An ultra-high-energy state amorphous wire with gradient structure and a preparation method and application thereof

Abstract

The application discloses a preparation method of an ultrahigh-energy-state amorphous wire with a gradient structure and belongs to the field of amorphous alloy materials, specifically to the method that the amorphous wire is subjected to cold-heat treatment or heat-cold treatment, the temperature of the heat treatment is 100-140 DEG C, and the temperature of the low-temperature environment is -190 to -200 DEG C; the energy state of the amorphous wire is improved by the cold-heat cycle method, the method has the advantages of simple operation, non-damage to the intrinsic structure of the amorphous wire and large energy state improvement range, and is an effective way to obtain the amorphous wire with high strength and large plasticity.

Description

Technical Field

[0001] This invention relates to the field of amorphous alloy materials, specifically to an ultra-high energy state amorphous wire with a gradient structure, its preparation method, and its application. Background Technology

[0002] Amorphous alloy wire is an amorphous alloy wire with a diameter in the micrometer range (several to tens of micrometers). Due to its unique structure of ultrafine nanocrystals (within 20 nm), it possesses superior mechanical and soft magnetic properties. Furthermore, with the continuous advancement of information manufacturing, electronic devices are developing towards miniaturization, high precision, and high integration. Amorphous alloy wire, with its micrometer-level size and excellent performance, can meet the needs of many precision instruments and sensors, and is gradually being applied in various fields. Examples include the application of its unique giant magnetoresistance effect in high-precision magnetic sensors, its excellent conductivity in communications, and its superior mechanical properties in cardiovascular guidewires in the biomedical field. In the future, with the rapid development of the automotive, metallurgical, defense, medical, chemical, and information industries, the application of amorphous alloy wire will become even more widespread and its applications even broader.

[0003] Amorphous alloys, due to their unique long-range disordered and short-range ordered atomic arrangement and the absence of defects such as grains, grain boundaries, and dislocations, exhibit high strength, high hardness, and excellent soft magnetic properties, attracting widespread attention. However, high strength and high ductility are a major contradiction between amorphous and crystalline materials, and this brittleness limits the widespread application of amorphous alloys.

[0004] From an energy perspective, amorphous alloys are metastable materials, and rejuvenation is the transition process from a low-energy state to a high-energy state. At the atomic level, rejuvenation increases the free volume (rheological units), enthalpy, and entropy within the atoms, thus increasing the disorder of the amorphous structure. This increased disorder helps to prevent the nucleation, expansion, and evolution of shear bands within the amorphous structure, thereby significantly improving the toughness and plasticity of the amorphous alloy. Therefore, improving the inhomogeneity of amorphous alloys, and thus enhancing their energy state, is beneficial in resolving the contradiction between strength and high plasticity, and is of great significance for the industrial application and development of amorphous alloys.

[0005] Existing rejuvenation methods, such as high-pressure torsion, elastic loading, non-uniform deformation at room temperature, and uniform deformation at room temperature, are all destructive and will damage the intrinsic structure of amorphous filaments. Furthermore, the energy state improvement is small and the operation is complicated. Summary of the Invention

[0006] To address the above problems, this invention provides an ultra-high energy state amorphous wire with a gradient structure, its preparation method, and its application.

[0007] The objective of this invention is achieved through the following technical solution:

[0008] A method for preparing an ultra-high energy state amorphous wire with a gradient structure involves cyclically subjecting the amorphous wire to cold-heat treatment or hot-cold treatment. The hot-cold treatment involves holding the wire at a high temperature for a period of time and then transferring it to a low temperature environment for a period of time. The cold-heat treatment involves holding the wire at a low temperature environment for a period of time and then transferring it to a high temperature environment for a period of time. This cold-heat treatment or hot-cold treatment is repeated several times.

[0009] The high-temperature environment has a temperature of 100 to 140°C, and the low-temperature environment has a temperature of -190 to -200°C.

[0010] Preferably, the high-temperature environment is provided by a vacuum drying oven, and the low-temperature environment is provided by liquid nitrogen;

[0011] Placing the material in a vacuum drying oven for thermal cycling can effectively prevent the oxidation of amorphous filaments, thus avoiding a decline in mechanical properties due to oxidation.

[0012] Preferably, the holding time in the low-temperature environment is 3-5 minutes, the holding time in the high-temperature environment is 5-10 minutes, and the number of cycles is 20-170.

[0013] Preferably, the amorphous wire is a Co-based, Fe-based, Ni-based, Cu-based, or Pd-based amorphous wire.

[0014] Preferably, the amorphous wire is prepared by a glass coating method.

[0015] Preferably, the method for preparing the amorphous wire is to immerse the glass-coated amorphous wire in an etching solution composed of hydrofluoric acid, sodium thiocyanate and hexamethylenetetramine for 100-150 seconds to remove the glass layer on the surface. After removing the amorphous wire from the etching solution, it is ultrasonically cleaned in anhydrous ethanol 3-5 times, dried, and stored in a vacuum drying oven for later use.

[0016] Preferably, the mass fractions of the hydrofluoric acid, sodium thiocyanate, and hexamethylenetetramine in the corrosive solution are 40%, 0.2%, and 0.8%, respectively.

[0017] Another aspect of the present invention is to provide an amorphous wire, which is prepared by the aforementioned preparation method.

[0018] Preferably, the diameter of the amorphous wire is 20-60 μm.

[0019] The amorphous wire described in this invention has excellent mechanical properties, good toughness and plasticity, and an energy state far higher than that of strips of the same composition. It can be used in military, energy, aerospace, information engineering and biomedical fields to manufacture miniaturized, high-precision and high-stability electronic devices and sensors.

[0020] The beneficial effects of this invention are as follows:

[0021] (1) Compared with other destructive rejuvenation methods, such as high pressure torsion, elastic loading, room temperature non-uniform deformation, room temperature uniform deformation, etc., the present invention innovatively uses the method of hot and cold cycling to improve the energy state of amorphous filaments. The method described in the present invention has the advantages of simple operation, no damage to the intrinsic structure of amorphous filaments, and large improvement in energy state. It is an effective way to obtain high-strength and high-plasticity amorphous filaments at the same time.

[0022] (2) The amorphous wire prepared by the present invention has an ultra-high energy state and has a structural feature of gradient distribution of soft and hard regions inside. Compared with the uniform distribution of soft and hard regions inside strips of the same composition, the non-uniformity of internal atomic arrangement is greatly enhanced, making the energy state of this ultra-high energy state amorphous wire with gradient structure much higher than that of strips of the same composition.

[0023] (3) This invention improves the energy state of amorphous wires, thereby enhancing the toughness and plasticity of amorphous wires, resolving the contradiction between high strength and high plasticity of amorphous alloys, and promoting the application of amorphous wires in military, energy, aerospace, information engineering and biomedical fields to manufacture miniaturized, high-precision and high-stability electronic devices and sensors.

[0024] (4) The method for preparing ultra-high energy state amorphous wire with gradient structure proposed in this invention has the advantages of simple operation, short preparation cycle, good universality, 100% yield, non-destructive and easy industrial mass production. Attached Figure Description

[0025] The present invention will be further described with reference to the accompanying drawings, but the embodiments in the drawings do not constitute any limitation on the present invention. For those skilled in the art, other drawings can be obtained based on the following drawings without creative effort.

[0026] Figure 1 This is a flowchart of the hot and cold cycle described in the embodiment;

[0027] Figure 2 These are the XRD patterns of the amorphous wire before and after the thermal cycling treatment;

[0028] Figure 3 These are differential scanning calorimetry (DSC) spectra of amorphous wires and amorphous strips of the same composition after thermal cycling treatment.

[0029] Figure 4 The graph shows the elastic modulus test results of amorphous wires and amorphous strips of the same composition after thermal cycling treatment.

[0030] Figure 5This is a schematic diagram showing the distribution of nanoscale flow units of amorphous wires and amorphous strips of the same composition after thermal cycling treatment;

[0031] Figure 6 This is a statistical chart showing the energy improvement ratio of the cold and hot cycle described in the embodiment and several conventional improvement methods;

[0032] Figure 7 These are the room temperature tensile stress-strain curves of amorphous wires and amorphous strips of the same composition after thermal cycling treatment;

[0033] Figure 8 This is a tensile cross-section SEM image of an amorphous wire after thermal cycling treatment. Detailed Implementation

[0034] The present invention will be further described in conjunction with the following embodiments.

[0035] Example

[0036] The embodiments of the present invention relate to an ultra-high energy state amorphous wire with a gradient structure, specifically prepared by thermal cycling of the amorphous wire. The amorphous wire is Co-based, Fe-based, Ni-based, Cu-based, or Pd-based. This embodiment takes a Co-based amorphous wire as an example, and its preparation process is as follows:

[0037] (1) Co-based amorphous wires were prepared by glass coating method to obtain glass-coated amorphous wires;

[0038] (2) The glass-coated amorphous wire is immersed in an etching solution containing 40% hydrofluoric acid, 0.2% sodium thiocyanate, and 0.8% hexamethylenetetramine for 120 seconds to remove the glass layer on the surface. Then the amorphous wire is taken out of the etching solution, placed in a beaker containing anhydrous ethanol, ultrasonically cleaned 5 times, dried, and stored in a vacuum drying oven for later use.

[0039] (3) The Co-based amorphous wire with the surface glass layer removed, at room temperature, is completely immersed in liquid nitrogen and frozen for 3 minutes. After being removed, it is placed in a vacuum drying oven and kept at 120°C for 8 minutes. Then it is taken out and allowed to cool naturally to room temperature. This cycle is repeated. See the flow chart of the hot and cold cycle. Figure 1 The process involved 150 cycles to obtain ultra-high energy state Co-based amorphous wires with a gradient structure.

[0040] Experimental Example

[0041] The structure, energy, and mechanical properties of the ultra-high energy state Co-based amorphous wires with gradient structures prepared in the examples were characterized and tested. Specifically:

[0042] (1) Crystal phase characterization

[0043] The amorphous wire (UHES-Wire) after thermal cycling treatment and the amorphous wire (Wire) prepared by glass coating method were analyzed by X-ray diffraction. Their XRD patterns are shown in [reference needed]. Figure 2 The XRD results of both showed only one obvious broad diffraction peak, indicating that both the amorphous wires after thermal cycling and the amorphous wires prepared by the precursor glass coating method are amorphous phases.

[0044] (2) Energy characterization

[0045] To demonstrate that the amorphous wires prepared by this method possess ultra-high energy states, the ultra-high energy state amorphous wires (UHES-Wire) and homologous ribbons (Ribbon) after thermal cycling were characterized by the following energy characteristics:

[0046] The differential scanning calorimetry (DSC) test procedure is as follows: Weigh 12 mg of amorphous wire, place it in a crucible, compact it, and put it into the DSC device for testing. Under an argon atmosphere, perform a temperature scan at a heating rate of 20 K / min to test its heat change; the same operation method is used for amorphous strips of the same composition.

[0047] See DSC test results Figure 3 By calculating the relaxation enthalpy of the two, it was found that amorphous wires have a higher relaxation enthalpy than strips of the same composition, that is, they have a higher energy state.

[0048] The nanoindentation test procedure is as follows: Amorphous wires are made into inlay samples that meet the requirements of nanoindentation testing. Indentation experiments are performed using a nanoindenter with a diamond tip. Indentation is performed along the diameter of the amorphous wire in load control mode. The load is linearly increased from 1 mN / s to a maximum load of 10 mN. The maximum load is maintained for 100 seconds, and then the load is finally unloaded to zero at a loading rate of 1 mN / s. The loading process is then continued. The same operation method is used for amorphous strips of the same composition.

[0049] See the test results for nanoindentation. Figure 4 The elastic modulus of amorphous filaments is much lower than that of strips of the same composition, meaning that the energy state of amorphous filaments is much higher than that of strips of the same composition. Furthermore, the elastic modulus of amorphous filaments exhibits a gradient distribution that gradually decreases from the center to the radius, while the elastic modulus of amorphous strips is almost uniform everywhere. The gradient distribution of the elastic modulus of amorphous filaments means that the internal nanoscale flow units also exhibit a gradient distribution, with a non-uniformity much greater than that of strips of the same composition.

[0050] Figure 5 This is a schematic diagram showing the distribution of nanoscale flow units in both systems. Figure 6Based on the DSC relaxation enthalpy calculation results of the two methods, a statistical chart was obtained by comparing the proportion of energy state improvement achieved by the method of this invention with the maximum improvement proportion of existing reported methods for improving energy state (irradiation treatment, recovery annealing, NaOH immersion treatment, elastic loading, high pressure torsion, surface shot peening, and rolling treatment).

[0051] (3) Mechanical testing

[0052] To demonstrate the high strength and high plasticity of the amorphous wires prepared by this method, the following mechanical tensile tests were conducted on the ultra-high energy state amorphous wires and strips of the same composition:

[0053] Tensile testing of ultra-high energy state amorphous wires was performed using DMA. The specific steps were as follows: A 5cm long amorphous wire was taken, and both ends of the amorphous wire were clamped using the DMA test fixture. The loading rate was 2×10⁻⁶. -4 Under the conditions of room temperature tensile testing;

[0054] Tensile tests were performed on strips of the same composition using a universal testing machine. The specific steps were as follows: A 5cm long amorphous strip was taken, and both ends of the amorphous strip were clamped using the test fixture of the universal testing machine. The loading rate was set to a strain rate of 2×10⁻⁶. -4 Under the conditions of room temperature tensile testing;

[0055] Figure 7 The room temperature tensile stress-strain curves of the two materials show that the ultra-high energy state amorphous wire exhibits higher tensile strength and toughness-plasticity. Figure 8 SEM images of the tensile cross-section of the amorphous wire also show that the ultra-high energy state amorphous wire undergoes necking and shear band crossing during the stretching process, which are all manifestations of its excellent toughness and plasticity.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A method for preparing an ultra-high-energy-state amorphous wire having a gradient structure, characterized by, The amorphous wire is subjected to a cold-heat treatment or a heat-cold treatment, the heat-cold treatment being a treatment of keeping the amorphous wire in a high-temperature environment for a period of time and then keeping the amorphous wire in a low-temperature environment for a period of time, the cold-heat treatment being a treatment of keeping the amorphous wire in a low-temperature environment for a period of time and then keeping the amorphous wire in a high-temperature environment for a period of time, and the cold-heat treatment or the heat-cold treatment is repeated for 20-170 times; The temperature of the high-temperature environment is 100-140℃, and the temperature of the low-temperature environment is -190--200℃. The keeping time of the low-temperature environment is 3-5min, and the keeping time of the high-temperature environment is 5-10min. The amorphous wire is prepared by a glass cladding method, and the preparation method is as follows: the glass cladded amorphous wire is immersed in a corrosion liquid composed of hydrofluoric acid, sodium thiocyanate and urotropine for 100-150s to remove the surface glass layer, the amorphous wire is taken out from the corrosion liquid and then is ultrasonically cleaned in anhydrous ethanol for 3-5 times, is dried, and is stored in a vacuum drying box for standby.

2. The method of claim 1, wherein the gradient structure is formed by controlling the deposition rate of the deposition source. The amorphous wire is a Co-based, Fe-based, Ni-based, Cu-based or Pd-based amorphous wire.

3. The method of claim 1, wherein the gradient structure is formed by controlling the deposition rate of the deposition source. The mass fraction of the hydrofluoric acid, the sodium thiocyanate and the urotropine in the corrosion liquid is 40%, 0.2% and 0.8% respectively.

4. An amorphous wire, characterized by, The amorphous wire is prepared by the preparation method of any one of claims 1-3.

5. The amorphous wire of claim 4, wherein The diameter of the amorphous wire is 20-60μm.

6. Application of the amorphous wire of claim 4 in electronic devices and / or sensors.

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