High strength and toughness nano-multilayer metallic glass with gradient composition and preparation method thereof

Abstract

The application belongs to the technical field of metal glass film preparation, and specifically discloses a high-strength and high-toughness nano-multilayer metal glass with gradient component design and a preparation method thereof. The high-strength and high-toughness nano-multilayer metal glass comprises periodically repeated gradient unit structures, each of which is stacked by six component layers; wherein, along the deposition direction from bottom to top, the atomic percentage of Cu in each component layer first decreases and then increases, and the atomic percentage of Ta first increases and then decreases. The application overcomes the shortcomings of the existing metal glass, which has high strength but low toughness, and greatly improves the plastic deformation capacity of the metal glass through the unique gradient structure design and the corrugated interface formed by high deposition gas pressure.

Description

Technical Field

[0001] This invention relates to the field of metallic glass thin film technology, and in particular to a high-strength and tough nano-multilayer metallic glass with gradient composition design and its preparation method. Background Technology

[0002] Metallic glasses (i.e., amorphous alloys) possess excellent properties at room temperature, including extremely high strength, high elastic limit, and good wear resistance, corrosion resistance, and radiation resistance, making them particularly suitable for microelectromechanical systems (MEMS) such as actuators and sensors. These superior properties stem from the unique atomic structure of metallic glasses, where the atomic arrangement exhibits long-range disorder and short-range order, lacking structural defects such as dislocations, twins, and stacking faults. While this unique atomic structure contributes to the extremely high strength of metallic glasses, it also results in almost zero plasticity at room temperature because the material lacks dislocation defects capable of supporting plastic deformation. Under high stress, the shear transition regions accumulated within the metallic glass are rapidly activated, forming embryonic shear bands along the direction of maximum shear stress. Once these embryonic shear bands grow to a critical size, they develop into mature through-shear bands, causing material failure. This extremely low plasticity makes metallic glasses highly susceptible to deformation damage during service, significantly reducing the service stability and lifespan of microelectronic devices. Therefore, if the plastic deformation capability of metallic glasses can be significantly enhanced, then metallic glass materials will have a broader application prospect in fields such as microelectronic devices.

[0003] Currently, the main methods to improve the plastic deformation capacity of metallic glasses are to hinder or suppress the occurrence of shear bands through microstructure design. For example, adding a crystalline phase to form amorphous-crystalline composite materials, or stacking two different amorphous materials to form nano-multilayer metallic glasses, all have their shortcomings. Amorphous-crystalline composite materials incorporate a relatively soft crystalline phase, resulting in a significant decrease in the overall strength of the composite. For instance, patent application number 201810326643.3 discloses a method for preparing nanocrystalline thin films with improved plasticity. Increasing the crystalline phase ratio from 66% to 80% reduces the overall strength of the material by approximately 26%. This plasticity improvement at the expense of strength fails to meet the high strength and high toughness design requirements of alloys. Nano-multilayer metallic glasses, without the addition of a relatively soft second phase, still maintain high strength characteristics. The nanoscale component layer size and numerous amorphous-amorphous interfaces can slightly hinder shear band propagation, thus bringing about a certain degree of plasticity improvement. However, this improvement in plasticity is not significant. For example, patent application number 202110983339.8 discloses a method for controlling the work hardening ability of amorphous / amorphous nanomultilayer films, and its invention uses Zr 50 Cu 50 / Ni 50 Nb 50The nano-multilayer metallic glass exhibits localized shear bands in micropillar compression tests, still displaying "brittle" deformation. This nano-multilayer metallic glass maintains high strength; therefore, further optimization of the nano-multilayer structure design is needed to improve its plastic deformation capacity while preserving strength. Summary of the Invention

[0004] In view of the above-mentioned problems, this invention provides a high-strength and high-toughness nano-multilayer metallic glass with gradient composition design and its preparation method. This invention overcomes the shortcomings of existing metallic glasses, which have high strength but low toughness, by significantly improving the plastic deformation capacity of the metallic glass through a unique gradient structure design and a corrugated interface formed by high deposition gas pressure.

[0005] To address the aforementioned issues, this invention provides a high-strength and tough nano-multilayer metallic glass with a gradient composition design, comprising a periodically repeating gradient unit structure, each gradient unit being composed of six component layers stacked together; wherein, along the deposition direction from bottom to top, the percentage of Cu atoms in each component layer first decreases and then increases, while the percentage of Ta atoms first increases and then decreases.

[0006] Preferably, the alloy composition of each component layer, from bottom to top along the deposition direction, is Cu 75 Ta 25 Cu 63 Ta 37 Cu 50 Ta 50 Cu 34 Ta 66 Cu 50 Ta 50 Cu 63 Ta 37 .

[0007] Preferably, the thickness of each component layer within each gradient unit is the same.

[0008] Preferably, the thickness of the component layer is no greater than 100 nm.

[0009] Preferably, the total thickness of the film is not less than 1.2 μm.

[0010] Preferably, there is a corrugated interface between adjacent component layers.

[0011] Based on the same inventive concept, this invention also provides a method for preparing high-strength and tough nano-multilayer metallic glasses with gradient composition design as described above, comprising the following steps: S1. Install the Cu target, Ta target, and substrate in the vacuum deposition chamber, and evacuate the vacuum deposition chamber to a vacuum state; S2. Inert gas is introduced into the vacuum deposition chamber, and the working pressure in the deposition chamber is adjusted to at least 1.6 Pa. The power supply to the target material is turned on and pre-sputter cleaning is performed, while the substrate is rotated. S3. The sputtering power of each metal target is independently adjusted for co-sputtering, and six component layers with gradient composition are deposited sequentially to obtain a gradient unit structure; S4. Repeat step S3 for gradient unit structure deposition until the total thickness of the film of the multilayer periodically repeated gradient unit structure reaches the predetermined value.

[0012] Preferably, step S3 specifically involves: independently adjusting the sputtering power of the Cu metal target to 113W and the sputtering power of the Ta metal target to 80W to obtain the first component layer Cu. 75 Ta 25 Amorphous thin films; by sequentially adjusting the sputtering power of the Cu / Ta metal target to 94W / 100W, 63W / 100W, 41W / 100W, 63W / 100W, and 94W / 100W, the 2nd to 6th component layers of Cu were obtained. 63 Ta 37 Cu 50 Ta 50 Cu 34 Ta 66 Cu 50 Ta 50 Cu 63 Ta 37 Amorphous thin films are obtained by stacking six component layers to form a gradient unit structure.

[0013] Preferably, the substrate is a monocrystalline silicon (100) substrate.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The nano-multilayer metallic glass of the present invention is simple to prepare. The corrugated amorphous / amorphous interface is obtained by using high deposition gas pressure, which can significantly improve the plastic deformation ability of the metallic glass film. (2) The present invention precisely controls the alloy element ratio by co-sputtering two metal targets, eliminating the need for multiple alloy targets and greatly reducing the preparation cost of gradient nano multilayer films. (3) The present invention is applicable to any binary amorphous system with a large amorphous formation range, and the composition of the constituent layers can be arbitrarily controlled by adjusting the sputtering power of each target cavity, thereby achieving precise control of the various properties of gradient nano-multilayer metallic glass. Attached Figure Description

[0015] Figure 1This is a schematic diagram of the gradient unit of the CuTa gradient nano-multilayer metallic glass described in Embodiment 1 of the present invention; wherein, (a) is a schematic diagram of the deposition structure; and (b) is a graph showing the content trend of Cu / Ta elements in each component layer of the same gradient unit. Figure 2 The XRD patterns are of the CuTa gradient nanolayered metallic glasses prepared in Examples 1-3 of this invention. Figure 3 The images shown are TEM images of CuTa gradient nano-multilayer metallic glasses prepared in Examples 1-3 of this invention; wherein, (a) is a cross-sectional TEM image of the CuTa gradient nano-multilayer metallic glass prepared in Example 3; (b) is a cross-sectional TEM image of the CuTa gradient nano-multilayer metallic glass prepared in Example 2; (c) is a cross-sectional TEM image of the CuTa gradient nano-multilayer metallic glass prepared in Example 1; (d) is a high-resolution TEM image of the CuTa gradient nano-multilayer metallic glass prepared in Example 3; (e) is a high-resolution TEM image of the CuTa gradient nano-multilayer metallic glass prepared in Example 2; and (f) is a high-resolution TEM image of the CuTa gradient nano-multilayer metallic glass prepared in Example 1. Figure 4 The images show the residual morphology of the microindentation experiment surface of the final samples prepared in Example 1 and Comparative Examples 1-2 of this invention. Figure 5 The images show the internal deformation of the final samples prepared in Example 1 and Comparative Examples 1-2 after microindentation experiments. (a) shows the residual surface morphology of the sample from Example 1 after microindentation; (b) is a TEM image of the cross-section below the indentation of the final sample prepared in Example 1 after microindentation; (c) shows the leftmost region of the three regions in (b); (d) shows the middle region of the three regions in (b); (e) shows the rightmost region of (b); (f) shows the residual surface morphology of the sample from Comparative Example 1 after microindentation; (g) is a TEM image of the cross-section below the indentation of the final sample prepared in Comparative Example 1 after microindentation; (h) shows the leftmost region of the three regions in (g); (i) shows the rightmost region of (g); and (j) shows the middle region of the three regions in (g). Figure 6 This is a comparison diagram of the strength and shear displacement of the shear band surface between Embodiment 1 and Comparative Example 1 of the present invention. Detailed Implementation

[0016] To make the present invention easier to understand, specific embodiments are described below to further illustrate the invention. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Unless otherwise defined, the technical terms used below have the same meaning as understood by those skilled in the art; unless otherwise specified, the raw materials and reagents involved herein can be purchased commercially or obtained by known methods.

[0017] To address the shortcomings of existing metallic glasses, which exhibit high strength but low toughness, this invention provides a high-strength and high-toughness nano-multilayer metallic glass with a gradient composition design and its preparation method. This invention overcomes the drawback of existing metallic glasses, which suffer from high strength but low toughness, by significantly improving the plastic deformation capacity of the metallic glass through a unique gradient structure design and a corrugated interface formed by high deposition gas pressure.

[0018] The following description, in conjunction with specific embodiments and comparative examples, further elaborates on this point.

[0019] Example 1 A CuTa gradient nanolayered metallic glass with a component layer thickness of 5 nm comprises a periodically repeating structure of 40 gradient units, each of which consists of 6 stacked component layers; as shown... Figure 1 As shown, along the deposition direction from bottom to top, the percentage of Cu atoms in each of the constituent layers first decreases and then increases, while the percentage of Ta atoms first increases and then decreases; the alloy composition of each of the constituent layers, along the deposition direction from bottom to top, is Cu 75 Ta 25 Cu 63 Ta 37 Cu 50 Ta 50 Cu 34 Ta 66 Cu 50 Ta 50 Cu 63 Ta 37 The thickness of each component layer in each gradient unit is the same, and all are 5 nm. The total thickness of the CuTa gradient nanolayered metallic glass is 1.2 μm.

[0020] The preparation method of CuTa gradient nanolayered metallic glass with a component layer thickness of 5 nm is as follows: (1) Install the Cu target (99.99% purity) and the Ta target (99.99% purity) on the No. 1 and No. 2 DC sputtering target cavities in the deposition chamber, respectively. Then, install the single crystal silicon (100) substrate on the tray in the deposition chamber, close the deposition chamber door, and evacuate the vacuum to 4×10. -5 Pa; (2) Introduce high-purity argon gas with a purity of 99.999%, adjust the argon gas flow rate to 25 sccm to make the working gas pressure in the deposition chamber 1.6 Pa, open DC sputtering target chambers 1 and 2 and set the power to 50 W, pre-sputter for 10 minutes to clean the oxide on the target surface. Then turn on the substrate rotary motor and set the speed to 20 r / min; (3) Adjust the power of DC sputtering target cavities No. 1 (Cu target) and No. 2 (Ta target) to 113W and 80W respectively, and open the baffle of the target cavity to co-sputter the first layer of Cu. 75 Ta 25 The amorphous thin film was co-sputtered to a deposition rate of 0.3801 nm / s. After 13.2 s, the baffles of both target cavities were closed. The power of DC sputtering target cavities 1 and 2 was then adjusted again to 94 W / 100 W, 63 W / 100 W, 41 W / 100 W, 63 W / 100 W, and 94 W / 100 W. After each power adjustment, the target cavity baffles were opened for co-sputtering. The deposition rates were 0.3958 nm / s, 0.3438 nm / s, 0.3069 nm / s, 0.3438 nm / s, and 0.3958 nm / s, with sputtering times of 12.6 s, 14.5 s, 16.3 s, 14.5 s, and 12.6 s, respectively. This yielded the 2nd to 6th elemental layers: Cu. 63 Ta 37 Cu 50 Ta 50 Cu 34 Ta 66 Cu 50 Ta 50 and Cu 63 Ta 37 Amorphous layer.

[0021] (4) Repeat step (3) 40 times until all 240 layers of film are deposited, and a CuTa gradient nano-multilayer glass with a total film thickness of 1.2 μm and a component layer thickness of 5 nm is obtained.

[0022] (5) Turn off the power supply to the target cavity, turn off the rotary motor, stop the argon gas supply, and remove the sample after the sample has cooled to room temperature by releasing the vacuum.

[0023] Example 2 The preparation method of CuTa gradient nanolayered metallic glass with a component layer thickness of 25 nm is as follows: (1) Same as Example 1; (2) Same as Example 1; (3) Adjust the power of DC sputtering target cavities No. 1 (Cu target) and No. 2 (Ta target) to 113W and 80W respectively, and open the baffle of the target cavity to co-sputter the first layer of Cu. 75 Ta 25 The amorphous thin film was co-sputtered to a deposition rate of 0.3801 nm / s. After 65.8 s, the baffles of both target cavities were closed. The power of DC sputtering target cavities 1 and 2 was then adjusted again to 94 W / 100 W, 63 W / 100 W, 41 W / 100 W, 63 W / 100 W, and 94 W / 100 W. After each power adjustment, the target cavity baffles were opened for co-sputtering. The deposition rates were 0.3958 nm / s, 0.3438 nm / s, 0.3069 nm / s, 0.3438 nm / s, and 0.3958 nm / s, with sputtering times of 62.7 s, 72.7 s, 81.5 s, 72.7 s, and 62.7 s, respectively. This yielded the second to sixth elemental layers: Cu. 63 Ta 37 Cu 50 Ta 50 Cu 34 Ta 66 Cu 50 Ta 50 and Cu 63 Ta 37 Amorphous layer; (4) Repeat step (3) 8 times until all 48 layers of film are deposited, and a CuTa gradient nano-multilayer glass with a total film thickness of 1.2 μm and a component layer thickness of 25 nm is obtained; (5) Same as Example 1.

[0024] Example 3 The preparation method of CuTa gradient nanolayered metallic glass with a component layer thickness of 100 nm is as follows: (1) Same as Example 1; (2) Same as Example 1; (3) Adjust the power of DC sputtering target cavities No. 1 (Cu target) and No. 2 (Ta target) to 113W and 80W respectively, and open the baffle of the target cavity to co-sputter the first layer of Cu. 75 Ta 25The amorphous thin film was co-sputtered to a deposition rate of 0.3801 nm / s. After 263.1 s, the baffles of both target cavities were closed. The power of DC sputtering target cavities 1 and 2 was then adjusted again to 94 W / 100 W, 63 W / 100 W, 41 W / 100 W, 63 W / 100 W, and 94 W / 100 W. After each power adjustment, the target cavity baffles were opened for co-sputtering. The co-sputtering deposition rates were 0.3958 nm / s, 0.3438 nm / s, 0.3069 nm / s, 0.3438 nm / s, and 0.3958 nm / s, respectively, with sputtering times of 252.7 s, 290.9 s, 325.8 s, 290.9 s, and 252.7 s, respectively. This yielded the 2nd to 6th elemental layers: Cu. 63 Ta 37 Cu 50 Ta 50 Cu 34 Ta 66 Cu 50 Ta 50 and Cu 63 Ta 37 Amorphous layer; (4) Repeat step (3) twice until all 12 layers of film are deposited, and a CuTa gradient nanomultilayer glass with a total film thickness of 1.2 μm and a component layer thickness of 100 nm is obtained. (5) Same as Example 1.

[0025] Comparative Example 1 A CuTa nanolayered metallic glass with a component layer thickness of 5 nm and no gradient structure is composed of Cu 37 Ta 63 The constituent layers and composition are Cu 57 Ta 43 The components are stacked alternately, and the specific steps of its preparation process are as follows: (1) Install the Cu target (99.99% purity) and the Ta target (99.99% purity) on the No. 1 and No. 2 DC sputtering target cavities in the deposition chamber, respectively. Then, install the single crystal silicon (100) substrate on the tray in the deposition chamber, close the deposition chamber door, and evacuate the vacuum to 4×10. -5 Pa; (2) Introduce high-purity argon gas with a purity of 99.999%, adjust the argon gas flow rate to 18 sccm to make the working gas pressure in the deposition chamber 0.3 Pa, open DC sputtering target chambers 1 and 2 and set the power to 50 W, pre-sputter for 10 minutes to clean the oxide on the target surface. Then turn on the substrate rotary motor and set the speed to 30 r / min; (3) Adjust the power of DC sputtering target cavities No. 1 (Cu target) and No. 2 (Ta target) to 25W and 100W respectively, and open the baffle of the target cavity to co-sputter the first layer of Cu.37 Ta 63 Amorphous thin films were co-sputtered at a deposition rate of 0.1819 nm / s. After 27.5 s, the baffles of both target cavities were closed. The power of DC sputtering target cavities 1 and 2 was then adjusted to 87 W and 100 W respectively, and the baffles of the target cavities were opened to deposit a Cu layer. 57 Ta 43 The amorphous thin film was co-sputtered with a deposition rate of 0.3194 nm / s and a sputtering time of 15.6 s. (4) Repeat step (3) 120 times until all 240 layers of film are deposited, to obtain CuTa nano-multilayer glass with a total film thickness of 1.2 μm, a component layer thickness of 5 nm, and no gradient structure. (5) Turn off the power supply to the target cavity, turn off the rotary motor, stop the argon gas supply, and remove the sample after the sample has cooled to room temperature by releasing the vacuum.

[0026] Comparative Example 2 Cu 50 Ta 50 The specific steps in the preparation process of ordinary metallic glass are as follows: (1) Install the Cu target (99.99% purity) and the Ta target (99.99% purity) on the No. 1 and No. 2 DC sputtering target cavities in the deposition chamber, respectively. Then, install the single crystal silicon (100) substrate on the tray in the deposition chamber, close the deposition chamber door, and evacuate the vacuum to 4×10. -5 Pa; (2) Introduce high-purity argon gas with a purity of 99.999%, adjust the argon gas flow rate to 18 sccm to make the working gas pressure in the deposition chamber 0.3 Pa, open DC sputtering target chambers 1 and 2 and set the power to 50 W, pre-sputter for 10 minutes to clean the oxide on the target surface. Then turn on the substrate rotary motor and set the speed to 30 r / min; (3) Adjust the power of DC sputtering target cavities No. 1 (Cu target) and No. 2 (Ta target) to 51W and 100W respectively, and open the baffle of the target cavity to co-sputter the first layer of Cu. 37 Ta 63 The amorphous thin film was co-sputtered at a rate of 0.2458 nm / s, and the baffles of the two target cavities were closed after 3254.7 s. (4) Turn off the power supply to the target cavity, turn off the rotary motor, stop the argon gas supply, and remove the sample after the sample has cooled to room temperature by releasing the vacuum.

[0027] Performance testing and results analysis: The CuTa gradient nanolayered metallic glasses prepared in Examples 1-3 were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM), and the results are as follows: Figure 2-3 As shown. By Figure 2-3It can be seen that the CuTa gradient nano-multilayer metallic glass prepared in Examples 1-3 of the present invention is a completely amorphous structure. The contrast of the 100nm and 50nm samples varies with the gradient between the layers, reflecting the gradient change of the element concentration of the component layers. The 5nm sample shows a continuous gradient change due to the small thickness of the component layers. Furthermore, due to the high deposition pressure (1.6Pa), the interface of the gradient nano-multilayer glass is corrugated rather than straight, which leads to the appearance of columnar structures.

[0028] The final samples prepared in Example 1 and Comparative Examples 1-2 were subjected to microindentation experiments. Specifically, the samples from Example 1 and Comparative Examples 1-2 were held under a pressure of 25g for 5 seconds, and the residual morphology of the sample surface was observed. The results are as follows: Figure 4 As shown. By Figure 4 It can be seen that no obvious shear bands appeared on the surface of the CuTa gradient nano-multilayer metallic glass (Example 1); the surface of the ordinary nano-metallic glass without gradient and columnar structures (Comparative Example 1) showed four obvious shear bands, as indicated by the white arrows; while the ordinary metallic glass without any structure (Comparative Example 2) had a large number of shear bands. The microindentation experiment showed that the ability of Comparative Example 2, Comparative Example 1, and Example 1 to withstand plastic deformation gradually increased, that is, the nano-multilayer structure improved the brittleness of the metallic glass, while the gradient and columnar structure designs further enhanced the plasticity of the nano-multilayer metallic glass.

[0029] The internal deformation of the sample after the above microindentation experiment was characterized, and the results are as follows: Figure 5 As shown. By Figure 5 It can be seen that the sample in Example 1 undergoes plastic deformation through the synergistic torsion of the component layers, and this synergistic torsion is hindered by the columnar structure, preventing it from developing into a localized through-shear band. Some torsions are even completely blocked by the columnar structure, such as... Figure 5 As shown in (d), the surface shear displacement caused by these twists is extremely small, so the sample exhibits almost uniform plastic deformation; Figure 5 As shown in (i), the sample of Comparative Example 1 exhibits severe shear bands caused by serious elemental mixing. These shear bands run through the entire sample, generating extremely large shear displacements on the surface, leading to overall shear instability and failure of the sample.

[0030] Further measurements of the surface shear displacement and strength of Example 1 and Comparative Example 1 were performed, and the results are as follows: Figure 6 As shown. By Figure 6 It can be seen that Example 1 has a wavelength of only 11.6 nm, while Comparative Example 1 has a wavelength of 83 nm, indicating a more pronounced localized deformation. Meanwhile, the strengths of the two samples are not significantly different (Example 1: 2.63 ± 0.09 GPa; Comparative Example 1: 3.11 ± 0.05 GPa). Figure 6As shown. This strength value is obtained by dividing the nanohardness by a factor of 2.7 (corresponding to nanohardnesses of 7.1±0.23GPa and 8.4±0.14GPa, respectively). Therefore, the deformation of the component layers beneath the indentation further illustrates the beneficial effect of the gradient nanomultilayer structure on enhancing the plastic deformation capability of metallic glasses, while this structure does not compromise the high strength of the metallic glasses.

[0031] The above embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the inventive concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A high-strength and tough nano-multilayer metallic glass with a gradient composition design, characterized in that, The structure comprises a periodically repeating gradient unit, each of which consists of six stacked component layers; wherein, from bottom to top along the deposition direction, the percentage of Cu atoms in each component layer first decreases and then increases, while the percentage of Ta atoms first increases and then decreases.

2. The high-strength and tough nano-multilayer metallic glass with gradient composition design according to claim 1, characterized in that, The alloy composition of each component layer, from bottom to top along the deposition direction, is Cu 75 Ta 25 Cu 63 Ta 37 Cu 50 Ta 50 Cu 34 Ta 66 Cu 50 Ta 50 Cu 63 Ta 37 .

3. The high-strength and high-toughness nano-multilayer metallic glass with gradient composition design according to claim 1, characterized in that, Each component layer within the gradient unit has the same thickness.

4. The high-strength and tough nano-multilayer metallic glass with gradient composition design according to claim 1, characterized in that, The thickness of the constituent layer is no greater than 100 nm.

5. The high-strength and tough nano-multilayer metallic glass with gradient composition design according to claim 1, characterized in that, The total thickness of the film is not less than 1.2 μm.

6. The high-strength and tough nano-multilayer metallic glass with gradient composition design according to claim 1, characterized in that, There is a corrugated interface between adjacent component layers.

7. The method for preparing high-strength and tough nano-multilayer metallic glasses with gradient composition design according to any one of claims 1-6, characterized in that, Includes the following steps: S1. Install the Cu target, Ta target, and substrate in the vacuum deposition chamber, and evacuate the vacuum deposition chamber to a vacuum state; S2. Inert gas is introduced into the vacuum deposition chamber, and the working pressure in the deposition chamber is adjusted to at least 1.6 Pa. The power supply to the target material is turned on and pre-sputter cleaning is performed, while the substrate is rotated. S3. Co-sputtering is performed by independently adjusting the sputtering power of Cu and Ta targets, and six component layers with gradient composition are deposited sequentially to obtain a gradient unit structure; S4. Repeat the gradient unit structure deposition step of S3 until the total thickness of the film of the multilayer periodically repeated gradient unit structure reaches the predetermined value.

8. The method for preparing high-strength and tough nano-multilayer metallic glass with gradient composition design according to claim 7, characterized in that, Step S3 specifically involves independently adjusting the sputtering power of the Cu metal target to 113W and the sputtering power of the Ta metal target to 80W to obtain the first component layer Cu. 75 Ta 25 Amorphous thin films; by sequentially adjusting the sputtering power of the Cu / Ta metal target to 94W / 100W, 63W / 100W, 41W / 100W, 63W / 100W, and 94W / 100W, the 2nd to 6th component layers of Cu were obtained. 63 Ta 37 Cu 50 Ta 50 Cu 34 Ta 66 Cu 50 Ta 50 Cu 63 Ta 37 Amorphous thin films are obtained by stacking six component layers to form a gradient unit structure.

9. The method for preparing high-strength and tough nano-multilayer metallic glass with gradient composition design according to claim 7, characterized in that, The substrate is a monocrystalline silicon (100) substrate.

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