阅读说明：本技术 一种可降解Zn-Ti二元生物医用材料及其制备方法 (Degradable Zn-Ti binary biomedical material and preparation method thereof ) 是由 童先 林继兴 王坤 于 2020-05-12 设计创作，主要内容包括：本发明涉及一种可降解Zn-Ti二元生物医用材料及其制备方法,所述Zn-Ti二元生物医用材料按质量百分比计,包括如下成份：Ti 0.01～2.5wt.％,余量为Zn,以提供一种具有更高的力学性能和更优异的细胞相容性的可降解Zn-Ti二元生物医用材料及其制备方法。(The invention relates to a degradable Zn-Ti binary biomedical material and a preparation method thereof, wherein the Zn-Ti binary biomedical material comprises the following components in percentage by mass: 0.01-2.5 wt% of Ti and the balance of Zn, so as to provide a degradable Zn-Ti binary biomedical material with higher mechanical property and more excellent cell compatibility and a preparation method thereof.)

1. A degradable Zn-Ti binary biomedical material is characterized in that: the Zn-Ti binary biomedical material comprises the following components in percentage by mass: 0.01-2.5 wt.% of Ti0.01 and the balance of Zn.

2. The degradable Zn-Ti binary biomedical material of claim 1, wherein: the Zn-Ti binary biological material comprises the following components in percentage by mass: 0.05-1 wt.% of Ti0.05 and the balance of Zn.

3. A method for preparing the degradable Zn-Ti binary biomedical material according to any one of claims 1 to 2, characterized in that: the method comprises the following steps:

a. preparing a zinc source and a titanium source according to a designed proportion, smelting in a protective atmosphere, and casting to obtain a Zn-Ti as-cast alloy ingot;

b. homogenizing the as-cast alloy ingot, and then cooling to room temperature;

c. preheating the homogenized alloy ingot, wherein the preheating temperature is 200-280 ℃, and the preheating time is 5-15 min;

d. and finally, carrying out multi-pass hot rolling treatment, wherein the pass reduction amount is 2-10% during hot rolling, the total deformation amount is 50-95%, and the temperature is kept for 1-5 min at 210-270 ℃ in the inter-pass heating process.

4. The preparation method of the degradable Zn-Ti binary biomedical material according to claim 3, characterized in that: according to step a, the zinc source is selected from a Zn ingot or an intermediate alloy consisting of Ti element, and the titanium source is selected from titanium foam or an intermediate alloy consisting of Zn element.

5. The preparation method of the degradable Zn-Ti binary biomedical material according to claim 4, wherein the preparation method comprises the following steps: when the zinc source is selected from a Zn ingot, the mass fraction of Zn in the Zn ingot is 99.999 wt.%; when the zinc source is selected from a Zn-3Ti master alloy, the mass fraction of Zn in the master alloy is 96.83 wt.%; when the titanium source is selected from titanium foam, the mass fraction of Ti in the titanium foam is 99.99 wt.%; when the titanium source is selected from a Zn-3Ti master alloy, the mass fraction of Ti in the master alloy is 3.17 wt.%.

6. The preparation method of the degradable Zn-Ti binary biomedical material according to claim 3, characterized in that: according to the step a, the smelting process is that firstly, a zinc source is smelted at 500-700 ℃, a titanium source is added after the zinc source is completely smelted, the titanium source is smelted at 520-720 ℃, after the titanium source is completely smelted, the mixture is stirred for 1-5 minutes and then stands for 5-10 minutes, slag on the liquid level of the alloy melt is removed, and the temperature is reduced by 20-50 ℃ on the basis of the smelting temperature of the titanium source, so that the alloy melt to be cast is obtained; and continuously introducing the protective atmosphere of argon or nitrogen in the smelting process.

7. The preparation method of the degradable Zn-Ti binary biomedical material according to claim 3, characterized in that: according to the step a, the casting molding process is to cast the alloy melt to be cast in a metal mold preheated at 200-250 ℃, and an as-cast alloy ingot is obtained after molding.

8. The preparation method of the degradable Zn-Ti binary biomedical material according to claim 3, characterized in that: according to the step b, the temperature of the homogenization treatment is 280-350 ℃, and the time of the homogenization treatment is 1-20 h.

9. The preparation method of the degradable Zn-Ti binary biomedical material according to claim 3, characterized in that: according to the step c, the preheating temperature is 220-260 ℃, and the preheating time is 5-10 min; the pass reduction amount is 5% during hot rolling, the total deformation amount is 60-90%, and the heat preservation time is 3-5 min at 230-250 ℃ in the inter-pass heating process.

10. The preparation method of the degradable Zn-Ti binary biomedical material according to claim 3, characterized in that: according to the step d, when the number of hot rolling passes is less than 5, the threading speed of the rolling mill is 5-8 m/min, and when the number of hot rolling passes is more than or equal to 5, the threading speed of the rolling mill is 10-20 m/min.

Technical Field

The invention relates to the technical field of biomedical metals, in particular to a degradable Zn-Ti binary biomedical material and a preparation method thereof.

Background

The degradable metal implant material has good biocompatibility and biodegradability, can be gradually degraded by body fluid in vivo, and the released degradation product brings appropriate host reaction to organisms. Therefore, the medical device is widely applied to clinical medicine, such as bone fixing elements, bone replacement elements, vascular stents and the like. At present, the degradable metals mainly comprise three types, namely magnesium-based, iron-based and zinc-based. The application of magnesium-based and iron-based biomaterials in biomedicine has entered the clinical use stage, and particularly, the application of degradable magnesium-based biomaterials in implants such as bone fixation and scaffolds is very extensive. There are currently marketed DREAMS 2G magnesium alloy stents which show significantly reduced late luminal loss in vivo for 6 months, with no intrastent thrombosis (references: Haude M, Inc H, Abizand A, et al, safety and performance of The second-generation drug-free available in vivo, metallic scaffoldings in tissues with de-novo coronary arteries (BIOSVE-II): 6month results of a pro-active, multicentre, non-randomised, first-in-man triple J, The left, 2016, 31-39. (R.H.)). For Fe-based implants, however, it has been reported that no inflammation and thrombosis was observed around the stent after implanting 8 pure iron stents into the coronary arteries of miniature pigs for 4 weeks (ref: Wu C, Hu X, Qiu H, et al. TCT-571A prediction in mini-swing bone array [ J ]. Journal of American College of medicine, 2012,60(17Supplement): B166.). Although magnesium-based and iron-based biomaterials have good biocompatibility and magnesium and iron play important roles in human metabolism as essential elements, magnesium-based alloys have the problems of too high degradation rate, hydrogen bubble generation, poor mechanical property integrity and the like, while iron-based materials have the defects of too low degradation rate, and the defects seriously hinder the popularization and application of the magnesium-based and iron-based biomaterials.

Zinc and its alloys have attracted considerable attention in recent years as a potential biodegradable medical material due to their suitable degradation rate and acceptable cellular compatibility. Zinc is one of the essential trace elements of six enzymes in the human body, and plays a crucial role in physiological activities, including participation in RNA and DNA metabolism, signal transduction and gene expression, and regulation of apoptosis (ref: Tapio H, Tew K D. Trace elements in human physiology and cytotoxicity [ J ]. Biomedicine & Pharmacotherapy,2003,57(9): 399-411.). In addition, zinc has an osteoinductive effect on bone tissue (ref: Ilich J Z, Kerstetter JE. Nutrition in bone health reconstructed: a storage beyond calcium [ J ]. Journal of the American College of Nutrition,2000,19(6): 715-737.). However, pure zinc has poor strength and ductility and low recrystallization temperature, thus seriously affecting the application and development of zinc-based degradable materials. At present, in order to improve the mechanical property of the zinc-based degradable material, alloying treatment is mainly added and deformation treatment process is combined. Alloying treatment elements include magnesium, strontium, calcium, copper, manganese, silver, iron, lithium, germanium, and the like. The deformation treatment process mainly comprises rolling, extruding, drawing, equal channel angular pressing and the like.

Titanium is used as a beneficial element for human bodies, and has good biocompatibility and no mutation such as carcinogenesis, teratogenesis and the like. Titanium can stimulate phagocyte and enhance immunity. The recommended daily intake of an adult is 0.3-2 mg. The titanium content in normal adults is 15 mg (ref: Gropper S, Smith J L. advanced nutrition and human metabolism [ M ]. Cengage Learning, 2012.). Titanium and its alloy are considered as an ideal implant material due to good wear resistance, corrosion resistance, mechanical properties and biocompatibility, and are widely used in internal fixation surgery of orthopedics. In addition, titanium is generally used as an alloying element as a grain refiner for aluminum alloys and magnesium alloys, and thus may also be used as an alloying element for zinc-based biomedical materials.

At present, no research on the preparation and corresponding performance of the Zn-Ti binary system degradable alloy is reported, so that the application of the Zn-Ti binary system alloy as a degradable biomedical material at the next stage is proposed.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a degradable Zn-Ti binary biomedical material with higher mechanical property and more excellent cell compatibility and a preparation method thereof.

The technical scheme of the invention is realized as follows: the degradable Zn-Ti binary biomedical material comprises the following components in percentage by mass: 0.01-2.5 wt.% of Ti, and the balance of Zn.

By adopting the technical scheme, the alloying element Ti with proper content is added into the pure zinc to perform alloying action on the pure zinc and effectively improve the cell activity, so that the Zn-Ti binary alloy has higher mechanical properties including strength, elongation, hardness and the like and has more excellent cell compatibility than the pure zinc.

The invention is further configured to: the Zn-Ti binary biological material comprises the following components in percentage by mass: 0.05-1 wt.% of Ti, and the balance of Zn.

By adopting the technical scheme, the proportion can really meet various performances of the biomedical material, can effectively control the element content of Ti, and because the Ti-rich precipitated phase is formed less when the Ti component is too low, the second phase strengthening effect on the matrix is weaker, the mechanical property and the hardness of the alloy are lower, and the requirements of the biomaterial are difficult to meet. When Ti is too high, coarse eutectic Zn (Ti) phase and peritectic TiZn appear in the alloy₁₆The phase will crack the Zn matrix, resulting in severe degradation of the mechanical properties of the alloy, and therefore Ti composition control is required.

The invention is further configured to: the method comprises the following steps:

a. preparing a zinc source and a titanium source according to a designed proportion, smelting in a protective atmosphere, and casting to obtain a Zn-Ti as-cast alloy ingot;

b. homogenizing the as-cast alloy ingot, and then cooling to room temperature;

c. preheating the homogenized alloy ingot, wherein the preheating temperature is 200-280 ℃, and the preheating time is 5-15 min;

d. and finally, carrying out multi-pass hot rolling treatment, wherein the pass reduction amount is 2-10% during hot rolling, the total deformation amount is 50-95%, and the temperature is kept for 1-5 min at 210-270 ℃ in the inter-pass heating process.

By adopting the technical scheme, the Zn ion-bearing material with excellent biological performance is obtained by adopting the traditional casting and deformation treatment and optimizing the process in the deformation treatment processTi is very important in the process of deformation treatment, the inter-pass heat treatment is very important, and because the zinc alloy has high cooling speed, the hot rolling treatment of only one pass can be carried out after single heat treatment in the middle of rolling, and the multi-pass rolling cannot be carried out, so that the cracking of the rolled zinc alloy plate caused by quick cooling is avoided. Meanwhile, the control of the preheating temperature before rolling and the heating temperature between passes is also important, and if the temperature is lower than the temperature range, microcracks and more serious edge cracks can occur in the rolling process due to the large deformation resistance of the zinc alloy. And above this temperature range, coarsening of crystal grains is caused, resulting in a decrease in mechanical properties of the alloy. Meanwhile, the higher the temperature is, the higher the friction coefficient of the sample surface is in the rolling process, the peeling phenomenon is easy to occur, and the defects of poor surface quality and low dimensional precision of a rolled piece are caused, the cooling mode is air cooling or water cooling, the alloy ingot is air cooled or water cooled to the room temperature, the purpose is to improve the element segregation in the Zn-Ti alloy, the alloy is a Zn-Ti binary biological material which is formed by properly preparing Ti element and has excellent mechanical property, proper degradation rate and good biocompatibility, so the excellent performance can be obtained, on one hand, reasonable component optimization is carried out, on the other hand, after the alloy is properly deformed, the intermediate phase of the Zn-Ti alloy is in strip distribution along the grain elongation direction (deformation direction), dynamic recrystallization occurs in the hot rolling process, the intermediate phase accumulated at the grain boundary can play a role in inhibiting the growth of recrystallized grains, the mechanical property of the alloy is improved; at the same time, part of the elongated eutectic Zn (Ti) phase and TiZn₁₆The phases are crushed under the action of rolling force, and the crushed intermediate phase can play a role in blocking the movement of crystal grains, so that the mechanical property of the alloy is obviously improved; in addition, the second phase is more dispersed, the alloy crystal grains are uniform, and the mechanical property of the alloy is promoted. In addition, the preparation process is simple and suitable for large-scale industrial production.

The invention is further configured to: according to step a, the zinc source is selected from a Zn ingot or an intermediate alloy consisting of Ti element, and the titanium source is selected from titanium foam or an intermediate alloy consisting of Zn element.

By adopting the technical scheme, the extraction and preparation of elements are facilitated, so that the Zn-Ti binary alloy has higher mechanical properties including strength, elongation, hardness and the like and has more excellent cell compatibility than pure zinc.

The invention is further configured to: according to step a, the zinc source is selected from master alloys consisting of Ti elements, and when the zinc source is selected from Zn ingots, the mass fraction of Zn in the Zn ingots is 99.999 wt.%; when the zinc source is selected from a Zn-3Ti master alloy, the mass fraction of Zn in the master alloy is 96.83 wt.%; when the titanium source is selected from titanium foam, the mass fraction of Ti in the titanium foam is 99.99 wt.%; when the titanium source is selected from a Zn-3Ti master alloy, the mass fraction of Ti in the master alloy is 3.17 wt.%.

By adopting the technical scheme, the preparation method is convenient to produce and manufacture, and has excellent mechanical property, proper degradation rate and good biocompatibility.

The invention is further configured to: according to the step a, the smelting process is that firstly, a zinc source is smelted at 500-700 ℃, a titanium source is added after the zinc source is completely smelted, the titanium source is smelted at 520-720 ℃, after the titanium source is completely smelted, the mixture is stirred for 1-5 minutes and then stands for 5-10 minutes, slag on the liquid level of the alloy melt is removed, and the temperature is reduced by 20-50 ℃ on the basis of the smelting temperature of the titanium source, so that the alloy melt to be cast is obtained; and continuously introducing the protective atmosphere of argon or nitrogen in the smelting process.

By adopting the technical scheme, the melting of the titanium source can be effectively accelerated and the excessive burning loss of the added zinc source and the titanium source can be avoided by proper temperature adjustment, and in addition, in the melting process, the titanium source needs to be pressed below the liquid level when being added because the specific gravity of the titanium is obviously smaller than that of the zinc, so that the phenomenon that the titanium source floats upwards to cause the incapability of melting can be avoided.

The invention is further configured to: according to the step a, the casting molding process is to cast the alloy melt to be cast in a metal mold preheated at 200-250 ℃, and an as-cast alloy ingot is obtained after molding.

By adopting the technical scheme, the processing can be efficiently carried out, and the production and the manufacture are convenient.

The invention is further configured to: according to the step b, the temperature of the homogenization treatment is 280-350 ℃, and the time of the homogenization treatment is 1-20 h.

By adopting the technical scheme, the preparation process can improve the finished product rate of the preparation and greatly improve the working efficiency.

The invention is further configured to: according to the step c, the preheating temperature is 220-260 ℃, and the preheating time is 5-10 min; the pass reduction amount is 5% during hot rolling, the total deformation amount is 60-90%, and the heat preservation time is 3-5 min at 230-250 ℃ in the inter-pass heating process.

By adopting the technical scheme, dynamic recrystallization occurs in the hot rolling process, the intermediate phase accumulated at the crystal boundary can play a role in inhibiting the growth of recrystallized grains, the mechanical property of the alloy is improved, and meanwhile, part of slender eutectic Zn (Ti) phase and TiZn phase₁₆The phases are crushed under the effect of the rolling force. The crushed intermediate phase can play a role in hindering the movement of crystal grains, and is obvious for improving the mechanical property of the alloy.

The invention is further configured to: according to the step d, when the number of hot rolling passes is less than 5, the threading speed of the rolling mill is 5-8 m/min, and when the number of hot rolling passes is more than or equal to 5, the threading speed of the rolling mill is 10-20 m/min.

Through adopting above-mentioned technical scheme, during the hot rolling of initial pass, adopt the threading speed of slower rolling mill, can avoid because threading speed is too fast and lead to the sample front end to fly up, arouse the inhomogeneous phenomenon of deformation, and then follow-up promotion threading speed can accelerate rolling efficiency on the one hand, and on the other hand prevents that sample afterbody temperature from dropping too fast, is favorable to rolling deformation's stability.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is an XRD pattern of an as-cast and hot-rolled Zn-0.2Ti alloy according to an embodiment of the present invention;

FIG. 2 is a metallographic representation of the as-cast and hot-rolled Zn-0.2Ti alloy of the present invention; wherein FIG. 2(a) is a metallographic structure diagram of an as-cast Zn-0.2Ti alloy, and FIG. 2(b) is a metallographic structure diagram of a hot-rolled Zn-0.2Ti alloy;

FIG. 3 is a graph of polarization curves and corrosion rates after 1 month immersion in Hanks' solution for as-cast and hot-rolled Zn-0.2Ti alloys in accordance with an embodiment of the present invention; wherein FIG. 3(a) is a polarization curve of as-cast and hot rolled Zn-0.2Ti alloys, and FIG. 3(b) is a graph of corrosion rates of as-cast and hot rolled Zn-0.2Ti alloys after immersion in Hanks' solution for 1 month;

FIG. 4 is a graph of the cell activity of a hot rolled Zn-0.2Ti alloy according to an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.