Preparation method of magnesium-containing micro-arc oxidation coating on surface of titanium alloy

Abstract

The invention discloses a preparation method of a magnesium-containing micro-arc oxidation coating on the surface of a titanium alloy, and relates to the technical field of titanium alloy surface treatment.The preparation method comprises the steps that a micro-arc oxidation electrolyte is prepared, micro-arc oxidation equipment is used, and the magnesium-containing micro-arc oxidation coating on the surface of the titanium alloy is prepared by setting micro-arc oxidation conditions. Wherein the parameters of the micro-arc oxidation condition are as follows: the maximum voltage is set to be 450V, the frequency is set to be 250Hz, and the duty ratio is 30%. According to the method for preparing the uniform micro-arc oxidation coating with biological activity on the surface of the titanium and titanium alloy orthopedic implant, the coating obtained through the method contains Mg / P and other active substances, meanwhile, the hardness, abrasion resistance and corrosion resistance of the titanium and titanium alloy orthopedic implant are remarkably improved, and the higher performance requirement of orthopedic implant medical instruments is met.

Description

Technical Field

[0001] The invention relates to the technical field of conductive film materials, and in particular to a method for preparing a magnesium-containing micro-arc oxidation coating on the surface of a titanium alloy. Background Art

[0002] At present, with the continuous innovation of medical devices, the research and development of orthopedic implant medical devices with excellent bioactivity and diverse biological functions has become a key trend. Titanium (Ti) and its alloys have attracted much attention in the field of biomedical implants due to their high strength, excellent corrosion resistance and good biocompatibility. However, factors such as its mechanical properties, wear resistance, fatigue resistance and corrosion resistance have a decisive influence on the reliability and effectiveness of titanium and titanium alloy orthopedic implant medical devices. Therefore, improving its bioactivity, wear resistance, corrosion resistance and antibacterial properties through surface modification technology has become a core way to improve the use effect of such devices.

[0003] Micro-arc oxidation (MAO), an advanced surface modification technology, has been successfully applied in areas such as dental implants. During the MAO process, titanium and titanium alloy orthopedic implants are immersed in an electrolyte solution. High voltage is applied, generating localized discharge (PD). Under the high temperature and pressure of the arc, a thin, porous, insulating oxide film—titanium dioxide (TiO2)—is formed on the implant surface. Its roughness and porosity reach the micrometer level. As the voltage increases, the oxide film breaks down, and a dense, bright, short-lived pattern of small, mobile sparks appears on the titanium alloy surface. At this point, elements from the electrolyte begin to enter the film and react with elements in the matrix to form new compounds. Leveraging this characteristic, certain elements can be introduced into the MAO coating by adding specific components to the electrolyte. Subsequently, as the voltage and film thickness increase, the sparks gradually grow larger, their movement slows, and the film grows rapidly. Because the oxide film breakdown always occurs in relatively weak areas, the resulting film is uniform and consistent. From a biological perspective, the porous structure of the coating produced by MAO provides an ideal environment for bone cell growth. At the same time, by changing the electrolyte composition, titanium and titanium alloy orthopedic implants can also be given certain biological activity.

[0004] Magnesium (Mg) is an essential element for the human body, containing approximately 20-30g of magnesium in an adult's body, of which 60%-65% is found in bones and teeth, and 27% is distributed in soft tissues. The recommended daily intake is approximately 330mg. As a crucial trace element in bone tissue and an essential active component in systemic biological activities, magnesium ions are believed to play a crucial role in bone tissue repair. Studies have shown that magnesium ions can significantly promote the proliferation, migration, adhesion, and osteogenic differentiation of mesenchymal stem cells. Furthermore, magnesium ions can promote the proliferation, migration, adhesion, and osteogenic activity of osteoblasts and inhibit their apoptosis through the TRPM / PI3K signaling pathway. Furthermore, magnesium ions can modulate the immune response in the bone environment, transform macrophage phenotypes, promote the secretion of pro-osteogenic factors, reduce the secretion of inflammatory factors, and alleviate the inflammatory response. They can also promote the proliferation, migration, adhesion, and angiogenesis of endothelial cells, thereby promoting angiogenesis. Therefore, introducing magnesium ions onto the surface of titanium alloys can impart excellent bioactivity to titanium and titanium alloy orthopedic implants.

[0005] Existing titanium alloy surface treatment technologies still have limitations in improving bioactivity, wear resistance, and corrosion resistance. Some technologies make it difficult to precisely control the composition and structure of coatings, resulting in unstable performance. Others are complex and costly, making them unsuitable for large-scale production. Therefore, developing an efficient, stable, and cost-effective method for preparing magnesium-containing micro-arc oxidation coatings on titanium alloy surfaces is of great practical significance. Summary of the Invention

[0006] The present invention provides a method for preparing a magnesium-containing micro-arc oxidation coating on the surface of a titanium alloy. The purpose of the present invention is to improve the biological inertness of titanium and titanium alloy orthopedic implants. A method for preparing a uniform and bioactive micro-arc oxidation coating on the surface of the titanium and titanium alloy orthopedic implants is provided. The coating obtained by this method contains active substances such as Mg / P, and at the same time significantly improves the hardness, wear resistance and corrosion resistance of titanium and titanium alloy orthopedic implants, thereby meeting the higher performance requirements of orthopedic implant medical devices.

[0007] The present invention provides a method for preparing a magnesium-containing micro-arc oxidation coating on a titanium alloy surface. The method comprises preparing a micro-arc oxidation electrolyte, using a micro-arc oxidation device, and setting micro-arc oxidation conditions to prepare the magnesium-containing micro-arc oxidation coating on the titanium alloy surface.

[0008] The parameters of the micro-arc oxidation conditions include: the maximum voltage is set to 450V, the frequency is set to 250Hz, and the duty cycle is set to 30%.

[0009] Furthermore, the micro-arc oxidation electrolyte is prepared using a phosphate system, wherein the concentration of sodium dihydrogen phosphate is controlled at 2-5 g / L, the concentration of potassium dihydrogen phosphate is 30 g / L, the pH of the electrolyte is adjusted to between 6 and 9 by sodium hydroxide or acetic acid, and after being fully stirred, 2-8 g / L of MgO is added.

[0010] Furthermore, the micro-arc oxidation equipment is mainly composed of a computer-controllable micro-arc oxidation power supply, an electrolytic cell, a prepared micro-arc oxidation electrolyte, an electric stirrer, test materials and a cathode stainless steel plate; the micro-arc oxidation power supply provides a pulse current with adjustable current, frequency and duty cycle; cooling water circulates in the interlayer of the electrolytic cell; and the stirrer makes the temperature of the reaction solution uniform and accelerates the removal of gas generated by the reaction.

[0011] Furthermore, the micro-arc oxidation conditions also include: pressurizing the sample using a constant pressure method, and the reaction time is 10 to 20 minutes.

[0012] Furthermore, the preparation method specifically includes the following steps:

[0013] Use sandpaper to grind titanium and titanium alloy orthopedic implants until the surface is bright and without obvious scratches, then ultrasonically clean them with anhydrous ethanol for 20 minutes, and then ultrasonically clean them with pure water for 20 minutes, with the temperature controlled at 30-50°C;

[0014] Fix the treated titanium and titanium alloy orthopedic implants in the electrolyte, ensure that there are no bubbles wrapped around the surface, and adjust the distance between the cathode plate and the anode to 30-40mm.

[0015] Furthermore, the method further includes setting the micro-arc oxidation power supply parameters, turning on the cooling water device to keep the electrolyte at the set temperature, turning on the stirrer, and controlling the stirring speed at 100-300 rpm.

[0016] Furthermore, after everything is ready, the power of the micro-arc oxidation device is turned on, and the micro-arc oxidation process is started on the surface of titanium and titanium alloy orthopedic implants. After the oxidation time reaches 15 minutes, the voltage is adjusted to zero and the power is turned off.

[0017] Furthermore, after the power is turned off, the sample is quickly taken out, rinsed with deionized water for 5-10 minutes to remove the residual electrolyte on the surface, and dried in a hot air dryer for 15-30 minutes to ensure that there is no moisture residue on the sample surface.

[0018] Furthermore, after drying, the loose film layer on the surface is removed by manual polishing until the surface becomes uniform gray-black.

[0019] Furthermore, after polishing, the product is ultrasonically cleaned with deionized water, dried in a cool and ventilated place, and bagged and sealed.

[0020] The above technical solution provided by the embodiment of the present invention has at least the following advantages compared with the prior art:

[0021] The embodiment of the present invention provides a method for preparing a magnesium-containing micro-arc oxidation coating on the surface of a titanium alloy. At present, with the continuous innovation of medical devices, more and more metal surface treatment technologies have emerged, aiming to obtain orthopedic implant medical devices with biological activity and more biological functions. Surface modification can enhance the biological activity, wear resistance, corrosion resistance and antibacterial properties of titanium (Ti) and its alloy orthopedic implant medical devices, and improve the use effect of titanium and titanium alloy orthopedic implant medical devices. By adding a certain amount of MgO to the micro-arc oxidation electrolyte, a uniform and Mg-containing micro-arc oxidation coating is formed on the surface of titanium and titanium alloy orthopedic implant medical devices. 2+ The introduction of magnesium ions can give titanium and titanium alloy orthopedic medical devices biological activity. 2+ The release of can regulate the immune response in the bone environment, transform macrophage phenotype, promote the secretion of osteogenic factors, reduce the secretion of inflammatory factors, reduce inflammatory response, and promote the proliferation, migration and adhesion of vascular endothelial cells, angiogenesis, and promote angiogenesis. Specifically:

[0022] 1. Enhanced biological activity: By adding MgO to the electrolyte, the prepared micro-arc oxidation coating contains Mg 2+ , which can give titanium and titanium alloy orthopedic implants good bioactivity. 2+ It can regulate the immune response in the bone environment, transform the phenotype of macrophages, promote the secretion of osteogenic factors, reduce the secretion of inflammatory factors, alleviate the inflammatory response, and at the same time promote the proliferation, migration and adhesion of vascular endothelial cells, enhance the angiogenic ability, promote angiogenesis, and facilitate the bone integration of implants in the body.

[0023] 2. Enhanced Comprehensive Performance: The prepared coating contains active substances such as Mg and P, significantly improving the hardness, wear resistance, and corrosion resistance of titanium and titanium alloy orthopedic implants. The dense and uniform coating structure effectively resists external friction and corrosion, extending the life of the implant and improving its reliability in the complex in vivo environment.

[0024] 3. Process advantages: The preparation method of the present invention is simple to operate, stable in process, and easy to control. The equipment and raw materials used are common and low in cost, making it suitable for large-scale industrial production and conducive to promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0027] Figure 1 Schematic diagram of the micro-arc oxidation equipment provided by the present invention; wherein: 1, micro-arc oxidation power supply 2, stirrer 3, titanium alloy orthopedic implant 4, electrolyte 5, cooling water. DETAILED DESCRIPTION

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0029] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.

[0030] In a first aspect, the present invention provides a method for preparing a magnesium-containing micro-arc oxidation coating on a titanium alloy surface, such as Figure 1 As shown, the preparation method comprises the following steps:

[0031] Depositing a first ITO target material on a substrate by a first magnetron sputtering method to form a first ITO layer;

[0032] Depositing a quantum dot dispersion on the first ITO layer using a solution deposition method to form a transition layer;

[0033] Depositing a second ITO target material on the transition layer by a second magnetron sputtering method to form a second ITO layer, and then annealing to obtain the composite transparent conductive film;

[0034] The quantum dot dispersion is prepared by dispersing silver selenide quantum dots and bismuth quantum dots in a solvent at a weight ratio of 100:(11-27).

[0035] An embodiment of the present invention provides a method for preparing a magnesium-containing micro-arc oxidation coating on a titanium alloy surface. The present invention introduces a transition layer formed by silver selenide quantum dots and bismuth quantum dots in an appropriate proportion into an ITO film to obtain a composite transparent conductive film with a sandwich structure. This method not only promotes the transmission and distribution of electrons and reduces the resistivity of the resulting composite film, but also maintains its excellent optical properties, thereby providing a new means for preparing ITO thin film materials with a high quality factor.

[0036] The silver selenide quantum dots in the present invention can be directly prepared using commercially available products or prepared in-house according to a preparation method disclosed in the prior art, such as the aqueous co-precipitation method. Specifically, the preparation method of the silver selenide quantum dots in the following examples and comparative examples of the present invention is carried out with reference to the prior art - CN107039187A, and specifically comprises the following process: adding 6 mL of a deionized water solution of 8 mmol / L silver nitrate to a flask, then adding 0.8 mL of 3-mercaptopropionic acid and 5 mg of polyvinylpyrrolidone, then adding ammonia water to adjust the pH to 10.5, stirring for 10 minutes, then adding 6 mL of a deionized water solution of 4 mmol / L Na2SeSO3, continuing to stir for 10 minutes, centrifuging, and drying the resulting particles to obtain silver selenide quantum dots.

[0037] The bismuth quantum dots in the present invention can be directly obtained by using commercially available products or by making them in-house according to the preparation methods disclosed in the prior art. Specifically, the preparation methods of bismuth quantum dots in the following examples and comparative examples of the present invention are carried out with reference to the prior art-CN104400002A, and specifically include the following process: 0.6 g of glucose and 0.6 g of glycine are dissolved in 30 mL of deionized water to obtain solution A; 0.153 g of bismuth nitrate is added to the solution A and stirred for 10 min to obtain solution B; 10 mL of a 0.01 g / mL sodium borohydride solution is added to the solution B to obtain solution C; the solution C is reacted at 130° C. for 30 minutes, cooled to room temperature after the reaction, and the reaction product is filtered using a filter membrane with a pore size of 0.22 μm. The filtrate is then dialyzed for 24 h using a dialysis bag with a molecular cutoff of 1000. After the dialysis is completed, the liquid in the dialysis bag is freeze-dried to obtain bismuth quantum dots.

[0038] In some specific embodiments, the preparation method of the magnesium-containing micro-arc oxidation coating on the surface of the titanium alloy provided by the present invention also includes: pre-treating the substrate before using a first magnetron sputtering method to deposit a first ITO target material on the substrate to form a first ITO layer; the pretreatment includes: ultrasonically cleaning the substrate with acetone, deionized water and anhydrous ethanol in sequence, and then placing it in a vacuum oven for drying.

[0039] In some specific embodiments, the substrate may be a conventional soda-lime glass substrate (with a size of 2 cm×2 cm) or the like.

[0040] In some specific embodiments, the weight ratio of the silver selenide quantum dots to the bismuth quantum dots is 100:21.5, and the solvent includes ethanol.

[0041] In some specific embodiments, the working condition parameters of the first magnetron sputtering method include: sputtering temperature of 120-140°C, magnetron sputtering power density of 15-30 mW / cm 2 The magnetron sputtering pressure is 0.3-0.6 Pa, the magnetron sputtering gas is composed of oxygen with a flow rate of 5-10 sccm and argon with a flow rate of 120-150 sccm, and the weight ratio of Sn and In in the first ITO target material is 5:95.

[0042] In some specific embodiments, the thickness of the first ITO layer is 35-45 nm, preferably 40 nm.

[0043] In some specific embodiments, the method of depositing the quantum dot dispersion on the first ITO layer by a solution deposition method to form a transition layer includes the following process:

[0044] The silver selenide quantum dots and the bismuth quantum dots are added to the solvent in proportion, and ultrasonically mixed and stirred for 40 to 60 minutes at an ultrasonic power of 500 to 700 W and a stirring speed of 300 to 400 rpm to obtain the quantum dot dispersion having a total quantum dot concentration of 0.005 to 0.01 g / mL;

[0045] The quantum dot dispersion is sprayed onto the first ITO layer at room temperature, and then vacuum dried at a pressure of less than 10 Pa and a temperature of 35 to 45° C. for 2 to 3 hours to form the transition layer.

[0046] In some specific embodiments, the thickness of the transition layer is 10-20 nm, preferably 15 nm.

[0047] In some specific embodiments, the working condition parameters of the second magnetron sputtering method include: sputtering temperature of 160-170°C, magnetron sputtering power density of 15-30 mW / cm 2 The magnetron sputtering pressure is 0.3-0.6 Pa, the magnetron sputtering gas is composed of oxygen with a flow rate of 5-10 sccm and argon with a flow rate of 120-150 sccm, and the weight ratio of Sn and In in the second ITO target is 5:95.

[0048] In some specific embodiments, the thickness of the second ITO layer is 30-40 nm, preferably 35 nm.

[0049] In some specific embodiments, the annealing working condition parameters include: a temperature of 195 to 220° C., preferably 210° C.; and a time of 30 to 45 minutes.

[0050] In a second aspect, based on the same inventive concept, the present invention provides a composite transparent conductive film, which is prepared by the preparation method of the magnesium-containing micro-arc oxidation coating on the surface of the titanium alloy described in any one of the first aspects.

[0051] The film layer structure of the composite transparent conductive film provided by the embodiment of the present invention comprises, from bottom to top, a first ITO layer, a transition layer and a second ITO layer.

[0052] It should be noted that the component raw materials involved in the composite transparent conductive film and the preparation method thereof provided in the embodiments of the present invention, unless otherwise specified or specifically explained, can be directly commercially available products or homemade using existing disclosed preparation methods; at the same time, the steps and parameters involved, unless otherwise specified or specifically explained, can be carried out in accordance with the ITO film preparation process steps and parameters disclosed in the prior art or directly using existing equipment according to the instruction manual, and the present invention document will not elaborate on them one by one.

[0053] The technical solutions provided by the present invention are as follows:

[0054] Preparation of micro-arc oxidation electrolyte: A phosphate system that can prepare a dense, uniform and highly wear-resistant micro-arc oxidation layer is selected. Among them, the concentration of sodium dihydrogen phosphate is controlled at 2-5g / L, which participates in the reaction in the electrolyte and helps to build a stable coating structure; phosphoric acid is used to increase the strength and thickness of the oxide film and enhance the overall performance of the coating; the concentration of potassium dihydrogen phosphate is 30g / L, which provides the necessary ion environment for the reaction. The pH of the electrolyte is adjusted to between 6 and 9 by sodium hydroxide (NaOH) or acetic acid (CH3COOH). Within this pH range, the activity and reaction rate of various ions are more suitable, which can ensure the smooth progress of the micro-arc oxidation reaction. After fully stirring, add 2-8g / L of MgO to the electrolyte to make the micro-arc oxidation layer contain Mg. 2+ , thereby enhancing the biological activity of the coating.

[0055] Micro-arc oxidation equipment: such as Figure 1As shown, it mainly consists of a computer-controlled micro-arc oxidation power supply, an electrolytic cell, the micro-arc oxidation electrolyte prepared as described above, an electric stirrer, test materials, and a cathode stainless steel plate. The micro-arc oxidation power supply can provide pulse current with adjustable current, frequency, and duty cycle. By precisely controlling these parameters, the progress of the micro-arc oxidation reaction and the growth rate of the coating can be controlled. The electrolytic cell is used to contain the electrolyte and provide a reaction site for micro-arc oxidation. Cooling water circulates in the interlayer, which can effectively control the temperature of the reaction process and avoid affecting the quality of the coating due to excessive temperature. The micro-arc oxidation electrolyte is prepared according to the above-mentioned specific formula to provide the necessary material basis for the formation of the coating. The stirrer is used to make the temperature of the reaction solution uniform and accelerate the removal of gases generated by the reaction to ensure the stability and uniformity of the reaction system.

[0056] Micro-arc oxidation conditions: The sample was pressurized using a constant voltage method, with a maximum voltage set at 450V. This voltage ensures a full micro-arc oxidation reaction on the titanium alloy surface, forming an ideal coating structure. The frequency was set at 250Hz, with a duty cycle of 30%. This combination of parameters helps control spark generation and energy release, resulting in more uniform coating growth. The reaction time was 15 minutes, which ensures sufficient coating growth while avoiding overreaction that could degrade the coating quality.

[0057] Specific implementation steps:

[0058] Use sandpaper to grind titanium and titanium alloy orthopedic implants until the surface is bright and without obvious scratches. Then, use anhydrous ethanol for ultrasonic cleaning for 20 minutes and pure water for ultrasonic cleaning for 20 minutes, with the temperature controlled at 30-50℃.

[0059] Fix the treated titanium or titanium alloy orthopedic implant in the electrolyte to ensure that there are no bubbles wrapped around the surface, and adjust the distance between the cathode plate and the titanium or titanium alloy orthopedic implant, i.e., the anode, to 30-40 mm.

[0060] Set the micro-arc oxidation power supply parameters; at the same time, turn on the cooling water device to keep the electrolyte at the set temperature;

[0061] During the above process, the stirrer is turned on and the stirring speed is controlled at 100-300 rpm to evenly distribute the components in the electrolyte and ensure that the coating generated during the micro-arc oxidation process has uniform composition and consistent thickness.

[0062] When everything is ready, turn on the power of the micro-arc oxidation device, and start the micro-arc oxidation process on the surface of titanium and titanium alloy orthopedic implants. After the oxidation time reaches 15 minutes, the voltage is adjusted to zero and the power is turned off.

[0063] Then quickly remove the sample and rinse with deionized water to remove any residual electrolyte on the surface. Rinsing typically takes 5-10 minutes. Dry the sample in a hot air dryer to ensure no residual moisture on the surface. Drying takes 15-30 minutes. Then, manually polish the sample to remove any loose film until the surface is a uniform gray-black color. Ultrasonic clean with deionized water, dry in a cool, well-ventilated place, and seal in bags.

[0064] The present invention will be further described below in conjunction with specific examples. It should be understood that these examples are intended to illustrate the present invention only and are not intended to limit the scope of the invention. The experimental methods in the following examples where specific conditions are not specified are generally measured in accordance with national standards. If there are no corresponding national standards, then the methods are carried out in accordance with general international standards, conventional conditions, or the conditions recommended by the manufacturer.

[0065] Example 1

[0066] Prepare the micro-arc oxidation electrolyte: Weigh 3g of sodium dihydrogen phosphate, an appropriate amount of phosphoric acid, and 30g of potassium dihydrogen phosphate, add deionized water, and stir to dissolve. Adjust the pH of the electrolyte to 7 with sodium hydroxide solution, then add 5g of MgO and stir thoroughly to obtain the micro-arc oxidation electrolyte.

[0067] Micro-arc oxidation equipment preparation: Install and debug the computer-controlled micro-arc oxidation power supply, electrolytic cell, prepared micro-arc oxidation electrolyte, electric stirrer, titanium alloy orthopedic implant sample, and cathode stainless steel plate. Ensure that the cooling water circulation system in the electrolytic cell interlayer is operating normally and the stirrer is functioning properly.

[0068] Micro-arc oxidation condition setting: using the constant voltage method, the maximum voltage of the micro-arc oxidation power supply was set to 450 V, the frequency was set to 250 Hz, and the duty cycle was set to 30%.

[0069] Specific implementation: Use sandpaper to grind the titanium alloy orthopedic implant sample until the surface is bright and scratch-free, and then use anhydrous ethanol and pure water to ultrasonically clean it at 40°C for 20 minutes. Fix the treated sample in the electrolyte and adjust the distance between the cathode plate and the anode (sample) to 35mm. Set the micro-arc oxidation power supply parameters, turn on the cooling water device and the agitator, and control the stirring speed at 200rpm. Turn on the power of the micro-arc oxidation device and carry out a micro-arc oxidation reaction for 15 minutes. After the reaction is completed, adjust the voltage to zero and turn off the power. Quickly remove the sample, rinse with deionized water for 8 minutes, and use a hot air dryer to dry at 25°C for 20 minutes. Manually polish to remove the loose film layer on the surface until the surface is uniformly gray-black, then ultrasonically clean with deionized water, dry in a cool and ventilated place, and seal in bags.

[0070] Example 2

[0071] Prepare the micro-arc oxidation electrolyte: Weigh 2g of sodium dihydrogen phosphate, an appropriate amount of phosphoric acid, and 30g of potassium dihydrogen phosphate, add deionized water, and stir to dissolve. Adjust the pH of the electrolyte to 6 with acetic acid solution, then add 4g of MgO and stir thoroughly to obtain the micro-arc oxidation electrolyte.

[0072] Preparation of micro-arc oxidation equipment: same as in Example 1.

[0073] Micro-arc oxidation conditions were the same as those in Example 1.

[0074] Specific implementation: Use sandpaper to grind the titanium alloy orthopedic implant sample until the surface is bright and scratch-free, and then use anhydrous ethanol and pure water to ultrasonically clean it at 35°C for 20 minutes. Fix the treated sample in the electrolyte and adjust the distance between the cathode plate and the anode (sample) to 30mm. Set the micro-arc oxidation power supply parameters, turn on the cooling water device and the agitator, and control the stirring speed at 150rpm. Turn on the power of the micro-arc oxidation device and carry out a micro-arc oxidation reaction for 15 minutes. After the reaction is completed, adjust the voltage to zero and turn off the power. Quickly remove the sample, rinse with deionized water for 6 minutes, and use a hot air dryer to dry at 20°C for 18 minutes. Manually polish to remove the loose film layer on the surface until the surface is uniformly gray-black, then ultrasonically clean with deionized water, dry in a cool and ventilated place, and seal in bags.

[0075] Example 3

[0076] Prepare the micro-arc oxidation electrolyte: Weigh 4g of sodium dihydrogen phosphate, an appropriate amount of phosphoric acid, and 30g of potassium dihydrogen phosphate, add deionized water, and stir to dissolve. Adjust the pH of the electrolyte to 8 with sodium hydroxide solution, then add 6g of MgO and stir thoroughly to obtain the micro-arc oxidation electrolyte.

[0077] Preparation of micro-arc oxidation equipment: same as in Example 1.

[0078] Micro-arc oxidation conditions were the same as those in Example 1.

[0079] Specific implementation: Use sandpaper to grind the titanium alloy orthopedic implant sample until the surface is bright and scratch-free, and then use anhydrous ethanol and pure water to ultrasonically clean it at 45°C for 20 minutes. Fix the treated sample in the electrolyte and adjust the distance between the cathode plate and the anode (sample) to 40mm. Set the micro-arc oxidation power supply parameters, turn on the cooling water device and the agitator, and control the stirring speed at 250rpm. Turn on the power of the micro-arc oxidation device and carry out a micro-arc oxidation reaction for 15 minutes. After the reaction is completed, adjust the voltage to zero and turn off the power. Quickly remove the sample, rinse with deionized water for 10 minutes, and use a hot air dryer to dry at 30°C for 25 minutes. Manually polish to remove the loose film layer on the surface until the surface is uniformly gray-black, then ultrasonically clean with deionized water, dry in a cool and ventilated place, and seal in bags.

[0080] The performance test of the magnesium-containing micro-arc oxidation coating on the titanium alloy surface prepared in the above embodiment showed that the coating contained rich Mg 2+ , has good biological activity, and can effectively promote cell proliferation and differentiation; the hardness, wear resistance and corrosion resistance of the coating are significantly improved compared to untreated titanium alloys, meeting the performance requirements of orthopedic implant medical devices.

[0081] Various embodiments of the present invention may be presented in the form of a range; it should be understood that the description in a range format is only for convenience and brevity and should not be construed as an inflexible limitation on the scope of the invention; therefore, the range description should be considered to have specifically disclosed all possible subranges and single numerical values ​​within the range. For example, the description of a range from 1 to 6 should be considered to have specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. In addition, whenever a numerical range is indicated herein, it is intended to include any cited numeral (fractional or integer) within the indicated range.

[0082] The foregoing description is intended only to provide specific embodiments of the present invention, which will enable those skilled in the art to understand and implement the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not intended to be limited to the embodiments shown herein, but is intended to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for preparing a magnesium-containing micro-arc oxidation coating on a titanium alloy surface, characterized in that: The preparation method includes preparing a micro-arc oxidation electrolyte, using a micro-arc oxidation device, and setting micro-arc oxidation conditions to prepare a magnesium-containing micro-arc oxidation coating on the surface of a titanium alloy; The parameters of the micro-arc oxidation conditions include: the maximum voltage is set to 450V, the frequency is set to 250Hz, and the duty cycle is set to 30%.

2. The method for preparing a magnesium-containing micro-arc oxidation coating on a titanium alloy surface according to claim 1, characterized in that: The micro-arc oxidation electrolyte is prepared using a phosphate system, wherein the concentration of sodium dihydrogen phosphate is controlled at 2-5 g / L, and the concentration of potassium dihydrogen phosphate is 30 g / L. The pH of the electrolyte is adjusted to between 6 and 9 using sodium hydroxide or acetic acid, and after being fully stirred, 2-8 g / L of MgO is added.

3. The method for preparing a magnesium-containing micro-arc oxidation coating on a titanium alloy surface according to claim 1, characterized in that: The micro-arc oxidation equipment mainly consists of a computer-controlled micro-arc oxidation power supply, an electrolytic cell, a prepared micro-arc oxidation electrolyte, an electric stirrer, test materials, and a cathode stainless steel plate; the micro-arc oxidation power supply provides a pulse current with adjustable current, frequency, and duty cycle; Cooling water circulates in the interlayer of the electrolytic cell; the stirrer makes the temperature of the reaction solution uniform and accelerates the removal of gas generated by the reaction.

4. The method for preparing a magnesium-containing micro-arc oxidation coating on a titanium alloy surface according to claim 1, characterized in that: The micro-arc oxidation conditions also include: pressurizing the sample using a constant pressure method, and the reaction time is 10 to 20 minutes.

5. The method for preparing a magnesium-containing micro-arc oxidation coating on a titanium alloy surface according to any one of claims 1 to 4, characterized in that: The preparation method is specifically The following processes are included: Use sandpaper to grind titanium and titanium alloy orthopedic implants until the surface is bright and without obvious scratches, then ultrasonically clean them with anhydrous ethanol for 20 minutes, and then ultrasonically clean them with pure water for 20 minutes, with the temperature controlled at 30-50°C; Fix the treated titanium and titanium alloy orthopedic implants in the electrolyte, ensure that there are no bubbles wrapped around the surface, and adjust the distance between the cathode plate and the anode to 30-40mm.

6. The method for preparing a magnesium-containing micro-arc oxidation coating on a titanium alloy surface according to claim 5, characterized in that: It also includes setting the micro-arc oxidation power supply parameters, turning on the cooling water device to keep the electrolyte at the set temperature, turning on the stirrer, and controlling the stirring speed at 100-300rpm.

7. The method for preparing a magnesium-containing micro-arc oxidation coating on a titanium alloy surface according to claim 6, characterized in that: After everything is ready, turn on the power of the micro-arc oxidation device, and start the micro-arc oxidation process on the surface of titanium and titanium alloy orthopedic implants. After the oxidation time reaches 15 minutes, the voltage is adjusted to zero and the power is turned off.

8. The method for preparing a magnesium-containing micro-arc oxidation coating on a titanium alloy surface according to claim 7, characterized in that: After the power is turned off, quickly remove the sample, rinse it with deionized water for 5-10 minutes to remove the residual electrolyte on the surface, and dry it in a hot air dryer for 15-30 minutes to ensure that there is no moisture residue on the sample surface.

9. The method for preparing a magnesium-containing micro-arc oxidation coating on a titanium alloy surface according to claim 8, characterized in that: After drying, manually polish to remove the loose film layer on the surface until the surface becomes a uniform gray-black color.

10. The method for preparing a magnesium-containing micro-arc oxidation coating on a titanium alloy surface according to claim 9, characterized in that: After polishing, use deionized water for ultrasonic cleaning, dry in a cool and ventilated place, and seal in bags.

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