Biomedical high-entropy alloy film and preparation method thereof

Abstract

The invention relates to the technical field of biomedicine, and discloses a preparation method of a biomedical high-entropy alloy film, which comprises the following steps: step 1, preparing target materials and a matrix, taking an HfMoNbZr quaternary alloy target and a Ta metal target as the target materials, and taking a silicon wafer and 316L stainless steel as the matrix; step 2, removing oil stains and binders on the surfaces of the silicon wafer and the 316L stainless steel substrate; and thirdly, under the vacuum condition, the HfMoNbZr quaternary alloy target and the Ta metal target are subjected to film deposition through a direct-current magnetron sputtering silicon wafer and a 316L stainless steel substrate, and the biomedical high-entropy alloy film is obtained. The biomedical high-entropy alloy film can be prepared, has excellent corrosion resistance and biocompatibility, can promote the development of a high-entropy alloy biomedical film material, and particularly provides a theoretical basis and application value in the aspects of stomatology and orthopedics artificial joints.

Description

Technical Field

[0001] The present invention relates to the field of biomedical technology, and in particular to a biomedical high entropy alloy film and a preparation method thereof. Background Art

[0002] Biomedical high-entropy alloy film is a high-entropy alloy film material coated on the outer surface of medical devices or equipment. Its preparation method is not only directly related to the quality of the final high-entropy alloy film, but also to the promotion and application of the high-entropy alloy film product in medical scenarios.

[0003] Although there are many types of biomedical materials currently, such as metals, ceramics, polymers and their composites, high entropy alloys are always one of the best medical material choices due to their advantages such as high hardness and excellent corrosion resistance.

[0004] In order to better utilize the advantages of high entropy alloy materials themselves, the method of preparing high entropy alloy films has become increasingly important. On the one hand, it is necessary to increase the additional cost as little as possible. On the other hand, it is necessary to make the high entropy alloy film layer have more product performance than the unprocessed high entropy alloy material itself while not losing the properties of the high entropy alloy material itself.

[0005] The common method for preparing high entropy alloy thin films is arc melting. Although this method can obtain biomaterials that meet clinical medical value, that is, can obtain film materials that take both corrosion resistance and biocompatibility into consideration, it is difficult to obtain a uniform unidirectional solid solution high entropy alloy due to the limitation of cooling rate. The corrosion resistance of the film material formed is weak, and it cannot really solve the contradiction between corrosion resistance and biocompatibility.

[0006] For example, patent CN110423933A discloses a biomedical TiZrHfNbTa high entropy alloy and its preparation method. By adding highly biocompatible elements: Ti, Zr, and Nb, the prepared high entropy alloy has good biocompatibility, but its corrosion resistance is weak (corrosion current density is about 1.7×10-7A / cm2), and it is impossible to truly achieve both corrosion resistance and biocompatibility. In short, the high entropy alloy prepared by this method is not an ideal membrane material.

[0007] In addition, the preparation method is very complicated, requiring high-precision alloy ingredients and then smelting in a vacuum smelting furnace to obtain a master alloy, and finally cold rolling the master alloy and sealing it in a vacuum quartz tube for annealing and water quenching. The complex preparation process also affects the qualified rate of high-entropy alloy materials and high-entropy alloy films to a certain extent.

[0008] For example, patent CN117259763A discloses a high-entropy alloy powder for biological coating on the surface of metal implants and its preparation method. TiTaZrNbMo high-entropy alloy powder can be prepared by mechanical alloying method. High-entropy alloy coating with good biological properties can be obtained by using various surface coating technologies with the obtained high-entropy alloy powder as raw material. However, the whole process of preparing the powder first and then depositing the coating has a high production cost. The preparation of the powder requires graded ball milling in a ball mill, and there are many grinding steps, which takes a long time and requires high precision control. It is difficult to obtain high-entropy alloy materials that meet the requirements. The cost of using it for large-scale high-entropy alloy film production is too high, which is not conducive to promotion in biomedical scenarios.

[0009] Therefore, it is urgent to propose a new method for preparing high entropy alloy films to improve corrosion resistance and truly achieve both corrosion resistance and biocompatibility. At the same time, the preparation method consumes less cost and can be mass-produced in biomedical scenarios. Summary of the invention

[0010] The present invention aims to provide a method for preparing a biomedical high entropy alloy film, which can prepare a biomedical high entropy alloy film with excellent corrosion resistance and biocompatibility at a relatively low cost, and can promote the development of high entropy alloy biomedical film materials, especially in stomatology and orthopedic artificial joints, providing a theoretical basis and application value.

[0011] The basic scheme provided by the present invention is: a method for preparing a biomedical high entropy alloy film, the method comprising the following steps:

[0012] Step 1: prepare the target material and substrate, using HfMoNbZr quaternary alloy target and Ta metal target as the target material, and silicon wafer and 316L stainless steel as the substrate;

[0013] Step 2: removing oil stains and adhesives from the surface of the silicon wafer and the 316L stainless steel substrate;

[0014] Step three: Under vacuum conditions, HfMoNbZr quaternary alloy target and Ta metal target are deposited on silicon wafers and 316L stainless steel substrates by DC magnetron sputtering to obtain biomedical high entropy alloy films.

[0015] Furthermore, in step 1, the purity of the HfMoNbZr quaternary alloy target is greater than 99.95%, and the atomic ratio thereof is 1:1:1:1; the purity of the Ta metal target is greater than 99.95%.

[0016] Furthermore, in step 1, the substrate is single-sided polished, the thickness of the silicon wafer is 480-515 μm, and the thickness of the 316L stainless steel is 2-3 mm.

[0017] Furthermore, in step 2, the specific operation of removing oil and adhesive on the surface of the silicon wafer and the 316L stainless steel substrate is as follows: after rinsing the silicon wafer and the 316L stainless steel substrate with deionized water, the silicon wafer and the 316L stainless steel substrate are successively placed in a petroleum ether solution and anhydrous ethanol reagent for ultrasonic cleaning at a frequency of 30 kHz for 15 to 30 minutes, and the surface is blown dry after cleaning.

[0018] Furthermore, in step three, the conditions for thin film deposition include: the DC magnetron sputtering power of the HfMoNbZr quaternary alloy target is 190-210W, and the DC magnetron sputtering power of the Ta metal target is 40-60W.

[0019] Furthermore, the film deposition conditions also include: the distance between the HfMoNbZr quaternary alloy target and the silicon wafer and the 316L stainless steel substrate is 8 to 11 cm, and the background vacuum is less than 2×10 -3 Pa, the preparation temperature is room temperature, the deposition time is 120 min, the argon flow rate is 38-42 sccm, and the argon purity is ≥99.99%.

[0020] The present invention also provides a biomedical high entropy alloy film, which is obtained by depositing a HfMoNbZr quaternary alloy target and a Ta metal target through DC magnetron sputtering with a silicon wafer and 316L stainless steel as a substrate. The atomic percentage of each element in the film is respectively Hf 17-19%, Mo 16-18%, Nb 14-16%, Zr 13-15%, and Ta 32-34%.

[0021] Furthermore, the film has a body-centered cubic structure.

[0022] Furthermore, the corrosion current density of the film in a simulated human body solution is 3 to 5 nA / cm2, the corrosion potential is -0.2 to -0.3 V, and the relative cell activity is 105 to 109%.

[0023] Furthermore, a method for preparing a biomedical high entropy alloy film is provided for the application of the film in biomaterials.

[0024] The working principle and advantages of the present invention are: thin film deposition is performed on a silicon wafer and a 316L stainless steel substrate simultaneously by direct current magnetron sputtering using a HfMoNbZr quaternary alloy target and a Ta metal target, so as to obtain a biomedical high entropy alloy film with excellent corrosion resistance and biocompatibility.

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] This method simplifies the preparation process, adopts DC magnetron sputtering, and cleverly uses dual targets and dual substrates. HfMoNbZr quaternary alloy target and Ta metal target are used as targets, and silicon wafers and 316L stainless steel are used as substrates. The characteristics of the materials themselves are fully utilized, so that the corrosion resistance is continuously improved during the thin film preparation process, and the corrosion resistance of the final film material is greatly improved, truly taking into account both corrosion resistance and biocompatibility.

[0027] The existing DC magnetron sputtering technology is to apply a DC voltage between the target material (usually a pure metal or alloy to be deposited) and the substrate to generate plasma discharge, and then sputter out the target atoms or molecules, which are deposited on the substrate to form a thin film. The element content in the film prepared by this technology is easier to control accurately, the process is simple, and the prepared film has good uniformity; and this technology has the advantage of being less limited by the cooling rate, which can make up for the defects of the arc melting method to a certain extent. Therefore, the present invention proposes to use DC magnetron sputtering technology to prepare high entropy alloy films.

[0028] Conventional DC magnetron sputtering technology uses a single target material and a single substrate to prepare thin films. The present invention, based on a comprehensive consideration of the difficulty of controlling the preparation process and the preparation cost, proposes a DC magnetron sputtering method using dual targets and dual substrates. Taking into account the special application scenarios suitable for biomedicine, especially the application scenarios in stomatology and orthopedic artificial joints, the safety of elements, etc., HfMoNbZr quaternary alloy target and Ta metal target are preferably used as targets for thin film deposition, and deposition is performed by DC magnetron sputtering, which reduces the trial and error cost of thin film preparation and meets the performance requirements of special biomedical application scenarios.

[0029] Based on the application of dual-target and dual-substrate DC magnetron sputtering technology, the influence of Ta element content on the formation of body-centered cubic (BCC) structure of the film was discovered, thereby obtaining a range of film preparation conditions that can produce film with good performance characteristics such as corrosion resistance and biocompatibility.

[0030] In the process of preparing five-element high-entropy alloy biofilms, it is necessary to adjust the parameters of DC magnetron sputtering. In the process of adjusting parameters and preparing films, it is found that the elements of the HfMoNbZr quaternary alloy target are all refractory metals. When the Ta-magnetron power is adjusted so that the metal Ta is within a certain element content range, it can promote the formation of the body-centered cubic (BCC) structure of the film, and can make the stability of the solid solution better, so that the film has better corrosion resistance. Attempts have been made to prepare it using only quaternary alloys and too much metal Ta element content, but the corrosion resistance of the film did not continue to improve, but decreased. Based on this discovery, the research and development ideas were adjusted, and the metal Ta element content was adjusted, so that the good corrosion resistance of the present invention is mainly due to the proportion of the metal Ta element content, and within this metal Ta element content, the prepared film has good biocompatibility. Usually, in the process of preparing the film, too much metal Ta will cause the precipitation of α-Ta phase, weaken the solid solution strengthening effect, and make the corrosion resistance and performance of the film worse. The Ta element content obtained in the present invention is too much compared with the commonly used content, but the obtained film unexpectedly has good corrosion resistance and biocompatibility. Therefore, only within the conditions of the present invention can the good performance characteristics such as corrosion resistance and biocompatibility appear at the same time.

[0031] The applicant found that researchers have made great progress in biomedical materials, but some materials are not compatible with the advantages of biocompatibility and excellent corrosion resistance. Among many materials, medical metal materials have always been the first choice for medical materials in the medical field due to their excellent corrosion resistance and biocompatibility. Among them, 316L stainless steel has been widely used in the past due to its suitable mechanical properties, easy processing and low price, especially as the first choice for temporary implants in oral medicine and orthopedic artificial joints. After being implanted in the human body, 316L stainless steel is in a constant temperature physiological environment containing water, oxygen, enzymes, etc. for a long time. Due to its poor corrosion resistance, it will suffer from more serious corrosion. In addition, the subsequent reaction products of the metal ions contained in 316L stainless steel are toxic, among which Fe and Cr salts are metal hard acids with low cytotoxicity, and the released Ni cations have moderate cytotoxicity. Therefore, 316L stainless steel is often used in temporary implants, but is restricted as a permanent implant.

[0032] Based on the discovery of this application scenario and application needs, it is proposed to deposit high entropy alloy thin films using HfMoNbZr quaternary alloy target and Ta metal target by DC magnetron sputtering on silicon wafers and 316L stainless steel as substrates, and optimize the preparation method and material selection to balance the cost and improve the performance. First, the increasingly mature DC magnetron sputtering technology is used to amortize the preparation cost, so that the additional cost required in the preparation method is less, and the consistency of the preparation process can be effectively guaranteed, the overall cost can be reduced, and the production cost can be reduced without sacrificing the material performance. At the same time, compared with the existing high entropy alloy preparation method, this method abandons unnecessary links, effectively saves at least one-third of the time cost, greatly improves the production speed, and can further reduce the preparation cost through scale effect. Secondly, in terms of material selection, the appropriate target material is selected, which can not only ensure the corrosion resistance of stainless steel, but also take into account biocompatibility, so as to find the optimal balance between cost and performance. The film in the embodiment has excellent corrosion resistance, can extend its service life, and has good biocompatibility. In particular, after coating with silicon wafer and 316L stainless steel as the substrate, the biocompatibility and corrosion resistance are better than 316L stainless steel within a certain period of time, which can solve a series of problems in the biomedical use of 316L stainless steel.

[0033] Through the technical means of the present invention, it is possible to meet the corrosion resistance and biocompatibility requirements of biomedical scenarios while achieving effective cost control, making stainless steel more competitive and valuable in the biomedical field. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A schematic flow chart of a method for preparing a biomedical high entropy alloy film provided by an embodiment of the present invention;

[0035] Figure 2 XRD patterns of the films of Examples 1 and 2 of the present invention;

[0036] Figure 3 The potentiodynamic polarization curves of the films of Examples 1 and 2 of the present invention in PBS simulated human body solution;

[0037] Figure 4 Nanohardness diagram of the thin film of Examples 1 to 2 of the present invention;

[0038] Figure 5 The potentiodynamic polarization curves of the films of Comparative Examples 1 and 2 of the present invention in PBS simulated human body solution;

[0039] Figure 6 This is a graph showing the relative cell viability of the films of Comparative Examples 1 to 2 of the present invention and Example 2 of the present invention. DETAILED DESCRIPTION

[0040] The following is further described in detail through specific implementations, but the implementation of the present invention is not limited thereto. Unless otherwise specified, the technical means used in the following implementations are conventional means well known to those skilled in the art; the experimental methods used are all conventional methods; the materials, reagents, etc. used can all be obtained from commercial channels.

[0041] like Figure 1 As shown, a biomedical high entropy alloy film and a preparation method thereof include the following steps:

[0042] Step 1: prepare the target material and substrate, using HfMoNbZr quaternary alloy target and Ta metal target as the target material, and silicon wafer and 316L stainless steel as the substrate;

[0043] Specifically, the purity of the HfMoNbZr quaternary alloy target is greater than 99.95%, the atomic ratio in the quaternary alloy target is approximately equal, and the purity of the Ta metal target is greater than 99.95%; the substrate silicon wafer is single-sided polished and has a thickness of 480 to 515 μm, and the thickness of the 316L stainless steel is 2 to 3 mm.

[0044] Step 2: removing oil stains and adhesives from the surface of the silicon wafer and the 316L stainless steel substrate;

[0045] Specifically, after rinsing the silicon wafer and the 316L stainless steel substrate with deionized water, the silicon wafer and the 316L stainless steel substrate are successively placed in a petroleum ether solution and anhydrous ethanol reagent for ultrasonic cleaning at a frequency of 30 kHz for 15 to 30 minutes. After the cleaning is completed, the surface is blown dry with a hair dryer. During the drying process, the silicon wafer and the 316L stainless steel substrate are kept in a straight line with the air outlet of the hair dryer and at a 45° angle to the ground.

[0046] Step 3: Under vacuum conditions, HfMoNbZr quaternary alloy target and Ta metal target are deposited on silicon wafers and 316L stainless steel substrates by DC magnetron sputtering to obtain biomedical high entropy alloy films.

[0047] Specifically, the dried silicon wafer and 316L stainless steel substrate are fixed on the sample stage, placed on the rotating stage, and the substrate baffle is closed. The HfMoNbZr quaternary alloy target and the Ta metal target are respectively fixed on a copper platform connected to a DC power supply, and a magnet with an unbalanced magnetic field is installed on the back of the copper. The distance between the HfMoNbZr quaternary alloy target and the Ta metal target and the 316L stainless steel substrate is 8 to 11 cm, preferably 9 to 10 cm, and more preferably 9 cm. The chamber door is closed and the background vacuum is drawn to 2×10 -3Pa, the preparation temperature is room temperature, inert gas argon is introduced, the thin film deposition pressure is controlled, the argon flow rate is 38-42sccm, preferably 39-41sccm, and more preferably 40sccm, and the argon purity is ≥99.99%; the HfMoNbZr quaternary alloy target and the Ta metal target DC magnetron sputtering power are turned on respectively, the quaternary alloy target magnetron sputtering power is 190-210W, preferably 195-205W, and more preferably 200W; the Ta metal target magnetron sputtering power is 40-60W, preferably 45-55W, and more preferably 50W; pre-sputtering for 10min to remove impurities on the target surface, after pre-sputtering, the substrate baffle is opened to deposit the five-element high entropy alloy biomedical film, the sample rotation speed is 15r / min, the deposition time is 120min, and after the coating is completed, the cathode power is turned off and the sample is taken out.

[0048] Examples 1 and 2 of the present invention are carried out according to the steps of the above-mentioned biomedical high entropy alloy film preparation method, wherein the details are slightly different. The films prepared in Examples 1 and 2 of the present invention are tested for surface XRD, nanohardness, corrosion resistance and biocompatibility of Example 2. The specific detection methods are as follows:

[0049] The phase structure of the film prepared by the present invention is obtained by an X-ray diffractometer (mart Lab, Rigaku), wherein the scanning speed is 2° / min, the 2θ range is 30°~80°, the step size is 0.01°, the acceleration voltage is 30kV, and the emission current is 40mA. The corrosion resistance is obtained by an electrochemical workstation (DH7000, DONGHUA) using a dynamic potential polarization curve test, and a conventional three-electrode system is used in a PBS solution at a temperature of 37±1°C and pH=7.4. The hardness is obtained by a nanoindenter (TTX-NHT3, Anton Paar), wherein the load is set to 10mN. The biocompatibility is obtained by MTT method (Solaibao).

[0050] Example 1

[0051] The specific process parameters of the biomedical high entropy alloy film prepared by DC magnetron sputtering in this example are: the back vacuum degree is 2×10 -3 Pa, the target was fixed at 45° to the horizontal direction, the target spacing was 11 cm, the substrate deposition temperature was room temperature, the argon flow rate during thin film deposition was 38 sccm, the thin film deposition pressure was 0.48 Pa, the quaternary alloy target power was 200 W, the Ta metal target power was 30 W, the deposition time was 120 min, and the sample was taken out after completion.

[0052] The results of this embodiment show that the atomic percentages of the elements in the film are calculated to be Hf 21.3%, Mo 18.6%, Nb 17.7%, Zr 17.0%, and Ta 25.4%; the phase structure is as follows: Figure 2As shown, it shows a body-centered cubic structure (BCC); the corrosion current density is 4.94nA / cm2, the corrosion potential is -0.24V, and the pitting potential is 1.21V ( Figure 3 ); the hardness is 13.6GPa( Figure 4 ).

[0053] Example 2

[0054] The specific process parameters of the biomedical high entropy alloy film prepared by DC magnetron sputtering in this example are: the back vacuum degree is 2×10 -3 Pa, the target was fixed at 45° to the horizontal direction, the target spacing was 10 cm, the substrate deposition temperature was room temperature, the argon flow rate during thin film deposition was 39 sccm, the thin film deposition pressure was 0.50 Pa, the quaternary alloy target power was 200 W, the Ta metal target power was 50 W, the deposition time was 120 min, and the sample was taken out after completion.

[0055] The results of this embodiment show that the atomic percentages of the elements in the film are calculated to be Hf 18.7%, Mo 17.6%, Nb 15.6%, Zr 14.5%, and Ta 33.6%; the phase structure is a body-centered cubic structure (BCC) ( Figure 2 ); the corrosion current density is 3.62nA / cm 2 , the corrosion potential is -0.22V, and the pitting potential is greater than 1.46V ( Figure 3 ); hardness is 12.0GPa( Figure 4 ); the relative cell viability was 107.83% ( Figure 6 ).

[0056] Comparative Example 1

[0057] This comparative example uses only 316L stainless steel, which is rinsed with deionized water, cleaned with petroleum ether solution and anhydrous ethanol reagent in an ultrasonic bath at a frequency of 30 kHz for 15 to 30 minutes, and its surface is dried with a hair dryer.

[0058] The results of this comparative example show that the corrosion current density is 81.20 nA / cm 2 , the corrosion potential is -0.17V, and the pitting potential is 0.37V ( Figure 5 ), poor corrosion resistance; relative cell activity was 95.36% ( Figure 6 ).

[0059] Comparative Example 2

[0060] The specific process parameters of this comparative example using only DC magnetron sputtering to prepare biomedical high entropy alloy thin films are: the back vacuum degree is 2×10 -3Pa, the target was fixed at 45° to the horizontal direction, the target spacing was 11 cm, the substrate deposition temperature was room temperature, the argon flow rate during thin film deposition was 40 sccm, the thin film deposition pressure was 0.47 Pa, the quaternary alloy target power was 200 W, the deposition time was 120 min, and the sample was taken out after completion.

[0061] The results of this comparative example show that the calculated atomic percentages of the elements in the film are Hf 26.6%, Mo 24.2%, Nb 23.8%, and Zr 25.4%; the corrosion current density is 5.99nA / cm2, the corrosion potential is -0.23V, and the pitting potential is 1.17V ( Figure 5 ), poor corrosion resistance; relative cell activity was 102.46% ( Figure 6 ).

[0062] Compared with Comparative Example 2, the corrosion current density of Example 2 is 3.62nA / cm 2 , the corrosion potential is -0.22 V, the pitting potential is greater than 1.46 V, and the relative cell activity is 107.83%, which indicates that the film obtained in Example 2 has both excellent corrosion resistance and biocompatibility.

[0063] In summary, based on the application scenarios of 316L stainless steel in biomedicine, its application defects, and the discovery of performance requirements to be improved, the present invention proposes to deposit high entropy alloy thin films using HfMoNbZr quaternary alloy targets and Ta metal targets by DC magnetron sputtering with silicon wafers and 316L stainless steel as substrates, and finds the optimal balance between cost and performance from the aspects of preparation method and material selection, and then proposes a cost-balanced and high-performance thin film preparation method. The comprehensive application of dual-target and magnetron sputtering technology creatively discovered the influence of Ta content on the formation of BCC structure, thereby obtaining the condition range for the simultaneous appearance of good performance characteristics such as corrosion resistance and biocompatibility. When applied in stomatology and orthopedic artificial joints, the shapes and types of thin film deposition objects are different. With the preparation method of the present invention, each parameter is easy to control, and the film preparation time, film uniformity, area, thickness, etc. are suitable for batch production. It not only has excellent corrosion resistance and good biocompatibility, but also can be significantly improved in film uniformity, production efficiency, and reduced material waste. At the same time, the performance is guaranteed to be continuously good within the limited implantation time of stomatology and orthopedic artificial joints, further balancing performance, cost, and biomedical time. The film prepared by the present invention and the preparation method expand the database of biomedical high entropy alloy films and provide a new technical approach for the preparation of future biomaterials.

[0064] The above is only an embodiment of the present invention. The common sense such as the known specific structure and characteristics in the scheme is not described in detail here. The ordinary technicians in the relevant field are aware of all the common technical knowledge in the technical field to which the invention belongs before the application date or priority date, can obtain all the existing technologies in the field, and have the ability to apply the conventional experimental means before that date. The ordinary technicians in the relevant field can improve and implement the present invention in combination with their own abilities under the enlightenment given by this application. Some typical known structures or known methods should not become obstacles for the ordinary technicians in the relevant field to implement this application. It should be pointed out that for the technicians in this field, without departing from the structure of the present invention, several deformations and improvements can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent.

Claims

1. A method for preparing a biomedical high entropy alloy film. It is characterized in that The method comprises the following steps: Step 1: prepare the target material and substrate, using HfMoNbZr quaternary alloy target and Ta metal target as the target material, and silicon wafer and 316L stainless steel as the substrate; Step 2: removing oil stains and adhesives from the surface of the silicon wafer and the 316L stainless steel substrate; Step 3: Under vacuum conditions, HfMoNbZr quaternary alloy target and Ta metal target are deposited on silicon wafers and 316L stainless steel substrates by DC magnetron sputtering to obtain biomedical high entropy alloy films.

2. A method for preparing a biomedical high entropy alloy film according to claim 1, It is characterized in that In step 1, the purity of the HfMoNbZr quaternary alloy target is greater than 99.95%, and the atomic ratio thereof is 1:1:1:1; the purity of the Ta metal target is greater than 99.95%.

3. The method for preparing a biomedical high entropy alloy film according to claim 1, It is characterized in that In step 1, the substrate is single-sided polished, the thickness of the silicon wafer is 480-515 μm, and the thickness of the 316L stainless steel is 2-3 mm.

4. The method for preparing a biomedical high entropy alloy film according to claim 1, It is characterized in that In step 2, the specific operation of removing oil and adhesive on the surface of the silicon wafer and the 316L stainless steel substrate is as follows: after rinsing the silicon wafer and the 316L stainless steel substrate with deionized water, the silicon wafer and the 316L stainless steel substrate are placed in a petroleum ether solution and anhydrous ethanol reagent for ultrasonic cleaning in succession, with a frequency of 30 kHz and a time of 15 to 30 minutes. After cleaning, the surface is blown dry.

5. The method for preparing a biomedical high entropy alloy film according to claim 1, It is characterized in that In step three, the conditions for thin film deposition include: a DC magnetron sputtering power of 190 to 210 W for the HfMoNbZr quaternary alloy target and a DC magnetron sputtering power of 40 to 60 W for the Ta metal target.

6. A method for preparing a biomedical high entropy alloy film according to claim 5, It is characterized in that In step 3, the film deposition conditions also include: the distance between the HfMoNbZr quaternary alloy target and the silicon wafer and the 316L stainless steel substrate is 8 to 11 cm, and the background vacuum is less than 2×10 -3 Pa, the preparation temperature is room temperature, the deposition time is 120 min, the argon flow rate is 38-42 sccm, and the argon purity is ≥99.99%.

7. A biomedical high entropy alloy film, It is characterized in that The film is deposited by using a HfMoNbZr quaternary alloy target and a Ta metal target through direct current magnetron sputtering with a silicon wafer and 316L stainless steel as a substrate. The atomic percentage of each element in the film is respectively Hf 17-19%, Mo 16-18%, Nb 14-16%, Zr 13-15%, and Ta 32-34%.

8. The biomedical high entropy alloy film according to claim 1, It is characterized in that The film has a body-centered cubic structure.

9. The biomedical high entropy alloy film according to claim 1, It is characterized in that The corrosion current density of the film in the simulated human body solution is 3-5 nA / cm 2 The corrosion potential is -0.2~-0.3V, and the relative cell activity is 105~109%.

10. Application of the film made by the method for preparing a biomedical high entropy alloy film according to any one of claims 1 to 6 in biomaterials.

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