WO2020042745A1

WO2020042745A1 - Mg-zn-sn series magnesium alloy with controllable degradation rate, preparation method and application thereof

Info

Publication number: WO2020042745A1
Application number: PCT/CN2019/094179
Authority: WO
Inventors: 王敬丰; 蒋伟燕; 潘复生
Original assignee: 重庆大学
Priority date: 2018-08-27
Filing date: 2019-07-01
Publication date: 2020-03-05
Also published as: CN108823476A

Abstract

The disclosure belongs to the technical field of metal materials and relates to an Mg-Zn-Sn series magnesium alloy with a controllable degradation rate, a preparation method therefor, and an application thereof. The Mg-Zn-Sn series magnesium alloy comprises the following elementary composition by weight percentage: 0.9%-5.0% of Zn, 0.5%-1.9% of Sn, and the remainder comprising Mg and unavoidable impurities. The preparation method of the alloy comprises: selecting raw materials of each component according to a composition ratio of the Mg-Zn-Sn series magnesium alloy and smelting the same under a protective atmosphere, the smelting temperature being 690-790 °C; after the components of the alloy are completely melted, reducing the temperature to 630-680°, and letting the components stand at a constant temperature for 30-120 minutes, followed by cooling to obtain an ingot of the Mg-Zn-Sn series magnesium alloy. A combined technique of controlling the alloy composition and melting process effectively controls the content, the morphology, and distribution of the secondary phase in the alloy, significantly improves the corrosion resistance of the alloy, and achieves excellent control of the degradation rate.

Description

Mg-Zn-Sn series magnesium alloy with controllable degradation rate, preparation method and application thereof

Cross-reference to related applications

This application requires a Chinese patent application filed with the Chinese Patent Office on August 27, 2018 with the application number 201810983934.X and the name "Mg-Zn-Sn series magnesium alloy with controllable degradation rate and its preparation method and application" Priority, the entire contents of which are incorporated herein by reference.

Technical field

The disclosure belongs to the technical field of metal materials, and relates to biologically applied magnesium alloy metal materials, and in particular, to a Mg-Zn-Sn series magnesium alloy with controllable degradation rate, and a preparation method and application thereof.

Background technique

With the development of medicine and materials science, people hope that the materials implanted in the body will only serve as a temporary replacement, and gradually degrade and absorb with the regeneration of tissues or organs, in order to minimize the long-term impact of the implanted materials on the body. Metal materials have been applied in many aspects as implant materials due to their comprehensive properties such as high mechanical strength, elasticity and plasticity. Corrosion of metal implant materials by body fluids is unavoidable. Although some metal elements are indispensable for performing cell functions or vitamin synthesis, when the content is higher than a certain value, the human body cannot accept it. Body fluid corrosion will lead to the gradual loss of metal implant materials, which will affect the material performance. More importantly, the products of corrosion escape from the surface of metal materials into biological tissues, which may lead to undesired results. Biodegradable orthopedic implant materials Considering the design of the alloy from the perspective of application, the material's biocompatibility, mechanical properties and corrosion properties should be taken into account.

In recent years, as a new generation of revolutionary metal medical materials, magnesium alloys have attracted special attention due to their biodegradable properties. Degradable biomedical magnesium alloy materials are designed to provide short-term support during the healing of damaged / diseased tissues, after which they gradually degrade and absorb. This requires materials with appropriate mechanical properties and corresponding corrosion resistance for progressive degradation. Within 12-18 weeks of bone tissue healing, screws, needles, and other orthopedic implants should remain mechanically intact during the load-bearing period. Mg-based alloys must have both high strength and low modulus close to human bones to avoid stress shielding effects. Some researchers have proposed specific mechanical and corrosion requirements for biomaterials used during bone fixation. The corrosion rate in simulated body fluid at 37 ℃ needs to be <0.5mm / year, the strength is higher than 200MPa, and the elongation is greater than 10%. In addition, as a Cenozoic degradation material, magnesium alloys must be biocompatible and bioactive in the human body. Therefore, the alloying elements should be selected from the essential elements of the living body. Among them, the human nutrition elements Ca, Mn, Zn, Sn, Al, Sr, etc. are all ideal selection elements for degradable magnesium-based alloys.

At present, the degradable biomedical magnesium alloy has set off an extensive research boom, but the existing problem is still difficult to control the degradation rate and hydrogen evolution rate. The degradation rate of the magnesium alloy is too fast. In the process of use, the load bearing capacity or the degradation rate will be insufficient. Too fast results in the failure of biological implant materials, the hydrogen evolution rate is too fast, exceeds the body's tolerance, will cause the formation of subcutaneous bubbles, and cause tissue necrosis. Both of these conditions will seriously affect the application of magnesium alloy biomaterials in the medical field. Therefore, in the design of biodegradable magnesium-based medical devices, the design and research of biodegradable magnesium medical alloys with low hydrogen evolution and controlled degradation is the direction we consider.

Among the above-mentioned common human nutrition elements, Zn and Sn have higher solid solubility in magnesium. The solid solubility of Zn in magnesium is 2.4 at.%, And the solid solubility of Sn in magnesium is 3.36at.%, Which can be enhanced by solid solution to improve its mechanical properties to meet the needs of medical support. At present, Mg-Zn series biomedical magnesium alloys have been widely studied because they can simultaneously improve mechanical and corrosion resistance properties. Mg-Sn binary alloys have also caused biomedical researchers due to their good ductility and low hydrogen evolution rate. If the two are added at the same time, combined with the characteristics of Zn element to improve mechanics and Sn element to suppress hydrogen evolution, it will be possible to obtain a biomedical magnesium alloy material with low hydrogen evolution and controllable degradation rate. In addition, both are human nutritional elements, and proper addition in magnesium alloys can also ensure their biocompatibility in the human body. According to literature investigation, it is found that there are very few reports on Mg-Zn-Sn ternary alloys as biomedical degradable materials.

Summary of the Invention

The purpose of the present disclosure includes, for example, providing a method for preparing a Mg-Zn-Sn-based magnesium alloy with controllable degradation rate, and effectively controlling the content of the second phase in the alloy through the combination of alloy composition control, smelting process and post-processing process. The morphology and distribution regulate the biomechanical and bio-corrosion resistance of alloys to meet the needs of a rapidly developing modern society for controlled degradation of metal-based implanted orthopedic materials.

The purpose of the present disclosure includes, for example, providing a Mg-Zn-Sn-based magnesium alloy with a controlled degradation rate. The alloy has a special structure and morphology under a specific composition and preparation process, which greatly improves the alloy's biological corrosion resistance. At the same time, it has no toxicity, good biocompatibility, and excellent comprehensive properties such as strength and plasticity.

The purpose of the present disclosure includes, for example, the application of a Mg-Zn-Sn-based magnesium alloy with a controlled degradation rate. The Mg-Zn-Sn-based magnesium alloy prepared by the present disclosure has a controlled degradation rate and has excellent biological properties. And it has excellent mechanical properties and good corrosion controllability, so it can be widely used in biomedical fields.

The object of the present disclosure includes, for example, providing a biodegradable product made of the Mg-Zn-Sn series magnesium alloy with controllable degradation rate, which can alleviate the degradation of the existing magnesium alloy material under the physiological environment of the human body The speed is too fast, the rate of hydrogen evolution is too fast, the defects that affect the clinical treatment effect and human health.

The present disclosure provides a method for preparing a Mg-Zn-Sn-based magnesium alloy with controllable degradation rate. The Mg-Zn-Sn-based magnesium alloy includes the following weight percentages of elemental components:

Zn 0.9% to 5.0%, Sn 0.5% to 1.9%, the balance includes Mg and unavoidable impurities;

The preparation method of the Mg-Zn-Sn series magnesium alloy includes the following steps:

According to the group distribution ratio of the Mg-Zn-Sn-based magnesium alloy, the raw materials of each component are taken and smelted in a protective atmosphere. The melting temperature is 690-790 ° C. After all the alloying elements are melted, the temperature is reduced to 630-680. After standing at ℃ for 30 to 120 minutes, it was cooled to obtain a Mg-Zn-Sn-based magnesium alloy ingot.

In one or more embodiments, the Mg-Zn-Sn-based magnesium alloy includes the following elemental components by weight: Zn 0.9% to 4.5%, Sn 0.6% to 1.8%, and the balance includes Mg and unavoidable Impurities.

In one or more embodiments, the Mg-Zn-Sn-based magnesium alloy includes the following elements by weight: Zn 1.0% to 4.0%, Sn 0.7% to 1.5%, and the balance includes Mg and unavoidable Impurities.

In one or more embodiments, the method for preparing the Mg-Zn-Sn-based magnesium alloy includes the following steps: According to the composition ratio of the Mg-Zn-Sn-based magnesium alloy, the raw materials of each component are taken. Smelting is performed in a protective atmosphere. The melting temperature is 700 to 780 ° C. After all alloying elements are melted, the temperature is lowered to 640 to 670 ° C for 30 to 90 minutes, and then cooled to obtain a Mg-Zn-Sn series magnesium alloy ingot.

In one or more embodiments, the method for preparing the Mg-Zn-Sn-based magnesium alloy includes the following steps: According to the composition ratio of the Mg-Zn-Sn-based magnesium alloy, the raw materials of each component are taken. Smelting is performed in a protective atmosphere. The melting temperature is 710-760 ° C. After all the alloying elements are melted, the temperature is lowered to 650-670 ° C for 30 to 60 minutes, and then cooled to obtain a Mg-Zn-Sn series magnesium alloy ingot.

In one or more embodiments, the smelting is performed in an electromagnetic induction melting furnace;

In one or more embodiments, during the smelting process, a mixed gas of one or more of argon, sulfur hexafluoride, carbon dioxide, and sulfur hexafluoride is used as a protective gas;

In one or more embodiments, the cooling method includes at least one of a salt water bath, water quenching, furnace cooling or air cooling.

In one or more embodiments, the raw materials are pure magnesium ingots, pure tin ingots, and pure zinc ingots.

The present disclosure also provides a Mg-Zn-Sn-based magnesium alloy with a controllable degradation rate, which is prepared by using the above preparation method;

In one or more embodiments, the Mg-Zn-Sn-based magnesium alloy includes the following elements by weight: Zn 0.9% to 5.0%, Sn 0.5% to 1.9%, and the balance includes Mg and unavoidable Impurities.

The present disclosure provides an application of the Mg-Zn-Sn-based magnesium alloy with controllable degradation rate in the field of biomedicine.

In one or more embodiments, the Mg-Zn-Sn series magnesium alloy with controllable degradation rate is used for preparing vascular scaffolds, bone tissue replacement or repair materials, and tissue engineering scaffold materials.

The present disclosure provides a biodegradable product made of the Mg-Zn-Sn series magnesium alloy with controllable degradation rate;

In one or more embodiments, the article is an article for medical applications; the article includes an implant or an internal stent.

In one or more embodiments, the implant is a bone tissue repair scaffold, a fixation screw, a rivet, a bone plate, or an intramedullary needle.

In one or more embodiments, the internal stent is a vascular stent, a tracheal stent, an esophageal stent, an intestinal stent, or a urethral stent.

In one or more embodiments, the article is a temporary or short-term biomedical implant device, including a degradable cardiovascular stent and a cardiovascular peripheral stent, an orthopedic internal fixation implant, or a tissue engineering stent.

The benefits of this disclosure include at least:

1. The present disclosure adopts a non-toxic composition design, in which the metal elements Sn and Zn are essential trace elements of the human body, and the method of controlling the composition of the alloy and the melting process is used to effectively control the content of the second phase and the morphology of the alloy. And distribution can greatly improve the corrosion resistance of the alloy. According to the present disclosure, the second phase structure in the alloy exhibits a dispersed distribution through an appropriate processing process, which is beneficial to the mode of achieving uniform corrosion of the alloy.

2. The second phase is an important factor affecting the corrosion performance of magnesium alloys. The addition of alloying elements with higher solid solubility in magnesium makes the alloying elements reduce the content of the second phase in a solid solution manner, thereby controlling the galvanic couple. The effect of corrosion improves the corrosion performance of the alloy. The present disclosure achieves the purpose of improving the bio-corrosion performance of the alloy by regulating the microstructure, content, and distribution of the second phase particles in the alloy.

3. Under the specific composition and preparation process, the alloy designed in the present disclosure forms a special structure and morphology, which greatly improves the biological corrosion resistance of the alloy. Compared with Mg-Zn-based magnesium alloy without Sn element, the grains are finer, the content of the second phase is increased, and it shows an irregular distribution, which makes the corrosion resistance value of the alloy measured by weight loss as low as 0.45mm .y ^-1 and below, the corrosion rate obtained by hydrogen evolution is as low as 0.23mm.y ^-1 and below, the operation is simple and easy to implement, and it has huge application potential in the field of degradable biomedical metal materials.

4. The preparation process adopted in the present disclosure is simple, the test parameters are convenient to control, and the portability is strong. The alloying elements contained are essential trace elements of the human body, the cost is low, and the method can be widely used in the field of biomedical implant materials.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the specific embodiments of the present disclosure or the technical solutions in the prior art, the accompanying drawings used in the specific embodiments or the description of the prior art will be briefly introduced below. Obviously, the appendixes in the following description The drawings are some embodiments of the present disclosure. For a person of ordinary skill in the art, other drawings can be obtained based on the drawings without paying creative labor.

FIG. 1 is a metallographic micrograph of the alloy material of Example 1, Example 2, Comparative Example 1, and Comparative Example 2, where (a) is a metallographic micrograph of a 2Mg-4Zn alloy of Comparative Example, and (b) is an example Metallographic microstructure of 1Mg-4Zn-1Sn alloy, (c) is a metallographic microstructure of Example 1Mg-4Zn-1.5Sn alloy, and (d) is a metallographic microstructure of Comparative Example 1Mg-4Zn-2Sn alloy;

2 is an XRD pattern of the alloy material of Example 1, Example 2, Comparative Example 1 and Comparative Example 2;

3 is a mechanical property diagram of the alloy material of Example 1, Example 2, Comparative Example 1 and Comparative Example 2;

4 is a corrosion rate diagram of the alloy material of Example 1, Example 2, Comparative Example 1 and Comparative Example 2;

5 is a cell survival rate of culturing RCR cells in an extract of the alloy material of Example 1 and Example 2;

FIG. 6 is a graph of the corrosion rate of the alloy material of Example 2 and Comparative Example 3. FIG.

detailed description

The embodiments of the present disclosure will be described in detail below in conjunction with the embodiments and examples, but those skilled in the art will understand that the following embodiments and examples are only used to illustrate the present disclosure and should not be considered as limiting the scope of the present disclosure. Based on the embodiments in the present disclosure, all other embodiments obtained by a person having ordinary skill in the art without making creative efforts fall within the protection scope of the present disclosure. If the specific conditions are not specified, the normal conditions or the conditions recommended by the manufacturer shall be followed.

In at least one embodiment, a method for preparing a Mg-Zn-Sn-based magnesium alloy with controllable degradation rate is provided. The Mg-Zn-Sn-based magnesium alloy includes the following elements by weight:

According to the composition ratio of the Mg-Zn-Sn series magnesium alloy, the raw materials of each component are taken and smelted in a protective atmosphere. The melting temperature is 690-790 ° C. After all the alloying elements are melted, the temperature is reduced to 630-680. After standing at ℃ for 30 to 120 minutes, it was cooled to obtain a Mg-Zn-Sn-based magnesium alloy ingot.

Because the standard electrode potential of magnesium (-2.37V) is very low, the corrosion resistance of magnesium is poor in the physiological environment of the human body. The characteristics of magnesium and magnesium alloys that can be corroded and degraded in the human environment are designed to be degradable by adding appropriate alloying elements and Biomedical magnesium alloys with controlled degradation rate are of great significance to meet the requirements of human plant material applications.

Zn and Sn are uniform human nutrition elements. The standard electrode potentials of Zn and Sn are:

Zn ²⁺ (aq) + 2e = Zn (s), -0.76V

Sn ²⁺ (aq) + 2e = Sn (s), -0.14V

Adding appropriate amounts of Zn and Sn elements to the magnesium alloy can ensure its biocompatibility in the human body and also have biological activity. In addition, Zn and Sn elements with high solid solubility are effective solid solution strengthening elements of magnesium. The strength and elongation of the alloy can be improved by solid solution strengthening. At the same time, ternary mesophases are not formed in the Zn and Sn elements. The phase particles are small and dispersed, which is conducive to the development of the alloy tending to uniform corrosion mode. In addition, the dissolution of Zn and Sn elements in the magnesium matrix can increase the self-corrosion potential of the Mg matrix, making it difficult for the Mg matrix to undergo the Mg dissolution reaction, and the Sn element has a higher hydrogen evolution overpotential, which suppresses the precipitation of hydrogen during the corrosion process. At the same time, participating in the formation of the corrosion product film can increase the density of the product film, passivate the alloy in the corrosion medium, increase the corrosion resistance, and delay the corrosion process. Therefore, it is necessary to study the Mg-Zn-Sn ternary alloy formed by adding a certain amount of Sn element to the Mg-Zn alloy, and it has a broad application prospect in the actual degradable metal-based biomedical materials.

In view of this, the present disclosure effectively controls the content of the second phase, the microstructure and the distribution of the alloy by controlling the combination of the alloy composition and the melting process, and proposes an alloy element with a high solid solubility to enhance the corrosion resistance of the magnesium alloy. A design method to reduce the hydrogen evolution rate and effectively control the microstructure morphology of the second phase of the alloy to prepare a controllable and degradable low hydrogen evolution biomedical magnesium alloy material, thereby meeting the urgent needs of orthopedic clinical growing short-term implantation and fixation materials.

Further, the present disclosure selects beneficial elements of Zn and Sn from numerous medical implanted metal elements, and adjusts the proportion relationship of the composition of each element, optimizes the amount of each element, performs alloying under a specific process, and exerts each element. The interaction between itself and each element avoids the introduction of unfavorable elements such as cytotoxicity and genetic toxicity. The prepared Mg-Zn-Sn series magnesium alloy is non-toxic, has good biocompatibility and excellent mechanical properties, especially The degradation rate is controllable, which improves the corrosion resistance and has a positive effect on the medical field. Specifically from the perspective of biological effects and mechanical properties of alloying elements:

From the perspective of the biological effects of zinc (Zn), Zn participates in the formation of enzyme active sites of various important human enzymes such as alkaline phosphatase and carbonic anhydrase, and has catalytic, structural, and regulatory functions in metal enzymes; Zn Although it cannot directly act on the target gene sequence, most zinc-binding proteins can regulate cell differentiation, renewal, and directly participate in the regulation of gene expression; Zn can enhance the immune function of the human body, maintain the growth and development of the body, and also can maintain Barrier Function of Vascular Endothelial Cell Membrane. From the perspective of the mechanical properties of magnesium alloys, Zn has the dual effects of solid solution strengthening and aging strengthening; Zn can improve the morphology of Mg ₂ Sn phase and its phase relationship with the matrix, and improve the aging hardening reaction of the alloy; Zn has the Higher solid solubility can exert solid solution strengthening effect. At the same time, Zn has more obvious grain refining effect in magnesium alloys. Zn can both increase the strength of magnesium alloys and improve the toughness of magnesium alloys. Adding an appropriate amount of Zn to Mg alloy can slow down the degradation rate of magnesium alloy materials in vivo. In the Mg-Zn-Sn-based magnesium alloy of the present disclosure, the preferred content of Zn is 0.9% to 5.0%. Typical but non-limiting, the content of Zn may be, for example, 0.9%, 1%, 1.2%, 1.5%, 1.6 %, 1.8%, 2%, 2.2%, 2.5%, 2.6%, 2.8%, 3%, 3.2%, 3.5%, 3.6%, 3.8%, 4%, 4.5% or 5%.

From the perspective of the biological effect of tin (Sn), usually, the toxicity of Sn is very small, and animals have ingested large doses of Sn, and no special toxicity has been found. A 70 kg adult needs about 7.0 mg of Sn per day. From the perspective of the mechanical properties of magnesium alloys, the addition of Sn element can improve the plastic deformation ability and strength of the alloy, reduce the cracking tendency during hot working, and have a significant aging strengthening ability. Sn magnesium has a strong solid solution strengthening effect, which can effectively refine the grains, form particles with high hardness, high melting point and good thermal stability, and improve the mechanical properties of magnesium alloys. Adding an appropriate amount of Sn to the magnesium alloy can increase the strength of the material and ensure that the alloy has sufficient mechanical properties when used as a plant material. In the Mg-Zn-Sn-based magnesium alloy of the present disclosure, the preferred content of Sn is 0.5% to 1.9%. Typical but non-limiting, the content of Sn may be, for example, 0.5%, 0.6%, 0.8%, 1%, 1.2 %, 1.4%, 1.5%, 1.6%, 1.7%, 1.8% or 1.9%.

Magnesium ion (Mg ²⁺ ) is the second most important cation in human cells and is not harmful to the human body. In addition, magnesium also has a variety of special physiological functions. It can activate a variety of enzymes in the body, inhibit abnormal nerve excitement, and maintain nucleic acid structure. It is involved in protein synthesis, muscle contraction and temperature regulation in the body.

The weight percentages of Zn and Sn in this disclosure are calculated based on the weight of Mg-Zn-Sn-based magnesium alloys; the balance includes Mg and unavoidable impurities, and refers to the Mg-Zn-Sn-based magnesium alloys of this disclosure In addition to Zn and Sn, it also includes magnesium and unavoidable impurities. Among them, the sum of the weight percentages of Zn, Sn and Mg and unavoidable impurities is 100%, and the weight percentage of unavoidable impurities does not exceed 0.15%. It is preferably not more than 0.10%.

In one or more embodiments, the unavoidable impurities include, but are not limited to, elements such as Fe, Si, Cu, and Cr.

In one or more embodiments, the melting temperature is typically but not limited to 690 ° C, 700 ° C, 710 ° C, 720 ° C, 730 ° C, 740 ° C, 750 ° C, 760 ° C, 770 ° C, 780 ° C, or 790 ℃; Typical but non-limiting temperature for cooling can be 630 ℃, 640 ℃, 650 ℃, 660 ℃, 670 ℃ or 680 ℃; Typical but non-limiting time for standing and holding can be 30min, 35min, 40min, 45min, 50min, 55min, 60min, 65min, 70min, 80min, 90min, 100min, 110min or 120min.

The present disclosure optimizes the smelting and processing conditions of alloy materials, and cooperates with the optimal adjustment of the proportion of each element to avoid the introduction of unfavorable alloying elements and reduce oxide impurities or element burnout. The alloy is made under appropriate preparation and processing processes. The second-phase structure in the alloy exhibits a diffuse distribution, which is conducive to the uniform corrosion mode of the alloy, and further improves the comprehensive performance of the magnesium alloy. The preparation process is simple, the time is short, it is easy to operate and control, the equipment is simple, the production cost is low, and the portability is strong.

The present disclosure adopts a combination of alloy composition control, smelting process and post-processing process to effectively control the content of the second phase, the microstructure and distribution of the alloy, and can greatly improve the biomechanics and biological corrosion resistance of the alloy. Good control.

By further optimizing the composition in the Mg-Zn-Sn-based magnesium alloy, the comprehensive properties of the Mg-Zn-Sn-based magnesium alloy can be further improved, so that it has better biocompatibility, mechanical properties, and corrosion resistance, and has suitable properties. The rate of hydrogen evolution and degradation.

By further optimizing the preparation process of Mg-Zn-Sn-based magnesium alloys, including adjustment of parameters such as melting temperature, the overall performance of Mg-Zn-Sn-based magnesium alloys can be further improved, making them have better biocompatibility and mechanical properties. And anti-corrosion performance, with suitable hydrogen evolution rate and degradation rate.

In one or more embodiments, during the smelting process, a mixed gas of one or more of argon, sulfur hexafluoride, carbon dioxide, and sulfur hexafluoride is used as the protective gas; preferably, argon is used as the protective gas. Protective gas;

In one or more embodiments, the cooling method includes at least one of a salt water bath, water quenching, furnace cooling, or air cooling; preferably, a salt water bath is used for cooling.

The disclosure adopts an electromagnetic induction melting furnace for smelting, which helps to improve the absorption rate and the uniformity of distribution, and can accelerate the dissolution and diffusion of alloying elements. It is a one-time success, the process is simple, the test parameters are convenient to control, and the time consumption is short. Burnout of alloying elements and strong portability.

The raw materials used in the preparation of the Mg-Zn-Sn-based magnesium alloy material are:

High purity magnesium ingot with a purity of ≥99.98% (parts by mass, the same below);

High-purity zinc ingot with a purity of ≥99.99%;

High purity tin ingot with a purity of ≥99.95%.

In one or more embodiments, the preparation method includes:

(a) The raw materials are high-purity magnesium ingots (purity not less than 99.98%), high-purity zinc ingots (purity not less than 99.99%), and high-purity tin ingots (purity not less than 99.95%). The percentage of Zn is 0.9% to 5.0%, Sn is 0.5% to 1.9%, and the rest are proportioning ingredients of Mg and unavoidable impurities;

(b) The raw materials are added to an electromagnetic induction furnace for melting. During the smelting process, argon is preferably used as a protective gas, the temperature is raised to 690-790 ° C, and the raw materials are uniformly and fully melted under electromagnetic induction stirring. After all melting, the temperature was lowered to 630-680 ° C for 30 to 120 minutes, and then taken out and cooled in a brine bath to obtain a Mg-Zn-Sn-based magnesium alloy ingot.

In at least one embodiment, a Mg-Zn-Sn-based magnesium alloy with controllable degradation rate is provided, and is prepared by using the preparation method described above.

In at least one embodiment, an application of the aforementioned Mg-Zn-Sn-based magnesium alloy with controllable degradation rate in the field of biomedicine is provided. The applications include applications in the preparation of vascular scaffolds, bone tissue replacement or repair materials, and tissue engineering scaffold materials.

In at least one embodiment, a biodegradable article made of the Mg-Zn-Sn-based magnesium alloy with a controlled degradation rate as described above is provided;

In one or more embodiments, the article is an article for medical applications;

In one or more embodiments, the product is a temporary or short-term biomedical implant device, including a degradable cardiovascular stent and a cardiovascular peripheral stent, an orthopedic internal fixation implant or a tissue engineering stent;

In one or more embodiments, the article includes an orthopedic fixation device or an intravascular cardiovascular stent.

In one or more embodiments, the article includes, but is not limited to, an implantable stent or implantable orthopaedic device. Among them, implantable stents include vascular stents, tracheal stents, esophageal stents, intestinal stents, or urethral stents. Implantable devices include bone tissue repair stents, fixation bone screws, rivets, bone plates, or intramedullary needles.

It can be understood that the application of the Mg-Zn-Sn-based magnesium alloy with controllable degradation rate in the second aspect of the present disclosure, the application of Mg-Zn-Sn-based magnesium alloy with controllable degradation rate in the third aspect, and the fourth aspect The preparation method of the biodegradable products and the aforementioned Mg-Zn-Sn-based magnesium alloy with controllable degradation rate is based on the same disclosed concept, and therefore has at least the same advantages as the aforementioned preparation method, which will not be repeated here. .

The disclosure is further described below with reference to specific embodiments, comparative examples, and drawings.

Example 1

A Mg-Zn-Sn-based magnesium alloy with controllable degradation rate includes the following weight percentages of elemental components: Zn 4.0%, Sn 1.0%, and the balance includes Mg and unavoidable impurities.

The Mg-Zn-Sn-based magnesium alloy of Example 1 is designated as Mg-4Zn-1Sn.

Example 2

A Mg-Zn-Sn series magnesium alloy with controllable degradation rate includes the following weight percentages of elemental components: Zn 4.0%, Sn 1.5%, and the balance includes Mg and unavoidable impurities.

The Mg-Zn-Sn-based magnesium alloy of Example 2 is represented as Mg-4Zn-1.5Sn.

Comparative Example 1

A Mg-Zn-Sn series magnesium alloy with controllable degradation rate includes the following weight percentages of elemental components: Zn 4.0%, Sn 2.0%, and the balance includes Mg and unavoidable impurities.

The Mg-Zn-Sn-based magnesium alloy of Comparative Example 1 is designated as Mg-4Zn-2Sn.

Comparative Example 2

A Mg-Zn-based magnesium alloy includes the following elements in weight percentage: Zn 4.0%, and the balance includes Mg and unavoidable impurities.

The Mg-Zn-based magnesium alloy of Comparative Example 2 is designated as Mg-4Zn.

Comparative Example 3

Medical magnesium alloy materials in the prior art;

Use existing biomedical magnesium alloy materials such as pure Mg, Mg-Zn-Zr, Mg-Zn-Zr-Y, JDBM, AZ31, WE43.

FIG. 1 shows the metallographic microstructure of the alloy material of Example 1, Example 2, Comparative Example 1, and Comparative Example 2, where (a) is the metallographic microstructure of the 2Mg-4Zn alloy of Comparative Example, and (b) is the implementation The metallographic microstructure of Example 1Mg-4Zn-1Sn alloy, (c) is the metallographic microstructure of Example 2Mg-4Zn-1.5Sn alloy, and (d) is the metallographic microstructure of Comparative Example 1Mg-4Zn-2Sn alloy. Figure 2 shows the XRD patterns of the alloy materials of Example 1, Example 2, Comparative Example 1, and Comparative Example 2, which are Mg-4Zn, Mg-4Zn-1Sn, Mg-4Zn-1.5Sn, and Mg from bottom to top, respectively. -4Zn-2Sn. FIG. 3 shows the mechanical properties of the alloy materials of Example 1, Example 2, Comparative Example 1, and Comparative Example 2, which are Mg-4Zn, Mg-4Zn-1Sn, Mg-4Zn-1.5Sn, and Mg-4Zn-2Sn. FIG. 4 shows the corrosion rate diagrams of the alloy materials of Example 1, Example 2, Comparative Example 1, and Comparative Example 2. From left to right are Mg-4Zn, Mg-4Zn-1Sn, Mg-4Zn-1.5Sn, and Mg-4Zn-2Sn.

It can be seen from the microstructure diagram in Fig. 1 that the Mg-4Zn alloy containing Sn is finer than the Mg-4Zn alloy without Sn, and the white second-phase particles gradually grow with the increase of the Sn content. It can be known from the XRD detection analysis in FIG. 2 that the white second-phase particles are Mg ₂ Sn phases. Most of Zn and Sn elements exist in the form of a solid solution. From Figures 3 and 4, it can be seen from the tensile curves of the alloys that the yield strength of the four alloys is higher than 100 MPa, the tensile strength is higher than 200 MPa, and the elongation is greater than 10%, which indicates that the alloy system ( Mg-Zn-Sn series) can meet the mechanical performance requirements of biomedical implant materials, and its weightless corrosion rate in PBS solution at 37 ° C reflects that Mg-4Zn-1.5Sn alloy has the lowest weightless corrosion rate. low 0.45mm.y ^-1, less than the prior art 0.5mm.y ^-1, indicating that moderate the rate of degradation of Sn can be added to control the alloy ideal value. The corrosion rate of Mg-4Zn-2Sn in Comparative Example 1 is greater than the corrosion rates of Examples 1 and 2. This indicates that the content of Sn is important for the regulation of the degradation rate. It also illustrates the 0.5% to 1.9% of the present disclosure. The amount of Sn added will control the degradation rate to a more reasonable range. In addition, the above series of figures and data show that the Mg-Zn-Sn-based magnesium alloy with controllable degradation rate of the present disclosure will have great potential for application in the biomedical field.

FIG. 5 shows the cell viability of RCR cells cultured in the extracts of the alloy materials of Examples 1 and 2. It can be seen from Figure 5 that Mg-4Zn-1Sn and Mg-4Zn-1.5Sn alloy materials have higher cell survival rates. Both alloy materials have maintained cell survival rates of more than 100%, indicating that Mg-4Zn -1Sn and Mg-4Zn-1.5Sn alloy extracts can promote the growth of RCR cells.

FIG. 6 shows a corrosion rate diagram of the alloy material of Example 2 and Comparative Example 3, that is, a comparison diagram of corrosion rates of Mg-4Zn-1.5Sn alloy material and other existing biomedical magnesium alloy materials. As can be seen from FIG. 6, the corrosion rate of the Mg-4Zn-1.5Sn alloy material of the present disclosure is as low as 0.45 mm.y ^-1 , which is significantly lower than that of other existing magnesium alloy materials. The alloy material has good controllability of corrosion and controllable degradation rate.

Example 3

A method for preparing a Mg-Zn-Sn-based magnesium alloy with controllable degradation rate. The Mg-Zn-Sn-based magnesium alloy includes the following elements by weight: Zn 5.0%, Sn 1.9%, and the balance includes Mg And inevitable impurities;

The preparation method of the Mg-Zn-Sn series magnesium alloy includes:

(a) The raw materials are high-purity magnesium ingots (purity not less than 99.98%), high-purity zinc ingots (purity not less than 99.99%), and high-purity tin ingots (purity not less than 99.95%). Zn 5.0%, Sn 1.9%, and the rest are proportioned with Mg and unavoidable impurities;

(b) Add each raw material to the electromagnetic induction furnace for smelting. During the smelting process, argon is used as a protective gas, the temperature is raised to 750 ° C, and the raw material is uniformly and fully melted under electromagnetic induction stirring. After all the alloying elements are melted, After cooling down to 680 ° C for 70 minutes, it was taken out and cooled in a brine bath to obtain a Mg-Zn-Sn-based magnesium alloy ingot.

Example 4

A method for preparing a Mg-Zn-Sn-based magnesium alloy with controllable degradation rate, which is different from Example 3 in that:

The Mg-Zn-Sn-based magnesium alloy includes the following weight percentages of elemental components: Zn 3.0%, Sn 1.2%, and the balance includes Mg and unavoidable impurities;

The rest are the same as in Example 3.

Example 5

The Mg-Zn-Sn-based magnesium alloy includes the following weight percentages of elemental components: Zn 2.5%, Sn 1%, and the balance includes Mg and unavoidable impurities;

The rest are the same as in Example 3.

Example 6

The Mg-Zn-Sn-based magnesium alloy includes elemental components in the following weight percentages: Zn 1.0%, Sn 0.5%, and the balance includes Mg and unavoidable impurities;

The rest are the same as in Example 3.

Example 7

In the preparation method,

(b) Add each raw material to the electromagnetic induction furnace for smelting. During the smelting process, argon is used as a protective gas, the temperature is raised to 740 ° C, and the raw materials are uniformly and fully melted under electromagnetic induction stirring. After all the alloying elements are melted, After cooling down to 670 ° C for 60 minutes, it was taken out and cooled in a brine bath to obtain a Mg-Zn-Sn series magnesium alloy ingot;

The rest are the same as in Example 3.

Example 8

In the preparation method,

(b) Add each raw material to the electromagnetic induction furnace for smelting. During the smelting process, a carbon dioxide and sulfur hexafluoride mixed gas is used as a protective gas, the temperature is raised to 720 ° C, and the raw materials are uniformly and fully melted under electromagnetic induction stirring. After all the alloying elements have been melted, the temperature is lowered to 660 ° C for 45 minutes, and the mixture is taken out and cooled in a brine bath to obtain a Mg-Zn-Sn series magnesium alloy ingot;

The rest are the same as in Example 3.

Example 9

In the preparation method,

(b) Add each raw material to the electromagnetic induction furnace for smelting. During the smelting process, a mixture of carbon dioxide and sulfur hexafluoride is used as a protective gas. The temperature is raised to 690 ° C and the raw materials are uniformly and fully melted under electromagnetic induction stirring. After all the alloying elements are melted, the temperature is lowered to 630 ° C for 30 minutes, and then taken out for water quenching and cooling to obtain a Mg-Zn-Sn series magnesium alloy ingot;

The rest are the same as in Example 3.

Comparative Example 4

The Mg-Zn-Sn-based magnesium alloy includes the following weight percentages of elemental components: Zn 6.5%, Sn 0.2%, and the balance includes Mg and unavoidable impurities;

The rest are the same as in Example 3.

What is different from Example 3 is that the contents of Zn and Sn in this comparative example are not within the content range provided by the present disclosure.

Comparative Example 5

The Mg-Zn-Sn-based magnesium alloy includes the following weight percentages of elemental components: Zn 0.5%, Sn 3.0%, and the balance includes Mg and unavoidable impurities;

The rest are the same as in Example 3.

Comparative Example 6

The Mg-Zn-Sn-based magnesium alloy includes the following weight percentages of elemental components: Zn 7.2%, Sn 1.8%, and the balance includes Mg and unavoidable impurities;

The rest are the same as in Example 3.

Different from Example 3, the content of Zn in this comparative example is out of the content range provided by the present disclosure.

Comparative Example 7

In the preparation method,

(b) Add each raw material to the electromagnetic induction furnace for smelting. During the smelting process, argon is used as a protective gas, the temperature is raised to 810 ° C, and the raw materials are uniformly and fully melted under electromagnetic induction stirring. After all the alloying elements are melted, After cooling to 700 ° C for 10 minutes, it was taken out and cooled in a brine bath to obtain a Mg-Zn-Sn series magnesium alloy ingot;

The rest are the same as in Example 3.

What is different from Example 3 is that the smelting temperature, the cooling and holding temperature, and the like in the preparation method of this comparative example are not within the scope provided by the present disclosure.

Comparative Example 8

A method for preparing a Mg-Zn-Sn-based magnesium alloy with a controlled degradation rate, which is different from Example 1 in that:

In the preparation method,

(b) The raw materials are added to an electromagnetic induction furnace for melting. During the melting process, argon is used as a protective gas, the temperature is raised to 650 ° C, and the raw materials are uniformly and fully melted under electromagnetic induction stirring. After all the alloying elements are melted, After cooling to 500 ° C for 15 minutes, it was taken out and cooled in a brine bath to obtain a Mg-Zn-Sn series magnesium alloy ingot;

The rest are the same as in Example 3.

Different from Example 3, the smelting temperature and cooling and holding temperature in the preparation method of this comparative example are not within the range provided by the present disclosure.

Performance Testing

The room temperature mechanical properties and in vitro degradation rate tests were performed on the alloy materials of the examples and comparative examples. The test results are shown in Table 1.

Table 1 Test results of room temperature mechanical properties and in vitro degradation rate of the alloys of the examples and comparative examples

It can be seen from Table 1 that the contents of Zn and Sn in the biomedical Mg-Zn-Sn series magnesium alloy have a certain effect on their mechanical properties and corrosion properties. The alloy systems with Zn and Sn contents in the scope of the present disclosure are all Can meet the requirements of biomedical implant materials for mechanical properties and corrosion properties.

Furthermore, the effects of alloying elements Zn and Sn on the mechanical properties of materials are described as follows: Zn and Sn are alloying elements with higher solid solubility. When the content of Zn is less than 6wt.%, Zn will be mainly solid-soluble. Forms exist in magnesium alloys, and the Sn content is less than 3wt.%, Which is mainly in the form of solid solution. When alloying elements form a solid solution, the mechanical properties of the material will be improved by solid solution strengthening; and the excess alloy Chemical elements will form second-phase particles in the alloy and precipitate out of the matrix. If they have a small and dispersed distribution morphology, the mechanical properties of the material will be enhanced by diffusion strengthening. If the second-phase particles are coarse, they may be related to the matrix. If there is a gap between them, the mechanical properties will be deteriorated. Furthermore, the content of Zn and Sn within the scope of the present disclosure and the magnesium alloy material prepared in accordance with the preparation method of the present disclosure, that is, the mechanical properties of the alloy material of Examples 1-9 such as tensile strength, yield strength, and elongation The overall mechanical properties are better than the alloy materials of Comparative Examples 1-8.

At the same time, it can be seen from Table 1 that the degradation rate of the alloy materials of Examples 1-9 in vitro is significantly lower than that of the alloy materials of Comparative Examples 1-8. This is due to the fact that the characteristics of the secondary phase structure in the alloy have a significant effect on the degradation rate. The Zn and Sn elements in the solid solution state can reduce the degradation rate of the magnesium matrix by increasing the corrosion resistance of the magnesium matrix. When the content of the second phase formed in the alloy is small and distributed in a finely dispersed manner, no significant galvanic corrosion will occur, and the effect on the degradation rate will be small. Once these second phases are coarsened, the galvanic corrosion effect will accelerate the degradation of the magnesium matrix. Therefore, by controlling the content of Zn and Sn elements and the process conditions, changing the proportion of Zn and Sn elements in the solid solution and the second phase, the Mg-Zn-Sn series magnesium alloy with controllable degradation rate can be obtained, and the corrosion controllability can be controlled. Well, make it more suitable for human use.

In addition, the melting temperature, standing temperature and time in the preparation method also have certain effects on the mechanical properties and corrosion properties of the material. When the alloy is prepared, the melting temperature is too high or too low, and the standing time is too short, which will affect the quality of the ingot, bring macro segregation, cracks, looseness, etc., and affect the various properties of the alloy.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure, but not limited thereto; although the present disclosure has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: The technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and these modifications or replacements do not deviate the essence of the corresponding technical solutions from the technical solutions of the embodiments of the present disclosure. range.

Industrial applicability

Claims

A method for preparing a Mg-Zn-Sn-based magnesium alloy with controllable degradation rate, wherein the Mg-Zn-Sn-based magnesium alloy includes the following weight percentages of elemental components:

Zn 0.9% to 5.0%, Sn 0.5% to 1.9%, the balance includes Mg and unavoidable impurities;

The preparation method of the Mg-Zn-Sn series magnesium alloy includes the following steps:

According to the group distribution ratio of the Mg-Zn-Sn-based magnesium alloy, the raw materials of each component are taken and smelted in a protective atmosphere. The melting temperature is 690-790 ° C. After all the alloying elements are melted, the temperature is reduced to 630-680. After standing at ℃ for 30 to 120 minutes, it was cooled to obtain a Mg-Zn-Sn-based magnesium alloy ingot.
The method for preparing a Mg-Zn-Sn-based magnesium alloy with controllable degradation rate according to claim 1, wherein the Mg-Zn-Sn-based magnesium alloy includes the following elemental components by weight: Zn 0.9% to 4.5 %, Sn 0.6% to 1.8%, the balance includes Mg and unavoidable impurities.
The method for preparing a Mg-Zn-Sn-based magnesium alloy with controllable degradation rate according to claim 1, wherein the Mg-Zn-Sn-based magnesium alloy includes the following weight percentage of elemental components: Zn 1.0% ～ 4.0%, Sn 0.7% ～ 1.5%, the balance includes Mg and unavoidable impurities.
The method for preparing a Mg-Zn-Sn-based magnesium alloy with controllable degradation rate according to any one of claims 1-3, wherein the method for preparing the Mg-Zn-Sn-based magnesium alloy includes the following steps: The composition ratio of the Mg-Zn-Sn series magnesium alloy is described. The raw materials of each component are taken and smelted in a protective atmosphere. The melting temperature is 700-780 ° C. After all the alloying elements are melted, the temperature is reduced to 640-670 ° C. After holding for 30 to 90 minutes, it was cooled to obtain a Mg-Zn-Sn-based magnesium alloy ingot.
The method for preparing a Mg-Zn-Sn-based magnesium alloy with controllable degradation rate according to any one of claims 1-4, wherein the method for preparing the Mg-Zn-Sn-based magnesium alloy includes the following steps: The composition ratio of the Mg-Zn-Sn series magnesium alloy is described. The raw materials of each component are taken and smelted in a protective atmosphere. The smelting temperature is 710-760 ° C. After all the alloying elements are melted, the temperature is reduced to 650-670 ° C. After holding for 30 to 60 minutes, it was cooled to obtain a Mg-Zn-Sn-based magnesium alloy ingot.
The method for preparing a Mg-Zn-Sn-based magnesium alloy with controllable degradation rate according to any one of claims 1 to 5, wherein the smelting is performed in an electromagnetic induction melting furnace.
The method for preparing a Mg-Zn-Sn-based magnesium alloy with controllable degradation rate according to any one of claims 1 to 6, wherein in the smelting process, argon, sulfur hexafluoride, carbon dioxide, and six One or more mixed gases in the sulfur fluoride mixed gas are used as the protective gas;
The method for preparing a Mg-Zn-Sn-based magnesium alloy with controllable degradation rate according to any one of claims 1 to 7, wherein the cooling method includes at least one of salt water bath, water quenching, furnace cooling or air cooling .
The method for preparing a Mg-Zn-Sn-based magnesium alloy with controllable degradation rate according to any one of claims 1 to 8, wherein raw materials are pure magnesium ingots, pure tin ingots, and pure zinc ingots.
A Mg-Zn-Sn-based magnesium alloy with controllable degradation rate, which is prepared by using the preparation method according to any one of claims 1 to 9;

Preferably, the Mg-Zn-Sn-based magnesium alloy includes the following weight percentages of elemental components: Zn 0.9% to 5.0%, Sn 0.5% to 1.9%, and the balance includes Mg and unavoidable impurities.
The use of the Mg-Zn-Sn-based magnesium alloy with controllable degradation rate according to claim 10 in the field of biomedicine.
The application according to claim 11, wherein the Mg-Zn-Sn series magnesium alloy with controllable degradation rate is used for preparing vascular scaffolds, bone tissue replacement or repair materials, and tissue engineering scaffold materials.
A biodegradable product made of the Mg-Zn-Sn series magnesium alloy with controllable degradation rate according to claim 10.
The biodegradable article according to claim 13, wherein the biodegradable article is an article for medical applications; the article comprises an implant or an internal stent.
The biodegradable article according to claim 14, wherein the implant is a bone tissue repair scaffold, a fixation screw, a rivet, a bone plate, or an intramedullary needle.
The biodegradable article according to claim 14, wherein the internal stent is a vascular stent, a tracheal stent, an esophageal stent, an intestinal stent, or a urethral stent.