Metallic glass structure heterogeneity regulation and control method based on high-frequency electric pulse

Abstract

The invention discloses a metal glass structure heterogeneity regulation and control method based on high-frequency electric pulses. Comprising the following steps: preparing metal glass nanowires in situ under a transmission electron microscope, applying high-frequency electric pulses to the metal glass nanowires one by one, and observing the microstructure heterogeneity of the metal glass nanowires by using the transmission electron microscope after applying at least one high-frequency electric pulse every time until the metal glass nanowires with the target microstructure are obtained. According to the method disclosed by the invention, the preparation and forming of the metal glass can be accurately regulated and controlled at the atomic scale, the defects of a traditional method are avoided, and meanwhile, the in-situ preparation and regulation and control of the metal glass nanowire can be realized.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of metal nanomaterial processing, and particularly relates to a method for regulating the non-uniformity of the microstructure of metal glass through high-frequency electric pulses, which is used for the controllable forming of metal glass nanostructures. BACKGROUND

[0002] Metal glass has important application prospects in micro-electro-mechanical system (MEMS) due to its long-range disordered atomic structure, which exhibits excellent mechanical properties such as high strength and high elastic limit. However, the structural non-uniformity (such as local atomic clusters and free volume distribution) directly affects the controllability of material properties. Studies have shown that atomic-scale clusters (<1 nm) directly affect the shear band nucleation during the deformation process of metal glass, and chemical segregation on the scale of tens of nanometers significantly affects the fracture toughness of the material. This multi-scale coupling feature poses higher requirements for the processing technology of metal glass.

[0003] Traditional processing methods include heat treatment, mechanical loading or chemical treatment, which have significant limitations:

[0004] Heat treatment can usually only promote the structural relaxation of metal glass, which is easy to cause large-scale crystallization and destroy the amorphous characteristics;

[0005] Mechanical loading can cause surface damage and adversely affect the service stability of metal glass;

[0006] Chemical methods may introduce impurities of heteroatoms and are only suitable for specific compositions.

[0007] The external field regulation techniques developed in recent years, such as static high-pressure treatment and strong magnetic field annealing, have made some progress, but also have defects such as low energy efficiency.

[0008] In summary, precise regulation of the non-uniformity of the atomic structure of metal glass is crucial for its reliable application in micro-nano systems, but existing technologies cannot achieve precise regulation of the atomic structure of metal glass. Therefore, there is an urgent need for a method that can efficiently, non-contact and precisely regulate the non-uniformity of the structure of metal glass. SUMMARY

[0009] To solve the limitations of current metal glass processing methods, the purpose of the present application is to propose a method for regulating the non-uniformity of the microstructure of metal glass based on high-frequency electric pulses, which can regulate the preparation and forming of metal glass at the atomic scale and avoid the defects of traditional methods.

[0010] The technical solution adopted by the present application is:

[0011] I. A method for regulating the non-uniformity of the structure of metal glass based on high-frequency electric pulses

[0012] The metal glass structure non-uniformity regulation method comprises the following steps:

[0013] S1, under a transmission electron microscope, aligning and contacting two metal fractures in horizontal height, in-situ welding a metal glass nanowire.

[0014] Specifically, the metal and the metal glass nanowire are of the same material, tungsten, molybdenum, tantalum or amorphous alloy.

[0015] Preferably, the process of in-situ welding the metal glass nanowire under the transmission electron microscope is specifically as follows:

[0016] S1.1, preparing two metal wires by treating a metal wire with a diameter of 0.25 mm by using a physical shearing method;

[0017] S1.2, after arranging the fractures of the two metal wires oppositely, loading the two metal wires on a sample table;

[0018] S1.3, under the observation of a transmission electron microscope, after aligning and contacting the fractures of the two metal wires in horizontal height, applying an electric pulse with a single voltage of 0.1-5 V and a pulse width of 5 ns to the two metal wires to weld and form a metal glass nanowire.

[0019] Preferably, the metal glass nanowire welded has a characteristic diameter of 1-100 nm.

[0020] S2, applying high-frequency electric pulses to the metal glass nanowire one by one, after applying one or more high-frequency electric pulses, in-situ obtaining a transmission electron microscope picture of the metal glass nanowire by using the transmission electron microscope, obtaining an intensity curve of a fast Fourier transform image by fast Fourier transform, and judging whether the metal glass nanowire with the target non-uniformity is obtained according to the intensity curve of the fast Fourier transform image.

[0021] Specifically, the high-frequency electric pulse has a voltage of 0.1-5 V and a pulse width of 5 ns, and the interval between two adjacent high-frequency electric pulses is 0.8-1.2 s, and after applying 1-10 high-frequency electric pulses, the transmission electron microscope picture of the metal glass nanowire is in-situ obtained by using the transmission electron microscope.

[0022] Specifically, the process of judging whether the metal glass nanowire with the target non-uniformity is obtained according to the intensity curve of the fast Fourier transform image is as follows: when the peak position deviation, the difference between the peak intensity ratios, the difference between the half-height widths or the difference between the peak sharpnesses between the intensity curve and the intensity curve corresponding to the target non-uniformity are all less than a preset error threshold, it is judged that the metal glass nanowire with the target non-uniformity is obtained.

[0023] Specifically, the evolution direction of the non-uniformity of the metallic glass nanowire is regulated by adjusting the voltage of the high-frequency electric pulse, and the voltage of the high-frequency electric pulse is adjusted in a range of 0.1-5V.

[0024] Specifically, the regulation process is as follows: when the voltage of the high-frequency electric pulse is less than the change threshold of the metallic glass nanowire, the non-uniformity of the metallic glass nanowire increases; and when the voltage of the high-frequency electric pulse is greater than the change threshold of the metallic glass nanowire, the non-uniformity of the metallic glass nanowire decreases.

[0025] Preferably, the metallic glass nanowire is made of tantalum, the non-uniformity of the metallic glass nanowire increases when the voltage of the high-frequency electric pulse is 0.25V, and the non-uniformity of the metallic glass nanowire decreases when the voltage of the high-frequency electric pulse is 0.38V.

[0026] Specifically, the change threshold of the metallic glass nanowire is calibrated as follows: under a transmission electron microscope, two metal fractures are aligned in horizontal height and in contact with each other, and then the metallic glass nanowire is welded in situ; a series of high-frequency electric pulses with decreasing voltage are applied to the metallic glass nanowire; at each voltage, 1-30 high-frequency electric pulses are applied to obtain a relationship curve between the half-width of the intensity curve or the peak sharpness and the number of pulses; if the half-width or the peak sharpness decreases with the increase of the number of pulses, the current voltage is greater than the change threshold; and if the change rate of the half-width or the change rate of the peak sharpness is less than a preset threshold, the corresponding voltage is taken as the change threshold.

[0027] S3, the non-uniformity of the metallic glass nanowire is regulated multiple times by repeating step S2 until the metallic glass nanowire with the target non-uniformity is obtained or the in-situ regulation is completed.

[0028] II. A metallic glass structure non-uniformity regulation system for implementing the above-mentioned metallic glass structure non-uniformity regulation method

[0029] The metallic glass structure non-uniformity regulation system comprises:

[0030] A sample stage comprising a fixed end and a movable end arranged opposite to each other, and loading two metal wires respectively;

[0031] A high-frequency pulse generator for applying high-frequency electric pulses to the two metal wires on the sample stage;

[0032] A transmission electron microscope for in-situ welding of the metallic glass nanowire and in-situ acquisition of the electron microscope image of the metallic glass nanowire;

[0033] The data processing module is used for performing fast Fourier transform on the electron microscope picture to obtain an intensity curve of a fast Fourier transform image, and judging whether the metal glass nanowire with the purpose non-uniformity is obtained according to the intensity curve of the fast Fourier transform image.

[0034] The present application has the following advantages:

[0035] 1. The method can precisely regulate the preparation and forming of the metal glass at the atomic scale, and avoid the defects of the traditional method.

[0036] 2. The method can realize the regulation of the local free volume and the order degree of the metal glass nanowire.

[0037] 3. The method can realize the optimization of the electric pulse processing parameters and the customized regulation of the microstructure of the metal glass. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 is a schematic diagram of the electric pulse processing equipment and method adopted by the embodiment of the present application;

[0039] Figure 2 is a transmission electron microscope group diagram for regulating the atomic cluster proportion distribution of the metal glass by the electric pulse in the embodiment 1 of the present application; wherein, (a) and (b) are respectively the morphology diagram (upper diagram), the high resolution image (lower diagram) and the corresponding fast Fourier transform (FFT) image (upper right of the lower diagram) of the metal glass nanowire before and after the electric pulse processing; (c) is the intensity curve of the high resolution image FFT after different pulse times;

[0040] Figure 3 is a transmission electron microscope group diagram for regulating the local order degree of the metal glass by the electric pulse in the embodiment 2 of the present application; wherein, (a) and (b) are respectively the morphology diagram (upper diagram), the high resolution image (lower diagram) and the corresponding fast Fourier transform image (upper right of the lower diagram) of the metal glass nanowire before and after the electric pulse processing; (c) is the intensity curve of the high resolution image FFT after different pulse times;

[0041] Figure 4 is a schematic diagram of the principle of regulating the non-uniformity of the metal glass structure, wherein, (a) illustrates the regulation of the atomic cluster proportion distribution of the metal glass by the electric pulse; (b) illustrates the regulation of the local order degree of the metal glass by the electric pulse; (c) illustrates the interaction between the electron and the atomic cluster in the electric pulse action process, which leads to the transformation of the high-energy state cluster to the relaxation state or even the crystalline state. DETAILED DESCRIPTION

[0042] The present application will be further described in detail below in combination with the drawings and specific embodiments.

[0043] In the present application, the non-uniformity of the metal glass structure is adjusted by the interaction between electrons and atomic clusters, and the principle of gradual evolution of the microstructure is shown in Figure 4 The red circles represent the atoms of high-energy-state clusters, which have a large free volume; the blue circles represent the atoms of relaxation-state clusters, which have a relatively close atomic spacing; and the green balls represent the atoms of nanocrystalline clusters, which have a local periodic ordered arrangement.

[0044] Figure 4 Fig. (a) of the drawings shows the principle of adjusting the proportion distribution of atomic clusters of the metal glass by the electric pulse. After a high-frequency electric pulse with a small voltage (less than the change threshold of the metal glass nanowire) is applied, the proportion distribution of different atomic clusters changes, and the microstructure non-uniformity of the metal glass nanowire increases.

[0045] Figure 4 Fig. (b) of the drawings shows the principle of adjusting the local order degree of the metal glass by the electric pulse. Figure 4 Fig. (c) of the drawings shows the principle of the interaction between electrons and atomic clusters during the action of the electric pulse, which leads to the transformation of the high-energy-state clusters into the relaxation-state or even the crystalline state. After a high-frequency electric pulse with a large voltage (greater than the change threshold of the metal glass nanowire) is applied, the order degree of the atomic clusters increases, and the microstructure non-uniformity of the metal glass nanowire decreases.

[0046] As shown in Figure 1 It can be seen that the evolution of the non-uniformity of the metal glass structure is caused by the interaction between electrons and atomic clusters in the pulse process, which leads to the structural and energy changes.

[0047] The first aspect of the present application provides a method for adjusting the non-uniformity of the metal glass structure based on a high-frequency electric pulse.

[0048] The method specifically includes the following steps:

[0049] S1, under a transmission electron microscope, aligning and contacting two metal fractures in the horizontal height, and then in-situ welding a metal glass nanowire.

[0050] The metal and the metal glass nanowire are made of the same material, such as tungsten, molybdenum, tantalum or amorphous alloy.

[0051] Specifically, the process of in-situ welding the metal glass nanowire under the transmission electron microscope is specifically as follows:

[0052] S1.1, a physical shearing method is used to process a metal wire with a diameter of 0.25 mm, and two sections of the metal wire are prepared;

[0053] S1.2, after arranging the fractures of the two sections of the metal wire opposite to each other, the two sections of the metal wire are loaded on a sample stage, and a sample stage loaded with a metal substrate is obtained;

[0054] S1.3, placing the sample stage loaded with the metal substrate into the sample cavity of the transmission electron microscope, under the observation of the transmission electron microscope, aligning the fracture surfaces of the two metal wires in the horizontal height and making them contact with each other, and then applying a single voltage pulse of 0.1-5V and a pulse width of 5ns to the two metal wires by using a high-frequency pulse generator to weld the metal glass nanowires.

[0055] In step S1.3, the characteristic diameter of the metal glass nanowires welded is 1-100nm, and the size of the metal glass nanowires is determined by the pulse signal parameters and the type of metal and other conditions.

[0056] S2, applying high-frequency electric pulses to the metal glass nanowires one by one, after applying one or more high-frequency electric pulses, obtaining the electron microscope image of the metal glass nanowires in situ by using the transmission electron microscope, obtaining the intensity curve of the fast Fourier transform image by fast Fourier transform, and determining whether the metal glass nanowires with the desired non-uniformity are obtained according to the intensity curve of the fast Fourier transform image.

[0057] In the above method, the voltage of the high-frequency electric pulse is 0.1-5V, the pulse width is 5ns, the interval between the application of two adjacent high-frequency electric pulses is 0.8-1.2s, preferably 1s, and the electron microscope image of the metal glass nanowires is obtained in situ by using the transmission electron microscope after applying 1-10 high-frequency electric pulses.

[0058] In step S2, the non-uniformity of the metal glass structure is adjusted by using the interaction between electrons and atomic clusters during the application of high-frequency electric pulses. The non-uniformity is reflected by the proportional distribution of different atomic clusters and the order degree of atomic clusters.

[0059] In step S2, when the peak position deviation, the difference between the peak intensity ratios, the difference between the half-height widths, or the difference between the peak sharpness of the intensity curve and the intensity curve corresponding to the desired non-uniformity are all less than a preset error threshold, it is determined that the metal glass nanowires with the desired non-uniformity are obtained.

[0060] In a specific implementation, the intensity curve corresponding to the desired non-uniformity can be obtained by molecular dynamics simulation or experimental calibration. The experimental calibration can be: pre-acquiring the FFT intensity curve of the metal glass nanowires with the target performance.

[0061] In step S2, the evolution direction of the non-uniformity of the metallic glass nanowire is regulated by adjusting the voltage of the high-frequency electric pulse in the range of 0.1-5 V. The regulation mode is as follows: when the voltage of the high-frequency electric pulse is less than the change threshold of the metallic glass nanowire, the non-uniformity of the metallic glass nanowire increases; when the voltage of the high-frequency electric pulse is greater than the change threshold of the metallic glass nanowire, the non-uniformity of the metallic glass nanowire decreases. For example, when the voltage of the high-frequency electric pulse is 0.25 V, the non-uniformity of the metallic glass nanowire increases; when the voltage of the high-frequency electric pulse is 0.38 V, the non-uniformity of the metallic glass nanowire decreases.

[0062] The change threshold of the metallic glass nanowire is calibrated as follows: under a transmission electron microscope, the two metal fractures are aligned in the horizontal height and in contact with each other, and then the metallic glass nanowire is welded in situ; a series of high-frequency electric pulses with decreasing voltages are applied to the metallic glass nanowire; at each voltage, 1-30 high-frequency electric pulses are applied to obtain the relationship curve between the half-width of the intensity curve or the peak sharpness and the pulse number; if the half-width or the peak sharpness continuously decreases with the increase of the pulse number, the current voltage is greater than the change threshold; if the change rate of the half-width or the peak sharpness is less than a preset threshold, i.e., the half-width of the intensity curve or the peak shape does not change significantly, the corresponding voltage is taken as the change threshold.

[0063] S3, the non-uniformity of the metallic glass nanowire is regulated multiple times by repeating step S2 until the metallic glass nanowire with the desired non-uniformity is obtained or the in-situ regulation is completed.

[0064] The second aspect of the present application provides a metallic glass structure non-uniformity regulation system.

[0065] The system of the present application comprises:

[0066] A sample stage comprising a fixed end and a movable end arranged opposite to each other, and loading two metal wires respectively;

[0067] A high-frequency pulse generator for applying high-frequency electric pulses to the closed loop formed by the contact of the two metal wires on the sample stage;

[0068] A transmission electron microscope for in-situ welding of the metallic glass nanowire and in-situ acquisition of the electron microscope image of the metallic glass nanowire;

[0069] A data processing module for fast Fourier transform of the electron microscope image to obtain the intensity curve of the fast Fourier transform image, and judging whether the metallic glass nanowire with the desired non-uniformity is obtained according to the intensity curve of the fast Fourier transform image.

[0070] Further, the data processing module stores a pre-calibrated intensity curve corresponding to the target non-uniformity.

[0071] The specific implementation of the present application is as follows:

[0072] All embodiments of the present application are completed by using the device as shown in Figure 2 The device includes a high-frequency pulse generator, a transmission electron microscope, and a sample stage, the pulse generator is used to apply a pulse bias, the transmission electron microscope is used to observe the morphology and microstructure of the metallic glass, and the sample stage is used to weld the sample and implement processing.

[0073] The sample stage includes a fixed end and a movable end, which are arranged opposite to each other and do not contact, and load two metal substrates respectively. The substrates at both ends are connected to the output and input interfaces of the pulse generator. The sample stage further includes a piezoelectric driving module, during implementation, the movable end can be accurately moved in the three-dimensional directions of up and down, left and right, and front and back through the piezoelectric driving module. The metal glass nanowire is formed by applying an electric pulse to the metal substrates in contact through the pulse generator.

[0074] The steps of implementing the method of the present application by using the above device are as follows:

[0075] S1, two metal fractures are prepared by using a physical shearing method. Specifically, the metal wire is cut into two sections by using a beak forceps, and is cut to an appropriate length respectively. The two sections of the metal wire are installed on the fixed end and the movable end of the sample stage, and the fractures are arranged opposite to each other.

[0076] S2, the movable end and the fixed end of the sample stage are connected to the output and input interfaces of the pulse generator, the voltage is set to 0.1-5V, the pulse width is 5ns, the mode is manual trigger, and the voltage size is determined according to the specific metal type.

[0077] S3, the sample stage is placed into the sample cavity of the transmission electron microscope, the metal fracture of the movable end is controlled to approach the fixed end by using the piezoelectric driving module, and the two metal fractures are aligned in the horizontal height.

[0078] S4, under the observation of the transmission electron microscope, the metal substrate of the movable end is controlled to contact the metal substrate of the fixed end, a single electric pulse is applied, and the metal substrates are welded to form a metal glass nanowire.

[0079] S5, the voltage size is adjusted, multiple high-frequency electric pulses are applied to the metal glass nanowire, the non-uniformity of the metal glass structure is adjusted by using the interaction of electrons and atomic clusters, the microstructure of the metal glass is gradually evolved, and a metal glass nanowire with specific microstructure characteristics is prepared.

[0080] In step S5, the current structural information can be obtained between each two high-frequency electric pulses, and then it is determined whether to continue to apply the pulses.

[0081] Embodiment 1

[0082] In this embodiment, a tantalum wire with a diameter of 0.25 mm is used to prepare a metallic glass nanowire, and the proportion distribution of the metallic glass atomic clusters is adjusted by high-frequency electric pulses. The specific process is as follows:

[0083] S1, mounting the sample: a tantalum wire with a diameter of 0.25 mm and a suitable length is placed in an acetone solution and ultrasonically cleaned for 5 min, then cut into two sections with a beveled forceps, and the two fracture surfaces formed are simply used as the metal substrate. Then the two sections of the metal wire are trimmed to a length matching the loading area of the sample stage, and then the metal substrate is fixed at the movable end and the fixed end of the sample stage with the fracture surfaces facing each other.

[0084] S2, connecting the equipment: the movable end and the fixed end of the sample stage are respectively connected to the output and input interfaces of the pulse generator, the voltage is set to 0.25 V, the pulse width is 5 ns, the rising edge is 2 ns, and the mode is manual triggering.

[0085] S3, welding the prepared metallic glass nanowire in the transmission electron microscope: the sample stage is placed in the transmission electron microscope, and the areas protruding from the fracture surface of the metal substrate at both ends are selected as the contact sites. The movable end of the metal substrate is contacted with the metal substrate at the fixed end by using a piezoelectric driving module, a single pulse is loaded, and a tantalum metallic glass nanowire with a characteristic diameter of about 20 nm is formed.

[0086] S4, a pulse is applied between the movable end and the fixed end of the sample stage one by one, and the microstructure changes of the metallic glass during the pulse processing are observed by using the transmission electron microscope. After 30 pulse loadings, the size of the nanowire does not change significantly, and it always maintains an amorphous structure. The peak shift and peak separation of the FFT results of the high-resolution image show that the proportion distribution of the atomic clusters is constantly changing.

[0087] Figure 2 is the transmission electron microscope group image for adjusting the proportion distribution of the metallic glass atomic clusters by electric pulses in this embodiment. Among them, (a) and (b) are the electron microscope images of the metallic glass nanowire before and after the electric pulse processing, including the morphology, high resolution and the corresponding FFT images. The diameter of the nanowire is about 20 nm, and there is no significant size change before and after the processing. The lower end of the nanowire is connected to the output end of the pulse power supply, and a total of 30 pulse voltages with a size of 0.25 V and a width of 5 ns are input during the processing. (c) is the intensity curve of the high-resolution image FFT before and after the processing and during the processing, which represents the change of the non-uniformity of the metallic glass structure.

[0088] From Figure 3It can be seen that the processing method can regulate the proportion distribution of atomic clusters in the metallic glass, and the regulation is specifically shown as the shift and peak splitting of the FFT peak position of the high-resolution atomic image.

[0089] Compared with the prior art which cannot realize the directional regulation of the local free volume of the metallic glass, the embodiment realizes the regulation of the local free volume through the small-voltage high-frequency electric pulse, and gradually increases the structural non-uniformity of the metallic glass.

[0090] Embodiment 2

[0091] As Figure 4 and Figure 3 (b) shown.

[0092] Different from embodiment 1, the pulse generator is set to 0.38V, and the others are the same as embodiment 1. After 30 times of pulse loading, the size of the nanowire does not change obviously, the local nanocrystalline structure appears, and the FFT result of the high-resolution image shows that the order degree of the metallic glass structure is increased.

[0093] Figure 3 The transmission electron microscope group diagram in the embodiment is used for regulating the local order degree of the metallic glass through the electric pulse.

[0094] Wherein, (a) and (b) are the electron microscope pictures of the metallic glass nanowire before and after the electric pulse processing, including the morphology, the high-resolution and the corresponding FFT image. The diameter of the nanowire is about 20nm, and there is no obvious size change before and after the processing. The lower end of the nanowire is connected to the output end of the pulse power supply, and the total input of the processing process is 30 pulse voltages with the size of 0.38V and the width of 5ns. (c) is the intensity curve of the FFT of the high-resolution image before and after the processing, which represents the change of the structural non-uniformity of the metallic glass.

[0095] From ​ It can be seen that the processing method can increase the local order degree of the metallic glass, and the regulation is specifically shown as the formation of the nanocrystalline and the decrease of the half-height width of the FFT of the high-resolution atomic image.

[0096] The traditional annealing heat treatment process is easy to cause the crystallization of the amorphous structure, and due to the size effect, the temperature uniformity of the nanowire is difficult to control, which greatly increases the difficulty of accurately regulating the structural non-uniformity of the metallic glass. The embodiment replaces the whole annealing by the local joule heat effect and the current-atomic cluster interaction of the electric pulse, avoids the whole crystallization, maintains the stability of the amorphous main structure and improves the order degree of the structure.

[0097] In summary, based on the regulation method provided by the application, the determination and optimization of the electric pulse processing parameters can be realized through the real-time dynamic electric pulse loading, and then the directional regulation of the non-uniformity can be realized.

[0098] The above detailed description is used to explain and illustrate the present application, but not to limit the present application, any modification and change made to the present application within the spirit and protection scope of the claims of the present application, all fall into the protection scope of the present application.

[0099] The above description is only the preferred embodiment of the present application, therefore, any equivalent change or modification made to the structure, features and principles described in the scope of the present application patent application, all fall into the scope of the present application patent application.

Claims

1. A method for controlling the non-uniformity of metallic glass structures based on high frequency electrical pulses, characterized in that, The method comprises the following steps: S1, under a transmission electron microscope, two metal fractures are aligned in horizontal height and in contact with each other, and then metal glass nanowires are in-situ welded; S2, high-frequency electric pulses are applied to the metal glass nanowires one by one, after one or more high-frequency electric pulses are applied, an electron microscope picture of the metal glass nanowires is obtained in-situ by using the transmission electron microscope, an intensity curve of a fast Fourier transform image is obtained by fast Fourier transform, and whether the metal glass nanowires with a target non-uniformity are obtained is determined according to the intensity curve of the fast Fourier transform image; S3, the non-uniformity of the metal glass nanowires is controlled multiple times by repeating step S2 until the metal glass nanowires with the target non-uniformity are obtained or the in-situ control is completed.

2. The method of claim 1, wherein: The metal and the metal glass nanowires are made of the same material, tungsten, molybdenum, tantalum or amorphous alloy.

3. The method of claim 2, wherein: In step S2, the voltage of the high-frequency electric pulse is 0.1-5V, the pulse width is 5ns, the interval between two adjacent high-frequency electric pulses is 0.8s-1.2s, and after 1-10 high-frequency electric pulses are applied, the electron microscope picture of the metal glass nanowires is obtained in-situ by using the transmission electron microscope.

4. The method of claim 3, wherein: In step S2, when the peak position offset difference, the peak intensity ratio difference and the half-height width difference or the peak shape sharpness difference between the intensity curve and the intensity curve corresponding to the target non-uniformity are all less than a preset error threshold, it is determined that the metal glass nanowires with the target non-uniformity are obtained.

5. The method of claim 3, wherein: In step S2, the evolution direction of the non-uniformity of the metal glass nanowires is controlled by adjusting the voltage of the high-frequency electric pulse, and the voltage adjustment range of the high-frequency electric pulse is 0.1-5V. The control mode is specifically as follows: when the voltage of the high-frequency electric pulse is less than a change threshold of the metal glass nanowires pre-marked, the non-uniformity of the metal glass nanowires increases; when the voltage of the high-frequency electric pulse is greater than the change threshold of the metal glass nanowires pre-marked, the non-uniformity of the metal glass nanowires decreases.

6. The method of claim 5, wherein: The marking process of the change threshold of the metal glass nanowires is specifically as follows: Under a transmission electron microscope, two metal fractures are aligned in horizontal height and in contact with each other, and then metal glass nanowires are in-situ welded; A series of high-frequency electric pulses with decreasing voltages are applied to the metal glass nanowires; at each voltage, 1-30 high-frequency electric pulses are applied, and a relationship curve between the half-height width or the peak shape sharpness of the intensity curve and the pulse number is obtained; If the half-height width or the peak shape sharpness decreases with the increase of the pulse number, the current voltage is greater than the change threshold, and if the change rate of the half-height width or the change rate of the peak shape sharpness with the pulse number is less than a preset threshold, the corresponding voltage is taken as the change threshold.

7. The method of claim 5, wherein the metal glass structure is a bulk metallic glass. The material of the metal glass nanowires is tantalum, the non-uniformity of the metal glass nanowires increases when the voltage of the high-frequency electric pulse is 0.25V, and the non-uniformity of the metal glass nanowires decreases when the voltage of the high-frequency electric pulse is 0.38V.

8. The method of claim 1 or 7, wherein: The process of in-situ welding of the metal glass nanowires under the transmission electron microscope is specifically as follows: S1.1, a physical shearing method is used to process a metal wire with a diameter of 0.25mm, and two metal wires are prepared; S1.2, after the two broken ends of the two metal wires are arranged oppositely, the two metal wires are loaded on the sample stage; S1.3, under the observation of the transmission electron microscope, after the two broken ends of the two metal wires are aligned in the horizontal height and contact with each other, an electric pulse with a single voltage of 0.1-5V and a pulse width of 5ns is applied to the two metal wires to weld the metal glass nanowire.

9. The method of claim 8, wherein: In step S1.3, the characteristic diameter of the metal glass nanowire welded is 1-100nm.

10. A system for implementing the method of claim 1-9 for controlling the non-uniformity of metallic glass structures, characterized in that, It comprises: a sample stage comprising a fixed end and a movable end arranged oppositely, respectively loading two metal wires; a high-frequency pulse generator for applying a high-frequency electric pulse to the two metal wires on the sample stage; a transmission electron microscope for in-situ welding of the metal glass nanowire and in-situ acquisition of the electron microscope picture of the metal glass nanowire; a data processing module for fast Fourier transform of the electron microscope picture, obtaining the intensity curve of the fast Fourier transform image, and judging whether the metal glass nanowire with the purpose of non-uniformity is obtained according to the intensity curve of the fast Fourier transform image.

Images