阅读说明：本技术 一种含铁抗菌钛合金及制备方法 (Iron-containing antibacterial titanium alloy and preparation method thereof ) 是由 张二林 王晓燕 秦高梧 于 2021-09-15 设计创作，主要内容包括：本发明属于有色金属材料钛合金领域,涉及一种含铁抗菌钛合金及制备方法。在纯钛或钛合金中添加所述重量百分数的铁元素,通过后续的材料加工工艺就可以获得含铁抗菌钛合金,其中铁元素的重量百分数不超过25％。所述的纯钛和钛合金包括已知的纯钛、α、α+β和β钛合金,例如Ti-6Al-4V,Ti-6Al-7Nb,也包括其他各种钛合金。所述添加铁元素的方式,可以是纯铁,也可以是换算后的含铁中间合金。该合金对常见的细菌具有强抑菌和杀菌效果,可有效地杀灭>90％与之接触的细菌,起到抗感染、抗炎症和防霉的作用,可以广泛地应用于医疗卫生、餐厨用品以及其他工业领域。(The invention belongs to the field of non-ferrous metal material titanium alloy, and relates to an iron-containing antibacterial titanium alloy and a preparation method thereof. The iron element with the weight percentage is added into the pure titanium or the titanium alloy, and the iron-containing antibacterial titanium alloy can be obtained through the subsequent material processing technology, wherein the weight percentage of the iron element is not more than 25%. The pure titanium and titanium alloys include known pure titanium, alpha + beta and beta titanium alloys such as Ti-6Al-4V, Ti-6Al-7Nb, and also include other various titanium alloys. The iron element may be added as pure iron or as a converted iron-containing intermediate alloy. The alloy has strong bacteriostatic and bactericidal effects on common bacteria, can effectively kill more than 90 percent of bacteria in contact with the alloy, has the functions of resisting infection, inflammation and mildew, and can be widely applied to the fields of medical treatment and health, kitchen supplies and other industries.)

1. An iron-containing antibacterial titanium alloy is characterized in that the weight percentage of iron element in the iron-containing antibacterial titanium alloy is not more than 25%.

2. The iron-containing antimicrobial titanium alloy of claim 1, wherein the titanium alloy has an elemental iron content of no more than 15% by weight.

3. The iron-containing antimicrobial titanium alloy of claim 1, wherein the titanium alloy has an elemental iron content of no more than 10% by weight.

4. The method for preparing an iron-containing antibacterial titanium alloy according to any one of claims 1 to 3,

adding the iron element in percentage by weight into the pure titanium or the titanium alloy, and then obtaining the iron-containing antibacterial titanium alloy through a subsequent process; the pure titanium and titanium alloys include known pure titanium, alpha + beta, and beta titanium alloys;

the mode of adding the iron element is pure iron, or a converted intermediate alloy containing iron, or an intermediate alloy consisting of Fe and other required alloy elements;

producing the iron-containing antibacterial titanium alloy ingot, plate or bar by adopting an ingot metallurgy method or a powder metallurgy method, but not limited to the two methods;

and carrying out high-temperature homogenization heat treatment on the obtained titanium alloy ingot, plate or bar, wherein the treatment temperature is not lower than the eutectic transformation temperature of the iron element in the titanium alloy.

5. The method of claim 4, wherein the titanium alloy includes but is not limited to Ti-6Al-4V or Ti-6Al-7 Nb.

6. The method of claim 4, wherein the high temperature homogenization heat treatment temperature does not exceed a eutectic transformation temperature of elemental iron in the titanium alloy.

7. The method according to claim 4 or 5, wherein the heat treatment is carried out at a temperature of not less than 600 ℃ and not more than 900 ℃.

8. The production method according to claim 4 or 5, characterized in that the time of the high-temperature homogenizing heat treatment is not shorter than 30 minutes.

9. The production method according to claim 7, wherein the time of the high-temperature homogenization heat treatment is not shorter than 30 minutes.

10. The production method according to claim 4, 5 or 9, characterized in that the time of the high-temperature homogenization heat treatment is not shorter than 2 hours.

Technical Field

The invention belongs to the field of non-ferrous metal material titanium alloy, and relates to an iron-containing antibacterial titanium alloy and a preparation method thereof.

Background

Titanium and titanium alloys are widely used in the manufacture of medical devices, tableware and kitchen utensils due to their good biosafety. Meanwhile, due to the good biological safety of the titanium alloy, microorganisms such as bacteria are particularly easy to adhere and spread on the surface of the titanium and the titanium alloy, and propagate in large quantities, so that a bacterial film is formed. In the application of medical devices, serious postoperative complications such as bacterial infection may occur. According to statistics, more than 500 million cases of implant materials are used for fracture every year in China, and the incidence rate of biomaterial-related infection is 0.5-6%. Although there is no statistical data on tableware, kitchenware and the like, the problems of mildew caused by bacteria, food deterioration and the like are receiving increasing attention.

The existing antibacterial material designs mostly select Cu ions and Ag ions with good antibacterial performance, the good antibacterial performance is obtained through the Cu ions or the Ag ions dissolved out of the surface of the material, and the antibacterial performance is generated by titanium and titanium alloy after the surface treatment through ultraviolet irradiation. Materials and surface coatings that obtain antibacterial properties through Cu ions and Ag ions require a large amount of Cu ions or Ag ions to be dissolved out while obtaining good antibacterial properties, possibly causing metal ion allergy. Therefore, it is an option to develop a new antibacterial titanium alloy material.

Iron has a number of valencies, including 0, +2, +3, +4, +5 and + 6. Wherein the +2 valence and the +3 valence are relatively common, the +2 valence ferrous ion is an important component of hemoglobin and is used for transporting oxygen, the +4 valence, the +5 valence and the +6 valence are rare, and only the +3 valence ferric ion can have good antibacterial performance. It is reported that the minimum concentration (MIC) value of copper ion for antibacterial is not less than 10. mu.M, the minimum concentration of silver ion for antibacterial is 30. mu.M, but the minimum concentration value of + 3-valent iron ion for antibacterial is 0.8. mu.M. It can be seen that the +3 valent iron ion has more effective antibacterial effect only from the antibacterial minimum concentration value. Under normal circumstances, the iron element reacts with the surrounding water or solution to form +2 valence and a very small amount of +3 valence, which is why the conventional iron, steel and stainless steel materials do not have good antibacterial performance despite the iron-rich element and the iron ion elution.

In order to obtain a ferrous titanium alloy material with stable properties, the preparation method can be divided into an ingot metallurgy method and a powder metallurgy method, but is not limited to the two methods.

Firstly, the ingot metallurgy method forms an ingot through burdening, smelting and casting in sequence, and then forms a plate or a bar with a certain shape through the steps of high-temperature cogging, high-temperature hot forging, normal-temperature rolling or drawing and the like. The specific gravity of the iron element is 7.8g/cm³And the specific gravity of the titanium element is 4.5g/cm³Therefore, in the smelting process, the iron element is easy to generate specific gravity segregation, so that the chemical composition of the titanium alloy is not uniform, and the dissolved + 3-valent iron ions cannot meet the concentration requirement, so that the antibacterial performance cannot be obtained. The chemical components of the titanium alloy are homogenized by regulating and controlling the heat treatment temperature and time.

② the method of powder metallurgy generally comprises the following steps: powder mixing, pre-pressing, (hot pressing) sintering and extrusion/rolling. The iron-titanium alloy obtained by the powder metallurgy method is easier to generate the segregation of chemical elements, but the phenomenon of chemical composition non-uniformity can be reduced from three aspects. Firstly, the alloy powder with more uniform components is obtained by methods such as ball milling and the like in the process of mixing the powder. Second, increasing the sintering temperature and the sintering time during sintering also makes the chemical composition of the alloy more uniform. Thirdly, the high temperature homogenization heat treatment eliminates the possible structural and chemical composition inhomogeneities that may still exist during the extrusion/rolling process.

Compared with the ingot metallurgy method, the powder metallurgy method requires a relatively high homogenization temperature and a long time to reduce segregation of metal elements and non-uniformity of chemical components during the preparation process.

Disclosure of Invention

The invention provides an iron-containing antibacterial titanium alloy and a preparation method thereof. When a titanium alloy having such characteristics is brought into contact with bacteria, oxygen in the aqueous solution first forms nano-sized titanium oxide with titanium. In the production of nano titanium oxideBy reacting iron atoms in the titanium alloy with chloride ions in the bacteria matrix solution to form FeCl₃，FeCl₃Readily soluble in water, i.e. by the following reaction: fe + Cl^-→FeCl₃；FeCl₃→Fe⁺³+Cl^-(ii) a Form +3 valent iron ions, which dissolve into the surrounding matrix. Then, the + 3-valent iron ions are dissociated into the interior of the bacteria, and are combined with proteins in the bacteria to generate ROS oxidation reaction radicals, so that the cell walls of the bacteria are damaged, and the bacteria are killed. At the same time from FeCl₃The dissociated Cl ions react with other iron atoms in the titanium alloy to form FeCl₃Dissociating new + 3-valent iron ions; more + 3-valent iron ions are dissolved out repeatedly, and when a certain concentration is reached, good antibacterial performance is shown.

An iron-containing antibacterial titanium alloy, wherein the weight percentage of iron element in the iron-containing antibacterial titanium alloy is not more than 25%. The iron-containing titanium alloy containing a certain amount of copper element or silver element or containing both copper element and silver element can obtain better antibacterial effect under the combined bactericidal action of copper ions, silver ions and + 3-valent iron ions.

Further characterized in that the weight percentage of the iron element in the titanium alloy is not more than 15 percent.

Further characterized in that the weight percentage of the iron element in the titanium alloy is not more than 10 percent.

The preparation of the iron-containing antibacterial titanium alloy comprises the following steps:

the iron element with the weight percentage is added into the pure titanium or the titanium alloy, and then the iron-containing antibacterial titanium alloy can be obtained through the subsequent material processing technology. The pure titanium and titanium alloys include known pure titanium, alpha + beta and beta titanium alloys such as Ti-6Al-4V, Ti-6Al-7Nb, and also include other various titanium alloys.

The iron element may be added as pure iron, or as a converted iron-containing intermediate alloy, such as a Ti — Fe intermediate alloy, or an intermediate alloy of Fe and other desired alloying elements.

The specific preparation process can adopt an ingot metallurgy method or a powder metallurgy method to produce the iron-containing antibacterial titanium alloy ingot, plate or bar with a certain shape, but is not limited to the two methods.

And carrying out high-temperature homogenization heat treatment on the obtained titanium alloy ingot, plate or bar, wherein the treatment temperature is not higher than the eutectic transformation temperature of the iron element in the titanium alloy.

Further, the temperature of the heat treatment is not lower than 600 ℃ and not higher than 900 ℃;

further, the time of the high-temperature homogenization heat treatment is not shorter than 30 minutes.

Further, the time of the high-temperature homogenization heat treatment is not shorter than 2 hours.

The high temperature heat treatment temperature and time are adjusted within the parameter range to obtain the iron-containing antibacterial titanium alloy with more uniform chemical composition and different components.

The antibacterial iron alloy provided by the invention has good antibacterial performance, and the antibacterial rate to staphylococcus aureus and escherichia coli reaches more than 90%.

Detailed Description

Example 1

Respectively taking pure titanium and Ti-6Al-4V as matrixes, preparing titanium alloys with different iron contents by an ingot metallurgy method, and then detecting the antibacterial performance of the alloys. See table 1 for details.

Example 2

Respectively taking pure titanium and Ti-6Al-7Nb as matrixes, preparing titanium alloys with different iron contents by a powder metallurgy method, and then detecting the antibacterial performance of the alloys. See table 1 for details.

The sterilization rate of the iron-titanium-containing alloy after the iron-titanium-containing alloy acts on common bacteria (escherichia coli, staphylococcus aureus and the like) is calculated according to the following formula:

the sterilization rate (%) was [ (% viable cell count of control sample-viable cell count of antibacterial ferrotitanium alloy)/viable cell count of control sample ]. times.100%

In the formula, the viable count of the control sample is the viable count of the control sample after bacterial culture on pure titanium, and the viable count of the iron-titanium-containing alloy is the viable count of the iron-titanium-containing alloy after bacterial culture.

The bacteriostasis test is specified according to standards such as JIS Z2801-: 0.3mL of test bacterial liquid is respectively dripped on a control sample (pure titanium) and an iron-containing titanium alloy sample. Covering the cover film on each sample with a pair of sterilization tweezers to make the bacteria liquid uniformly contact with the samples, placing the samples in a sterilization plate, and culturing for 24 hours in a constant temperature incubator at 37 ℃ and at a relative humidity of more than 90%. Taking out the cultured samples for 24h, respectively adding 15mL of eluent, repeatedly cleaning the samples and the covering film, fully shaking up, respectively taking 0.1mL of the eluent, dropwise adding the eluent into a plate nutrient agar culture medium, making three parallel samples for each sample, uniformly coating the samples by using a sterilization triangular rake, culturing the samples in a thermostat at 37 ℃ for 48h, and counting the viable bacteria according to the method of GB/T4789.2.

The antibacterial mechanism of the invention is as follows: oxygen in the aqueous solution firstly forms nano-scale titanium oxide with titanium, and under the catalytic action of the nano-scale titanium oxide, iron atoms in the titanium alloy react with chloride ions contained in the aqueous solution to form FeCl which is easily dissolved in water₃The + 3-valent iron ions enter the aqueous solution to contact with the bacteria, and are combined with proteins in the bacteria to generate ROS oxidation reaction radicals, so that the cell walls of the bacteria are damaged, and finally the bacteria die. Under the catalytic action of the nano titanium oxide, more + 3-valent iron can be dissolved out in the form of ions, and further the sterilization effect is realized.

TABLE 1 antibacterial Fe-Ti-containing alloy and antibacterial ratio thereof

Table 1 shows that: the Fe-Ti alloy prepared by ingot metallurgy and powder metallurgy has antibacterial rate of more than 90% and even up to 99% to Escherichia coli and Staphylococcus aureus, and has excellent antibacterial property.

The titanium alloy with too much iron element will cause the insufficiency of other performances such as mechanical property, formability and corrosion resistance, in addition, the excessive dissolution of +3 valence iron ion may also cause biological toxicity, so the iron element content in the titanium alloy needs to be controlled.