A spheroidized grain medical magnesium alloy and preparation method thereof

Abstract

The embodiment of the present invention discloses a spheroidized grain medical magnesium alloy and a preparation method thereof, which are used to solve the technical problems of the current medical magnesium alloy with fast degradation rate and poor corrosion resistance. The spheroidized fine grain medical magnesium alloy in the embodiment of the present invention includes the following components by weight percentage: Ag: 10wt.%, Y: 2wt.%, Gd: 0.3wt.%-0.9wt.%, Sn: 0.25%; Ce: 0.2wt.%, Si: 0.25wt.%, Dy: 0.1wt.%, Er: 0.12wt.%, Sr: 0.08wt.%, Nd: 0.05wt.%, the remainder is Mg and unavoidable impurities; wherein the single impurity content does not exceed 0.02wt.%, and the total amount of impurities does not exceed 0.1wt.%. The spheroidized grain medical magnesium alloy in this embodiment has excellent corrosion resistance, can achieve uniform degradation during implantation, reduce medical costs, reduce the pain of doctors and patients, and at the same time improves the antibacterial property of the medical magnesium alloy, and can be repeatedly sterilized during implantation.

Description

Technical Field

[0001] The invention relates to the technical field of medical magnesium alloys, and in particular to a spheroidized grain medical magnesium alloy and a preparation method thereof. Background Art

[0002] Magnesium alloy has a low density and is close to the density of human bone, high specific strength and specific stiffness, excellent biocompatibility, and can be degraded and absorbed in the body. Compared with traditional medical metal materials, semi-solid magnesium alloy is used as a medical implant material.

[0003] Although existing medical magnesium alloys are more suitable for implantation in the human body than traditional metal materials, they degrade at a fast rate and have insufficient corrosion resistance when staying in the human body for a long time, making them unable to play a supporting and fixing function in the human body for a long time.

[0004] Therefore, finding a technical solution that can solve the above technical problems has become an important topic studied by technical personnel in this field. Summary of the invention

[0005] The embodiment of the present invention discloses a spheroidized grain medical magnesium alloy and a preparation method thereof, which are used to solve the technical problems of the current medical magnesium alloy having a fast degradation rate and poor corrosion resistance.

[0006] An embodiment of the present invention provides a spheroidized grain medical magnesium alloy, which includes the following components in weight percentage: Ag: 10wt.%, Y: 2wt.%, Gd: 0.3wt.%-0.9wt.%, Sn: 0.25%; Ce: 0.2wt.%, Si: 0.25wt.%, Dy: 0.1wt.%, Er: 0.12wt.%, Sr: 0.08wt.%, Nd: 0.05wt.%, and the remainder is Mg and unavoidable impurities; wherein the content of a single impurity does not exceed 0.02wt.%, and the total amount of impurities does not exceed 0.1wt.%.

[0007] Optionally, the microstructure of the spheroidized grain medical magnesium alloy is composed of spheroidal grains after semi-solid treatment.

[0008] Optionally, the average size of the spherical grains is 10 μm to 15 μm.

[0009] Optionally, the average sphericity S of the spherical grains is 0.75 to 0.8.

[0010] Optionally, the raw materials for preparing the spheroidized grain medical magnesium alloy are industrial pure magnesium, industrial pure silver and magnesium-based master alloy.

[0011] Optionally, the spheroidized grain medical magnesium alloy is prepared by a semi-solid rheoforming method or a thixoforming method.

[0012] The embodiment of the present invention discloses a method for preparing a spheroidized grain medical magnesium alloy, wherein the spheroidized grain medical magnesium alloy comprises the following components by weight percentage: Ag: 10wt.%, Y: 2wt.%, Gd: 0.3wt.%-0.9wt.%, Sn: 0.25%; Ce: 0.2wt.%, Si: 0.25wt.%, Dy: 0.1wt.%, Er: 0.12wt.%, Sr: 0.08wt.%, Nd: 0.05wt.%, and the remainder is Mg and unavoidable impurities; wherein the content of a single impurity does not exceed 0.02wt.%, and the total amount of impurities does not exceed 0.1wt.%;

[0013] The preparation method of the spheroidized grain medical magnesium alloy based on the above components is as follows:

[0014] S1. Weighing: weighing industrial pure magnesium, industrial pure silver and magnesium-based master alloy according to the chemical composition ratio of the spheroidized grain medical magnesium alloy;

[0015] S2, drying: preheating the weighed industrial pure magnesium, industrial pure silver and magnesium-based master alloy at 100-120°C for 15-20 minutes;

[0016] S3, preparing a semi-solid metal melt: smelting industrial pure magnesium in a 680-720°C heating furnace filled with protective gas, heating the industrial pure magnesium to 740-760°C after the industrial pure magnesium is fully melted, adding the preheated magnesium-based master alloy, adding industrial pure silver when the temperature rises to 740-760°C after the magnesium-based master alloy is melted, heating the temperature to 760-780°C and keeping it warm for 20-30 minutes, removing the surface scum, stirring vigorously for 10 minutes, standing and keeping it warm for 20-30 minutes, then skimming, degassing, and refining for 5 minutes, reducing the temperature to 710-730°C, keeping it warm and standing for 15-20 minutes, to obtain a semi-solid metal melt;

[0017] S4, rheoforming: the semi-solid metal melt flows through a slurry channel to a feed port of a die-casting machine, and fills a mold cavity in a pressure chamber, thereby obtaining the spheroidized grain medical magnesium alloy.

[0018] It can be seen from the above technical solutions that the embodiments of the present invention have the following advantages:

[0019] This embodiment optimizes the design of the composition of the medical magnesium alloy and chooses to add the Ag element that is harmless to the human body. Ag is a trace element in the human body. Silver ions and their compounds can destroy the inherent components of bacteria and kill bacteria. The activity of bacterial cell synthases is impaired, causing the cells to lose their ability to reproduce and grow. When the bacteria are inactivated, Ag+ will be freed to repeatedly destroy bacteria, without harming normal cells and beneficial bacteria in the human body. The addition of Ag is conducive to grain refinement and improving the strength of the alloy; adding an appropriate amount of rare earth elements can not only refine the grains, but also help spheroidize the grains and improve the mechanical properties. The rare earth element Y has a large solid solubility in Mg, and can achieve solid solution strengthening and precipitation strengthening in the alloy. Y can form an oxide film during the corrosion process to inhibit degradation and improve corrosion resistance. After the alloy is completely degraded, there is no residue in the human body and it will not cause harm to the body. The addition of the element Gd will reduce the solid solubility of the Y element, but can greatly increase the volume fraction of the precipitated phase, thereby further improving the mechanical properties of the medical magnesium alloy. The combined addition of Sn, Ce, Si, Dy, Er, Sr and Nd elements can significantly improve the forming properties, mechanical properties and corrosion resistance of medical magnesium alloys. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0021] Figure 1 This is a scanning electron microscope image of a spheroidized grain medical magnesium alloy provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0022] The embodiment of the present invention discloses a spheroidized grain medical magnesium alloy and a preparation method thereof, which are used to solve the technical problems of the current medical magnesium alloy having a fast degradation rate and poor corrosion resistance.

[0023] In order to enable those skilled in the art to better understand the scheme of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0024] Example

[0025] See also Figure 1, a spheroidized grain medical magnesium alloy is provided in an embodiment of the present invention, and the spheroidized grain medical magnesium alloy includes the following components in weight percentage: Ag: 10wt.%, Y: 2wt.%, Gd: 0.3wt.%-0.9wt.%, Sn: 0.25%; Ce: 0.2wt.%, Si: 0.25wt.%, Dy: 0.1wt.%; Er: 0.12wt.%, Sr: 0.08wt.%, Nd: 0.05wt.%, and the remainder is Mg and unavoidable impurities; wherein the content of a single impurity does not exceed 0.02wt.%, and the total amount of impurities does not exceed 0.1wt.%.

[0026] This embodiment optimizes the design of the composition of the medical magnesium alloy and chooses to add the Ag element that is harmless to the human body. Ag is a trace element in the human body. Silver ions and their compounds can destroy the inherent components of bacteria and kill bacteria. The activity of bacterial cell synthases is impaired, causing the cells to lose their ability to reproduce and grow. When the bacteria are inactivated, Ag+ will be freed to repeatedly destroy bacteria, without harming normal cells and beneficial bacteria in the human body. The addition of Ag is conducive to grain refinement and improving the strength of the alloy; adding an appropriate amount of rare earth elements can not only refine the grains, but also help spheroidize the grains and improve the mechanical properties. The rare earth element Y has a large solid solubility in Mg, and can achieve solid solution strengthening and precipitation strengthening in the alloy. Y can form an oxide film during the corrosion process to inhibit degradation and improve corrosion resistance. After the alloy is completely degraded, there is no residue in the human body and it will not cause harm to the body. The addition of the element Gd will reduce the solid solubility of the Y element, but can greatly increase the volume fraction of the precipitated phase, thereby further improving the mechanical properties of the medical magnesium alloy. The combined addition of Sn, Ce, Si, Dy, Er, Sr and Nd elements can significantly improve the forming properties, mechanical properties and corrosion resistance of medical magnesium alloys.

[0027] The spheroidized grain medical magnesium alloy in this embodiment has an excellent degradation rate during the actual implantation process and can achieve uniform degradation. While maintaining the supporting and fixing functions of the implant material, it can also reduce medical costs and alleviate the pain of patients.

[0028] Furthermore, if Figure 1 As shown, the microstructure of the spheroidized grain medical magnesium alloy in this embodiment is composed of spheroidal grains after semi-solid treatment.

[0029] The average size of the spherical grains is 10 μm to 15 μm.

[0030] The average sphericity S of the spherical grains is 0.75 to 0.8.

[0031] Furthermore, the raw materials for preparing the spheroidized grain medical magnesium alloy in this embodiment are industrial pure magnesium, industrial pure silver and magnesium-based master alloy.

[0032] Furthermore, the spheroidized grain medical magnesium alloy in this embodiment is prepared by a semi-solid rheoforming method or a thixoforming method.

[0033] It should be noted that the spheroidized grain medical magnesium alloy in this embodiment can be prepared by a semi-solid rheoforming method. Semi-solid metal slurry has good fluidity and can produce workpieces with complex shapes. In addition, the internal structure of the semi-solid spheroidized grain medical magnesium alloy is uniform, avoiding defects such as pores and inclusions, and the internal structure has a small grain size, which makes it have a high strength.

[0034] The above content is a detailed description of the composition and structure of the spheroidized grain medical magnesium alloy. The specific preparation method of the spheroidized grain medical magnesium alloy in this embodiment will be described in detail below.

[0035] The spheroidized fine grain medical magnesium alloy comprises the following components by weight percentage: Ag: 10wt.%, Y: 2wt.%, Gd: 0.3wt.%-0.9wt.%, Sn: 0.25%; Ce: 0.2wt.%, Si: 0.25wt.%, Dy: 0.1wt.%, Er: 0.12wt.%, Sr: 0.08wt.%, Nd: 0.05wt.%, and the remainder is Mg and unavoidable impurities; wherein the content of a single impurity does not exceed 0.02wt.%, and the total amount of impurities does not exceed 0.1wt.%;

[0036] The preparation method of the spheroidized grain medical magnesium alloy based on the above components is as follows:

[0037] S1. Weighing: weighing industrial pure magnesium, industrial pure silver and magnesium-based master alloy according to the chemical composition ratio of the spheroidized grain medical magnesium alloy;

[0038] S2, drying: preheating the weighed industrial pure magnesium, industrial pure silver and magnesium-based master alloy at 100-120°C for 15-20 minutes;

[0039] S3, preparing a semi-solid metal melt: smelting industrial pure magnesium in a 680-720°C heating furnace filled with protective gas, heating the industrial pure magnesium to 740-760°C after the industrial pure magnesium is fully melted, adding the preheated magnesium-based master alloy, adding industrial pure silver when the temperature rises to 740-760°C after the magnesium-based master alloy is melted, heating the temperature to 760-780°C and keeping it warm for 20-30 minutes, removing the surface scum, stirring vigorously for 10 minutes, standing and keeping it warm for 20-30 minutes, then skimming, degassing, and refining for 5 minutes, reducing the temperature to 710-730°C, keeping it warm and standing for 15-20 minutes, to obtain a semi-solid metal melt;

[0040] S4, rheoforming: the semi-solid metal melt flows through a slurry channel to a feed port of a die-casting machine, and fills a mold cavity in a pressure chamber, thereby obtaining the spheroidized grain medical magnesium alloy.

[0041] Finally, the corrosion rate of the obtained spheroidized grain medical magnesium alloy was tested. Specifically, the prepared spheroidized grain medical magnesium alloy casting was machined into a standard immersion specimen, and the average degradation rate in the simulated body fluid was <0.8 mm / y.

[0042] Experimental Example 1

[0043] The spheroidized fine grain medical magnesium alloy includes the following components in weight percentage: Ag: 10wt.%, Y: 2wt.%, Gd: 0.3wt.%, Sn: 0.25%; Ce: 0.2wt.%, Si: 0.25wt.%, Dy: 0.1wt.%, Er: 0.12wt.%, Sr: 0.08wt.%, Nd: 0.05wt.%, and the remainder is Mg and inevitable impurities.

[0044] Based on the spheroidized grain medical magnesium alloy of the above composition, the spheroidized grain medical magnesium alloy of the above composition is prepared according to the preparation method of the spheroidized grain medical magnesium alloy in the embodiment.

[0045] The prepared spheroidized grain medical magnesium alloy castings were machined into standard immersion specimens, and the average degradation rate in simulated body fluids was less than 0.78 mm / y.

[0046] Experimental Example 2

[0047] The spheroidized fine-grain medical magnesium alloy includes the following components in weight percentage: Ag: 10wt.%, Y: 2wt.%, Gd: 0.5wt.%, Sn: 0.25%; Ce: 0.2wt.%, Si: 0.25wt.%, Dy: 0.1wt.%, Er: 0.12wt.%, Sr: 0.08wt.%, Nd: 0.05wt.%, and the remainder is Mg and inevitable impurities.

[0048] Based on the spheroidized grain medical magnesium alloy of the above composition, the spheroidized grain medical magnesium alloy of the above composition is prepared according to the preparation method of the spheroidized grain medical magnesium alloy in the embodiment.

[0049] The prepared spheroidized grain medical magnesium alloy castings were machined into standard immersion specimens, and the average degradation rate in simulated body fluids was less than 0.68 mm / y.

[0050] Experimental Example 3

[0051] The spheroidized fine grain medical magnesium alloy includes the following components by weight percentage: Ag: 10wt.%, Y: 2wt.%, Gd: 0.7wt.%, Sn: 0.25%; Ce: 0.2wt.%, Si: 0.25wt.%, Dy: 0.1wt.%, Er: 0.12wt.%, Sr: 0.08wt.%, Nd: 0.05wt.%, and the remainder is Mg and inevitable impurities.

[0052] Based on the spheroidized grain medical magnesium alloy of the above composition, the spheroidized grain medical magnesium alloy of the above composition is prepared according to the preparation method of the spheroidized grain medical magnesium alloy in the embodiment.

[0053] The prepared spheroidized grain medical magnesium alloy castings were machined into standard immersion specimens, and the average degradation rate in simulated body fluids was <0.61 mm / y.

[0054] Experimental Example 4

[0055] The spheroidized fine grain medical magnesium alloy includes the following components in weight percentage: Ag: 10wt.%, Y: 2wt.%, Gd: 0.9wt.%, Sn: 0.25%; Ce: 0.2wt.%, Si: 0.25wt.%, Dy: 0.1wt.%, Er: 0.12wt.%, Sr: 0.08wt.%, Nd: 0.05wt.%, and the remainder is Mg and inevitable impurities.

[0056] Based on the spheroidized grain medical magnesium alloy of the above composition, the spheroidized grain medical magnesium alloy of the above composition is prepared according to the preparation method of the spheroidized grain medical magnesium alloy in the embodiment.

[0057] The prepared spheroidized grain medical magnesium alloy castings were machined into standard immersion specimens, and the average degradation rate in simulated body fluids was <0.52 mm / y.

[0058] From the above four experimental examples, it can be seen that the average degradation rate of spheroidized grain medical magnesium alloy in simulated body fluid is less than 0.8mm / y. It can be seen that spheroidized grain medical magnesium alloy has an excellent degradation rate and can achieve uniform degradation. While maintaining the supporting and fixing function of the implant material, it can also reduce medical costs and alleviate the pain of patients.

[0059] The above is a detailed introduction to a spheroidized grain medical magnesium alloy and a preparation method thereof provided by the present invention. For a person skilled in the art, according to the concept of the embodiments of the present invention, there may be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A spheroidized grain medical magnesium alloy, characterized in that: The spheroidized grain medical magnesium alloy comprises the following components by weight percentage: Ag: 10wt.%, Y: 2wt.%, Gd: 0.3 wt.%-0.9wt.%, Sn: 0.25wt.%; Ce: 0.2 wt.%, Si: 0.25 wt.%, Dy: 0.1 wt.%, Er: 0.12 wt.%, Sr: 0.08 wt.%, Nd: 0.05 wt.%, the balance is Mg and unavoidable impurities; The content of a single impurity shall not exceed 0.02wt.%, and the total amount of impurities shall not exceed 0.1wt.%.

2. The spheroidized grain medical magnesium alloy according to claim 1, characterized in that: The microstructure of the spheroidized grain medical magnesium alloy is composed of spheroidal grains after semi-solid treatment.

3. The spheroidized grain medical magnesium alloy according to claim 2, characterized in that: The average size of the spherical grains is 10 μm to 15 μm.

4. The spheroidized grain medical magnesium alloy according to claim 2, characterized in that: The average sphericity S of the spherical grains is 0.75-0.

8.

5. The spheroidized grain medical magnesium alloy according to claim 1, characterized in that: The raw materials for preparing the spheroidized grain medical magnesium alloy are industrial pure magnesium, industrial pure silver and magnesium-based master alloy.

6. The spheroidized grain medical magnesium alloy according to claim 1, characterized in that: The spheroidized grain medical magnesium alloy is prepared by a semi-solid rheoforming method or a thixoforming method.

7. A method for preparing a spheroidized grain medical magnesium alloy, characterized in that: The spheroidized grain medical magnesium alloy comprises the following components by weight percentage: Ag: 10wt.%, Y: 2wt.%, Gd: 0.3 wt.%-0.9wt.%, Sn: 0.25wt.%; Ce: 0.2 wt.%, Si: 0.25 wt.%, Dy: 0.1 wt.%, Er: 0.12 wt.%, Sr: 0.08 wt.%, Nd: 0.05 wt.%, the balance is Mg and unavoidable impurities; The content of a single impurity shall not exceed 0.02wt.%, and the total amount of impurities shall not exceed 0.1wt.%; The preparation method of the spheroidized grain medical magnesium alloy based on the above components is as follows: S1. Weighing: weighing industrial pure magnesium, industrial pure silver and magnesium-based master alloy according to the chemical composition ratio of the spheroidized grain medical magnesium alloy; S2. Drying: Preheat the weighed industrial pure magnesium, industrial pure silver and magnesium-based master alloy at 100-120°C for 15-20 minutes; S3, preparing a semi-solid metal melt: smelting industrial pure magnesium in a 680-720°C heating furnace filled with protective gas, heating the industrial pure magnesium to 740-760°C after the industrial pure magnesium is fully melted, adding the preheated magnesium-based master alloy, adding industrial pure silver when the temperature rises to 740-760°C after the magnesium-based master alloy is melted, heating the temperature to 760-780°C and keeping it warm for 20-30 minutes, removing the surface scum, stirring vigorously for 10 minutes, standing and keeping it warm for 20-30 minutes, then skimming, degassing, and refining for 5 minutes, then reducing the temperature to 710-730°C and keeping it warm for 15-20 minutes to obtain a semi-solid metal melt; S4, rheoforming: the semi-solid metal melt flows through a slurry channel to a feed port of a die-casting machine, and fills a mold cavity in a pressure chamber, thereby obtaining the spheroidized grain medical magnesium alloy.

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