CN104328312A - Medical biodegradable zinc alloy and preparation method thereof - Google Patents

Abstract

A medical biodegradable zinc alloy and a preparation method thereof, belonging to the field of material technology, the alloy composition contains Mg0.005-1%, Ag0.01-0.5%, Ca0.01-0.5%, Mn0.01-0.5 by weight percentage %, unavoidable impurities ≤ 0.2%, and the balance is Zn; the preparation method is: (1) Heat pure metallic zinc to 520±5°C, add metallic manganese, metallic silver, metallic calcium, and metallic magnesium in sequence after melting, and stir until Mix evenly; (2) Cool down to 460±5°C, press into hexachloroethane, keep it warm for 10~20min; (3) Keep the temperature down to 440±5°C for casting; (4) Keep warm at 300°C±5°C for 100~ 200min, heat up to 330~360℃ for 3~5 hours, then water-cooled to room temperature; (5) keep warm at 150~350℃ for 20~40min, then carry out high-temperature deformation, and air-cool to room temperature; (6) Perform multiple times of room temperature deformation- Intermediate annealing, and finally air cooling to room temperature. The zinc alloy of the invention can be used to prepare various degradable medical devices to meet different clinical use requirements.

Description

A kind of medical biodegradable zinc alloy and preparation method thereof

technical field

The invention belongs to the technical field of materials, and in particular relates to a medical biodegradable zinc alloy and a preparation method thereof.

Background technique

Due to their good mechanical properties and processing properties, metal materials have become widely used implant materials in clinical practice, mainly including pure metals (tantalum, niobium, zirconium, etc.), stainless steel, titanium alloys, cobalt-based alloys, shape memory alloys, precious metals, etc. These materials have good corrosion resistance and can remain stable for a long time after being implanted in the human body; but they also bring some problems, such as the need for secondary surgery to remove; the release of alloy elements may cause potential harm to the human body and other adverse effects.

In order to avoid the problems caused by the above-mentioned implant materials, a technique of using degradable implant materials has been proposed. The degradable implant materials currently used in clinical practice mainly include polymer materials and bioactive ceramic materials, but these degradable materials still have obvious defects: the mechanical properties of polymer materials are too low, and the acidic environment generated by degradation will increase the degree of inflammation. Possibility; the plasticity and toughness of bioactive ceramics are poor, which limits its application range. At present, metal-based degradable implant materials have not been clinically applied, and their development and research are still in progress, and mainly focus on magnesium alloys and iron-based alloys. However, there are some problems in the degradation rate of magnesium alloy and iron-based alloy as degradable implant materials. The biggest problem of magnesium alloy is that its degradation rate is too fast, which affects its biocompatibility and mechanical properties during use; while iron The biggest problem with base alloys is that the degradation rate is too slow, which will cause a series of adverse reactions similar to those of biologically inert materials.

The chemical activity of zinc metal is between magnesium and iron, so its corrosion rate is expected to be between the two, so that materials with appropriate degradation rates can be prepared. In addition, zinc is one of the essential trace elements for the human body. The zinc content in the adult body is 1.4~2.3g, and the daily dietary allowance of zinc for healthy adults is 15~40mg. There are certain advantages in terms of security. However, the mechanical properties of pure zinc are poor, and the strength and plasticity cannot meet the requirements of implant materials.

Contents of the invention

The purpose of the present invention is to provide a medical biodegradable zinc alloy and its preparation method, select metal elements harmless to the human body for alloying, and then heat-deform, cold-deform and heat-treat the alloy to obtain high strength, good plasticity, Degradable zinc alloy medical degradable material.

The composition of the medical biodegradable zinc alloy of the present invention contains Mg 0.005-1%, Ag 0.01-0.5%, Ca 0.01-0.5%, Mn 0.01-0.5%, unavoidable impurities ≤ 0.2%, and Zn .

The above-mentioned medical biodegradable zinc alloy has a tensile strength of 260-450 MPa, a tensile yield strength of 195-380 MPa, and an elongation of 5-30%.

The preparation method of medical biodegradable zinc alloy of the present invention is carried out according to the following steps:

(1) Prepare metal zinc, metal magnesium, metal silver, metal calcium and metal manganese as raw materials according to the above ingredients; heat pure metal zinc to 520±5°C, and add metal manganese, metal silver, and metal calcium in turn after the metal zinc melts and metal magnesium, after all the metals are melted, stir until they are evenly mixed to obtain an alloy melt;

(2) Cool the alloy melt to 460±5°C, press hexachloroethane into the alloy melt with a graphite bell jar, the pressed hexachloroethane is 0.2~0.3% of the total weight of the alloy melt, and then Keep it warm at 460±5℃ for 10~20min;

(3) After the heat preservation and standing, the alloy melt is cooled to 440±5°C and cast into a mold. During the casting process, the mold is cooled by water to obtain an ingot;

(4) The ingot is subjected to homogenization treatment. The homogenization treatment is carried out at 300°C±5 for 100-200 minutes; then the temperature is raised to 330-360°C for 3-5 hours, and then water-cooled to room temperature to obtain an ingot;

(5) Heat the ingot at 150-350°C for 20-40 minutes, then carry out high-temperature plastic deformation at 150-350°C, and then air-cool to room temperature to obtain a thermally deformed alloy; the high-temperature plastic deformation is extrusion, Rolling or forging, when extruding, the extrusion ratio is 16~150; when rolling or forging, the total deformation is 50~80%;

(6) Perform multiple normal temperature deformation-intermediate annealing on the heat-changing alloy, and each normal temperature deformation is divided into multiple passes of drawing or rolling. The total deformation of secondary normal temperature deformation is 60~80%; after each normal temperature deformation, an intermediate annealing is carried out, the intermediate annealing temperature is 150~300℃, and the time is 10~20min; when multiple normal temperature deformation - the total deformation of intermediate annealing When it reaches 92~98%, after the last intermediate annealing, it is air-cooled to room temperature to obtain a medical biodegradable zinc alloy.

In the above method, the tensile strength of the thermally deformable alloy is 220-400 MPa, the tensile yield strength is 160-360 MPa, and the elongation is 12-40%.

The above-mentioned medical biodegradable zinc alloy is plate, rod or wire.

The heating equipment adopted in the above steps 1 and 2 is a resistance furnace.

The ingot obtained in the above step 3 is a cylinder with a diameter of 40-60 mm or a square with a side length of 40-60 mm.

The above-mentioned medical biodegradable zinc alloy adopts the weight loss method, and its corrosion rate is 0.2~0.8mm/year measured in SBF solution at 37°C.

The advantages of the present invention are:

1. Zinc, magnesium, calcium, and manganese in medical biodegradable zinc alloys are all elements contained in the human body, and trace amounts of silver are harmless to the human body, and silver ions can be released during its degradation process to play a role in sterilization It can avoid infection after the device is implanted, thereby reducing the pain and trouble of the patient;

2. Medical biodegradable zinc alloys can be processed by extrusion, rolling, forging or drawing to obtain rods, wires, plates and profiles; the mechanical properties can be greatly changed through slight adjustments in the content of alloy elements , can meet the performance requirements of yield strength>200MPa, elongation>15%, and can control its degradation rate to about 0.5mm/year;

3. The rods, wires, plates and profiles of medical biodegradable zinc alloys have a wide range of sizes (Φ0.05~12mm or t0.1~20mm), which can be used for the preparation of different implant devices, such as bone nails, bone Plates, cardiovascular scaffolds, bone tissue engineering scaffolds, sutures, and composite devices made with other materials can be used to prepare various degradable devices to meet different clinical use requirements.

Description of drawings

Figure 1 shows the systemic toxicity test results of the medical biodegradable zinc alloy prepared in Example 1 of the present invention; wherein (a) myocardial tissue; (b) liver tissue; (c) kidney tissue;

Figure 2 is the X-ray image of the extruded zinc alloy obtained in Example 1 of the present invention after being implanted into New Zealand white rabbits, wherein (a) one week after implantation; (b) one month after implantation; (c) three weeks after implantation months later;

Fig. 3 is the photogram of the metallographic structure of the thermally deformable alloy in Example 1 of the present invention;

Fig. 4 is a curve diagram of tensile properties at room temperature of the thermally deformable alloy in Example 1 of the present invention;

Fig. 5 is a macroscopic view of the medical biodegradable zinc alloy and pure magnesium in Example 1 of the present invention after soaking in SBF solution at 37°C for 8 days, wherein (a) is the medical biodegradable zinc alloy of Example 1 of the present invention, (b) is pure magnesium;

Figure 6 is a graph showing the corrosion rate of the medical biodegradable zinc alloy and pure magnesium immersed in 37°C SBF solution in Example 1 of the present invention as a function of immersion time; in the figure, ◆ is pure magnesium, ▼ is medical biodegradable Degradation of zinc alloy;

Fig. 7 is the photogram of alloy metallographic structure after room temperature deformation in the embodiment of the present invention 1;

Fig. 8 is a curve diagram of tensile properties of the alloy at room temperature after deformation at room temperature in Example 1 of the present invention.

Detailed ways

The purity of zinc metal used in the embodiment of the present invention is 99.995%, the purity of magnesium metal is 99.99%, the purity of silver metal is 99.99%, the purity of calcium metal is 99.95%, and the purity of manganese metal is 99.995%.

The test method of the systemic toxicity test in the embodiment of the present invention is according to GB/T 16886.11-1997 Biological Evaluation of Medical Devices Part 11: Systemic Toxicity Test Standard.

The equipment used to observe the metallographic structure in the embodiment of the present invention is the GX71 inverted system metallographic microscope produced by OLYMPUS Company.

The standard used in the tensile test in the embodiment of the present invention is the national standard GB/T 228-2002 "Metallic Materials Normal Temperature Tensile Test Method", and the equipment is the AG-X100kN electronic universal material testing machine produced by Shimadzu Corporation.

The standard that test performance adopts in the embodiment of the present invention is national standard GB/T16545-1996 " the corrosion of metal and alloy---removal of corrosion product on corrosion sample ", SBF solution preparation is based on ISO/FDIS23317: Implants for surgery——In In vitro evaluation for apatite-forming ability of implant materials is carried out.

The ingot in the embodiment of the present invention is a cylinder with a diameter of 40-60 mm or a square with a side length of 40-60 mm.

Example 1

The composition contains Mg 0.05%, Ag 0.5%, Ca 0.1%, Mn 0.1% by weight percentage, unavoidable impurities ≤ 0.2%, and the balance is Zn;

Metal zinc, metal magnesium, metal silver, metal calcium and metal manganese are used as raw materials; pure metal zinc is heated to 520±5°C, and metal manganese, metal silver, metal calcium and metal magnesium are added sequentially after the metal zinc is melted, and when all the metal After melting, stir until evenly mixed to obtain alloy melt;

Cool down the alloy melt to 460±5°C, press hexachloroethane into the alloy melt using a graphite bell jar, the pressed hexachloroethane is 0.2% of the total weight of the alloy melt, and then heat it at 460±5°C Keep warm for 20 minutes;

After the heat preservation and standing, the alloy melt is cooled to 440±5°C and cast into the mold, and the mold is cooled by water during the casting process to obtain the ingot;

The ingot is kept at 300°C±5 for 100 minutes, then heated to 360°C for 3 hours, and then water-cooled to room temperature to obtain an ingot;

The ingot was kept at 200°C for 40 minutes, then subjected to high-temperature plastic deformation at 200°C, and then air-cooled to room temperature to obtain a thermally deformed alloy with a tensile strength of 220MPa, a tensile yield strength of 160MPa, and an elongation of 17%. The metallographic structure photo of the morphology alloy is shown in Figure 3, and the tensile performance curve at room temperature is shown in Figure 4;

The high-temperature plastic deformation is extrusion, and the extrusion ratio is 16;

The heat-changing shape alloy is subjected to multiple normal temperature deformation-intermediate annealing, and each normal temperature deformation is divided into multi-pass drawing, and the deformation amount of each drawing is 8~20%, and the total deformation amount of each normal temperature deformation is 60%. ~80%; carry out an intermediate annealing after each normal temperature deformation, the intermediate annealing temperature is 300 ℃, and the time is 10 minutes; when the total deformation of multiple normal temperature deformation-intermediate annealing reaches 92%, air cool to At room temperature, a medical biodegradable zinc alloy was obtained, with a tensile strength of 260MPa, a tensile yield strength of 195MPa, and an elongation of 14%. The corrosion rate was 0.2mm/year measured in SBF solution at 37°C by weight loss method, and the corrosion rate Figure 6 shows the curve of rate versus immersion time, Figure 7 shows the metallographic structure of the alloy deformed at room temperature, and Figure 8 shows the tensile property curve at room temperature.

Example 2

The composition contains Mg 1%, Ag 0.01%, Ca 0.5%, Mn 0.01% by weight percentage, unavoidable impurities ≤ 0.2%, and the balance is Zn;

Metal zinc, metal magnesium, metal silver, metal calcium and metal manganese are used as raw materials; pure metal zinc is heated to 520±5°C, and metal manganese, metal silver, metal calcium and metal magnesium are added sequentially after the metal zinc is melted, and when all the metal After melting, stir until evenly mixed to obtain alloy melt;

Cool the alloy melt to 460±5°C, press hexachloroethane into the alloy melt using a graphite bell jar, the pressed hexachloroethane is 0.25% of the total weight of the alloy melt, and then heat the alloy at 460±5°C Keep warm for 10 minutes;

After the heat preservation and standing, the alloy melt is cooled to 440±5°C and cast into the mold, and the mold is cooled by water during the casting process to obtain the ingot;

The ingot is kept at 300°C ± 5 for 150 minutes, then heated to 330°C for 5 hours, and then water-cooled to room temperature to obtain an ingot;

The ingot was kept at 250°C for 30 minutes, then subjected to high-temperature plastic deformation at 250°C, and then air-cooled to room temperature to obtain a thermally deformed alloy with a tensile strength of 400MPa, a tensile yield strength of 60340MPa, and an elongation of 12%;

The high-temperature plastic deformation is extrusion, and the extrusion ratio is 150;

The heat-changing shape alloy is subjected to multiple normal temperature deformation-intermediate annealing, and each normal temperature deformation is divided into multi-pass rolling, and the deformation amount of each rolling pass is 8~20%, and the total deformation amount of each normal temperature deformation is 60% ~80%; carry out an intermediate annealing after each normal temperature deformation, the intermediate annealing temperature is 150°C, and the time is 20min; when the total deformation of multiple normal temperature deformation-intermediate annealing reaches 94%, air cool to At room temperature, a medical biodegradable zinc alloy was obtained, with a tensile strength of 450MPa, a tensile yield strength of 380MPa, and an elongation of 5%. The corrosion rate was measured at 0.6mm/year in a 37°C SBF solution using the weight loss method.

Example 3

The composition contains Mg 0.005%, Ag 0.1%, Ca 0.15%, Mn 0.15% by weight percentage, unavoidable impurities ≤ 0.2%, and the balance is Zn;

Metal zinc, metal magnesium, metal silver, metal calcium and metal manganese are used as raw materials; pure metal zinc is heated to 520±5°C, and metal manganese, metal silver, metal calcium and metal magnesium are added sequentially after the metal zinc is melted, and when all the metal After melting, stir until evenly mixed to obtain alloy melt;

Cool the alloy melt to 460±5°C, press hexachloroethane into the alloy melt using a graphite bell jar, the pressed hexachloroethane is 0.3% of the total weight of the alloy melt, and then heat the alloy at 460±5°C Keep warm for 20 minutes;

After the heat preservation and standing, the alloy melt is cooled to 440±5°C and cast into the mold, and the mold is cooled by water during the casting process to obtain the ingot;

The ingot is kept at 300°C±5 for 200 minutes, then heated to 340°C for 3 hours, and then water-cooled to room temperature to obtain an ingot;

The ingot was kept at 350°C for 20 minutes, then subjected to high-temperature plastic deformation at 350°C, and then air-cooled to room temperature to obtain a thermally deformed alloy with a tensile strength of 270MPa, a tensile yield strength of 200MPa, and an elongation of 40%;

The high-temperature plastic deformation is extrusion, and the extrusion ratio is 80;

The heat-changing shape alloy is subjected to multiple normal temperature deformation-intermediate annealing, and each normal temperature deformation is divided into multi-pass drawing, and the deformation amount of each drawing is 8~20%, and the total deformation amount of each normal temperature deformation is 60%. ~80%; carry out an intermediate annealing after each normal temperature deformation, the intermediate annealing temperature is 150~300℃, and the time is 10~20min; when the total deformation of multiple normal temperature deformation-intermediate annealing reaches 95%, in the last intermediate After annealing, it was air-cooled to room temperature to obtain a medical biodegradable zinc alloy with a tensile strength of 320MPa, a tensile yield strength of 240MPa, and an elongation of 30%. The corrosion rate was measured at 0.5mm in 37°C SBF solution by the weight loss method. /year.

Example 4

The composition contains Mg 0.16%, Ag 0.43%, Ca 0.01%, Mn 0.05% by weight percentage, unavoidable impurities ≤ 0.2%, and the balance is Zn;

Metal zinc, metal magnesium, metal silver, metal calcium and metal manganese are used as raw materials; pure metal zinc is heated to 520±5°C, and metal magnesium, metal silver, metal calcium and metal manganese are added in turn after the metal zinc is dissolved, and when all the metal After melting, stir until evenly mixed to obtain alloy melt;

Cool down the alloy melt to 460±5°C, press hexachloroethane into the alloy melt using a graphite bell jar, the pressed hexachloroethane is 0.2% of the total weight of the alloy melt, and then heat it at 460±5°C Keep warm for 15 minutes;

After the heat preservation and standing, the alloy melt is cooled to 440±5°C and cast into the mold, and the mold is cooled by water during the casting process to obtain the ingot;

The ingot is kept at 300°C±5 for 100 minutes, then heated to 350°C for 4 hours, and then water-cooled to room temperature to obtain an ingot;

The ingot was kept at 150°C for 40 minutes, then subjected to high-temperature plastic deformation at 150°C, and then air-cooled to room temperature to obtain a thermally deformed alloy with a tensile strength of 220MPa, a tensile yield strength of 160MPa, and an elongation of 30%;

The high-temperature plastic deformation is rolling, and the total deformation is 80%;

The heat-changing shape alloy is subjected to multiple normal temperature deformation-intermediate annealing, and each normal temperature deformation is divided into multi-pass rolling, and the deformation amount of each rolling pass is 8~20%, and the total deformation amount of each normal temperature deformation is 60% ~80%; carry out an intermediate annealing after each normal temperature deformation, the intermediate annealing temperature is 150~300℃, and the time is 10~20min; when the total deformation of multiple normal temperature deformation-intermediate annealing reaches 98%, in the last After annealing, it was air-cooled to room temperature to obtain a medical biodegradable zinc alloy with a tensile strength of 270MPa, a tensile yield strength of 220MPa, and an elongation of 22%. The corrosion rate was measured at 0.8mm in 37°C SBF solution by weight loss method. /year.

Example 5

The composition contains Mg 0.47%, Ag 0.2%, Ca 0.38%, Mn 0.5% by weight percentage, unavoidable impurities ≤ 0.2%, and the balance is Zn;

Metal zinc, metal magnesium, metal silver, metal calcium and metal manganese are used as raw materials; pure metal zinc is heated to 520±5°C, and metal magnesium, metal silver, metal calcium and metal manganese are added in turn after the metal zinc is dissolved, and when all the metal After melting, stir until evenly mixed to obtain alloy melt;

Cool the alloy melt to 460±5°C, press hexachloroethane into the alloy melt using a graphite bell jar, the pressed hexachloroethane is 0.3% of the total weight of the alloy melt, and then heat the alloy at 460±5°C Keep warm for 10 minutes;

After the heat preservation and standing, the alloy melt is cooled to 440±5°C and cast into the mold, and the mold is cooled by water during the casting process to obtain the ingot;

The ingot is kept at 300°C ± 5 for 200 minutes, then heated to 330°C for 5 hours, and then water-cooled to room temperature to obtain an ingot;

The ingot was kept at 350°C for 20 minutes, then subjected to high-temperature plastic deformation at 350°C, and then air-cooled to room temperature to obtain a thermally deformed alloy with a tensile strength of 330MPa, a tensile yield strength of 270MPa, and an elongation of 36%;

The high-temperature plastic deformation is forging, and the total deformation is 50%;

The heat-changing shape alloy is subjected to multiple normal temperature deformation-intermediate annealing, and each normal temperature deformation is divided into multi-pass drawing, and the deformation amount of each drawing is 8~20%, and the total deformation amount of each normal temperature deformation is 60%. ~80%; carry out an intermediate annealing after each normal temperature deformation, the intermediate annealing temperature is 150 ℃, and the time is 20 minutes; when the total deformation of multiple normal temperature deformation-intermediate annealing reaches 96%, air cool to At room temperature, a medical biodegradable zinc alloy was obtained, with a tensile strength of 380MPa, a tensile yield strength of 300MPa, and an elongation of 26%. The corrosion rate was measured at 37°C SBF solution at 0.35mm/year by weight loss method.

Claims (5)

1. a medical bio degradable zinc alloy, it is characterized in that composition by weight percentage containing Mg 0.005 ~ 1%, Ag 0.01 ~ 0.5%, Ca 0.01 ~ 0.5%, Mn 0.01 ~ 0.5%, inevitable impurity≤0.2%, surplus is Zn.

2. a kind of medical bio degradable zinc alloy according to claim 1, it is characterized in that the tensile strength of this alloy is 260 ~ 450MPa, tensile yield strength is 195 ~ 380MPa, unit elongation 5 ~ 30%.

3. the preparation method of medical bio degradable zinc alloy according to claim 1, is characterized in that carrying out according to the following steps:

(1) metallic zinc, MAGNESIUM METAL, argent, calcium metal and manganese metal is prepared as raw material by composition according to claim 1; Pure metal zinc is heated to 520 ± 5 DEG C, after metallic zinc is dissolved, adds manganese metal, argent, calcium metal and MAGNESIUM METAL successively, after whole melting of metal, be stirred to and mix, obtain alloy melt;

(2) alloy melt is cooled to 460 ± 5 DEG C, utilizes graphite bell jar to be pressed into hexachloroethane in alloy melt, the hexachloroethane of press-in is 0.2 ~ 0.3% of alloy melt gross weight, then leaves standstill 10 ~ 20min 460 ± 5 DEG C of insulations;

(3) after the standing end of insulation, alloy melt being cooled to 440 ± 5 DEG C is poured in mould, and in casting cycle, die through water cooling, obtains ingot casting;

(4) ingot casting carries out Homogenization Treatments, and Homogenization Treatments is at 300 DEG C ± 5 insulation 100 ~ 200min; Then be warming up to 330 ~ 360 DEG C of insulations 3 ~ 5 hours, then water-cooled is to normal temperature, obtains ingot blank;

(5) ingot blank is incubated 20 ~ 40min at 150 ~ 350 DEG C, then carry out high temperature plastic distortion at 150 ~ 350 DEG C, then air cooling is to normal temperature, obtain heat-altered morphology alloy; Described high temperature plastic is deformed into extruding, rolling or forging, and when extruding, extrusion ratio is 16 ~ 150; When being rolled or forge, total deformation is 50 ~ 80%;

(6) heat-altered morphology alloy is carried out repeatedly normal temperature distortion-process annealing, each normal temperature distortion is divided into multi pass drawing or rolling, and the deflection of every time drawing or rolling is 8 ~ 20%, and the total deformation of each normal temperature distortion is 60 ~ 80%; Carry out a process annealing after each normal temperature distortion, intermediate anneal temperature is 150 ~ 300 DEG C, and the time is 10 ~ 20min; When the total deformation of repeatedly normal temperature distortion-process annealing reaches 92 ~ 98%, after process annealing, air cooling, to normal temperature, obtains medical bio degradable zinc alloy the last time.

4. the preparation method of medical bio degradable zinc alloy according to claim 3, it is characterized in that the tensile strength of described heat-altered morphology alloy is 220 ~ 400MPa, tensile yield strength is 160 ~ 360MPa, unit elongation 12 ~ 40%.

5. the preparation method of medical bio degradable zinc alloy according to claim 3, it is characterized in that described medical bio degradable zinc alloy adopts weight-loss method, in 37 DEG C of SBF solution, record its erosion rate is 0.2 ~ 0.8mm/year.