 23℃ and 50% relative humidity, with a tensile speed of 2mm / min; the specific test results are shown in Table 1.

[0094] (2) Adhesion performance test: Five 20cm long ultra-corrosion resistant titanium alloy wires were taken from each group of examples. A 10cm long section was selected at the same position in the middle section of each ultra-corrosion resistant titanium alloy wire. First, a cross-cut was made horizontally at the end of the selected section. Then, a cross-cut was made horizontally every 1cm. Next, a vertical cut was made from one end to the other end. Finally, the initial vertical cut line was used as the starting line, and vertical cuts were made every π / 6 arc degrees until the cut was complete. The five cut ultra-corrosion resistant titanium alloy wires were aligned side by side. Then, 1.5cm×10cm 3M tape was pasted onto the cut part. At 23℃ and 50% relative humidity, a multi-functional tensile testing machine was used to perform a 180° peel test at a tensile speed of 50mm / min. The coating on the 3M tape was observed to be peeled off.

[0095] (3) Corrosion resistance test: At a temperature of 70°C, the ultra-corrosion resistant titanium alloy wire was immersed in a 10wt% hydrochloric acid solution for 120h. The corrosion resistance of the ultra-corrosion resistant titanium alloy wire or the coating was observed.

[0096] (4) UV resistance test: The ultra-corrosion resistant titanium alloy wire was placed in a UV aging test chamber, and a UVA-340 (Type 1A) lamp was used to simulate natural light. At 60℃, the irradiance was 0.76W / (m²). 2 The light was subjected to cyclic ultraviolet aging treatment (nm), with each exposure lasting 4 hours and followed by a 1-hour interval, for a total of 50 hours; finally, its corrosion resistance was tested.

[0097] Table 1

[0098]

[0099] Results Analysis: Table 1 shows that the tensile strength of Comparative Example 1 is greater than that of Example 1. This is because the residual internal stress from processing in Comparative Example 1 leads to an artificially high tensile strength. Furthermore, analysis of the elongation at break shows that Example 1 exhibits a higher elongation at break (i.e., toughness). Based on practical applications, if titanium alloy wire is brittle, its application scope is extremely limited, making it difficult to meet actual needs. Therefore, the titanium alloy wire substrate prepared using the drawing process described in this invention will have more stable properties. This also suggests that it will exhibit better corrosion resistance.

[0100] Table 2

[0101]

[0102] Results Analysis: As can be seen from the data in Table 2 above, the comparative examples and comparative examples 2-5 show that the present invention comprehensively prepares an ultra-corrosion-resistant titanium alloy wire by activating the titanium alloy substrate and formulating the raw material composition of the corrosion-resistant coating. The corrosion-resistant coating layer on its surface has good weather resistance and adhesion, which can achieve long-term and effective protection for the titanium alloy wire.

[0103] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing an ultra-corrosion-resistant titanium alloy wire, characterized in that: Includes the following steps: S1: Titanium alloy bars are sequentially pretreated, drawn in multiple passes, heat treated once, fine drawn, heat treated twice, finished, inspected, and wound to obtain titanium alloy wire substrate; S2: The titanium alloy wire substrate is pretreated to obtain the pretreated titanium alloy wire substrate; S3: The corrosion-resistant coating is evenly sprayed onto the pretreated titanium alloy wire substrate, and after heat treatment, a corrosion-resistant coating layer is formed to obtain an ultra-corrosion-resistant titanium alloy wire. In S1, the process parameters for the multi-pass drawing are: single-pass diameter reduction rate of 10%~15%, drawing speed of 10m / min~30m / min, die cone angle of 8°~12°, and total deformation controlled at 60%~70%; The precision drawing process parameters are as follows: dimensional accuracy: if processed into titanium alloy wire substrate with a diameter of φ0.1mm~1mm, the tolerance is ±0.003mm; if processed into titanium alloy wire substrate with a diameter of φ1mm~6mm, the tolerance is ±0.01mm; the total deformation is controlled to be ≤90%. Lubricant needs to be applied before multi-pass drawing and precision drawing. The first heat treatment is an annealing treatment, and its process parameters are: annealing temperature of 700℃~750℃, annealing time of 30min~60min, and air cooling to room temperature; If the titanium alloy bar is an α alloy, the secondary heat treatment is an annealing treatment, and its process parameters are: annealing temperature of 700℃~800℃, annealing time of 30min~60min, and air cooling to room temperature; If the titanium alloy bar is an α+β alloy or a β alloy, the secondary heat treatment is solution treatment and aging treatment, and the process parameters are: solution treatment temperature is 880℃~950℃, water quenching; aging treatment temperature is 450℃~500℃, holding for 6h~12h, and air cooling to room temperature. The finishing process involves polishing the surface until the surface roughness Ra ≤ 0.4 μm. In S2, the pretreatment includes cleaning and activation. The activation process involves using plasma technology to activate the titanium alloy wire substrate, resulting in a pretreated titanium alloy wire substrate. The plasma technology parameters are: Ar / O2 mixed gas flow rate of 100 mL / min to 200 mL / min; gas pressure of 5 Pa to 10 Pa; discharge power of 100 W to 150 W; and plasma treatment time of 2 min to 4 min. In S3, the corrosion-resistant coating is obtained by mixing the following raw material components in parts by weight: 100 parts modified polyether ether ketone, 5 to 15 parts polyimide, 15 to 25 parts polyether imide, 5 to 15 parts graphite, 1 to 3 parts leveling agent, 0.8 to 1.2 parts ultraviolet absorber, and 0.5 to 1 part antioxidant; The modified polyether ether ketone is prepared as follows: (1) Under nitrogen protection, polyether ether ketone and sodium borohydride were added to dimethyl sulfoxide, stirred and heated to 115℃~125℃ for 8h~12h, the reaction was stopped, excess ice water was added to the reaction solution, the precipitate was precipitated, and after separation and purification, the hydroxyl content was determined by acid-base titration to obtain hydroxylated polyether ether ketone with a hydroxyl content of 1.5wt%~3wt%; (2) Under nitrogen protection, 2,4-dihydroxybenzophenone, 2-bromo-N-(bromoethyl)ethylamine and tetrabutylammonium bromide were added to a 50wt% sodium hydroxide aqueous solution, stirred and mixed evenly, and reacted at 55℃~65℃ for 4h~12h. The reaction was then stopped and the mixture was set aside for later use. (3) Add hydroxylated polyether ether ketone to N,N-dimethylformamide, stir and heat to 55℃~65℃, dissolve to obtain hydroxylated polyether ether ketone solution; slowly add hydroxylated polyether ether ketone solution to the prepared solution in (2), continue stirring at 55℃~65℃ for 4h~12h, stop the reaction, add excess ice water to the reaction solution, precipitate out, and after separation and purification, obtain benzophenone-polyether ether ketone; (4) Under nitrogen protection, benzophenone-polyether ether ketone, isocyanate-based silane coupling agent and dibutyltin dilaurate were added to N,N-dimethylformamide, stirred and heated to 70℃~85℃ for 1h~6h, the product was collected by vacuum distillation, washed with water and ground into powder of 20μm~30μm, the powder was then placed in 75wt% ethanol aqueous solution and soaked for 30min~60min, and then vacuum dried to obtain modified polyether ether ketone.

2. The method for preparing an ultra-corrosion-resistant titanium alloy wire according to claim 1, characterized in that: The ratio of the amounts of polyetheretherketone, sodium borohydride, and dimethyl sulfoxide added is 1g:(0.1~0.2)g:10mL; the molar ratio of the amounts of 2,4-dihydroxybenzophenone, 2-bromo-N-(bromoethyl)ethylamine, and tetrabutylammonium bromide added is 1:1:0.01; (2) the ratio of the amount of sodium hydroxide aqueous solution added to the weight of the solute is 1mL:1g, wherein the weight of the solute is 2,4-dihydroxybenzophenone. The total weight of methyl ketone, 2-bromo-N-(bromoethyl)ethylamine, and tetrabutylammonium bromide; the amount of hydroxylated polyether ether ketone added is 5 times the weight of 2,4-dihydroxybenzophenone added; (4) the ratio of the amount of benzophenone-polyether ether ketone, isocyanate-based silane coupling agent, dibutyltin dilaurate, and N,N-dimethylformamide added is 1g:(0.1~0.2)g:(0.005~0.01)g:10mL.

3. The method for preparing an ultra-corrosion-resistant titanium alloy wire according to claim 1, characterized in that: In S1, the pretreatment sequentially includes peeling and turning, alkaline washing, acid washing, and water washing. Among them, the turning depth of peeling turning is ≥0.3mm; The alkaline washing treatment is as follows: After peeling and turning, the titanium alloy bar is cleaned with an alkaline washing solution at 80℃~100℃ for 10min~20min to complete the alkaline washing treatment; the alkaline washing solution consists of the following components at the following concentrations: 80g / L~120g / L sodium hydroxide, 50g / L~80g / L sodium nitrate, and water as the solvent; Pickling is performed as follows: After alkaline washing, the titanium alloy rod is cleaned with pickling solution for 3 to 8 minutes at room temperature to complete the pickling process; the pickling solution consists of the following components at the following concentrations: 50 mL / L to 80 mL / L hydrofluoric acid, 150 to 200 mL / L nitric acid, and water as the solvent; The water washing process is as follows: after pickling, the titanium alloy rod is cleaned with running water for 5 to 10 minutes at room temperature, followed by vacuum drying to complete the water washing process.

4. The method for preparing an ultra-corrosion-resistant titanium alloy wire according to claim 1, characterized in that: In S2, the pretreatment includes cleaning and activation. The cleaning process involves cleaning the titanium alloy wire substrate with a neutral degreasing agent at 40℃~60℃ for 10min~20min; then cleaning the titanium alloy wire substrate with running water at room temperature for 5min~10min, followed by vacuum drying to complete the cleaning process.

5. The method for preparing an ultra-corrosion-resistant titanium alloy wire according to claim 1, characterized in that: In S3, the particle size of each raw material component of the corrosion-resistant coating is 20μm~30μm.

6. The method for preparing an ultra-corrosion-resistant titanium alloy wire according to claim 1, characterized in that: In S3, the spraying is electrostatic spraying, and its process parameters are: spraying voltage of 60kV~90kV and spraying thickness of 50μm~100μm.

7. The method for preparing an ultra-corrosion-resistant titanium alloy wire according to claim 1, characterized in that: In S3, the heat treatment parameters are: holding temperature of 340℃~370℃, holding time of 15min~30min, and air cooling to room temperature.

8. The ultra-corrosion-resistant titanium alloy wire prepared by the method for preparing ultra-corrosion-resistant titanium alloy wire according to any one of claims 1 to 7.

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