A method and system for thermomechanical rejuvenation of amorphous alloys

Abstract

The application discloses a kind of amorphous alloy thermomechanical rejuvenation processing method and system, belong to amorphous alloy material processing technical field, under the constant temperature condition lower than amorphous alloy glass transition temperature, stress is applied to amorphous alloy sample and is carried out creep loading, and amorphous alloy sample produces viscoelastic strain;After unloading stress, with greater than or equal to 0.2K / min cooling rate, amorphous alloy sample is linearly cooled from constant temperature condition to room temperature, and the recovery of viscoelastic strain is inhibited by cooling rate, and frozen residual viscoelastic strain is obtained, and it is frozen in the amorphous alloy sample, and young amorphous alloy is obtained;Wherein, cooling rate and frozen residual viscoelastic strain amount are positively correlated, and the rejuvenation degree of rejuvenated amorphous alloy is controlled by regulating cooling rate.The method can make unit frozen residual viscoelastic strain energy storage efficiency higher than plastic deformation mode by more than 2 orders of magnitude, and realize the efficient rejuvenation of amorphous alloy.

Description

Technical Field

[0001] This invention relates to the field of amorphous alloy material processing technology, and more specifically to a method and system for thermomechanical rejuvenation of amorphous alloys. Background Technology

[0002] Amorphous alloys, also known as metallic glasses, are metastable amorphous materials with high strength, high hardness, excellent corrosion resistance, and unique physicochemical properties, making them promising for applications in aerospace, precision instruments, and biomedicine. However, amorphous alloys typically exhibit brittle fracture characteristics at room temperature, limiting their engineering applications.

[0003] In recent years, thermomechanical aging technology for amorphous alloys has provided a new approach to improve their properties. By appropriately modifying mechanical deformation or thermal history, aging amorphous alloys can be restored to a "young" state with higher energy, thereby improving their plasticity and toughness.

[0004] Currently, thermomechanical rejuvenation technology for amorphous alloys mainly employs drastic plastic deformation (such as high-pressure torsion, cold rolling, etc.) or nominal elastic loading methods (such as low-temperature cyclic loading). The principle is to increase the material's free energy by inducing irreversible shear transformation or atomic-scale non-affine rearrangement within the material through stress. However, existing technologies often neglect the influence of cooling kinetics on energy retention after unloading. During the recovery phase after stress unloading, the viscoelastic strain with high energy storage potential generated during loading will recover in large quantities due to spontaneous atomic relaxation. This results in the inability to effectively retain the high-energy reversible micro-shear domains activated during loading and storing local elastic deformation energy within the material. Consequently, the viscoelastic strain energy storage potential is severely wasted, and high-efficiency rejuvenation cannot be achieved. Summary of the Invention

[0005] To address the problems existing in the above-mentioned fields, this invention proposes a thermomechanical aging treatment method and system for amorphous alloys. For the first time, it clarifies the positive correlation between a cooling rate greater than or equal to 0.2 K / min and the amount of viscoelastic strain freezing. By adjusting the cooling rate, the degree of aging can be precisely controlled, thereby achieving precise control over the microstructure and inhomogeneity of amorphous alloys.

[0006] To address the aforementioned technical problems, this invention discloses a method for thermomechanical rejuvenation of amorphous alloys, comprising the following steps: Under isothermal conditions below the glass transition temperature of the amorphous alloy, a creep loading is applied to the amorphous alloy sample to induce viscoelastic strain in the sample. After unloading the stress, the amorphous alloy sample is linearly cooled from the isothermal condition to room temperature at a cooling rate of greater than or equal to 0.2 K / min. The recovery of viscoelastic strain is suppressed by the cooling rate, the frozen residual viscoelastic strain is obtained, and it is frozen inside the amorphous alloy sample to obtain a youthful amorphous alloy. The cooling rate is positively correlated with the residual viscoelastic strain after freezing, and the degree of aging of the aging amorphous alloy is controlled by adjusting the cooling rate.

[0007] Preferably, the cooling rate is 0.2-5 K / min.

[0008] Preferably, obtaining the youthful amorphous alloy further includes evaluating the youthful efficiency of the youthful amorphous alloy, specifically including: By real-time monitoring of the evolution of residual viscoelastic strain over time during the entire creep-recovery process, the total residual viscoelastic strain value after cooling to room temperature is obtained. Based on the total residual strain value, the elastic strain at the moment of unloading is subtracted to obtain the frozen viscoelastic strain. Differential scanning calorimetry was used to perform heating tests on the aged amorphous alloy and obtain the heat flow curve. Baseline correction and integration are performed on the heat flux curve from the relaxation start temperature to the glass transition temperature to obtain the treated state relaxation enthalpy. The difference between the relaxation enthalpy of the treated state and the relaxation enthalpy of the amorphous alloy sample before creep loading is taken as the relaxation enthalpy increment. The ratio of the relaxation enthalpy increment to the frozen viscoelastic strain is used as the rejuvenation efficiency of the youthful amorphous alloy.

[0009] Preferably, the real-time monitoring of the evolution of residual viscoelastic strain over time during the entire creep-recovery process is obtained by monitoring the residual viscoelastic strain-time curve during unloading and cooling processes using a dynamic mechanical analyzer.

[0010] Preferably, the constant temperature condition is 363±30K.

[0011] Preferably, the applied stress is 100±50MPa.

[0012] Preferably, the creep loading time is 30-120 min.

[0013] Preferably, the amorphous alloy sample is any one of the La-Ce-Y-Ni-Al amorphous alloys.

[0014] Preferably, the method makes the residual viscoelastic strain energy storage efficiency per unit freeze more than two orders of magnitude higher than that of the plastic deformation mode.

[0015] Preferably, it further includes an amorphous alloy thermomechanical aging treatment system, comprising: The creep loading module is used to apply stress to an amorphous alloy sample under isothermal conditions below the glass transition temperature of the amorphous alloy to induce viscoelastic strain in the amorphous alloy sample. The module for generating a aging amorphous alloy is used to linearly cool the amorphous alloy sample from isothermal conditions to room temperature at a cooling rate greater than or equal to 0.2 K / min after stress relief. The cooling rate suppresses the recovery of viscoelastic strain, obtains frozen residual viscoelastic strain, and freezes it inside the amorphous alloy sample to obtain a aging amorphous alloy. The cooling rate is positively correlated with the frozen residual viscoelastic strain, and the degree of aging of the aging amorphous alloy is controlled by adjusting the cooling rate.

[0016] Compared with the prior art, the present invention has the following beneficial effects: The thermomechanical rejuvenation method for amorphous alloys proposed in this invention addresses the technical problem of existing technologies neglecting cooling kinetics, which leads to significant recovery of viscoelastic strain after unloading and hinders efficient rejuvenation. This method induces viscoelastic strain in the sample by applying stress under isothermal conditions below the glass transition temperature to induce creep loading. After unloading, the sample is linearly cooled to room temperature at a rate greater than or equal to 0.2 K / min. This cooling rate suppresses the recovery of viscoelastic strain, freezing the residual viscoelastic strain within the sample. Since the cooling rate is positively correlated with the frozen residual viscoelastic strain, the frozen residual viscoelastic strain can be quantitatively controlled by adjusting the cooling rate. This effectively preserves the viscoelastic strain with high energy storage potential generated during loading within the material, achieving efficient utilization of the viscoelastic strain energy storage potential and high-efficiency rejuvenation. Attached Figure Description

[0017] Figure 1 This is a flowchart of the thermomechanical aging treatment method for amorphous alloys proposed in this invention; Figure 2 Detailed steps of the thermomechanical rejuvenation treatment method for amorphous alloys provided in the embodiments of the present invention; Figure 3 The temperature and stress evolution process of the creep-recovery process is shown in the embodiment of the present invention. Figure 4 Strain evolution curves for recovery processes at different cooling rates provided in embodiments of the present invention; Figure 5 The heat flow evolution curves for the recovery process at different cooling rates are provided in the embodiments of the present invention. Figure 6 The evolution of relaxation enthalpy increment with effective applied strain under various mechanical rejuvenation strategies provided in the embodiments of the present invention; Figure 7 A comparison diagram of the rejuvenation efficiency of different mechanical strategies provided in the embodiments of the present invention; Figure 8 An evolution diagram of DMA testing for rejuvenation efficiency provided in an embodiment of the present invention. Detailed Implementation

[0018] The following will refer to the appendices in the embodiments of the present invention. Figures 1-8 The technical solutions in the embodiments of the present invention will be clearly and completely described. It should be understood that the terminology used in the present invention is only for describing particular implementation methods and is not intended to limit the present invention.

[0019] The core of the method proposed in this invention lies in freezing the viscoelastic strain by controlling the cooling rate, thereby achieving controllable adjustment of the rejuvenation degree. Under the aforementioned preferred process parameters (such as La-Ce-Y-Ni-Al alloys, cooling rate 0.2-5 K / min, etc.), the residual viscoelastic strain energy storage efficiency per unit of frozen strain can be more than two orders of magnitude higher than that of plastic deformation. Those skilled in the art will understand that, based on the positive correlation mechanism between cooling rate, frozen strain, and rejuvenation degree disclosed in this invention, even if the efficiency value fluctuates due to differences in material systems or specific process parameters, as long as the viscoelastic strain recovery is suppressed by the cooling rate and frozen inside the sample, it falls within the protection scope of this invention.

[0020] Example like Figure 1 As shown, this invention proposes a method for thermomechanical rejuvenation of amorphous alloys, comprising the following steps: S1: Under isothermal conditions below the glass transition temperature of the amorphous alloy, a creep loading is applied to the amorphous alloy sample to induce viscoelastic strain in the sample. S2: After unloading the stress, the amorphous alloy sample is linearly cooled from the isothermal condition to room temperature at a cooling rate of greater than or equal to 0.2 K / min. The recovery of viscoelastic strain is suppressed by the cooling rate, the frozen residual viscoelastic strain is obtained, and it is frozen inside the amorphous alloy sample to obtain a younger amorphous alloy. Among them, the cooling rate is positively correlated with the residual viscoelastic strain after freezing, and the degree of aging of the aging amorphous alloy can be controlled by adjusting the cooling rate.

[0021] Specifically, in step S1, this embodiment selects one of La, Ce, Y, Ni, and Al alloys (atomic percentage) as the experimental sample.

[0022] Experimental preparation stage The preparation process of this alloy includes melting high-purity elements using titanium as a getter in a high-purity argon atmosphere, and remelting the alloy ingot six times to ensure the chemical homogeneity of the alloy. Subsequently, a glassy ribbon about 1.5 mm wide and 35 micrometers thick was prepared by single-roll melt spinning process to serve as an amorphous alloy sample for the experiment. The surface was slightly polished to remove minor surface impurities, ensuring that the surface of the amorphous alloy sample was flat and crack-free, and avoiding surface defects from affecting the experimental results.

[0023] like Figure 2 As shown, the instrument preparation process includes preparing a commercial dynamic mechanical analyzer and a differential scanning calorimeter (DSC), and calibrating all instruments in advance to ensure that the instrument testing accuracy meets the experimental requirements. The dynamic mechanical analyzer needs to have a continuously adjustable cooling rate of 0.2-5 K / min to achieve tensile film testing mode, while the DSC can achieve a heating rate of 20 K / min. The temperature and stress evolution process of the creep-recovery process is as follows: Figure 3 As shown.

[0024] Experimental steps Specifically, in step S1, in this embodiment, the amorphous alloy sample is fixed on the tensile testing fixture of the dynamic mechanical analyzer (TA Q800). Under the isothermal condition of 363 K (lower than the glass transition temperature Tg≈488 K of the alloy), the sample is subjected to creep loading with stress of 100 MPa for 60 min to ensure that the sample generates sufficient viscoelastic strain. The strain recovery process is completed during the linear cooling process. Typical temperature-stress evolution can be referred to the corresponding experimental spectrum.

[0025] In step S2, the viscoelastic strain introduced by creep loading is approximately 1.5%. After creep completes, the stress is unloaded, and the cooling program of the Dynamic Mechanical Analyzer (DMA) is immediately initiated. Different cooling rates, such as 0.2 K / min, 1 K / min, 3 K / min, and 5 K / min, are set to linearly cool the sample from an isothermal condition of 363 K to room temperature. By rapidly cooling, the recovery of viscoelastic strain is suppressed, and frozen residual viscoelastic strain is obtained. The frozen residual viscoelastic strain is then frozen inside the sample, resulting in a youthful amorphous alloy.

[0026] Selection criteria for cooling rate range Cooling rate is a key process parameter for controlling the aging process of amorphous alloys. It should be noted that the cooling rate set in this invention is not arbitrarily chosen, but is limited to the range of 0.2–5 K / min based on the following technical considerations:

[0027] (1) Determination of the lower limit of cooling rate (≥0.2 K / min) When the cooling rate is below 0.2 K / min, the cooling process from isothermal conditions to room temperature is too slow, allowing sufficient time for spontaneous structural relaxation within the amorphous alloy sample. This results in significant or even complete recovery of the viscoelastic strain with high energy storage potential generated during creep loading. The present invention sets the lower limit of the cooling rate at 0.2 K / min based on the fact that this rate is close to the equilibrium cooling condition. If the cooling rate is below 0.2 K / min (e.g., 0.1 K / min), the viscoelastic strain will have ample time to relax and recover during cooling, causing the residual viscoelastic strain after freezing to near zero, thus failing to achieve an effective aging effect. Therefore, 0.2 K / min is the minimum critical rate for achieving a significant freezing effect.

[0028] (2) Determination of the upper limit of cooling rate (≤5 K / min) When the cooling rate exceeds 5 K / min, it is first limited by the maximum controllable linear cooling rate of the Dynamic Mechanical Analyzer (DMA) used in this invention. Cooling rates exceeding 5 K / min (e.g., 10 K / min or higher) cannot guarantee linear cooling throughout the entire process from isothermal conditions to room temperature, potentially leading to temperature overshoot or uneven cooling, affecting experimental repeatability and data reliability. Secondly, according to the positive correlation between the cooling rate and the frozen residual viscoelastic strain disclosed in this invention, theoretically, more viscoelastic strain can be frozen, thereby obtaining a higher relaxation enthalpy increment. However, limited by the controllable cooling capabilities of existing instruments and equipment, this embodiment uses 5 K / min as an upper limit example. Those skilled in the art, after understanding the positive correlation mechanism of this invention, can select higher cooling rates based on actual equipment conditions, all of which fall within the protection scope of this invention.

[0029] In summary, a cooling rate range of 0.2–5 K / min represents a reasonable balance between effectively suppressing viscoelastic strain recovery and ensuring sample integrity and equipment controllability. Within this range, the cooling rate is significantly positively correlated with the residual viscoelastic strain after freezing. By adjusting the cooling rate, the degree of aging can be quantitatively controlled, achieving a unit strain energy storage efficiency that is more than two orders of magnitude higher than that of plastic deformation. Deviating from this range (below 0.2 K / min or above 5 K / min) makes it difficult to consistently achieve the technical effects of this invention.

[0030] The method proposed in this invention further includes step S3: evaluating the rejuvenation efficiency of the aged amorphous alloy after step S2.

[0031] like Figure 4 As shown, the residual viscoelastic strain-time curve during the entire creep-recovery process is monitored in real time using DMA, and the total residual strain value after cooling to room temperature is obtained.

[0032] Subtract the instantaneous elastic strain ε from the total residual strain value. e Afterwards, the recoverable viscoelastic strain ε is obtained. an and irreversible viscoplastic strain ε vp .

[0033] The frozen viscoelastic strain Δε can be quantified by comparing the residual strain after cooling to room temperature at different cooling rates. For example, when the cooling rate is increased from 0.2 K / min to 5 K / min, the frozen viscoelastic strain increases from about 0% to about 0.6%, accounting for about 40% of the total viscoelastic strain generated during loading.

[0034] Differential scanning calorimetry (DSC) was used to perform heating tests on the aged amorphous alloy and obtain heat flow profiles. The heating rate was set to 20 K / min, and the test temperature range was from 323 K to 873 K (above the crystallization temperature).

[0035] A baseline was obtained using the same empty aluminum disk. Baseline correction was performed on the heat flow curve from the relaxation start temperature to the glass transition temperature. The treated-state relaxation enthalpy ΔH of the sample was calculated by integrating the baseline-corrected heat flow curve (integration range from relaxation start to Tg). 处理态 .

[0036] The as-cast relaxation enthalpy ΔH of the amorphous alloy specimen before creep loading 铸态 Using the reference state, calculate the strain-induced relaxation enthalpy increment: Δ(ΔH) =ΔH 处理态 -ΔH 铸态 ; Here, Δ(ΔH) is a positive value, representing the strength of the rejuvenation effect.

[0037] like Figure 5 As shown, the heat flow evolution curves of the recovery process at different cooling rates are plotted. The horizontal axis T(K) represents the test temperature in K, and the vertical axis Heat flow represents the heat flux in mW / mg. In this embodiment, the relaxation enthalpy increment Δ(ΔH) was measured at different cooling rates of 0.2 K / min, 0.3 K / min, 0.5 K / min, 1 K / min, 2 K / min, 3 K / min, and 5 K / min. Among them, the highest Δ(ΔH) was measured when the cooling rate was 5 K / min, which was 419 J / mol.

[0038] Viscoelastic strain can store considerable energy; therefore, freezing viscoelastic strain can improve the configuration energy of amorphous alloys. Specifically, the relaxation enthalpy increment Δ(ΔH) of the sample after freezing residual viscoelastic strain, measured by calorimetry using the method of this invention, corresponds to the degree of improvement in the configuration energy of the amorphous alloy, i.e., the degree of rejuvenation. The ratio of the relaxation enthalpy increment Δ(ΔH) to the frozen viscoelastic strain is taken as the rejuvenation efficiency.

[0039] It is worth noting that the energy (Δ(ΔH)) stored by the viscoelastic strain freezing method proposed in this invention far exceeds the mechanical work (Work done, WD) input during the loading process, with a ratio as high as 33, demonstrating extremely high energy storage efficiency. The core of the proposed method lies in defining the energy that can be stored per unit of frozen residual viscoelastic strain as the rejuvenation efficiency η, and the formula for calculating η is:

[0040] η =Δ(ΔH) / Δε; Where Δ(ΔH) is the relaxation enthalpy increment in J / mol, and Δε is the viscoelastic strain during freezing (dimensionless).

[0041] By combining Δε obtained from DMA and Δ(ΔH) obtained from DSC, the rejuvenation efficiency under different process parameters can be calculated.

[0042] Calculation results show that the rejuvenation efficiency achieved by the method proposed in this invention (isothermal creep + cooling rate control) is as high as 3.05 × 10⁻⁶. 4 This efficiency far exceeds the rejuvenation efficiency achieved by existing plastic deformation methods, with a difference of 2–4 orders of magnitude. It significantly taps into the energy storage and rejuvenation potential of amorphous alloys, solving the core problem of low rejuvenation efficiency of amorphous alloys in existing technologies.

[0043] like Figure 6 As shown, the evolution of relaxation enthalpy increment with effective applied strain under various mechanical rejuvenation strategies is illustrated. The horizontal axis represents the applied strain, covering a range of eight orders of magnitude from the elastic region to the severe plastic deformation region; the vertical axis represents the relaxation enthalpy increment Δ(ΔH), representing the degree of rejuvenation of the material after mechanical treatment. Figure 6 It can be seen that as the applied strain increases, the relaxation enthalpy increment Δ(ΔH) generally shows an upward trend. Among them, the relaxation enthalpy increment Δ(ΔH) in the low strain region (elastic to slight plastic deformation) increases more slowly, while the relaxation enthalpy increment Δ(ΔH) in the high strain region (such as high pressure torsion, cold rolling and other severe plastic deformation) increases significantly, indicating that severe deformation can effectively improve the enthalpy state of metallic glass.

[0044] like Figure 7The figure shows a comparison of rejuvenation efficiency for different mechanical strategies. The horizontal axis represents Tensile elastostatic loading, Sinusoidal elastic compression, Creep, Cycle-twist, Compressive elastostatic loading, Triaxial compression, Ultrasonic-plastic forming, Cold rolling, Mechanical milling, and High-pressure torsion. The vertical axis represents rejuvenation efficiency. By further comparing different mechanical strategies, it can be seen that the Creep creep loading method proposed in this invention can achieve a rejuvenation efficiency similar to that of cold rolling (strain of about 20%) with only about 0.3% strain.

[0045] Through analysis Figure 6 and Figure 7 It can be seen that the rejuvenation efficiency quantified by the method proposed in this invention is 2-4 orders of magnitude higher than that of severe plastic deformation methods such as high-pressure torsion and cold rolling, demonstrating the significant advantage of the proposed method in improving rejuvenation efficiency. The method proposed in this invention also includes step S4: continuing dynamic mechanical analysis on DMA after freezing viscoelastic strain to explore changes in its micro-relaxation behavior.

[0046] A framework for quantifying rejuvenation efficiency based on reversible and irreversible micro-shear domains is constructed. The frozen viscoelastic strain ε is decomposed into the viscoelastic strain contributed by reversible micro-shear domains and the plastic strain contributed by irreversible micro-shear domains.

[0047] like Figure 8 The figure shows the evolution of DMA testing for rejuvenation efficiency. In this embodiment, the test mode was creep loading with a displacement amplitude of 15 μm, a driving frequency of 1.5 Hz, a heating rate of 3 K / min, and the test temperature range covered the β relaxation region (323 K~500 K). The experimental results are as follows: Figure 8 As shown in (a), the curves of the storage modulus E' and loss modulus E'' of the sample as a function of temperature are obtained in real time. The slope of the curve represents the rejuvenation efficiency η. Calculations show that the rejuvenation efficiency η obtained by the method proposed in this invention through creep loading is η≈3.05×10 4 )Compare Figure 7 Other mechanical strategies, such as high-strain strategies like high-pressure torsion, are about 2 to 4 orders of magnitude higher, demonstrating that inelastic strain has a significantly better intrinsic efficiency than plastic strain in energy storage.

[0048] like Figure 8 As shown in (b)), with the increase of cooling rate (i.e., the increase of frozen viscoelastic strain), the relaxation peak intensity of the sample increases, and the relaxation peak temperature ΔT... β Moving towards lower temperatures, the effects of different mechanical strategies on the β-relaxation peak temperature were summarized and compared. It can be seen that the method proposed in this invention (creep within the viscoelastic strain range) has a similar effect on regulating the β-relaxation peak temperature as cold rolling (plastic strain ~20%), demonstrating its unique advantages in regulating atomic-scale structural inhomogeneity and dynamics.

[0049] Establishment of a youth-oriented framework Amorphous alloys accommodate viscoelastic and viscoplastic deformations through the formation and expansion of micro-shear domains. The viscoelastic strain and viscoplastic strain rates can be expressed as: ; ; in, n ( t () represents the number of micro-shear domains per unit volume. τ and τ It refers to relaxation and relaxation time. It is the volume fraction of the material. It represents the local shear strain when a single micro-shear domain is activated, and is the sample volume. Viscoelasticity corresponds to the reversible activation of the micro-shear domains, and to relaxation, with its density... ρ r This can be deduced as:

[0050] ; Energy stored in reversible sheared micro domains (SMDs) Mainly from β The elastic deformation energy of the local shear micro-region during relaxation can be described by the following equation: ; in, for β Relaxation activation energy; irreversible shear transformation occurs when micro-shear domains fuse together, resulting in permanent deformation. Irreversible micro-shear domains (SMDs) ρ ir The density is determined by relaxation:

[0051] ; Irreversible micro-shearing domains dissipate energy and are accompanied by heat release: ; in, For heat release, This is the relaxation activation energy. Based on this case, the reversible micro-shear domain density can be calculated from the creep results. irreversible micro-shearing domain density It can be calculated based on the high-pressure torsion results. This is consistent with the typical density of the shear transition region.

[0052] Based on the shear microregion in the quasi-point defect theory, it is clarified that the viscoelastic energy storage and rejuvenation limit originate from the transformation from reversible β relaxation to irreversible α relaxation. This breaks through the limitations of the traditional fictional temperature paradigm, provides a new theoretical perspective for the study of the rejuvenation mechanism of amorphous alloys, and enriches the theoretical system of thermomechanical processing of amorphous alloys.

[0053] This method addresses the technical challenges of quantitatively comparing the contributions of different strain types (elastic, viscoelastic, and plastic) to rejuvenation in existing amorphous alloy rejuvenation processes, and the lack of a unified evaluation standard for rejuvenation effects. By achieving controllable freezing and precise quantification of viscoelastic strain, and establishing a cross-strain region comparison system based on energy storage efficiency, this invention fills the technical gap in the quantitative evaluation framework for the thermomechanical rejuvenation of amorphous alloys. It provides a quantifiable and comparable technical basis for evaluating the effects of different rejuvenation strategies and optimizing processes, significantly improving the scientific rigor and operability of rejuvenation process design and optimization.

[0054] In summary, the method proposed in this invention successfully achieves ultra-efficient rejuvenation of amorphous alloys by precisely controlling the cooling rate to freeze creep-induced viscoelastic strain. This method is simple to operate, highly effective, and establishes a complete theoretical framework from macroscopic efficiency to microscopic mechanisms, opening up new pathways for the performance optimization and engineering applications of amorphous alloys.

[0055] This invention also proposes a thermomechanical aging treatment system for amorphous alloys, comprising: The creep loading module is used to apply stress to amorphous alloy samples under isothermal conditions below the glass transition temperature of amorphous alloys to induce viscoelastic strain in the amorphous alloy samples. After unloading the stress, the amorphous alloy sample was linearly cooled from the isothermal condition to room temperature at a cooling rate of greater than or equal to 0.2 K / min. The recovery of viscoelastic strain was suppressed by the cooling rate, the frozen residual viscoelastic strain was obtained, and it was frozen inside the amorphous alloy sample to obtain a younger amorphous alloy. Among them, the cooling rate is positively correlated with the residual viscoelastic strain after freezing, and the degree of aging of the aging amorphous alloy can be controlled by adjusting the cooling rate.

[0056] The method proposed in this invention combines dynamic mechanical analysis with calorimetry to construct a comprehensive model of rejuvenation efficiency spanning the elastic to plastic strain range (8 orders of magnitude of strain). It can clearly distinguish the contributions of elastic and plastic deformation to rejuvenation efficiency, fill the technical gap in the lack of a quantitative evaluation framework for strain-induced rejuvenation efficiency of amorphous alloys in the prior art, and provide a reliable method for the accurate measurement of rejuvenation efficiency.

[0057] The established quantitative index of rejuvenation efficiency provides a general reference for the design and optimization of mechanical rejuvenation strategies for amorphous alloys. It is applicable to the research and development and application of technologies related to thermomechanical processing, energy storage and rejuvenation of amorphous alloys, and can promote the industrial application of amorphous alloys in related fields. It has broad practicality and promotional value.

[0058] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

[0059] Furthermore, unless otherwise stated, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. All references to this specification are incorporated by way of citation to disclose and describe methods relating to those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

Claims

1. A method for thermomechanical rejuvenation of amorphous alloys, characterized in that, Includes the following steps: Under isothermal conditions below the glass transition temperature of the amorphous alloy, a creep loading is applied to the amorphous alloy sample to induce viscoelastic strain in the sample. After unloading the stress, the amorphous alloy sample is linearly cooled from the isothermal condition to room temperature at a cooling rate of greater than or equal to 0.2 K / min. The recovery of viscoelastic strain is suppressed by the cooling rate, the frozen residual viscoelastic strain is obtained, and it is frozen inside the amorphous alloy sample to obtain a youthful amorphous alloy. The cooling rate is positively correlated with the residual viscoelastic strain after freezing, and the degree of aging of the aging amorphous alloy is controlled by adjusting the cooling rate.

2. The thermomechanical aging treatment method for amorphous alloys according to claim 1, characterized in that, The cooling rate is 0.2-5 K / min.

3. The thermomechanical aging treatment method for amorphous alloys according to claim 1, characterized in that, The process of obtaining the youthful amorphous alloy further includes evaluating the youthful efficiency of the youthful amorphous alloy, specifically including: By real-time monitoring of the evolution of residual viscoelastic strain over time during the entire creep-recovery process, the total residual viscoelastic strain value after cooling to room temperature is obtained. Based on the total residual strain value, the elastic strain at the moment of unloading is subtracted to obtain the frozen viscoelastic strain. Differential scanning calorimetry was used to perform heating tests on the aged amorphous alloy and obtain the heat flow curve. Baseline correction and integration are performed on the heat flux curve from the relaxation start temperature to the glass transition temperature to obtain the treated state relaxation enthalpy. The difference between the relaxation enthalpy of the treated state and the relaxation enthalpy of the amorphous alloy sample before creep loading is taken as the relaxation enthalpy increment. The ratio of the relaxation enthalpy increment to the frozen viscoelastic strain is used as the rejuvenation efficiency of the youthful amorphous alloy.

4. The thermomechanical aging treatment method for amorphous alloys according to claim 1, characterized in that, The real-time monitoring of the evolution of residual viscoelastic strain over time during the entire creep-recovery process is obtained by monitoring the residual viscoelastic strain-time curve during unloading and cooling processes using a dynamic mechanical analyzer.

5. The thermomechanical aging treatment method for amorphous alloys according to claim 1, characterized in that, The constant temperature condition is 363±30K.

6. The thermomechanical aging treatment method for amorphous alloys according to claim 1, characterized in that, The applied stress is 100±50MPa.

7. The thermomechanical aging treatment method for amorphous alloys according to claim 1, characterized in that, The creep loading time is 30-120 min.

8. The thermomechanical aging treatment method for amorphous alloys according to claim 1, characterized in that, The amorphous alloy sample is any one of the La-Ce-Y-Ni-Al amorphous alloys.

9. The thermomechanical aging treatment method for amorphous alloys according to claim 1, characterized in that, The method enables the residual viscoelastic strain energy storage efficiency of a unit freeze to be more than two orders of magnitude higher than that of the plastic deformation method.

10. A thermomechanical aging treatment system for amorphous alloys, characterized in that, include: The creep loading module is used to apply stress to an amorphous alloy sample under isothermal conditions below the glass transition temperature of the amorphous alloy to induce viscoelastic strain in the amorphous alloy sample. The module for generating a aging amorphous alloy is used to linearly cool the amorphous alloy sample from isothermal conditions to room temperature at a cooling rate greater than or equal to 0.2 K / min after stress relief. The cooling rate suppresses the recovery of viscoelastic strain, obtains frozen residual viscoelastic strain, and freezes it inside the amorphous alloy sample to obtain a aging amorphous alloy. The cooling rate is positively correlated with the frozen residual viscoelastic strain, and the degree of aging of the aging amorphous alloy is controlled by adjusting the cooling rate.

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