WO2023045352A1 - Multi-stage structural membrane for biomedical use - Google Patents

Abstract

The present invention provides a multi-stage structural membrane for a biomedical use, comprising: a structure composed of Ti, Zr, and Ta, 3 to 4 layers, and a substrate being a titanium alloy. The prevent invention has the advantages that three materials are all "biophilic metals", and are non-toxic, non-magnetic and strong in corrosion resistance. The multi-stage structural membrane is facilitated to be used as a biomedical membrane layer, and belongs to a biofunctional membrane.

Description

A kind of multi-level structure membrane for biomedicine

Cross References to Related Applications

This application claims the benefit of Chinese application number 202111127188.2 filed on September 26, 2021. Said application number 202111127188.2 is hereby incorporated by reference in its entirety.

technical field

The invention relates to the technical field of biomedicine, in particular to a multi-level structure membrane for biomedicine.

Background technique

The surface corrosion resistance and biocompatibility of the existing medical titanium alloys are relatively poor, and the surface modification technology is mainly sprayed with Ti or HA coating, which has low bonding strength between the titanium alloy and the coating, and the film layer Defects of poor wear resistance;

For example, the notification number is CN1648286, and the patent title is "TiN-TiAIN series hard nanostructure multilayer film coating" (hereinafter referred to as prior art 1). The superimposed hard nanostructure multilayer film coating is a diamond-like (DLC) hard film, which is mainly used for knives or mechanical parts. It does not have "bio-affinity", and is not suitable as a film on the surface of biomedical materials. Preparation technology; in terms of preparation technology, it is necessary to use different reaction gases and special workpiece rotation mechanisms to prepare TiN and TiAlN nano-film coatings on the surface of the material, so the preparation process is relatively complicated;

Another example is that the announcement number is CN102703874B, the patent name is "Preparation method of magnetron sputtering deposition tantalum film on the surface of magnesium alloy" (hereinafter referred to as prior art 2) and the announcement number is CN103695854A, the patent name is "PVD method coating tantalum or niobium The patent of “Technology for Making Corrosion-resistant Metal Materials” (hereinafter referred to as prior art 3), its tantalum film layers are all single-layer films, and the structure is simple, so that in practical applications, the magnesium alloy substrate is exposed after the single-layer film peels off, and the The potential difference between the substrate and the film layer will accelerate the corrosion rate of the magnesium alloy substrate at the film rupture position; and in the prior art 2, if the deposition thickness is too thick, there is a high risk of film rupture due to the influence of residual stress in the single film layer; Existing technology 3 has no requirements on the surface state of the substrate before the preparation of the film layer, and there is no polishing and cleaning process, resulting in low bonding strength between the PVD tantalum film or niobium film and the substrate, and it is easy to peel off. Tradition is old.

It can be seen that there is an urgent need for a medical titanium alloy with good surface corrosion resistance and biocompatibility, high bonding strength between the titanium alloy and the coating, good wear resistance of the film layer, and suitable for biomedical orthopedic implants.

Contents of the invention

The invention provides a multi-level structure film for biomedical use, and proposes to prepare a multi-layer structure biophilic film layer by physical vapor deposition on the surface of a titanium alloy, so as to overcome at least one of the above-mentioned technical defects.

In order to realize the foregoing invention object, the present invention provides following technical scheme:

The first aspect of the present invention protects a multi-level structure film for biomedicine, comprising: the structure is composed of Ti, Zr and Ta, and the number of layers is 3-4.

Preferably, the transition layer is a Ti, Zr, Ta layer, and the service layer (exposed layer/outermost layer) is a tantalum coating.

The second aspect of the present invention protects the method for preparing the multi-level structure film described in the first aspect, including: installing several targets on different targets in the magnetron sputtering apparatus, and then according to the specific structural layer of the multi-level structure film To control the sputtering sequence of different targets, to control the deposition thickness of each film layer in a single modulation period, and finally obtain the required multi-level structure film;

Wherein, one target corresponds to one target, and the substrate used in the magnetron sputtering apparatus is titanium alloy.

Preferably, the target material is a titanium target, a zirconium target, or a tantalum target, and the tantalum target is the outermost layer of the multi-level structure film.

Preferably, the specific steps of the method of the second aspect protected by the present invention are as follows:

S1. Install the titanium target, zirconium target and tantalum target on the three targets in the magnetron sputtering apparatus respectively;

S2. After the three targets are placed, the vacuum chamber is evacuated to 4×10 ^-4 ~ 6×10 ^-4 Pa, filled with argon, and the sputtering pressure is adjusted to 1×10 ^-1 ~ 4×10 ^-1 Pa ;Adjust the valve of the argon gas flowmeter to stabilize the working pressure of the vacuum chamber at 3×10 ^-1 ~6×10 ^-1 Pa;

S3. The heating temperature of the substrate is 200-300°C, the speed of the substrate table is set at 5-15rpm, the parameter of the current limiting valve is adjusted to 40-60°, and the DC bias power supply is a negative bias voltage of -250V to -350V. Pre-sputter at 100w for 10min to 15min, complete sputter cleaning, and open the baffle;

S4. Cool the product obtained in step S3 to room temperature, take it out, and then ultrasonically clean it in absolute ethanol for 5-10 minutes and air-dry it to prepare a multi-level structure membrane.

Preferably, in step S3, before the pre-sputtering, the base distance of the target is set to 50-90 mm, and then the sputtering target baffle and the substrate baffle are opened for pre-sputtering.

Preferably, in step S3, when sputtering the target, the current loaded on the target is 0.1-0.8A, the sputtering power is 60-100w, and the sputtering time is 120-240min.

Preferably, in step S3, the sputtering sequence and sputtering time of different targets are controlled according to the structure of the multi-level structure film and the requirements of the deposition thickness of each film layer.

A kind of multi-level structure membrane that is used for biomedicine of the present invention, its advantage is:

1. The film layers of the multi-level structure film prepared by this method are titanium, zirconium and tantalum film layers, and the service layer (exposed layer/outermost layer) is a tantalum coating, which is mainly used for modification on the surface of biomedical titanium alloy TC4 Deposition; the three materials are all "biophilic metals", non-toxic, non-magnetic, and strong corrosion resistance, which is beneficial to be used as a biomedical film layer, which belongs to the biological functional film;

2. In the multi-layer structure film, the specific material thickness of the film layer can be designed according to specific needs, and the material and sequence of each layer of film can be controlled by controlling the sputtering sequence of the target to control the deposition of each film layer in a single modulation cycle , the modulating layer can be composed of 3-4 layers, and the three layers of Ti, Zr, and Ta can be arranged and combined arbitrarily, such as: Ti-Zr-Ta film, Zr-Ti-Ta film, Ta-Ti-Zr- Ta film, etc., are more practical;

3. The structural film layer designed by the present invention, because the modulation cycle thickness is moderate, each layer of metal film in the modulation layer is a corrosion-resistant metal. After the surface film layer fails, the second layer of film can still provide strong corrosion resistance. The matrix is in direct contact with the environment, reducing the risk of ion release from the matrix alloy;

4. In the preparation method of the present invention, 3 target positions are set in the magnetron sputtering apparatus to simultaneously put into three metal targets of Ti, Zr and Ta, which improves the preparation efficiency;

5. The thickness of each layer in the multi-level structure film of the present invention is controlled within 1um, which reduces the risk of friction failure caused by residual stress when the thickness of single-layer film deposition increases; in addition, the matrix alloy needs to be polished and cleaned before use. It can increase the bonding strength between the film layer and the matrix alloy, and the wear resistance of the film layer is strong in actual service.

Description of drawings

The accompanying drawings are used to provide a further understanding of the present invention, and constitute a part of the specification to explain the present invention together, but not to limit the present invention. In the attached picture:

Fig. 1 is a comparison diagram of the multi-level structure film prepared in Example 1 of the present invention and the comparison alloy TC4 matrix structure;

Fig. 2 is a comparison diagram of the structure of the multi-level structure film prepared in Example 2 of the present invention and the comparison alloy TC4 matrix;

Fig. 3 is a comparison diagram of the multi-level structure film prepared in Example 3 of the present invention and the comparison alloy TC4 matrix structure.

Detailed ways

The preferred embodiments of the present invention will be described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described here are only used to illustrate and explain the present invention, and are not intended to limit the present invention.

The mechanism of the invention is: in the surface modification technology, the magnetron sputtering can realize the two typical characteristics of substrate heating and high-speed preparation. During sputtering, three targets can be sputtered and deposited at the same time, and the film preparation efficiency is high. Among the sputtered materials, titanium, zirconium, and tantalum metals all have excellent corrosion resistance, good surface mechanical properties and good biological phase Capacitance. The tantalum film layer has the best service performance as the exposed layer, and the rest of the transition layer can increase the bonding strength between the film layers, reduce the risk of matrix ion precipitation after the exposed layer falls off, increase the film thickness, and reduce the cost of the film layer.

Embodiment one

Divided into the following steps:

1. Submerge the titanium alloy substrate in acetone, deionized water and absolute ethanol for ultrasonic cleaning for 10 minutes, and air-dry; wear powder-free disposable rubber gloves, and clamp the sample on the sample holder in the vacuum chamber of the equipment , use the hair dryer to clean the surface of the sample and the sample holder again; the target size is φ76.2*5mm, the high-purity titanium target with a purity of 99.995%, the high-purity zirconium target with a purity of 99.9% and the high-purity target with a purity of 99.95% The pure tantalum targets are respectively installed on the three magnetron sputtering targets, and the target baffles are pushed to block the sputtering targets; the door of the vacuum chamber is locked to ensure its sealing.

2. Turn on the cooling water system and turn on the main power supply of the equipment. Turn on the mechanical pump and the fore-stage valve until the vacuum of the fore-stage valve is 5Pa; close the fore-stage valve, open the bypass valve, and the ionization gauge until the vacuum of the chamber is 5Pa; close the bypass valve, open the fore-stage valve of the molecular pump, and the molecular pump , the main valve, and the vacuum degree of the vacuum chamber is evacuated to 4×10 ^-4 Pa; the vacuum chamber is filled with argon gas, and the sputtering pressure is adjusted to 1×10 ^-1 Pa. The heating temperature of the substrate is 200° C., and the rotation speed of the substrate table is set at 5 rpm. Open the shut-off valve, set the parameters of the flow-limiting valve, and adjust it to 40°, then adjust the switch of the argon flowmeter to stabilize the pressure of the vacuum chamber at 6×10 ^-1 Pa. Turn on the bias power supply, adjust the bias voltage for cleaning, and the cleaning time is 10 minutes; the DC bias power supply is negative bias -250V, load it on the sample stage for auxiliary deposition; set the target base distance to 50mm, open the sputtering target baffle and the substrate The baffle; the current loaded on the target by the DC constant current power supply is 0.1A; when sputtering the tantalum target, the sputtering power is 60w. The sputtering power is 100w and the pre-sputtering is performed for 5 minutes, and the sputtering cleaning is completed. Open the baffle, and according to the requirements of the deposition thickness of each film layer, the total sputtering time is 240min.

3. After sputtering for a certain period of time, close the target baffle, power source, flow controller, stop valve, main power supply and cooling water. After the sample was cooled to room temperature, it was ultrasonically cleaned in absolute ethanol for 5 minutes and air-dried. The Ta-Ti-Zr-Ta four-layer multi-level film sample was prepared, as shown in Figure 1. This embodiment has more and the total thickness of the film layer is 1.1 μm .

Design embodiment two, embodiment three, and the difference between embodiment two, embodiment three and embodiment one is that the parameters shown in the following table 1 are different in the preparation process (wherein, embodiment two, embodiment three The structural diagrams of the obtained products are shown in Figure 2 and Figure 3, respectively), see Table 1 below for details:

Table 1 embodiment one to three prepares the parameter comparison of tantalum metal coating process

The product that above-mentioned three embodiments obtain is carried out following correlation performance test:

1. Firstly, the multi-stage structure membrane samples obtained in the above three examples were carried out in a 5% sodium chloride solution environment based on GB/T 10125-2012 "Artificial Atmosphere Corrosion Test Salt Spray Test" respectively. In the salt spray test, the sample is cleaned, weighed, placed, observed, and the salt spray test machine is maintained and adjusted in sequence according to the standard. The test period is 1440 hours (two months), and the corrosion performance correlation Data (comparative example is set simultaneously, as the comparison alloy TC4 substrate prepared by prior art mode), the corrosion resistance test result is as shown in table 2 below:

Table 2: Test standard and salt spray test test result of the embodiment of the present invention one, two, three

It can be seen from Table 2 that the corrosion resistance of the multi-stage structure membrane sample prepared by the method of the present invention is more excellent, and the weight loss after 1440h is 54.0628g/m ² , compared with the matrix TC4 alloy, the corrosion resistance in sodium chloride solution has improved 87.13%.

2. The multi-level structure film sample is based on GB/T 4340.1-2009 "Vickers Hardness Test of Metallic Materials Part 1: Test Method", and the surface microhardness performance test results are shown in Table 3 below:

Table 2: Test standard and salt spray test test result of the embodiment of the present invention one, two, three

It can be seen from the above table 3 that at the gear of 100gf force, the loading and holding time is set to 10s, each sample

Measured at 30 points, the surface hardness of the multi-level structure membrane sample of this embodiment was significantly enhanced, and the hardness was 408HV,

Compared with the alloy TC4 matrix, the hardness increased by 30.8%.

The present invention utilizes metal titanium, zirconium, and tantalum to provide multi-level nanostructure modification layers for titanium alloys, develops novel tantalum film materials and preparation techniques thereof, and utilizes various "biophilic metals" (ie, Titanium, zirconium, tantalum) as the modulation layer material, the modulation layer structure is designed, and a variety of new multi-level structure multi-layer film structures that can be combined and arranged are constructed; the multi-level structure film obtained is compared with the matrix titanium alloy (TC4) , the corrosion resistance in the sodium chloride salt spray test has increased by 87.13-88.06%, and the surface microhardness has increased by 24.4-30.8%, both of which have been significantly improved;

The multilayer film with multi-level structure involved in the present invention can realize the purpose of "light weight-functionalization-low cost". The exposed layer is metal tantalum, which can provide the best biocompatibility, corrosion resistance, and wear resistance, which is beneficial to the proliferation of human cells and reduces the degree of corrosion and wear during service; and the method of preparing a transition layer can Effectively enhance the stability of the outermost tantalum film;

The preparation method of the invention reduces the cost of preparing the tantalum coating on the surface, and the preparation efficiency is high due to the improvement of the process technology.

The steps and the like not described in detail in the present invention are all achievable by conventional technologies, and thus will not be described in detail.

Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention also intends to include these modifications and variations.

Claims (8)

1. A multi-level structure film for biomedicine is characterized in that the structure is composed of Ti, Zr and Ta, the number of layers is 3-4, and the matrix is titanium alloy.
2. A multi-level structure film for biomedical use according to claim 1, characterized in that: the transition layer is Ti, Zr, Ta layer, and the service layer (exposed layer/outermost layer) is a tantalum coating.
3. Prepare a kind of method for biomedical multi-level structure film as described in claim 1 or 2, it is characterized in that: several target materials are respectively installed on the different targets in the magnetron sputtering apparatus, then according to multi-level The specific structural layer of the structural film is used to control the sputtering sequence of different targets, so as to control the deposition thickness of each film layer in a single modulation period, and finally obtain the required multi-level structural film;

   Wherein, one target corresponds to one target, and the substrate used in the magnetron sputtering apparatus is titanium alloy.
4. The method according to claim 3, wherein the target material is a titanium target, a zirconium target, a tantalum target, and the tantalum target is the outermost layer of the multi-level structure film.
5. According to the described method of claim 4, it is characterized in that: be specifically the following steps:

   S1. Install the titanium target, zirconium target and tantalum target on the three targets in the magnetron sputtering apparatus respectively;

   S2. After the three targets are placed, the vacuum chamber is evacuated to 4×10 ^-4 ~ 6×10 ^-4 Pa, filled with argon, and the sputtering pressure is adjusted to 1×10 ^-1 ~ 4×10 ^-1 Pa ;Adjust the valve of the argon gas flowmeter to stabilize the working pressure of the vacuum chamber at 3×10 ^-1 ~6×10 ^-1 Pa;

   S3. The heating temperature of the substrate is 200-300°C, the speed of the substrate table is set at 5-15rpm, the parameter of the current limiting valve is adjusted to 40-60°, and the DC bias power supply is a negative bias voltage of -250V to -350V. Pre-sputter at 100w for 10min to 15min, complete sputter cleaning, and open the baffle;

   S4. Cool the product obtained in step S3 to room temperature, take it out, and then ultrasonically clean it in absolute ethanol for 5-10 minutes and air-dry it to prepare a multi-level structure membrane.
6. The method according to claim 5, characterized in that: in step S3, before the pre-sputtering, the base distance of the target is set to 50-90 mm, and then the sputtering target baffle and the substrate baffle are opened for pre-sputtering.
7. The method according to claim 5, characterized in that: in step S3, when sputtering the target, the current loaded on the target is 0.1-0.8A, the sputtering power is 60-100w, and the sputtering time is 120-240min.
8. The method according to claim 5, characterized in that in step S3, the sputtering sequence and sputtering time of different targets are controlled according to the structure of the multi-level structure film and the requirements of the deposition thickness of each film layer.

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