Precipitation strengthening type implantable magnesium alloy and preparation process thereof

Abstract

The invention relates to a precipitation strengthening type biomedical magnesium alloy capable of being degraded in vivo and a preparation process of the precipitation strengthening type biomedical magnesium alloy. The magnesium alloy comprises the following components in percentage by mass: 5.0-6.0% of Zn, 1.0-2.0% of Yb, 0.3-0.5% of Zr and the balance Mg. A submicron second phase is dispersed and distributed in a magnesium matrix. The process comprises the following steps: smelting an alloy ingot according to design components to ensure that initial grains are equiaxed, uniform and fine, carrying out solution treatment to ensure that the second phase is fully dissolved into the matrix, and carrying out aging treatment to fully disperse and separate out the submicron second phase. The magnesium alloy prepared by the process has the advantages of corrosion resistance, high strength, good biocompatibility and complete degradation in vivo, and is suitable for biological implants such as intravascular stents, bone nails, bone lamellas and the like which simultaneously require certain strength and corrosion service cycle. According to the precipitation strengthening type biomedical magnesium alloy and the preparation process, the heavy rare earth element ytterbium (Yb) is introduced into an alloy system so as to regulate and control the morphology and distribution of a precipitated phase, the corrosion resistance of a matrix alloy is effectively improved while the matrix is strengthened by means of dispersed precipitation of the fine second phase, and the problem of too fast corrosion in biomedicine is solved. The preparation process is universal and efficient, and has a good popularization prospect.

Description

technical field [0001] The invention belongs to the technical field of bioalloy processing, and in particular relates to a precipitation-enhanced biomedical implantable magnesium alloy material and a preparation process thereof. Background technique [0002] Magnesium alloys have attracted extensive attention in the field of biomedical implant materials because of their good biocompatibility, degradability, and similar density and elastic modulus to human bones. Studies have shown that scaffolds and bone plates made of magnesium alloys are not only harmless after implantation into the human body, but also can gradually degrade in the biological environment of the human body, saving patients from the pain of secondary operations, so they have significant advantages in the field of clinical application . However, the high degradation rate of magnesium alloys often leads to the loss of mechanical integrity before the end of the service period, which greatly limits the further ...

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Problems solved by technology

For example, the coating method, the film layer may be relatively loose or poorly bonded, and complexing agents need to be added, and the energy consumption is extremely high, which increases the production cost; at the same time, the complex process leads to a short production cycle, which is not suitable for large-scale production; high equipment requirements , the maintenance cost of the instrument will also increase, so it has great limitations in industrial applications

Large plastic deformation method, the structure of the prepared material is not uniform enough, the production efficiency is low, it is not suitable for large-scale production, the size of the material is limited, it is difficult to prepare large-size samples, the cost is high, and the process line is complicated

Element addition method: The addition of multi-element alloying elements has a good improvement on the corrosion resistance of biomedical magnesium alloys, but it will also bring different problems, such as: excessive Zn will reduce the corrosion resistance of magnesium alloys; Al has neural Toxicity, which will inhibit the growth of the matrix; the addition of some rare earth elements will lead to cell proliferation and thrombus; Fe and Cu will lead to a decrease in the corrosion resistance of magnesium alloys

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