阅读说明：本技术 一种医用可降解高熵合金及其制备方法与应用 (Medical degradable high-entropy alloy and preparation method and application thereof ) 是由 宁靠 李贻成 宋坤 刘江 于 2020-07-31 设计创作，主要内容包括：本发明提供了一种医用可降解高熵合金及其制备方法与应用,所述高熵合金的化学成分为：Zn、Mg、Ca和Li,按质量百分比计,Zn为30～60％、Mg为20～50％、Ca为5～15％,Li为5～15％。通过熔炼、铸造、机加工、旋锻和无心磨得到医用可降解高熵合金。本发明的医用可降解高熵合金原材料成本低廉,制备的高熵合金降解速度适中且可控,强度高、韧性好。(The invention provides a medical degradable high-entropy alloy and a preparation method and application thereof, wherein the high-entropy alloy comprises the following chemical components: 30-60% of Zn, 20-50% of Mg, 5-15% of Ca and 5-15% of Li in percentage by mass. The medical degradable high-entropy alloy is obtained through smelting, casting, machining, rotary swaging and centerless grinding. The medical degradable high-entropy alloy disclosed by the invention is low in raw material cost, and the prepared high-entropy alloy is moderate and controllable in degradation speed, high in strength and good in toughness.)

1. A medical degradable high-entropy alloy is characterized in that the high-entropy alloy comprises the following chemical components: 30-60% of Zn, 20-50% of Mg, 5-15% of Ca and 5-15% of Li in percentage by mass.

2. The preparation method of the medical degradable high-entropy alloy of claim 1, characterized by comprising the following steps:

step 1, smelting: respectively smelting a zinc-magnesium alloy, a zinc-lithium alloy, a magnesium-zinc alloy, a magnesium-calcium alloy and a zinc-calcium alloy simultaneously to obtain six alloy melts;

step 2, casting: pouring the six alloy melts obtained in the step 1 into the same mold at the same time, and cooling to obtain a medical degradable high-entropy alloy ingot;

step 3, machining, rotary swaging and centerless grinding: and (3) machining the high-entropy alloy cast ingot obtained in the step (2) according to a drawing, then performing rotary swaging, and performing centerless grinding treatment on a blank obtained after rotary swaging to obtain the medical degradable high-entropy alloy.

3. The preparation method of the medical degradable high-entropy alloy according to claim 2, wherein the outer diameter of the high-entropy alloy ingot obtained in the step 2 is 27 mm.

4. The preparation method of the medical degradable high-entropy alloy according to claim 3, wherein in the step 3, the machining mode is turning, the single-side turning amount is 0.50-1.00 mm each time, the outer diameter of the turned high-entropy alloy ingot is 20 +/-0.05 mm, the surface is clean, and no air holes or impurities exist.

5. The method for preparing the medical degradable high-entropy alloy according to claim 4, wherein the swaging is performed in nine passes, the first pass and the second pass of swaging are hot swaging, and annealing treatment is performed after the sixth pass of swaging.

6. The preparation method of the medical degradable high-entropy alloy according to claim 5, wherein the hot-swaging temperature is 170-200 ℃.

7. The preparation method of the medical degradable high-entropy alloy according to claim 6, wherein the annealing treatment is performed at 150-180 ℃ for 30-60 min.

8. The preparation method of the medical degradable high-entropy alloy according to claim 7, wherein the swaging process is as follows: the first rotary swaging is carried out until the outer diameter is 17mm, the second rotary swaging is carried out from 17mm to 15mm, the third rotary swaging is carried out from 15mm to 13.5mm, the fourth rotary swaging is carried out from 13.5mm to 12mm, the fifth rotary swaging is carried out from 12mm to 10.5mm, the sixth rotary swaging is carried out from 10.5mm to 9mm, the seventh rotary swaging is carried out from 9mm to 7.5mm, the eighth rotary swaging is carried out from 7.5mm to 6mm, and the ninth rotary swaging is carried out from 6mm to 5.3 mm.

9. The preparation method of the medical degradable high-entropy alloy according to claim 8, wherein the single-side grinding amount of the centerless grinding is 0.01-0.1 mm, the smaller the blank size is, the smaller the grinding amount of each time is, and after the centerless grinding treatment, the outer diameter of the blank is 5.3 +/-0.01 mm, and the length of the blank is not less than 1000 mm.

10. Use of the medical degradable high-entropy alloy according to claim 1 or claims 2-9, wherein the high-entropy alloy can be used in an orthopedic implant apparatus, and the orthopedic implant apparatus comprises a fixing screw, a fixing rivet or an intramedullary needle.

Technical Field

The invention relates to the field of medical degradable implant materials, in particular to a medical degradable high-entropy alloy and a preparation method and application thereof.

Background

Zinc ions are essential nutrient elements of human bodies and participate in a large number of metabolic activities of the human bodies, and the American clinical innovation organization recommends that the human bodies must take 2.5-6.4 mg of zinc every day, and adults take about 300 mg of zinc every day to possibly have certain toxic reaction. About 0.2-0.3 mg of zinc is released by a zinc-based degradable bone nail every day, even if all zinc ions are released into blood vessels, the intake of the zinc-based degradable bone nail is far lower than the necessary intake of a human body, namely the zinc ions released by the zinc-based degradable orthopedic implant medical instrument in a degrading way can not cause systemic toxicity. Research also finds that zinc ions are transported in human tissues very rapidly, so that zinc-based degradable orthopedic implant instruments do not have zinc enrichment, cytotoxicity or necrosis nearby.

Zinc ions have a plurality of functions in human bodies and are very important for the human bodies, wherein one important function is to promote the growth of bone tissues. Researchers find that zinc ions activate osteoblast aminoacyl tRNA synthetase and can effectively inhibit the differentiation and growth of osteoclasts, so that the existence of the zinc ions not only promotes the increase of the content of bone calcium salt, but also is beneficial to promoting the increase of the content of bone collagen, and the zinc ions can directly promote the osteogenesis function. In addition, it was found that zinc ions promote the binding of cartilage oligomeric matrix protein to collagen, and are a catalytic element for the growth and regeneration of cartilage.

The bone nail and the bone plate are common medical equipment implantation instruments for fixing fracture and ligament injury, and the traditional bone nail and the bone plate are made of non-degradable metal, so that secondary operation is required, and great trauma is caused to a patient. Meanwhile, the traditional metal material has too high strength, and is easy to cause stress shielding, so that injured bone tissues are difficult to regenerate and heal.

Degradable medical materials in the human body are becoming the focus of research and development, among which degradable high molecular materials, pure iron and iron-based alloys, pure magnesium and magnesium-based alloys are the most deeply studied materials in recent years. The degradable high polymer material has too low strength, and can be broken frequently in the clinical use process, and the clinical applicability is greatly limited. Pure iron and iron-based alloys have much higher strength and toughness than polymeric materials, but iron degrades too slowly and can degrade completely for years. More seriously, the rust-like substances produced during iron degradation expand several times in volume and have a pronounced tendency to migrate. The degradation products of pure magnesium and magnesium-based alloy are nontoxic and degradable, but the corrosion resistance is very poor, and the degradation products can be degraded quickly in human bodies and can not provide enough mechanical support time.

Pure zinc and zinc-based alloy are also medical degradable materials, but the defects of low strength, high processing difficulty and uncontrollable degradation speed still exist when the zinc-based alloy is applied to medical materials. At present, the problems of strength improvement, processing difficulty and easiness, uncontrollable degradation and the like are solved by adding alloy elements.

Disclosure of Invention

The invention provides a medical degradable high-entropy alloy and a preparation method and application thereof, and aims to solve the problems of insufficient mechanical properties, unsatisfactory degradation speed, narrow application range and the like of the conventional magnesium-based material and zinc-based material.

In order to achieve the above object, an embodiment of the present invention provides a medical degradable high-entropy alloy, and the chemical components of the high-entropy alloy are: 30-60% of Zn, 20-50% of Mg, 5-15% of Ca and 5-15% of Li in percentage by mass.

The embodiment of the invention also provides a preparation method of the medical degradable high-entropy alloy, which comprises the following steps:

step 1, smelting: respectively smelting a zinc-magnesium alloy, a zinc-lithium alloy, a magnesium-zinc alloy, a magnesium-calcium alloy and a zinc-calcium alloy simultaneously to obtain six alloy melts;

step 2, casting: and (3) pouring the six alloy melts obtained in the step (1) into the same mould at the same time. Cooling to obtain a medical degradable high-entropy alloy ingot;

step 3, machining, rotary swaging and centerless grinding: and (3) machining the high-entropy alloy cast ingot obtained in the step (2) according to a drawing, then performing rotary swaging, and performing centerless grinding treatment on a blank obtained after rotary swaging to obtain the medical degradable high-entropy alloy.

Preferably, the outer diameter of the high-entropy alloy ingot obtained in the step 2 is 27 mm.

Preferably, in the step 3, the machining mode is turning, the single-side turning amount is 0.50-1.00 mm each time, the outer diameter of the turned high-entropy alloy ingot is 20 +/-0.05 mm, the surface is clean, and no air holes or impurities exist.

Preferably, the rotary swaging is performed in nine passes, the first pass and the second pass of rotary swaging are hot rotary swaging, and the annealing treatment is performed after the sixth pass of rotary swaging.

Preferably, the hot rotary swaging temperature is 170-200 ℃.

Preferably, the temperature of the annealing treatment is 150-180 ℃, and the time is 30-60 min.

Preferably, the swaging process is as follows: the first rotary swaging is carried out until the outer diameter is 17mm, the second rotary swaging is carried out from 17mm to 15mm, the third rotary swaging is carried out from 15mm to 13.5mm, the fourth rotary swaging is carried out from 13.5mm to 12mm, the fifth rotary swaging is carried out from 12mm to 10.5mm, the sixth rotary swaging is carried out from 10.5mm to 9mm, the seventh rotary swaging is carried out from 9mm to 7.5mm, the eighth rotary swaging is carried out from 7.5mm to 6mm, and the ninth rotary swaging is carried out from 6mm to 5.3 mm.

Preferably, the single-side grinding amount of each time of the centerless grinding is 0.01-0.1 mm, the smaller the size of the blank is, the smaller the grinding amount of each time is, and after the centerless grinding treatment, the outer diameter of the blank is 5.3 +/-0.01 mm, and the length of the blank is not less than 1000 mm.

The embodiment of the invention also provides application of the medical degradable high-entropy alloy in an orthopedic implantation instrument, wherein the orthopedic implantation instrument comprises a fixing screw, a fixing rivet or an intramedullary needle.

The scheme of the invention has the following beneficial effects: the medical degradable high-entropy alloy has low cost of raw materials, and the internal disorder degree of the material is improved by mixing a plurality of components in a large proportion, so that the mechanical property of the medical degradable material is improved in a large proportion. The prepared high-entropy alloy has high strength, good toughness and moderate and controllable degradation speed.

Drawings

FIG. 1 is a schematic view of a mold used in the present invention.

Fig. 2 is a schematic view of the internal structure of the mold used in the present invention.

Detailed Description

In order to make the technical problems, technical solutions and advantages of the present invention more apparent, the following detailed description is given with reference to the accompanying drawings and specific embodiments.