CN118222995A - High-entropy alloy nitride film for medical instrument and preparation method thereof - Google Patents

Abstract

The invention provides a high-entropy alloy nitride film for medical equipment and a preparation method thereof, belonging to the technical field of coatings. The invention provides a high-entropy alloy nitride film for medical equipment, which comprises the following steps: performing magnetron sputtering on TiZrTaWVNb alloy targets to obtain the high-entropy alloy nitride film on the surface of the substrate; the magnetron sputtering is carried out in a flowing atmosphere; the atmosphere includes a rare gas and nitrogen; the flow rate of the rare gas is 15-60 sccm; the flow of the nitrogen is 3-25 sccm. The invention improves the toughness and hardness of the high-entropy alloy by adjusting the type of the high-entropy alloy and the flow of nitrogen and rare gas.

Description

A high entropy alloy nitride film for medical devices and preparation method thereof

Technical Field

The present invention relates to the technical field of coatings, and in particular to a high entropy alloy nitride film for medical devices and a preparation method thereof.

Background technique

The toughness and hardness of materials are related to the surface state of the materials. Surface treatment of materials can effectively improve their toughness and hardness. Compared with alloying, surface treatment is simple to operate and has lower costs. Therefore, using surface modification technology to improve the performance of titanium alloys has become a hot topic of research.

High entropy alloys are composed of 5 or more metal or non-metal elements in equimolar or near molar ratios, with the content of each element ranging from 5% to 35%. In the preparation of high entropy nitride alloy materials from high entropy alloys, nitrogen is generally introduced into the chamber. For example, Braic V et al. prepared (TiZrNbHfTa)N multi-nitride and (TiZrNbHfTa)C carbide coatings on Ti ₆ Al ₄ V alloys by co-sputtering transition metal targets (Ti, Zr, Nb, Hf, Ta) in a reaction atmosphere (Braic V, Balaceanu M, Braic M, et al. Characterization of multi-principal-element (TiZrNbHfTa)N and (TiZrNbHfTa)C coatings for biomedical applications [J]. Journal of the Mechanical Behavior of Biomedical Materials, 2012, 10: 197-205.). However, existing high entropy alloy films still have the disadvantages of insufficient hardness and toughness.

Summary of the invention

The object of the present invention is to provide a high entropy alloy nitride film for medical devices and a preparation method thereof. The high entropy alloy nitride film prepared by the present invention has high hardness and good toughness.

In order to achieve the above-mentioned invention object, the present invention provides the following technical solutions:

The present invention provides a method for preparing a high entropy alloy nitride film for medical devices, comprising the following steps:

Performing magnetron sputtering on the TiZrTaWVNb alloy target to obtain the high entropy alloy nitride film on the surface of the substrate;

The magnetron sputtering is carried out in a flowing gas atmosphere;

The gas includes a rare gas and nitrogen; the flow rate of the rare gas is 15-60 sccm; the flow rate of the nitrogen is 3-25 sccm.

Preferably, the vacuum degree of the magnetron sputtering is less than 4×10 ^-3 Pa, and the power is 80-190W.

Preferably, the working gas pressure of the magnetron sputtering is 0.4-1 Pa, and the sputtering time is 30-100 min.

Preferably, the substrate comprises one of metal, cemented carbide and single crystal Si.

Preferably, before the magnetron sputtering, the method further includes: polishing and cleaning the substrate.

Preferably, the cleaning comprises: immersing the substrate in ethanol and acetone successively for ultrasonic cleaning, and then performing ion cleaning.

Preferably, the frequency of the ultrasound is independently 15-30 kHz; and the time is independently 10-15 min.

Preferably, the ion cleaning is carried out in a protective atmosphere, the vacuum degree of the ion cleaning is 2-4 Pa, the time is 10-20 min, and the DC power supply power is 80-190 W.

The present invention also provides a high entropy alloy nitride film prepared by the preparation method described in the above technical solution.

The invention provides a high entropy alloy nitride film for medical equipment, comprising the following steps: magnetron sputtering a TiZrTaWVNb alloy target to obtain the high entropy alloy nitride film on a substrate surface; the magnetron sputtering is performed in a flowing atmosphere; the atmosphere comprises a rare gas and nitrogen; the flow rate of the rare gas is 15-60 sccm; the flow rate of the nitrogen is 3-25 sccm.

The Ti, Zr, Ta, W, V and Nb elements in the high entropy alloy selected by the present invention are all strong nitride-forming elements. After magnetron sputtering, a solid solution of the high entropy alloy nitride is formed, and the formation of the solid solution improves the hardness of the film; the multiple components in the high entropy alloy nitride form a nanocomposite structure, and the phase interface of the nanocomposite structure can inhibit the expansion of cracks, thereby improving the fracture toughness of the film.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 shows the deposition rates of the films in Comparative Example 1 and Examples 1 to 5;

FIG2 is a comparison diagram of elements of the membranes in Comparative Example 1 and Examples 1 to 5;

FIG3 is an XRD diffraction pattern of the films in Comparative Example 1 and Examples 1 to 5;

FIG4 is a cross-sectional SEM morphology of the membranes in Comparative Example 1 and Examples 1 to 5; FIG4 (a) is a cross-sectional SEM morphology of the membrane in Comparative Example 1; FIG4 (b) to (f) are cross-sectional SEM morphology of the membranes in Examples 1 to 5;

FIG5 is a HRTEM cross-sectional morphology of the film of Example 2;

FIG6 is a schematic diagram showing the results of hardness and elastic modulus of the films in Comparative Example 1 and Examples 1 to 5;

FIG. 7 is a schematic diagram showing the fracture toughness results of the films in Comparative Example 1 and Examples 1 to 5.

Detailed ways

The present invention provides a high entropy alloy nitride film for medical devices, comprising the following steps:

Performing magnetron sputtering on the TiZrTaWVNb alloy target to obtain the high entropy alloy nitride film on the surface of the substrate;

The magnetron sputtering is carried out in a flowing gas atmosphere;

The gas includes a rare gas and nitrogen; the flow rate of the rare gas is 15-60 sccm; the flow rate of the nitrogen is 3-25 sccm.

In the present invention, before the magnetron sputtering, it is preferred to further include: polishing and ion cleaning the substrate. After polishing, the substrate preferably has a flatness TIR of <3 μm, a warpage TTV of <10 μm, a curvature BOW of <10 μm, and a roughness of <1 nm.

In the present invention, the substrate preferably includes one of metal, cemented carbide and single crystal Si.

In the present invention, the cleaning preferably includes: immersing the substrate in ethanol and acetone successively for ultrasonic cleaning, and then performing ion cleaning; the frequency of the ultrasonic cleaning is preferably independently 15~30kHz, more preferably 20~25kHz; the time is preferably independently 10~15min, more preferably 12~13min.

In the present invention, the ion cleaning is preferably carried out in a protective atmosphere, the time is preferably 10 min, the DC power supply power of the ion cleaning is preferably 180 W, and the vacuum degree is preferably 2-4 Pa. In the present invention, it is preferred to evacuate to 5×10 ^-3 Pa and then fill with a rare gas until the vacuum degree of the ion bombardment is reached.

In the present invention, the vacuum degree of the magnetron sputtering is preferably less than 4×10 ^-3 Pa, the working gas pressure is preferably 0.4~1Pa, more preferably 0.5~0.8Pa; the power is preferably 80~190W, more preferably 100~150W, and further preferably 120~130W; the sputtering time is preferably 30~100min, more preferably 40~60min. The magnetron sputtering is carried out in a flowing atmosphere; the atmosphere includes a rare gas and nitrogen; the flow rate of the rare gas is 15~60sccm, preferably 25~50sccm, and more preferably 30~40sccm; the flow rate of the nitrogen is 3~25sccm, preferably 5~20sccm, and more preferably 10~15sccm.

The preparation method of the high entropy alloy nitride film provided by the present invention is described in detail below in conjunction with the embodiments, but they should not be understood as limiting the protection scope of the present invention.

Preparation, characterization and measurement instruments used in the examples of the present invention:

JGP-450 magnetron sputtering system, Shenyang Scientific Instrument Research and Development Center Co., Ltd., Chinese Academy of Sciences;

D8 Advance X-ray diffractometer, Bruker, Germany;

Quanta FEG450 scanning electron microscope, FEI Company, USA;

Bruker TI-980 nanoindenter, Bruker, Germany;

JXA-8530F PLUS field emission electron probe microanalyzer, JEOL, Japan;

Tecnai G2 20 high-resolution transmission electron microscope, FEI Company, USA.

Comparative Example 1

The single crystal silicon substrate (size: 20 mm×10 mm×0.65 mm, flatness TIR<3μm, warpage TTV<10μm, curvature BOW<10μm, roughness<1nm) after mirror polishing was cleaned in analytical pure alcohol and acetone using 15~30kHz ultrasonic cleaning for 15min;

Ion cleaning: After the sample is loaded, it is placed in the sample chamber, and the vacuum is evacuated to 5×10 ^-3 Pa. Then, Ar gas is turned on and the vacuum is maintained at 2~4Pa. The substrate is pre-sputtered by ion bombardment for 10 minutes. The DC power supply power is 180W.

The vacuum chamber was evacuated to 3×10 ^-3 Pa, the argon flow rate was 25 sccm, the nitrogen flow rate was 0 sccm, and the TiZrTaWVNb alloy target with an equal molar ratio was sputtered. The working gas pressure during sputtering was 0.5 Pa, the film sputtering power was 180 W, and the sputtering time was 60 min.

Example 1

The only difference from Comparative Example 1 is that the nitrogen flow rate is 5 sccm.

Example 2

The only difference from Comparative Example 1 is that the nitrogen flow rate is 10 sccm.

Example 3

The only difference from Comparative Example 1 is that the nitrogen flow rate is 15 sccm.

Example 4

The only difference from Comparative Example 1 is that the nitrogen flow rate is 20 sccm.

Example 5

The only difference from Comparative Example 1 is that the nitrogen flow rate is 25 sccm.

The deposition rates of the films in Comparative Example 1 and Examples 1 to 5 were calculated respectively, and the results are shown in FIG1 .

It can be seen from Figure 1 that with the increase of _N2 flow rate, the deposition rate of the film gradually decreased from 83.28nm/min to 33.77nm/min.

The element contents of the films in Comparative Example 1 and Examples 1 to 5 were measured respectively, and the results are shown in FIG2 .

It can be seen from Figure 2 that: 1) When _N2 is not introduced, the contents of the five metal elements in the high entropy alloy coating are between 11.62 and 24.59 at.%, and the prepared TiZrTaWVNb film meets the definition of high entropy alloy, and the atomic ratio of each element is in the range of 5% to 35%. However, due to the different sputtering yields of Ar ⁺ for Ti, Zr, Ta, W, V, and Nb, the deposition rates are different, resulting in differences in the content of each element in the high entropy alloy nitride film; 2) With the increase of _N2 flow rate, the N content in the high entropy alloy nitride film increases rapidly and then tends to stabilize. 3) With the further increase of nitrogen flow rate, the nitrogen content is greater than 30%.

XRD test was performed on the films in Comparative Example 1 and Examples 1 to 5, and the results are shown in FIG3 .

As can be seen from Figure 3, when the _N2 flow rate is 0, the diffraction peak of the TiZrTaWVNb film is not sharp but rather broad, indicating that the film is in an amorphous state. After the nitrogen is introduced, the crystallinity of the (TiZrTaWVNb) _Nx film shows a trend of first strengthening and then weakening. When _N2 :Ar=5:25, the crystallinity of the (TiZrTaWVNb) _Nx film is the strongest, and the (111) plane is the preferred orientation. The FCC in Figure 3 represents the face-centered cubic structure.

The cross sections of the membranes in Comparative Example 1 and Examples 1 to 5 were observed by SEM, and the results are shown in Figure 4. Figure 4 (a) is the SEM morphology of the cross section of the membrane in Comparative Example 1; Figures 4 (b) to (f) are the SEM morphology of the cross sections of the membranes in Examples 1 to 5.

As shown in Figure 4, the prepared (TiZrTaWVNb) _Nx high entropy alloy nitride film is relatively dense and uniform, and is well bonded to the substrate. No obvious internal defects were observed. When the nitrogen flow rate was 0, no visible grain features were observed in the cross-sectional fracture of the film. As the nitrogen flow rate increased, the thickness of the film gradually decreased, which was mainly due to the decrease in sputtering rate. It was also found that with the increase in nitrogen flow rate, the film may change from an amorphous phase to a crystalline phase due to the formation of a nitride structure.

The cross section of the high entropy alloy nitride film of Example 2 was observed by HRTEM, and the results are shown in Figure 5. As shown in Figure 5, the film is well bonded to the substrate. In addition, the film is composed of a large number of nanocrystals and amorphous materials. From the selected regional electron diffraction pattern, (111), (200) and (220) crystal planes can be observed, indicating that the (TiZrTaWVNb)N film has an FCC structure.

The hardness and elastic modulus of the membrane cross sections in Comparative Example 1 and Examples 1 to 5 were measured respectively, and the results are shown in FIG6 .

As shown in Figure 6, the hardness and elastic modulus of the (TiZrTaWVNb) _Nx high entropy alloy nitride film first increase and then decrease with the increase of _N2 flow rate. When _N2 :Ar=5:25, the hardness and elastic modulus of the film are the best, which are 20.5 and 210.5GPa respectively. When nitrogen is not introduced, the hardness and elastic modulus of the TiZrTaWVNb high entropy alloy nitride film are 14.4 and 177.4, GPa respectively, which is significantly improved compared with the substrate hardness.

Nanoindentation high-load toughness test was performed on the films in Comparative Example 1 and Examples 1 to 5, respectively, and the toughness results obtained are shown in FIG. 7 .

As shown in FIG7 , with the increase of the flow rate ratio of nitrogen to argon, the toughness of the film increases first and then decreases. When N ₂ :Ar=10:25, the fracture toughness of (TiZrTaWVNb)N _x reaches a maximum value of 1.41 MPa·m ^1/2 .

The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims (9)

1. A method for preparing a high entropy alloy nitride film for medical devices, characterized in that it comprises the following steps: Performing magnetron sputtering on the TiZrTaWVNb alloy target to obtain the high entropy alloy nitride film on the surface of the substrate; The magnetron sputtering is carried out in a flowing gas atmosphere; The gas includes a rare gas and nitrogen; the flow rate of the rare gas is 15-60 sccm; the flow rate of the nitrogen is 3-25 sccm. 2. The preparation method according to claim 1, characterized in that the vacuum degree of the magnetron sputtering is less than 4×10 ^{- 3} Pa and the power is 80~190W. 3. The preparation method according to claim 1 or 2, characterized in that the working gas pressure of the magnetron sputtering is 0.4~1Pa, and the sputtering time is 30~100min. 4 . The preparation method according to claim 1 , wherein the substrate comprises one of metal, cemented carbide and single crystal Si. 5 . The preparation method according to claim 1 , characterized in that, before the magnetron sputtering, it also includes: polishing and cleaning the substrate. 6 . The preparation method according to claim 5 , wherein the cleaning comprises: immersing the substrate in ethanol and acetone successively for ultrasonic treatment, and then performing ion cleaning. 7. The preparation method according to claim 6, characterized in that the frequency of the ultrasound is independently 15-30 kHz; and the time is independently 10-15 min. 8. The preparation method according to claim 6 is characterized in that the ion cleaning is carried out in a protective atmosphere, the vacuum degree of the ion cleaning is 2-4 Pa, the time is 10-20 min, and the DC power supply power is 80-190 W. 9. A high entropy alloy nitride film prepared by the preparation method according to any one of claims 1 to 8.