Preparation method of medical titanium alloy

Abstract

The invention relates to the field of titanium alloy production, in particular to a preparation method of a medical titanium alloy, which is used for overcoming the defects of complex process and high cost of an existing preparation method of the medical titanium alloy, and the defects of poor microstructure uniformity and poor antibacterial and bacteriostatic performance of the prepared medical titanium alloy. According to the preparation method, the medical titanium alloy is prepared in a powder metallurgy mode, the technological process is simple, secondly, the elemental metal powder is subjected to particle shape modification before sintering, particles of the elemental metal powder are similar to spheres, the uniformity of all structures and the uniformity of element distribution during sintering are effectively improved, and the medical titanium alloy is obtained. The silver-containing hydroxyapatite coating can be formed through vacuum magnetron sputtering, so that the mechanical property of the titanium alloy can be further improved, the antibacterial property of the titanium alloy can be greatly improved, and the implantation infection risk and the probability of medical negligence are reduced.

Description

Technical Field

[0001] The invention relates to the field of titanium alloy production, and in particular to a method for preparing a medical titanium alloy. Background Art

[0002] Titanium alloys generally have excellent properties of high strength, good corrosion resistance and high heat resistance. They are mainly used in aerospace, petrochemical, automobile manufacturing and other fields, and have broad application prospects; at the same time, high-performance titanium alloys are also widely used in the medical field. Due to the particularity of the application parts, medical titanium alloys have high requirements for elastic modulus, strength, corrosion resistance, etc. In the existing technology, the preparation method of medical titanium alloys has the defects of complex process and high cost, and the process of preparing titanium alloys by powder processing technology has the defects of poor powder particle shape and poor uniformity of microstructure after sintering, and also has the disadvantage of poor antibacterial and antibacterial performance, which in turn affects the overall performance of medical titanium alloy products.

[0003] Therefore, it is of great significance to develop a medical titanium alloy and a preparation method thereof. Summary of the invention

[0004] In order to overcome the above-mentioned technical problems, the purpose of the present invention is to provide a method for preparing a medical titanium alloy: by weighing single metal powders Ti, Nb, Zr, and Sn according to a weight ratio to obtain a mixed powder, by placing the mixed powder in a mixer, performing particle shape modification, and mixing evenly to obtain a metal mixed powder, by loading the metal mixed powder into a mold, pressing and molding, to obtain a preform, by placing the preform in a high-temperature furnace for sintering, to obtain a titanium alloy, by pressing silver-containing hydroxyapatite into a target material, vacuum magnetron sputtering the titanium alloy to form a silver-containing hydroxyapatite coating, to obtain a medical titanium alloy, the defects of the existing medical titanium alloy preparation method, such as complex process and high cost, and the defects of poor powder particle shape and poor microstructure uniformity after sintering in the process of preparing titanium alloy by powder processing technology, as well as poor antibacterial and antibacterial properties, which further affects the overall performance of the medical titanium alloy product.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A method for preparing a medical titanium alloy comprises the following steps:

[0007] Step 1: weigh single metal powders Ti, Nb, Zr and Sn according to a weight ratio to obtain a mixed powder;

[0008] Step 2: placing the mixed powder in a mixer, modifying the particle shape, and mixing evenly to obtain a metal mixed powder;

[0009] Step 3: Put the metal mixed powder into the mold and press it into shape to obtain a preform;

[0010] Step 4: placing the preform in a high temperature furnace for sintering to obtain a titanium alloy;

[0011] Step 5: Press the silver-containing hydroxyapatite into a target material, perform vacuum magnetron sputtering on the titanium alloy to form a silver-containing hydroxyapatite coating, and obtain a medical titanium alloy.

[0012] As a further solution of the present invention: the weight ratio of the elemental metal powders Ti, Nb, Zr and Sn in step one is Ti:Nb:Zr:Sn=60-70:20-30:2-6:6-10.

[0013] As a further solution of the present invention: the weight ratio of the elemental metal powder is Ti:Nb:Zr:Sn=65:25:3:7.

[0014] As a further solution of the present invention: the mixer in step 2 is a horizontal pot mill, the mixed powder is added to the grinding pot of the horizontal pot mill, and the grinding medium is added at the same time, and the horizontal pot mill is started for grinding, and the grinding medium is a combination of zirconia balls and zirconia columns.

[0015] As a further embodiment of the present invention: the mass ratio of the mixed powder to the grinding medium in the grinding jar is 1:1-5;

[0016] The zirconia balls in the grinding medium are mixed zirconia balls of 10 mm balls, 5 mm balls, 3 mm balls and 1 mm balls in a mass ratio of 2:5:5:3;

[0017] The size of the zirconium oxide column in the grinding medium is 1-3 mm in bottom circle diameter and 1-5 mm in length;

[0018] The mass ratio of zirconia balls to zirconia columns is 2-5:1;

[0019] The rotation speed of the grinding jar is 60-400 rpm, and the grinding time is 1-5 hours.

[0020] As a further solution of the present invention: a dispersant is further added into the grinding jar, wherein the dispersant is one of triethanolamine and polyethylene glycol, and the amount of the dispersant is 0.5-2% of the mass of the mixed powder.

[0021] As a further solution of the present invention: the pressing method in step three is cold isostatic pressing, the molding pressure is 300-700 MPa, and the holding time is 2-10 min.

[0022] As a further scheme of the present invention: the high-temperature furnace in step four is a tubular furnace, and the sintering atmosphere is flowing argon. Before sintering, argon is passed through the tubular furnace for 1-2 hours; the sintering process is: from room temperature to 500°C, the heating rate is 5°C / min, and the temperature is kept for 30 minutes, then from 500°C to 1000°C, the heating rate is 7°C / min, and the temperature is kept for 30 minutes, then from 1000°C to 1400°C, the heating rate is 5°C / min, and the temperature is kept for 4 hours, then the temperature is cooled to 800°C with the furnace, and finally added into water for quenching to obtain titanium alloy.

[0023] As a further solution of the present invention: the conditions of the vacuum magnetron sputtering in step five are: the sputtering target base distance is 60 mm, the rotation speed of the rack for placing the titanium alloy is 15 r / min, the reaction gas is argon, the argon flow rate is 20 sccm, the working gas pressure is 0.5 Pa, the temperature is 350°C, and the sputtering time is 120 min.

[0024] As a further solution of the present invention: the silver-containing hydroxyapatite in step 5 is prepared by the following steps:

[0025] Calcium nitrate tetrahydrate, trisodium citrate and deionized water are added to a three-necked flask equipped with a stirrer, a thermometer and a constant pressure dropping funnel, and stirred for 1-2 hours at a temperature of 25-30°C and a stirring rate of 400-500r / min. Then, silver nitrate is added and stirred for 30-50 minutes. Then, the pH is adjusted to 9-9.5 with sodium hydroxide solution, and then diammonium hydrogen phosphate solution is added dropwise while stirring, and the dropping rate is controlled to 1-2 drops / s. After the addition is completed, ammonia water is used to adjust the pH to 1 0-11, then continue to stir the reaction for 2-3h, then raise the temperature to 80-85℃ and continue to stir the reaction for 8-10h. After the reaction is completed, cool the reaction product to room temperature, then vacuum filter, wash the filter cake with distilled water 3-5 times, then place it in a vacuum drying oven, dry it at a temperature of 100-110℃ for 8-10h, then grind it through a 200-mesh sieve, then place it in a tubular furnace, calcine it at a temperature of 600-620℃ for 1-1.5h, and then cool it with the furnace to obtain silver-containing hydroxyapatite.

[0026] As a further solution of the present invention: the dosage ratio of the calcium nitrate tetrahydrate, trisodium citrate, deionized water, silver nitrate and diammonium hydrogen phosphate solution is 0.15-0.18 mol: 0.05 mol: 100 mL: 0.03-0.07 mol: 45-50 mL, the molar concentration of the diammonium hydrogen phosphate solution is 1.8-2.0 mol / L, the mass fraction of the sodium hydroxide solution is 30-35%, and the mass fraction of the ammonia water is 20-22%.

[0027] Beneficial effects of the present invention:

[0028] The invention discloses a preparation method of a medical titanium alloy, comprising the following steps: weighing single metal powders Ti, Nb, Zr and Sn according to a weight ratio to obtain a mixed powder; placing the mixed powder in a mixer to modify the particle shape and uniformly mix the mixed powder to obtain a metal mixed powder; loading the metal mixed powder into a mold to press and form a preform; placing the preform in a high-temperature furnace to sinter the preform to obtain a titanium alloy; pressing silver-containing hydroxyapatite into a target material, vacuum magnetron sputtering the titanium alloy to form a silver-containing hydroxyapatite coating to obtain a medical titanium alloy; the preparation method prepares the medical titanium alloy by adopting a powder metallurgy method, and the process is simple; secondly, by modifying the particle shape of the single metal powder before sintering so that the particles are similar to a sphere, the uniformity of various tissues and the uniformity of element distribution during sintering are effectively improved, and various properties of the medical titanium alloy product can be significantly improved; finally, vacuum magnetron sputtering is performed to form a target material containing silver. Silver hydroxyapatite coating, hydroxyapatite has chemical and physical properties similar to those of bone tissue, and is often used in bone regeneration replacement materials. It has good biocompatibility, can promote the adhesion and osteogenic differentiation of osteoblasts on the coating surface, and can further improve the mechanical properties of titanium alloys. By adding metallic silver thereto, its antibacterial properties can be greatly improved, reducing the risk of implant infection and the probability of medical accidents. Finally, the elastic modulus of the medical titanium alloy prepared by this preparation method ranges from 57.1GPa to 60.2GPa, the elongation at break ranges from 12.2 to 15.9%, the ultimate tensile strength ranges from 760 to 798MPa, the antibacterial rate of Staphylococcus aureus ranges from 98.9 to 99.5%, and the antibacterial rate of Streptococcus mutans ranges from 99.3 to 99.9%. DETAILED DESCRIPTION

[0029] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only 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 creative work are within the scope of protection of the present invention.

[0030] Embodiment 1:

[0031] This embodiment is a method for preparing a medical titanium alloy, comprising the following steps:

[0032] Step 1: Weigh each elemental metal powder according to the following weight proportions, including 60 parts of Ti powder, 30 parts of Nb powder, 3 parts of Zr powder, and 7 parts of Sn powder;

[0033] Step 2: placing the mixed powder in a mixer, modifying the particle shape, and mixing evenly to obtain a metal mixed powder;

[0034] The mixer is a horizontal pot mill, the mixed powder is added into the grinding pot of the horizontal pot mill, and the grinding medium is added at the same time, and the horizontal pot mill is started for grinding, and the grinding medium is a combination of zirconia balls and zirconia columns;

[0035] Wherein, the mass ratio of the mixed powder to the grinding medium in the grinding jar is 1:3;

[0036] The zirconia balls in the grinding medium are mixed zirconia balls of 10 mm balls, 5 mm balls, 3 mm balls and 1 mm balls in a mass ratio of 2:5:5:3;

[0037] The size of the zirconium oxide column in the grinding medium is 2 mm in bottom circle diameter and 4 mm in length;

[0038] Wherein, the mass ratio of the zirconia balls to the zirconia columns is 2:1;

[0039] Wherein, the rotation speed of the grinding jar is 100 rpm, and the grinding time is 3 hours;

[0040] The grinding tank is further added with a dispersant, which is triethanolamine, and the amount of the dispersant is 1% of the mass of the mixed powder;

[0041] Step 3: Put the metal mixed powder into the mold and press it into shape to obtain a preform;

[0042] The pressing method is cold isostatic pressing, the molding pressure is 300 MPa, and the holding time is 8 min.

[0043] Step 4: placing the preform in a high temperature furnace for sintering to obtain a titanium alloy;

[0044] The high-temperature furnace is a tubular furnace, and the sintering atmosphere is flowing argon. Before sintering, argon is passed through the tubular furnace for 2 hours. The sintering process is: from room temperature to 500°C, the heating rate is 5°C / min, and the temperature is kept for 30 minutes, then from 500°C to 1000°C, the heating rate is 7°C / min, and the temperature is kept for 30 minutes, then from 1000°C to 1400°C, the heating rate is 5°C / min, and the temperature is kept for 4 hours, then the temperature is cooled to 800°C with the furnace, and finally added into water for quenching treatment to obtain titanium alloy.

[0045] Step 5: pressing the silver-containing hydroxyapatite into a target material, performing vacuum magnetron sputtering on the titanium alloy to form a silver-containing hydroxyapatite coating to obtain a medical titanium alloy;

[0046] The conditions of the vacuum magnetron sputtering are as follows: the distance between the sputtering target and the substrate is 60 mm, the rotation speed of the rack for placing the titanium alloy is 15 r / min, the reaction gas is argon, the argon flow rate is 20 sccm, the working gas pressure is 0.5 Pa, the temperature is 350° C., and the sputtering time is 120 min;

[0047] Wherein, the silver-containing hydroxyapatite is prepared by the following steps:

[0048] 0.15 mol calcium nitrate tetrahydrate, 0.05 mol trisodium citrate and 100 mL deionized water were added to a three-necked flask equipped with a stirrer, a thermometer and a constant pressure dropping funnel, and stirred for 1 h at a temperature of 25 ° C and a stirring rate of 400 r / min. Then, 0.03 mol silver nitrate was added and the stirring reaction was continued for 30 min. Then, the pH was adjusted to 9 with a mass fraction of 30% sodium hydroxide solution, and then 45 mL of a molar concentration of 1.8 mol sodium hydroxide solution was added dropwise while stirring. l / L of diammonium hydrogen phosphate solution, control the dropping rate to 1 drop / s, adjust the pH to 10 with 20% ammonia water after the dropwise addition, then continue to stir the reaction for 2h, then raise the temperature to 80℃ and continue to stir the reaction for 8h. After the reaction is completed, cool the reaction product to room temperature, then vacuum filter, wash the filter cake with distilled water 3 times, then place it in a vacuum drying oven, dry it at 100℃ for 8h, then grind it through a 200-mesh sieve, then place it in a tubular furnace, calcine it at 600℃ for 1h, and then cool it with the furnace to obtain silver-containing hydroxyapatite.

[0049] Embodiment 2:

[0050] This embodiment is a method for preparing a medical titanium alloy, comprising the following steps:

[0051] Step 1: Weigh each elemental metal powder according to the following weight proportions, including 65 parts of Ti powder, 25 parts of Nb powder, 3 parts of Zr powder, and 7 parts of Sn powder;

[0052] Step 2: placing the mixed powder in a mixer, modifying the particle shape, and mixing evenly to obtain a metal mixed powder;

[0053] The mixer is a horizontal pot mill, the mixed powder is added into the grinding pot of the horizontal pot mill, and the grinding medium is added at the same time, and the horizontal pot mill is started for grinding, and the grinding medium is a combination of zirconia balls and zirconia columns;

[0054] Wherein, the mass ratio of the mixed powder to the grinding medium in the grinding jar is 1:3;

[0055] The zirconia balls in the grinding medium are mixed zirconia balls of 10 mm balls, 5 mm balls, 3 mm balls and 1 mm balls in a mass ratio of 2:5:5:3;

[0056] The size of the zirconium oxide column in the grinding medium is 2 mm in bottom circle diameter and 4 mm in length;

[0057] Wherein, the mass ratio of the zirconia balls to the zirconia columns is 3:1;

[0058] Wherein, the rotation speed of the grinding jar is 200 rpm, and the grinding time is 5 hours;

[0059] The grinding tank is further added with a dispersant, which is triethanolamine, and the amount of the dispersant is 1% of the mass of the mixed powder;

[0060] Step 3: Put the metal mixed powder into the mold and press it into shape to obtain a preform;

[0061] The pressing method is cold isostatic pressing, the molding pressure is 700 MPa, and the holding time is 3 min.

[0062] Step 4: placing the preform in a high temperature furnace for sintering to obtain a titanium alloy;

[0063] The high-temperature furnace is a tubular furnace, and the sintering atmosphere is flowing argon. Before sintering, argon is passed through the tubular furnace for 2 hours. The sintering process is: from room temperature to 500°C, the heating rate is 5°C / min, and the temperature is kept for 30 minutes, then from 500°C to 1000°C, the heating rate is 7°C / min, and the temperature is kept for 30 minutes, then from 1000°C to 1400°C, the heating rate is 5°C / min, and the temperature is kept for 4 hours, then the temperature is cooled to 800°C with the furnace, and finally added into water for quenching treatment to obtain titanium alloy.

[0064] Step 5: pressing the silver-containing hydroxyapatite into a target material, performing vacuum magnetron sputtering on the titanium alloy to form a silver-containing hydroxyapatite coating to obtain a medical titanium alloy;

[0065] The conditions of the vacuum magnetron sputtering are as follows: the distance between the sputtering target and the substrate is 60 mm, the rotation speed of the rack for placing the titanium alloy is 15 r / min, the reaction gas is argon, the argon flow rate is 20 sccm, the working gas pressure is 0.5 Pa, the temperature is 350° C., and the sputtering time is 120 min;

[0066] Wherein, the silver-containing hydroxyapatite is prepared by the following steps:

[0067] 0.17 mol calcium nitrate tetrahydrate, 0.05 mol trisodium citrate and 100 mL deionized water were added to a three-necked flask equipped with a stirrer, a thermometer and a constant pressure dropping funnel, and stirred for 1.5 h at a temperature of 28 ° C and a stirring rate of 450 r / min. Then, 0.05 mol silver nitrate was added and the stirring reaction was continued for 40 min. Then, the pH was adjusted to 9.3 with a mass fraction of 33% sodium hydroxide solution, and then 48 mL of a molar concentration of 1.9 mol sodium hydroxide solution was added dropwise while stirring. l / L of diammonium hydrogen phosphate solution, controlling the dropping rate to 1 drop / s, after the dropwise addition is completed, adjust the pH to 10.5 with 21% ammonia water, then continue to stir the reaction for 2.5 hours, then raise the temperature to 83°C and continue to stir the reaction for 9 hours. After the reaction is completed, cool the reaction product to room temperature, then vacuum filter, wash the filter cake with distilled water 4 times, then place it in a vacuum drying oven, dry it at 105°C for 9 hours, then grind it through a 200-mesh sieve, then place it in a tubular furnace, calcine it at 610°C for 1.2 hours, and then cool it with the furnace to obtain silver-containing hydroxyapatite.

[0068] Embodiment 3:

[0069] This embodiment is a method for preparing a medical titanium alloy, comprising the following steps:

[0070] Step 1: Weigh each elemental metal powder according to the following weight proportions, including 70 parts of Ti powder, 20 parts of Nb powder, 3 parts of Zr powder, and 7 parts of Sn powder;

[0071] Step 2: placing the mixed powder in a mixer, modifying the particle shape, and mixing evenly to obtain a metal mixed powder;

[0072] The mixer is a horizontal pot mill, the mixed powder is added into the grinding pot of the horizontal pot mill, and the grinding medium is added at the same time, and the horizontal pot mill is started for grinding, and the grinding medium is a combination of zirconia balls and zirconia columns;

[0073] Wherein, the mass ratio of the mixed powder to the grinding medium in the grinding jar is 1:5;

[0074] The zirconia balls in the grinding medium are mixed zirconia balls of 10 mm balls, 5 mm balls, 3 mm balls and 1 mm balls in a mass ratio of 2:5:5:3;

[0075] The size of the zirconium oxide column in the grinding medium is 2 mm in bottom circle diameter and 4 mm in length;

[0076] Wherein, the mass ratio of the zirconia balls to the zirconia columns is 5:1;

[0077] Wherein, the rotation speed of the grinding jar is 400 rpm, and the grinding time is 1 hour;

[0078] Wherein, a dispersant is also added to the grinding jar, and the dispersant is polyethylene glycol, and the amount of the dispersant is 2% of the mass of the mixed powder;

[0079] Step 3: Put the metal mixed powder into the mold and press it into shape to obtain a preform;

[0080] The pressing method is cold isostatic pressing, the molding pressure is 600 MPa, and the holding time is 5 min.

[0081] Step 4: placing the preform in a high temperature furnace for sintering to obtain a titanium alloy;

[0082] The high-temperature furnace is a tubular furnace, and the sintering atmosphere is flowing argon. Before sintering, argon is passed through the tubular furnace for 2 hours. The sintering process is: from room temperature to 500°C, the heating rate is 5°C / min, and the temperature is kept for 30 minutes, then from 500°C to 1000°C, the heating rate is 7°C / min, and the temperature is kept for 30 minutes, then from 1000°C to 1400°C, the heating rate is 5°C / min, and the temperature is kept for 4 hours, then the temperature is cooled to 800°C with the furnace, and finally added into water for quenching treatment to obtain titanium alloy.

[0083] Step 5: pressing the silver-containing hydroxyapatite into a target material, performing vacuum magnetron sputtering on the titanium alloy to form a silver-containing hydroxyapatite coating to obtain a medical titanium alloy;

[0084] The conditions of the vacuum magnetron sputtering are as follows: the distance between the sputtering target and the substrate is 60 mm, the rotation speed of the rack for placing the titanium alloy is 15 r / min, the reaction gas is argon, the argon flow rate is 20 sccm, the working gas pressure is 0.5 Pa, the temperature is 350° C., and the sputtering time is 120 min;

[0085] Wherein, the silver-containing hydroxyapatite is prepared by the following steps:

[0086] 0.18 mol calcium nitrate tetrahydrate, 0.05 mol trisodium citrate and 100 mL deionized water were added to a three-necked flask equipped with a stirrer, a thermometer and a constant pressure dropping funnel, and stirred for 2 h at a temperature of 30 ° C and a stirring rate of 500 r / min. Then, 0.07 mol silver nitrate was added and the stirring reaction was continued for 50 min. Then, the pH was adjusted to 9.5 with a mass fraction of 35% sodium hydroxide solution, and then 50 mL of a molar concentration of 2.0 mol sodium hydroxide solution was added dropwise while stirring. l / L of diammonium hydrogen phosphate solution, control the dropping rate to 2 drops / s, adjust the pH to 11 with 22% ammonia water after the dropwise addition, then continue to stir the reaction for 3 hours, then raise the temperature to 85°C and continue to stir the reaction for 10 hours. After the reaction is completed, cool the reaction product to room temperature, then vacuum filter, wash the filter cake with distilled water 5 times, then place it in a vacuum drying oven, dry it at 110°C for 10 hours, then grind it through a 200-mesh sieve, then place it in a tubular furnace, calcine it at 620°C for 1.5 hours, and then cool it with the furnace to obtain silver-containing hydroxyapatite.

[0087] Comparative Example 1:

[0088] This comparative example is a method for preparing a medical titanium alloy, comprising the following steps:

[0089] Step 1: Weigh each elemental metal powder according to the following weight proportions, including 65 parts of Ti powder, 25 parts of Nb powder, 3 parts of Zr powder, and 7 parts of Sn powder;

[0090] Step 2: placing the mixed powder in a mixer, modifying the particle shape, and mixing evenly to obtain a metal mixed powder;

[0091] The mixer is a horizontal pot mill, the mixed powder is added into the grinding pot of the horizontal pot mill, and the grinding medium is added at the same time, and the horizontal pot mill is started for grinding, and the grinding medium is a combination of zirconia balls and zirconia columns;

[0092] Wherein, the mass ratio of the mixed powder to the grinding medium in the grinding jar is 1:3;

[0093] The zirconia balls in the grinding medium are mixed zirconia balls of 10 mm balls, 5 mm balls, 3 mm balls and 1 mm balls in a mass ratio of 2:5:5:3;

[0094] The size of the zirconium oxide column in the grinding medium is 2 mm in bottom circle diameter and 4 mm in length;

[0095] Wherein, the mass ratio of the zirconia balls to the zirconia columns is 3:1;

[0096] Wherein, the rotation speed of the grinding jar is 200 rpm, and the grinding time is 5 hours;

[0097] The grinding tank is further added with a dispersant, which is triethanolamine, and the amount of the dispersant is 1% of the mass of the mixed powder;

[0098] Step 3: Put the metal mixed powder into the mold and press it into shape to obtain a preform;

[0099] The pressing method is cold isostatic pressing, the molding pressure is 700 MPa, and the holding time is 3 min.

[0100] Step 4: placing the preform in a high temperature furnace for sintering to obtain a medical titanium alloy;

[0101] The high-temperature furnace is a tubular furnace, and the sintering atmosphere is flowing argon. Before sintering, argon is passed through the tubular furnace for 2 hours. The sintering process is: from room temperature to 500°C, the heating rate is 5°C / min, and the temperature is kept for 30 minutes. Then, the temperature is increased from 500°C to 1000°C, the heating rate is 7°C / min, and the temperature is kept for 30 minutes. Then, the temperature is increased from 1000°C to 1400°C, the heating rate is 5°C / min, and the temperature is kept for 4 hours. Then, the temperature is cooled to 800°C with the furnace, and finally, it is added into water for quenching to obtain medical titanium alloy.

[0102] Comparative Example 2:

[0103] This comparative example is a method for preparing a medical titanium alloy, comprising the following steps:

[0104] Step 1: Weigh each elemental metal powder according to the following weight proportions, including 65 parts of Ti powder, 25 parts of Nb powder, 3 parts of Zr powder, and 7 parts of Sn powder;

[0105] Step 2: placing the mixed powder in a mixer, modifying the particle shape, and mixing evenly to obtain a metal mixed powder;

[0106] The mixer is a horizontal pot mill, the mixed powder is added into the grinding pot of the horizontal pot mill, and the grinding medium is added at the same time, and the horizontal pot mill is started for grinding, and the grinding medium is a combination of zirconia balls and zirconia columns;

[0107] Wherein, the mass ratio of the mixed powder to the grinding medium in the grinding jar is 1:3;

[0108] The zirconia balls in the grinding medium are mixed zirconia balls of 10 mm balls, 5 mm balls, 3 mm balls and 1 mm balls in a mass ratio of 2:5:5:3;

[0109] The size of the zirconium oxide column in the grinding medium is 2 mm in bottom circle diameter and 4 mm in length;

[0110] Wherein, the mass ratio of the zirconia balls to the zirconia columns is 3:1;

[0111] Wherein, the rotation speed of the grinding jar is 200 rpm, and the grinding time is 5 hours;

[0112] The grinding tank is further added with a dispersant, which is triethanolamine, and the amount of the dispersant is 1% of the mass of the mixed powder;

[0113] Step 3: Put the metal mixed powder into the mold and press it into shape to obtain a preform;

[0114] The pressing method is cold isostatic pressing, the molding pressure is 700 MPa, and the holding time is 3 min.

[0115] Step 4: placing the preform in a high temperature furnace for sintering to obtain a titanium alloy;

[0116] The high-temperature furnace is a tubular furnace, and the sintering atmosphere is flowing argon. Before sintering, argon is passed through the tubular furnace for 2 hours. The sintering process is: from room temperature to 500°C, the heating rate is 5°C / min, and the temperature is kept for 30 minutes, then from 500°C to 1000°C, the heating rate is 7°C / min, and the temperature is kept for 30 minutes, then from 1000°C to 1400°C, the heating rate is 5°C / min, and the temperature is kept for 4 hours, then the temperature is cooled to 800°C with the furnace, and finally added into water for quenching treatment to obtain titanium alloy.

[0117] Step 5: Pressing hydroxyapatite into a target material, performing vacuum magnetron sputtering on the titanium alloy to form a hydroxyapatite coating to obtain a medical titanium alloy;

[0118] The conditions of the vacuum magnetron sputtering are as follows: the distance between the sputtering target and the substrate is 60 mm, the rotation speed of the rack for placing the titanium alloy is 15 r / min, the reaction gas is argon, the argon flow rate is 20 sccm, the working gas pressure is 0.5 Pa, the temperature is 350° C., and the sputtering time is 120 min;

[0119] Wherein, the hydroxyapatite is prepared by the following steps:

[0120] 0.17 mol calcium nitrate tetrahydrate, 0.05 mol trisodium citrate and 100 mL deionized water were added to a three-necked flask equipped with a stirrer, a thermometer and a constant pressure dropping funnel, and the reaction was stirred for 2.1 h at a temperature of 28 ° C and a stirring rate of 450 r / min. Then, the pH was adjusted to 9.3 with a 33% mass fraction of sodium hydroxide solution, and then 48 mL of a 1.9 mol / L diammonium hydrogen phosphate solution was added dropwise while stirring, and the dropping rate was controlled to 1 drop / s. After the dropwise addition was completed, the pH was adjusted to 10.5 with a 21% mass fraction of ammonia water, and then the reaction was continued to be stirred for 2.5 h, and then the temperature was raised to 83 ° C and the reaction was continued to be stirred for 9 h. After the reaction was completed, the reaction product was cooled to room temperature, and then vacuum filtered, the filter cake was washed 4 times with distilled water, and then placed in a vacuum drying oven, dried at a temperature of 105 ° C for 9 h, and then ground through a 200 mesh sieve to obtain hydroxyapatite.

[0121] The properties of the medical titanium alloys of Examples 1-3 and Comparative Examples 1-2 were tested, and the test results are as follows:

[0122]

[0123] Referring to the data in the above table, according to the comparison between Examples 1-3 and Comparative Examples 1-2, it can be seen that the medical titanium alloy in the present invention has excellent mechanical properties, and when a hydroxyapatite coating and a silver-containing hydroxyapatite coating are formed, the mechanical properties thereof can be effectively improved, and the formation of the silver-containing hydroxyapatite coating can also effectively improve the antibacterial and antimicrobial properties of the medical titanium alloy.

[0124] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0125] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the invention or exceed the scope defined by the claims, they shall all fall within the protection scope of the present invention.

Claims

1. A method for preparing a medical titanium alloy, characterized in that: The following steps are involved: Step 1: weighing single metal powders Ti, Nb, Zr and Sn according to a weight ratio to obtain a mixed powder; Step 2: placing the mixed powder in a mixer, modifying the particle shape, and mixing evenly to obtain a metal mixed powder; Step 3: Put the metal mixed powder into the mold and press it into shape to obtain a preform; Step 4: placing the preform in a high temperature furnace for sintering to obtain a titanium alloy; Step 5: Press the silver-containing hydroxyapatite into a target material, perform vacuum magnetron sputtering on the titanium alloy to form a silver-containing hydroxyapatite coating, and obtain a medical titanium alloy.

2. The method for preparing a medical titanium alloy according to claim 1, characterized in that: The weight ratio of the elemental metal powders Ti, Nb, Zr and Sn in step 1 is Ti:Nb:Zr:Sn=60-70:20-30:2-6:6-10.

3. The method for preparing a medical titanium alloy according to claim 1, characterized in that: The mixer in step 2 is a horizontal pot mill. The mixed powder is added to the grinding pot of the horizontal pot mill, and grinding media is added at the same time. The horizontal pot mill is started for grinding. The grinding media is a combination of zirconia balls and zirconia columns.

4. The method for preparing a medical titanium alloy according to claim 3, characterized in that: The mass ratio of the mixed powder to the grinding medium in the grinding jar is 1:1-5; The zirconia balls in the grinding medium are mixed zirconia balls of 10 mm balls, 5 mm balls, 3 mm balls and 1 mm balls in a mass ratio of 2:5:5:3; The size of the zirconium oxide column in the grinding medium is 1-3 mm in bottom circle diameter and 1-5 mm in length; The mass ratio of zirconia balls to zirconia columns is 2-5:1; The rotation speed of the grinding jar is 60-400 rpm, and the grinding time is 1-5 hours.

5. The method for preparing a medical titanium alloy according to claim 3, characterized in that: A dispersant is also added into the grinding jar. The dispersant is one of triethanolamine and polyethylene glycol. The amount of the dispersant is 0.5-2% of the mass of the mixed powder.

6. The method for preparing a medical titanium alloy according to claim 1, characterized in that: The pressing method in step three is cold isostatic pressing, the molding pressure is 300-700 MPa, and the holding time is 2-10 min.

7. The method for preparing a medical titanium alloy according to claim 1, characterized in that: The high-temperature furnace in step 4 is a tubular furnace, and the sintering atmosphere is flowing argon. Before sintering, argon is passed through the tubular furnace for 1-2 hours; the sintering process is: from room temperature to 500°C, the heating rate is 5°C / min, and the temperature is kept for 30 minutes, then from 500°C to 1000°C, the heating rate is 7°C / min, and the temperature is kept for 30 minutes, then from 1000°C to 1400°C, the heating rate is 5°C / min, and the temperature is kept for 4 hours, then the furnace is cooled to 800°C, and finally added into water for quenching to obtain titanium alloy.

8. The method for preparing a medical titanium alloy according to claim 1, characterized in that: The conditions of the vacuum magnetron sputtering in step five are: the distance between the sputtering target and the substrate is 60 mm, the rotation speed of the rack for placing the titanium alloy is 15 r / min, the reaction gas is argon, the argon flow rate is 20 sccm, the working gas pressure is 0.5 Pa, the temperature is 350°C, and the sputtering time is 120 min.

9. The method for preparing a medical titanium alloy according to claim 1, characterized in that: The silver-containing hydroxyapatite in step 5 is prepared by the following steps: Calcium nitrate tetrahydrate, trisodium citrate and deionized water are added to a three-necked flask for stirring reaction, and then silver nitrate is added to continue stirring reaction, and then the pH is adjusted with sodium hydroxide solution, and then diammonium hydrogen phosphate solution is added dropwise while stirring. After the addition is completed, the pH is adjusted with ammonia water, and then the stirring reaction is continued. After the reaction is completed, the reaction product is cooled, and then vacuum filtered, the filter cake is washed and dried, and then ground and sieved, and then calcined, and cooled with the furnace to obtain silver-containing hydroxyapatite.

10. The method for preparing a medical titanium alloy according to claim 9, characterized in that: The dosage ratio of the calcium nitrate tetrahydrate, trisodium citrate, deionized water, silver nitrate and diammonium hydrogen phosphate solution is 0.15-0.18 mol: 0.05 mol: 100 mL: 0.03-0.07 mol: 45-50 mL, the molar concentration of the diammonium hydrogen phosphate solution is 1.8-2.0 mol / L, the mass fraction of the sodium hydroxide solution is 30-35%, and the mass fraction of the ammonia water is 20-22%.

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