Heat treatment method for medical implant material

Abstract

The invention discloses a medical implant material heat treatment method, which relates to the technical field of medical implants, and comprises the following steps: surface treatment of a medical implant: firstly, carrying out burr removal and smoothing treatment on the surface of the medical implant needing to be subjected to heat treatment, namely, grinding and polishing the surface of the medical implant; and burrs or metal impurities possibly existing on the surface of the medical implant are removed. According to the method, the stress of the medical implant is eliminated through annealing treatment, so that the material distribution of the medical implant is more uniform, the hardness of the medical implant is reduced, the toughness and plasticity of the medical implant are improved, and the medical implant is difficult to break and deform; and finally, nitriding treatment is conducted, the wear resistance of the medical implant is further improved, the medical implant subjected to nitriding treatment is higher in corrosion resistance and not prone to being corroded by body fluid, and the service life of the medical implant is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of medical implants, and particularly relates to a heat treatment method for medical implant materials. Background Art

[0002] Medical implants are a general term for objects placed inside a patient's body during a surgical operation to promote the patient's postoperative recovery. They are commonly used in surgical operations such as artificial joints, bone trauma products, spinal orthopedic internal fixation systems, dental implants, dental prostheses, artificial heart valves, and interventional cardiovascular stents. Medical implants include metal implants and non-metal implants. Among them, metal implants are mainly various alloys, such as titanium alloys.

[0003] The currently used medical metal implant materials mainly have the following problems: First of all, the existing medical metal implants have poor wear resistance. Especially for implants at joint positions, as the activity time increases, the implants gradually wear, resulting in a shortened service life. At the same time, the existing medical implants have a high hardness, poor flexibility and fatigue strength, and are prone to breakage or deformation during daily use if the movement amplitude is large, affecting the use. Secondly, the existing medical metal implants have poor corrosion resistance. The implants exist in the body for a long time and are affected by the body fluids inside the body. The metal implants are corroded by each other. During this process, the metal generated by the corrosion of the implants will affect the body. Therefore, it is necessary to perform relevant treatments on the metal implants to improve the various properties of the implants. Summary of the Invention

[0004] The purpose of the present invention is to provide a heat treatment method for medical implant materials to solve the above problems.

[0005] To achieve the above purpose, the present invention provides the following technical solution: A heat treatment method for medical implant materials, comprising the following steps: S1: Surface treatment of medical implants: First, the surface of the medical implant to be heat-treated is subjected to deburring and smoothing treatment, that is, the surface of the medical implant is polished to remove possible burrs or metal impurities on the surface of the medical implant. After the deburring treatment is completed, the treated medical implant is detected. The medical implants that meet the requirements are subjected to the next operation, and the ones that do not meet the requirements are smoothed again until they meet the requirements. S2: Cleaning treatment of medical implants: After the surface treatment of medical implants, the treated medical implants are subjected to a cleaning treatment. During cleaning, first rinse the medical implants with clear water. After rinsing, soak the medical implants again with a cleaning solution. After soaking, place the medical implants in clear water again for cleaning to remove the residual cleaning solution. When the medical implants are cleaned with clear water multiple times, dry them and then perform heat treatment. S3: Heat treatment of medical implants: After the medical implants have been subjected to a cleaning treatment, place them in a heating device for heat treatment. After heat treatment, perform isothermal annealing on the medical implants. After annealing is completed and the medical implants are completely cooled, place the medical implants in the heating device again for heating. The heating temperature is higher than the annealing temperature. After heating is completed, quickly place the heated medical implants into a liquid medium for quenching. After quenching is completed, proceed to the next step. S4: Tempering treatment of medical implants: After the medical implants have been quenched, place them in a heating device again for heating. During heating, the temperature should be kept rising at a constant speed, and the highest temperature during heating in the tempering process should be lower than the highest temperature during quenching heating. After the tempering temperature rises to the highest temperature, keep the medical implants in a constant temperature state for heating for a period of time, and then let them cool naturally to the normal state, that is, the tempering treatment of the medical implants is completed. S5: Nitriding treatment of medical implants: After the heat treatment of medical implants is completed, place the medical implants in a negative pressure container containing a nitrogen-containing medium. At this time, the medical implants serve as the cathode. After energization, the nitrogen and hydrogen atoms in the medium are ionized, and a plasma region is formed between the anode and the cathode. Under the action of the strong electric field in the plasma region, the positive ions of nitrogen and hydrogen bombard the surface of the medical implants at high speed, thereby completing the nitriding treatment of the medical implants. After the nitriding treatment is completed, the heat treatment of the medical implants is completed.

[0006] Preferably, when the medical implants are subjected to nitriding treatment, during the high-speed bombardment of the positive ions of nitrogen and hydrogen, the high kinetic energy of the ions is converted into heat energy, heating the surface of the medical implants to the required temperature. Due to the bombardment of the ions, atomic sputtering occurs on the surface of the medical implants, so the medical implants are purified. At the same time, due to the adsorption and diffusion effects, nitrogen gradually penetrates into the surface of the medical implants.

[0007] Preferably, when the medical implant material is subjected to heat treatment, the medium in the heating device is a gas, and the heating gas is a mixed gas of nitrogen and oxygen. The volume ratio of the mixed gas is 65% - 85% nitrogen and 15% - 35% oxygen.

[0008] Preferably, during the surface treatment of the medical implants, first grind the surface of the medical implants with a grinding wheel, then polish the medical implants again with a cloth wheel or a nylon wheel, and finally wipe the medical implants with a sponge.

[0009] Preferably, when annealing the medical implant, raise the temperature of the heating device to 600 - 700 degrees Celsius. After the temperature is raised to the standard temperature, keep it warm for 3 - 4 hours. During the warming process, the temperature of the heating device shall not be lower than 600 degrees Celsius. After the warming time ends, use air cooling to let the metal implant cool naturally.

[0010] Preferably, when quenching the medical implant, put the medical implant into the heating device and heat the heating device to above the AC1 line. Generally, it needs to exceed the AC1 line by 50 - 70 degrees Celsius. After heating is completed, keep the medical implant warm for 5 - 8 hours. During the warming process, the internal temperature of the heating device shall not be lower than the AC1 line.

[0011] Preferably, when quenching the medical implant, the selected quenching liquid is an organic quenching liquid or quenching oil. The organic quenching liquid mainly includes polyvinyl alcohol aqueous solution, polyethylene glycol, polyamide polyethylene glycol aqueous solution, polyether aqueous solution, sodium polyacrylate aqueous solution, and polyacrylamide aqueous solution. The quenching oil is mainly preferably fast quenching oil.

[0012] Preferably, when tempering the medical implant, put the medical implant into the heating device and heat the heating device. The heating temperature shall not exceed the AC1 line, and the heating temperature range is 550 - 650 degrees Celsius. After heating is completed, keep it warm for 4 - 6 hours.

[0013] Preferably, during the nitriding treatment of the medical implant, the treatment time of the medical implant in the negative pressure container is 15 - 18 hours.

[0014] Preferably, after the medical implant undergoes nitriding treatment, it needs to be cleaned again. During cleaning, put the medical implant into the cleaning solution for ultrasonic cleaning. After cleaning is completed, clean the medical implant with clear water multiple times to remove the residual cleaning solution. After the medical implant is cleaned, the next processing operation can be carried out.

[0015] In summary, the technical effects and advantages of the present invention: In the present invention, the surface of the medical implant is first treated to make it smooth. Then, the medical implant is cleaned and then heat-treated. During the heat treatment, the stress of the medical implant is first eliminated through annealing treatment, so that the material distribution of the medical implant is more uniform. At the same time, the hardness of the medical implant is reduced, its toughness and plasticity are improved, and the medical implant is not easily broken or deformed, making it more durable. Then, quenching and tempering operations are carried out, thereby greatly improving the rigidity, hardness, wear resistance, fatigue strength and toughness of the medical implant. Finally, the heat-treated medical implant is nitrided to further improve the wear resistance of the medical implant, and at the same time enhance the strength and toughness of the medical implant. Finally, the nitrided medical implant has stronger corrosion resistance and is not easily corroded by body fluids, which is beneficial to extending its service life. Compared with traditional medical implants, the treated medical implant has higher strength, stronger toughness, is not easily broken or locked, and its wear resistance and corrosion resistance are significantly improved, making it safer to use and having a longer service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those skilled in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0017] Figure 1 It is a schematic diagram of the operation steps of a heat treatment method for a medical implant material proposed by the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

[0019] Embodiment: Refer to Figure 1 A heat treatment method for a medical implant material shown, which includes the following steps: S1: Surface treatment of the medical implant: First, the surface of the medical implant to be heat-treated is deburred and smoothed, that is, the surface of the medical implant is polished to remove possible burrs or metal impurities on the surface of the medical implant. After the deburring treatment is completed, the treated medical implant is inspected. The medical implant that meets the requirements is subjected to the next operation, and the one that does not meet the requirements is smoothed again until it meets the requirements. S2: Cleaning treatment of medical implants: After the surface treatment of medical implants, the treated medical implants are subjected to a cleaning treatment. During cleaning, first, the medical implants are rinsed with clean water. After rinsing, the medical implants are soaked again with a cleaning solution. After soaking, the medical implants are placed in clean water again for cleaning to remove the residual cleaning solution. When the medical implants are cleaned with clean water multiple times, they are dried and then subjected to heat treatment; S3: Heat treatment of medical implants: After the medical implants have been subjected to a cleaning treatment, they are placed in a heating device for heat treatment. After heat treatment, the medical implants are subjected to isothermal annealing. After annealing is completed, when the medical implants have completely cooled, the medical implants are placed in the heating device again for heating. The heating temperature is higher than the annealing temperature. After heating is completed, the heated medical implants are quickly placed in a liquid medium for quenching. After quenching is completed, the next operation is carried out; S4: Tempering treatment of medical implants: After the medical implants have been quenched, they are placed in a heating device again for heating. During heating, the temperature should be kept rising at a constant speed, and the highest temperature during heating in the tempering process should be lower than the highest temperature during quenching heating. After the tempering temperature rises to the highest temperature, the medical implants are heated at a constant temperature for a period of time, and then allowed to cool naturally to the normal state, that is, the tempering treatment of the medical implants is completed; S5: Nitriding treatment of medical implants: After the heat treatment of the medical implants is completed, the medical implants are placed in a negative pressure container containing a nitrogen-containing medium. At this time, the medical implants serve as the cathode. After being energized, the nitrogen and hydrogen atoms in the medium are ionized, and a plasma region is formed between the anode and the cathode. Under the action of the strong electric field in the plasma region, the positive ions of nitrogen and hydrogen bombard the surface of the medical implants at high speed, thereby completing the nitriding treatment of the medical implants. After the nitriding treatment is completed, the heat treatment of the medical implants is completed.

[0020] As a preferred implementation manner of this embodiment, when the medical implants are subjected to nitriding treatment, during the high-speed bombardment of the positive ions of nitrogen and hydrogen, the high kinetic energy of the ions is converted into heat energy, and the surface of the medical implants is heated to the required temperature. Due to the bombardment of the ions, atomic sputtering occurs on the surface of the medical implants, so the medical implants are purified. At the same time, due to the adsorption and diffusion effects, nitrogen gradually penetrates into the surface of the medical implants.

[0021] As a preferred implementation manner of this embodiment, when the medical implant material is subjected to heat treatment, the medium in the heating device is a gas, the heating gas is a mixed gas of nitrogen and oxygen, and the volume ratio of the mixed gas is 65% - 85% nitrogen and 15% - 35% oxygen.

[0022] As a preferred implementation manner of this embodiment, when the surface of the medical implant is treated, first, the surface of the medical implant is polished by a grinding wheel, then the medical implant is polished again by a cloth wheel or a nylon wheel, and finally, the medical implant is wiped by a sponge.

[0023] As a preferred implementation manner of this embodiment, when the medical implant is annealed, the temperature of the heating device is raised to 600 - 700 degrees Celsius. After the temperature is raised to the standard temperature, it is kept warm for 3 - 4 hours. During the heat preservation, the temperature of the heating device shall not be lower than 600 degrees Celsius. After the heat preservation time ends, the metal implant is naturally cooled by air cooling.

[0024] As a preferred implementation manner of this embodiment, when the medical implant is quenched, the medical implant is placed in a heating device, and the heating device is heated to above the AC1 line. Generally, it needs to exceed the AC1 line by 50 - 70 degrees Celsius. After heating is completed, the medical implant is kept warm for 5 - 8 hours. During the heat preservation, the internal temperature of the heating device shall not be lower than the AC1 line.

[0025] As a preferred implementation manner of this embodiment, when the medical implant is quenched, the selected quenching liquid is an organic quenching liquid or quenching oil. The organic quenching liquid mainly includes polyvinyl alcohol aqueous solution, polyethylene glycol, polyamide polyethylene glycol aqueous solution, polyether aqueous solution, sodium polyacrylate aqueous solution, and polyacrylamide aqueous solution. The quenching oil is mainly preferably fast quenching oil.

[0026] As a preferred implementation manner of this embodiment, when the medical implant is tempered, the medical implant is placed in a heating device, and the heating device is heated. The heating temperature shall not exceed the AC1 line, and the heating temperature range is 550 - 650 degrees Celsius. After heating is completed, it is kept warm for 4 - 6 hours.

[0027] As a preferred implementation manner of this embodiment, when the nitriding treatment of the medical implant is carried out, the treatment time of the medical implant in the negative pressure container is 15 - 18 hours.

[0028] As a preferred implementation manner of this embodiment, after the medical implant undergoes nitriding treatment, it needs to be cleaned again. When cleaning, the medical implant is placed in a cleaning solution for ultrasonic cleaning. After cleaning is completed, the medical implant is cleaned multiple times with clean water to remove the residual cleaning solution. After the medical implant is cleaned, the next processing operation can be carried out.

[0029] The working principle of the present invention: In the present invention, the surface of the medical implant is first treated to make it smooth. Then, after cleaning the medical implant, heat treatment is carried out. During the heat treatment, first, annealing treatment is performed to eliminate the stress of the medical implant, making the material distribution of the medical implant more uniform. At the same time, the hardness of the medical implant is reduced, and its toughness and plasticity are improved, so that the medical implant is not easily broken or deformed and is more durable. Then, quenching and tempering operations are carried out, thereby greatly improving the rigidity, hardness, wear resistance, fatigue strength and toughness of the medical implant. Finally, by carrying out nitriding treatment on the heat-treated medical implant, the wear resistance of the medical implant is further improved, and at the same time, the strength and toughness of the medical implant are enhanced. Finally, the nitrided medical implant has stronger corrosion resistance and is not easily corroded by body fluids, which is beneficial to extending its service life. Compared with traditional medical implants, the treated medical implant has higher strength, stronger toughness, is not easily broken or locked, and its wear resistance and corrosion resistance are significantly improved, making it safer to use and having a longer service life.

[0030] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A heat treatment method for a medical implant material, characterized in that, It includes the following steps: S1: Surface treatment of medical implant: First, the surface of the medical implant that needs heat treatment is deburred and smoothed, that is, the surface of the medical implant is polished to remove possible burrs or metal impurities on the surface of the medical implant. After the deburring treatment is completed, the treated medical implant is inspected. The medical implant that meets the requirements undergoes the next operation, and the one that does not meet the requirements is smoothed again until it meets the requirements; S2: Cleaning treatment of medical implant: After the surface treatment of the medical implant, the treated medical implant is cleaned. During cleaning, first, the medical implant is rinsed with clean water. After the rinsing is completed, the medical implant is soaked again with a cleaning solution. After the soaking is completed, the medical implant is placed in clean water again for cleaning to remove the remaining cleaning solution. When the medical implant is cleaned with clean water multiple times, it is dried and then heat-treated; S3: Heat treatment of medical implant: After the medical implant is cleaned, it is placed in a heating device for heating treatment. After the heating treatment, the medical implant is isothermally annealed. After the annealing is completed, when the medical implant is completely cooled, the medical implant is placed in the heating device again for heating. The heating temperature is higher than the annealing temperature. After the heating is completed, the heated medical implant is quickly placed in a liquid medium for quenching. After the quenching is completed, the next operation is carried out; S4: Tempering treatment of medical implant: After the medical implant is quenched, it is placed in a heating device again for heating. During heating, the temperature should rise evenly, and the highest temperature during heating in the tempering process should be lower than the highest temperature during quenching heating. After the tempering rises to the highest temperature, the medical implant is heated at a constant temperature for a period of time, and then it is allowed to cool naturally to the normal state, that is, the tempering treatment of the medical implant is completed; S5: Nitriding treatment of medical implant: After the heat treatment of the medical implant is completed, the medical implant is placed in a negative pressure container containing a nitrogen-containing medium. At this time, the medical implant serves as the cathode. After being energized, the nitrogen and hydrogen atoms in the medium are ionized, and a plasma region is formed between the anode and the cathode. Under the action of the strong electric field in the plasma region, the positive ions of nitrogen and hydrogen bombard the surface of the medical implant at high speed, thereby completing the nitriding treatment of the medical implant. After the nitriding treatment is completed, the heat treatment of the medical implant is completed.

2. The heat treatment method of a medical implant material according to claim 1, wherein: When the medical implant undergoes nitriding treatment, during the high-speed bombardment of the positive ions of nitrogen and hydrogen, the high kinetic energy of the ions is converted into heat energy, heating the surface of the medical implant to the required temperature. Due to the bombardment of the ions, atomic sputtering occurs on the surface of the medical implant, so the medical implant is purified. At the same time, due to the adsorption and diffusion effects, nitrogen gradually penetrates into the surface of the medical implant.

3. A heat treatment method for a medical implant material according to claim 1, characterized in that: When the medical implant material undergoes heat treatment, the medium in the heating device is a gas, and the heating gas is a mixed gas of nitrogen and oxygen. The volume ratio of the mixed gas is 65% - 85% nitrogen and 15% - 35% oxygen.

4. A heat treatment method for a medical implant material according to claim 1, characterized in that: When the surface of the medical implant is treated, first, the surface of the medical implant is polished by a grinding wheel, then the medical implant is polished again by a cloth wheel or a nylon wheel, and finally, the medical implant is wiped with a sponge.

5. A heat treatment method for a medical implant material according to claim 1, characterized in that: When the medical implant is annealed, the temperature of the heating device is raised to 600-700 degrees Celsius. After the temperature is raised to the standard temperature, it is kept warm for 3-4 hours. During the heat preservation, the temperature of the heating device shall not be lower than 600 degrees Celsius. After the heat preservation time ends, the metal implant is naturally cooled by air cooling.

6. A heat treatment method for a medical implant material according to claim 1, characterized in that: When the medical implant is quenched, the medical implant is placed in a heating device and the heating device is heated to above the AC1 line. Generally, it needs to exceed the AC1 line by 50-70 degrees Celsius. After heating is completed, the medical implant is kept warm for 5-8 hours. During the heat preservation, the internal temperature of the heating device shall not be lower than the AC1 line.

7. A heat treatment method for a medical implant material according to claim 1, characterized in that: When the medical implant is quenched, the selected quenching liquid is an organic quenching liquid or quenching oil. The organic quenching liquid mainly includes polyvinyl alcohol aqueous solution, polyethylene glycol, polyamide polyethylene glycol aqueous solution, polyether aqueous solution, sodium polyacrylate aqueous solution, and polyacrylamide aqueous solution. The quenching oil is mainly preferably fast quenching oil.

8. A heat treatment method for a medical implant material according to claim 1, characterized in that: When the medical implant is tempered, the medical implant is placed in a heating device and the heating device is heated. The heating temperature shall not exceed the AC1 line, and the heating temperature range is 550-650 degrees Celsius. After heating is completed, it is kept warm for 4-6 hours.

9. A heat treatment method for a medical implant material according to claim 1, characterized in that: When the nitriding treatment of the medical implant is carried out, the treatment time of the medical implant in the negative pressure container is 15-18 hours.

10. A heat treatment method for a medical implant material according to claim 1, characterized in that: After the medical implant undergoes nitriding treatment, it needs to be cleaned again. During cleaning, the medical implant is placed in a cleaning solution for ultrasonic cleaning. After cleaning is completed, the medical implant is cleaned multiple times with clean water to remove the residual cleaning solution. After the medical implant is cleaned, the next processing operation can be carried out.

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