Biomedical high-entropy alloy with high strength, plasticity and low modulus as well as preparation method and application of biomedical high-entropy alloy

Abstract

The invention provides a biomedical high-entropy alloy with high strength, plasticity and low modulus as well as a preparation method and application thereof, the biomedical high-entropy alloy with high strength, plasticity and low modulus has an expression of (TiZrNbX) 100-yOy, X is more than or equal to 0.55 and less than or equal to 0.75, y is more than or equal to 0.8 and less than or equal to 2.5, and the proportion of each element is a molar ratio. The preparation method of the alloy comprises the following steps: weighing a titanium rod, a zirconium rod, a niobium sheet and titanium dioxide according to an expression; and the weighed raw materials are placed in a water-cooled crucible of a vacuum melting furnace, titanium dioxide is evenly placed in gaps among the titanium rod, the zirconium rod and the niobium sheet, the vacuum melting furnace is vacuumized, melting is conducted, and the high-strength, high-plasticity and low-modulus biomedical high-entropy alloy is obtained. The high-strength, high-plasticity and low-modulus biomedical high-entropy alloy has excellent biocompatibility, high strength and plasticity and low Young modulus, and has very good application prospects and large-scale industrial popularization potential in the field of biomedical metal implant materials.

Description

Technical Field

[0001] The present invention relates to high entropy alloy technology, and in particular to a biomedical high entropy alloy with high strength, plasticity and low modulus, and a preparation method and application thereof. Background Art

[0002] For decades, bone disease has been one of the most common health problems, and sports syndromes including fractures, osteoarthritis, joint aging, and osteoma are becoming more and more common. It causes great harm to patients' bodies and minds, seriously affecting the overall quality of life of human beings, and due to the aging population, the number of people affected by bone diseases will gradually increase in the future. In response, the development of orthopedic implants has received great attention, aiming to replace or support damaged human bones.

[0003] At present, stainless steel, cobalt alloy, and titanium alloy are widely used in clinical practice due to their respective advantages. However, these alloys cannot have high strength, high plasticity, low modulus, good corrosion resistance, and biocompatibility. For example, cobalt-chromium alloy and Ti-6Al-4V have a higher Young's modulus than human bones, which will cause stress shielding. In addition, Ti-6Al-4V will release harmful Al and V ions into the surrounding human tissues, making the implant have to be renovated after long-term service or will have certain side effects on the body. Therefore, the development of orthopedic implant metal materials with excellent comprehensive performance and the improvement of the service performance of implants have become the hot spots of current scholars. New orthopedic implant metal materials with excellent comprehensive performance such as high strength plasticity, low elastic modulus, excellent corrosion resistance and good biocompatibility are urgently needed to be designed and developed. Summary of the invention

[0004] The purpose of the present invention is to propose a biomedical high-entropy alloy with high strength, plasticity and low modulus, in response to the problems of low strength and plasticity and high Young's modulus of existing biomedical implant materials. The alloy has excellent biocompatibility, high strength and plasticity and low Young's modulus, and has very good application prospects and large-scale industrial promotion potential in the field of medical metal implant materials.

[0005] It should be noted that, in the present invention, unless otherwise specified, the specific meaning of "including" in relation to composition limitations and descriptions includes both open-ended "including", "comprising", etc. and similar meanings, as well as closed-ended "composed of", "composed of", etc. and similar meanings.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is: a biomedical high entropy alloy with high strength, plasticity and low modulus, the expression is: (TiZrNb X ) 100-y O y, wherein 0.55≤X≤0.75, 0.8≤y≤2.5, and the ratio of each element is a molar ratio.

[0007] Furthermore, the biomedical high entropy alloy with strong plasticity and low modulus is expressed as: (TiZrNb X ) 100-y O y , wherein 0.55≤X≤0.65, 1.25≤y≤2.5, and the ratio of each element is a molar ratio.

[0008] Furthermore, the high-strength, plasticity and low-modulus biomedical high-entropy alloy is a single-phase BCC disordered solid solution structure.

[0009] Furthermore, the high-strength, plastic, and low-modulus biomedical high-entropy alloy has a yield strength of 863 MPa-1035 MPa, a fracture strength of 948 MPa-1041 MPa, an elongation of 8.45%-28%, an elastic modulus of 70.853 GPa-73.299 GPa, and a corrosion current density of 1.5×10 -7 -6.5×10 -8 A / cm 2 , the corrosion potential is -0.22-0.30V, and the high-strength, plasticity, and low-modulus biomedical high-entropy alloy has good biocompatibility.

[0010] Another object of the present invention is to disclose a method for preparing a biomedical high entropy alloy with high strength, plasticity and low modulus, comprising the following steps:

[0011] Step 1: Weigh titanium rod, zirconium rod, niobium sheet and titanium dioxide according to the expression;

[0012] Step 2: Place the weighed raw materials in a water-cooled crucible of a vacuum melting furnace, evenly place titanium dioxide in the gaps between the titanium rod, zirconium rod and niobium sheet, evacuate the vacuum melting furnace, and perform melting to obtain a cast alloy, which is a biomedical high-entropy alloy with high strength, plasticity and low modulus.

[0013] Furthermore, the titanium rod, zirconium rod and niobium sheet are all industrial-grade pure raw materials with a purity of 99.5wt.% or above.

[0014] Furthermore, before smelting, titanium alloy ingots are added to the vacuum arc furnace for smelting, and the residual oxygen in the vacuum arc furnace is absorbed to form an oxygen-free atmosphere before smelting.

[0015] Furthermore, during the vacuum arc melting process, the vacuum is first evacuated to 3×10 -3 Pa~5.5×10 -3 Pa, and then recoil argon to 0.05MPa~0.06MPa.

[0016] Furthermore, the vacuum arc melting temperature is 2100°C to 2300°C.

[0017] Furthermore, during the vacuum arc melting, the alloy ingot is turned over and melted six to eight times.

[0018] Another object of the present invention is to disclose the use of a biomedical high entropy alloy with high strength, plasticity and low modulus in the field of biomedical metal implant materials.

[0019] The high-strength, plastic, and low-modulus biomedical high-entropy alloy of the present invention, its preparation method, and use have the following advantages compared with the prior art:

[0020] 1) The high-strength, plasticity and low-modulus biomedical high-entropy alloy of the present invention adds an appropriate amount of O element to the high-entropy alloy for strengthening, and the strength and plasticity are synergistically improved, thereby obtaining a new high-entropy alloy material with excellent strength and plasticity.

[0021] 2) The high-strength, plastic, and low-modulus biomedical high-entropy alloy of the present invention has excellent biocompatibility and a relatively low elastic modulus, and can meet the special requirements of medical implant materials.

[0022] 3) The high-strength, plastic, and low-modulus biomedical high-entropy alloy of the present invention has a larger passivation range, a smaller self-corrosion current density, a higher self-corrosion potential, and excellent corrosion resistance.

[0023] 4) The high-strength, plastic, and low-modulus biomedical high-entropy alloy of the present invention is a cast alloy, which exhibits excellent mechanical properties in the cast state, does not require subsequent processing and heat treatment, has a simple process flow, and reduces costs.

[0024] In summary, the high-strength, plasticity, and low-modulus biomedical high-entropy alloy of the present invention has high strength and plasticity, low modulus, and excellent biocompatibility, and has very good application prospects and large-scale industrial promotion potential in the field of medical metal implant materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 (TiZrNb prepared in Example 1 0.6 ) 98 O 2 XRD spectrum of high entropy alloy ingot in as-cast condition;

[0026] Figure 2 (TiZrNb prepared in Example 1 0.6 ) 98 O 2 Microscopic morphology of high entropy alloy ingot in as-cast condition;

[0027] Figure 3 (TiZrNb prepared in Example 10.6 ) 98 O 2 Tensile engineering stress-engineering strain curve of high entropy alloy ingot in as-cast condition;

[0028] Figure 4 (TiZrNb prepared in Example 1 0.6 ) 98 O 2 Young's modulus of high entropy alloy ingot compared with that of 316 stainless steel and TC4 alloy;

[0029] Figure 5 (TiZrNb prepared in Example 1 0.6 ) 98 O 2 Potentiodynamic polarization curves of high entropy alloy ingot, 316 stainless steel and TC4 alloy. DETAILED DESCRIPTION

[0030] The present invention is further described below with reference to the examples. The description of the technical features described below is based on representative embodiments and specific examples of the present invention, but the present invention is not limited to these embodiments and specific examples. It should be noted that:

[0031] Unless otherwise stated, the units used in this specification are all international standard units, and the numerical values ​​and numerical ranges appearing in the present invention should be understood to include the inevitable systematic errors in industrial production.

[0032] In this specification, the numerical range expressed using "a numerical value A to a numerical value B" means a range including the endpoints A and B.

[0033] In the present specification, a numerical range expressed using "above" or "below" means a numerical range including the number.

[0034] In this specification, the word "may" means both performing a certain process and not performing a certain process.

[0035] In this specification, the use of "optional" or "optional" indicates that certain substances, components, execution steps, application conditions and other factors are used or not used.

[0036] In this specification, when "normal temperature" or "room temperature" is used, the temperature may be 15-25°C.

[0037] In this manual, the reagents or instruments used without indicating the manufacturer are all conventional products that can be obtained through commercial purchase.

[0038] The present invention discloses a biomedical high entropy alloy with high strength, plasticity and low modulus, which is expressed as follows: (TiZrNbX ) 100-y O y , wherein 0.55≤X≤0.75, 0.8≤y≤2.5, and the ratio of each element is a molar ratio.

[0039] The preparation method of the biomedical high-entropy alloy with high strength, plasticity and low modulus is as follows: the alloy is melted in a vacuum arc furnace, the raw materials titanium rod, zirconium rod and niobium sheet are uniformly mixed and put into a water-cooled copper crucible, and then titanium dioxide particles are evenly placed in the gap between the titanium rod, zirconium rod and niobium sheet, and the vacuum melting furnace is evacuated to a vacuum degree of 3×10 -3 When the argon gas is backwashed to 0.05Pa, smelting begins. Before smelting the alloy, the Ti alloy ingot is melted first to absorb the residual oxygen in the vacuum arc furnace. When smelting the alloy, it is necessary to turn over and smelt it at least 6 times, each time for one to two minutes to ensure uniform composition. After cooling, a biomedical high entropy alloy with high strength, plasticity and low modulus is obtained.

[0040] In the following examples, the prepared high-strength, plastic, and low-modulus high-entropy alloys were tested for mechanical properties, corrosion resistance, and biocompatibility. After the prepared high-strength, plastic, and low-modulus biomedical high-entropy alloys were cut into samples of the desired shape, mechanical properties, corrosion resistance, and biocompatibility experiments were performed. The specific testing process is as follows:

[0041] 1. Mechanical properties experiment:

[0042] The detection method is as follows:

[0043] Cut the ingot into pieces with a gauge length of 10 mm and a cross-sectional area of ​​2 × 1.5 mm 2 Dog bone shaped plate.

[0044] The prepared samples were stretched at room temperature with a strain rate of 0.001s -1 , the tensile engineering stress-strain curve and the true stress-strain curve were obtained, and the Young's modulus of the sample was obtained from the elastic deformation part of the true stress-strain curve using linear fitting.

[0045] 2. Corrosion resistance test

[0046] The detection method is as follows

[0047] Several high entropy alloy samples were cut from the ingot. The samples were small discs with a diameter of 15 mm and a thickness of 2 mm.

[0048] The cut samples were polished to 1000# with SiC sandpaper, ultrasonically cleaned with distilled water and anhydrous ethanol, and dried for later use;

[0049] A three-electrode electrochemical workstation was used, with the working electrode being the high entropy alloy sample, the counter electrode being the platinum sheet, and the Ag / AgCl electrode being the reference electrode. Under a constant temperature of 25°C, the potentiodynamic polarization curve of the high entropy alloy in PBS solution was tested, and the self-corrosion current density and corrosion potential were obtained to quantitatively evaluate the corrosion resistance of different high entropy alloys in a simulated body fluid environment.

[0050] 3. In vitro biocompatibility testing

[0051] The in vitro biocompatibility of high-entropy alloys was evaluated using MC3T3-E1 preosteoblasts.

[0052] The detection method is as follows

[0053] Several high entropy alloy samples were cut from the ingots, and the ordinary TC4 alloy was used as the control sample. The sample size was 10mm×10mm×2mm; the surface was ground with silicon carbide sandpaper of different grits until 3000 grit, and then mechanically polished with silicon dioxide solution, and then ultrasonically cleaned and sterilized with high-temperature and high-pressure steam at 121℃. The CCK-8 method was used to detect the changes in cell viability when MC3T3E1 cells were co-cultured with the samples for 1, 3, and 7 days. The cell survival was detected by cell live / dead staining when the samples were co-cultured with MC3T3E1 cells for 48 hours, and then the results were observed with a laser confocal microscope and photographed and recorded.

[0054] Example 1

[0055] This embodiment discloses a biomedical high entropy alloy with high strength, plasticity and low modulus, and its general formula is (TiZrNb 0.6 ) 98 O 2 , where the ratio of each element is a molar ratio.

[0056] The method for preparing the high-strength and high-plasticity antibacterial high-entropy alloy comprises the following steps:

[0057] (1) According to alloy composition (TiZrNb 0.6 ) 98 O 2 Prepare materials, wherein the ratio of each element in the alloy is a molar ratio; the titanium rod, zirconium rod and niobium sheet are all industrial grade pure raw materials with a purity of 99.5wt.% or above;

[0058] (2) Titanium rods, zirconium rods and niobium sheet raw materials are added into the electric arc furnace in sequence, and titanium dioxide particles are evenly placed in the gaps between the titanium rods, zirconium rods and niobium sheet raw materials. The electric arc furnace is evacuated to a vacuum degree of 3×10 -3Pa, argon is introduced into the furnace to a gas pressure of 0.05Pa. Before smelting, titanium alloy ingots are added to the vacuum arc furnace for smelting. After absorbing the residual oxygen in the vacuum arc furnace to form an oxygen-free atmosphere, the alloy is smelted at 2100℃~2300℃ and flipped six times to obtain a cast alloy, which is a biomedical high-entropy alloy with high strength, plasticity and low modulus.

[0059] Figure 1 (TiZrNb prepared in Example 1 0.6 ) 98 O 2 The XRD spectrum of the high entropy alloy ingot under cast conditions shows a single-phase BCC structure; Figure 2 (TiZrNb prepared in Example 1 0.6 ) 98 O 2 Microscopic morphology of high entropy alloy ingot under cast conditions; it can be seen that it has a typical dendritic morphology.

[0060] The mechanical properties of the high entropy alloy prepared in this embodiment were tested. The yield strength was 903MPa, the fracture strength was 967MPa, and the elongation was 28%. The tensile engineering stress-strain curve of the high entropy alloy ingot under cast conditions is as follows: Figure 3 As shown, a linear fit of the true stress-strain curve yields a Young's modulus of 71.822 GPa.

[0061] Figure 4 (TiZrNb prepared in Example 1 0.6 ) 98 O 2 Comparison of Young's modulus of high entropy alloy ingot with that of 316 stainless steel and TC4 alloy; it can be seen that the Young's modulus of this alloy is much lower than that of 316 stainless steel (195.6GPa), CoCrMo alloy (222.72GPa) and TC4 alloy (128.2GPa), which can better reduce the stress shielding effect.

[0062] The high entropy alloy sample prepared in this example was cut and tested for electrochemical potentiodynamic polarization curve, and compared with 316 stainless steel and TC4 alloy. Figure 5 (TiZrNb prepared in Example 1 0.6 ) 98 O 2 Potentiodynamic polarization curves of high entropy alloy ingot, 316 stainless steel and TC4 alloy. It can be seen that the corrosion current density of this alloy is 6.680×10 -8 A / cm 2 The corrosion potential is -0.2916V, which has better corrosion resistance than 316 stainless steel and TC4 alloy in the environment of simulated body fluid.

[0063] In vitro biocompatibility tests showed that it has good biocompatibility.

[0064] Example 2

[0065] This embodiment discloses a biomedical high entropy alloy with high strength, plasticity and low modulus, and its general formula is (TiZrNb 0.6 ) 98.25 O 1.75 The preparation method of the high-entropy alloy with high strength, plasticity and low modulus in this embodiment is the same as that in the first embodiment.

[0066] The yield strength is 876MPa, the fracture strength is 952MPa, and the elongation is 24%. The Young's modulus is 71.314GPa obtained by linear fitting of the true stress-strain curve, which is much lower than that of TC4 alloy. The corrosion current density of the alloy is 1.976×10 -7 A / cm 2 , the corrosion potential is -0.295V, and it has excellent corrosion resistance in simulated body fluid environment.

[0067] Example 3

[0068] This embodiment discloses a biomedical high entropy alloy with high strength, plasticity and low modulus, and its general formula is (TiZrNb 0.6 ) 98.5 O 1.5 The preparation method of the high-entropy alloy with high strength, plasticity and low modulus in this embodiment is the same as that in the first embodiment.

[0069] The yield strength is 863MPa, the fracture strength is 948MPa, and the elongation is 23%. The elastic modulus is 70.853GPa obtained by linear fitting of the true stress-strain curve, which is much lower than that of TC4 alloy. The corrosion current density of the alloy is 2.237×10 -7 A / cm 2 , the corrosion potential is -0.279V, and it has excellent corrosion resistance in simulated body fluid environment.

[0070] Example 4

[0071] This embodiment discloses a biomedical high entropy alloy with high strength, plasticity and low modulus, and its general formula is (TiZrNb 0.6 ) 97.5 O 2.5 The preparation method of the high-entropy alloy with high strength, plasticity and low modulus in this embodiment is the same as that in the first embodiment.

[0072] The yield strength is 1035MPa, the fracture strength is 1041MPa, and the elongation is 8.45%. The elastic modulus is 77.206GPa obtained by linear fitting of the true stress-strain curve, which is much lower than that of TC4 alloy. The corrosion current density of the alloy is 2.008×10 -7 A / cm 2 , the corrosion potential is -0.346V, and it has excellent corrosion resistance in simulated body fluid environment.

[0073] In summary, the (TiZrNb X ) 100-y O y This high-entropy alloy has high strength and plasticity in the cast condition and low Young's modulus, and these biophilic elements give it good biocompatibility.

[0074] The present invention is not limited to the high-strength, plastic, low-modulus biomedical high-entropy alloy described in any one of Examples 1-4, wherein changes in x, y and changes in the preparation method are all within the protection scope of the present invention.

[0075] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A biomedical high entropy alloy with high strength, plasticity and low modulus, characterized in that: The expression is: (TiZrNb X ) 100-y O y , wherein 0.55≤X≤0.75, 0.8≤y≤2.5, and the ratio of each element is a molar ratio.

2. The biomedical high entropy alloy with high strength, plasticity and low modulus according to claim 1, characterized in that: The biomedical high entropy alloy with high strength, plasticity and low modulus is a single-phase BCC disordered solid solution structure.

3. The biomedical high entropy alloy with high strength, plasticity and low modulus according to claim 1, characterized in that: Its yield strength is 863MPa-1035MPa, fracture strength is 948MPa-1041MPa, elongation is 8.45%-28%, elastic modulus is 70.853GPa-73.299GPa, and corrosion current density is 1.5×10 -7 -6.5×10 -8 A / cm 2 , the corrosion potential is -0.22-0.30V.

4. A method for preparing the biomedical high entropy alloy with high strength, plasticity and low modulus according to any one of claims 1 to 3, characterized in that: The following steps are involved: Step 1: Weigh titanium rod, zirconium rod, niobium sheet and titanium dioxide according to the expression; Step 2: Place the weighed raw materials in a water-cooled crucible of a vacuum melting furnace, evenly place titanium dioxide in the gaps between the titanium rod, zirconium rod and niobium sheet, evacuate the vacuum melting furnace, and perform melting to obtain a biomedical high-entropy alloy with high strength, plasticity and low modulus.

5. The method for preparing the biomedical high entropy alloy with high strength, plasticity and low modulus according to claim 4, characterized in that: The titanium rod, zirconium rod and niobium sheet are all industrial grade pure raw materials with a purity of 99.5wt.% or above.

6. The method for preparing the biomedical high entropy alloy with high strength, plasticity and low modulus according to claim 4, characterized in that: Before smelting, titanium alloy ingots are added to the vacuum arc furnace for smelting to absorb the residual oxygen in the vacuum arc furnace.

7. The method for preparing the biomedical high entropy alloy with high strength, plasticity and low modulus according to claim 4, characterized in that: During the vacuum arc melting process, the vacuum is first evacuated to 3×10 -3 Pa~5.5×10 -3 Pa, and then recoil argon to 0.05MPa~0.06MPa.

8. The method for preparing the biomedical high entropy alloy with high strength, plasticity and low modulus according to claim 4, characterized in that: The vacuum arc melting temperature is 2100°C to 2300°C.

9. The method for preparing the biomedical high entropy alloy with high strength, plasticity and low modulus according to claim 4, characterized in that: During the vacuum arc melting, the alloy ingot is turned over and melted six to eight times.

10. Use of the high-strength, plasticity and low-modulus biomedical high-entropy alloy according to any one of claims 1 to 3 in the field of biomedical metal implant materials.

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