Stress cycle apparatus for reducing hardness of amorphous alloys and applications thereof

Abstract

The application discloses a stress cycle device for reducing hardness of amorphous alloy and application thereof. The stress cycle device comprises three-arm connecting rods, a center connecting seat and three connecting rods fixedly connected to the center connecting seat and uniformly distributed in a 120-degree direction; a rolling bearing is fixedly connected to the end of the connecting rod; a driving motor is rigidly connected to the center connecting seat through a shaft connection structure; and a conveying platform is used for bearing and conveying the amorphous alloy strips to be treated. The stress cycle device is used for bearing and conveying the amorphous alloy strips to be treated by the conveying platform, the three connecting rods are rotated under the driving of the driving motor, the rolling bearings periodically roll and contact the amorphous alloy strips in the rotating process, and stress cycle loading on the amorphous alloy strips is realized.

Description

Technical Field

[0001] This invention relates to the field of amorphous alloy hardness control technology, specifically to a stress cycling device for reducing the hardness of amorphous alloys and its application. Background Technology

[0002] Iron-based amorphous alloys are a class of metallic materials without long-range ordered structures, prepared through rapid solidification processes. Their atomic arrangement exhibits typical amorphous characteristics. Due to the lack of traditional defect structures such as grain boundaries and dislocations, iron-based amorphous alloys typically possess high strength, high resistivity, low iron loss, and excellent soft magnetic properties, making them promising for applications in power electronics, transformer cores, inductors, motors, precision instruments, and structural applications. However, the rapid cooling process, while freezing the disordered structure, also retains a significant amount of structural energy and free volume within the material. This inevitably places the amorphous alloy in a metastable structural state with high internal stress and high energy. This structural characteristic results in macroscopically high hardness, insufficient local plasticity, and sensitivity to external stresses, affecting subsequent processing performance, flexibility, and reliability, and making them prone to cracking or brittle fracture, thus limiting their engineering applications. Therefore, how to reduce hardness and weaken internal stress without destroying the disordered amorphous structure is a crucial problem that urgently needs to be solved in the practical application of amorphous materials.

[0003] Existing methods for controlling hardness primarily rely on high-temperature annealing, which involves heating the material near its glass transition temperature to induce a shift in atomic structure towards lower energy states, thereby reducing internal stress and improving processing performance. This process is often categorized as structural relaxation. However, from a materials physics perspective, structural relaxation corresponds to the system's transition to even lower energy states, often accompanied by a reduction in free volume and structural densification. While this can reduce internal stress, it can also lead to localized hardening or decreased plasticity. Although high-temperature annealing can promote structural softening and reduce hardness to some extent, it also presents the following significant problems: (1) High-temperature treatment can easily cause surface or local crystallization, which will destroy the unique structure and properties of amorphous alloys and reduce their soft magnetic properties. If the temperature is not properly controlled, it may cause primary crystallization or nanocrystal precipitation, thereby destroying the amorphous structure and deteriorating its soft magnetic properties.

[0004] (2) The annealing process significantly reduces the toughness of the material and causes embrittlement, especially in iron-based amorphous alloys.

[0005] (3) It requires high temperature control accuracy, consumes a lot of energy, has high cost, has a narrow process window, and is difficult to achieve continuous processing.

[0006] (4) For strip or film materials, high-temperature annealing can easily cause warping, uneven thickness, unstable dimensions, deformation and deterioration of mechanical properties, which restricts their processing and use.

[0007] Furthermore, some studies have attempted to achieve structural changes using methods such as ion irradiation and laser shock. These methods inject high energy into the material through an external field to induce structural changes, which can alter material properties to some extent. However, these methods involve complex equipment, high costs, and are not continuous, and the energy input is difficult to control precisely, potentially introducing material damage or surface defects, making them unsuitable for large-scale processing in engineering applications. In summary, there is an urgent need for a new method and apparatus that can effectively reduce the hardness of iron-based amorphous alloys at room temperature or even low temperatures, avoid embrittlement and crystallization, ensure safe and controllable processing, and enable continuous strip processing. Therefore, this invention aims to solve the following core technical problems: (1) Effectively reduce the hardness of iron-based amorphous alloys without raising the temperature or avoiding high temperature conditions.

[0008] (2) To achieve controllable, stable and repeatable periodic mechanical stress on amorphous strips to induce room temperature structural changes.

[0009] (3) Ensure that the stress loading process does not cause damage to the material, crystallization, or significant temperature rise.

[0010] (4) Construct a room temperature or even low temperature mechanical loading system that can achieve continuous processing and is suitable for industrial application of long strip materials.

[0011] Further analysis from the perspective of structural regulation mechanisms reveals that recent studies have shown another type of process, amorphous rejuvenation, which, in contrast to traditional structural relaxation, involves external mechanical or physical stimulation to induce amorphous systems to transition to higher energy states, significantly altering the local structural state of the material. During rejuvenation, shear transformation zones (STZs) or free volumes within the material are activated and restructured, increasing the number of local soft regions and resulting in higher overall plasticity and lower macroscopic hardness. This mechanism provides a new approach to reducing the hardness of amorphous alloys without relying on high temperatures; however, currently, there is a lack of an engineered device and a continuous implementation method to stably and controllably achieve this process.

[0012] Therefore, developing a technical method based on mechanical stress cycling that can stably induce the rejuvenation of amorphous structures, increase the distribution of soft areas, and reduce hardness at room temperature, while possessing low energy consumption, no thermal damage, and a device system suitable for continuous processing of strip materials, is of great significance for expanding the engineering applications of iron-based amorphous alloys.

[0013] The following existing technologies were found through a search: Patent specification CN120536683A discloses a method for optimizing the soft magnetic properties of iron-based amorphous alloys through cyclic stress annealing. This method induces relaxation of the amorphous structure by applying periodic mechanical stress instead of heat treatment. The technical steps are: applying periodic stress to the iron-based amorphous alloy to induce periodic strain in the sample, with the peak strain ≤2% and the valley strain lower than the peak. Stress cycling is performed at low temperature to improve soft magnetic properties and avoid annealing embrittlement. The stress can be applied through bending, tension, or other forms. This prior art proposes that mechanical stress can induce structural relaxation at low temperatures, focusing on improving the soft magnetic properties of the material (such as reducing coercivity), and achieving material optimization by applying periodic strain. However, this prior art does not provide a specific device to support it, nor does it solve the following key problems: it does not address how to stably, controllably, and continuously generate periodic stress; it does not provide a specific device structure, making it difficult to guarantee the repeatability of the stress waveform; it is not applicable to continuous strip processing scenarios, failing to meet industrial production needs; it does not solve the problem of local crystallization caused by heat generated by friction; and it lacks a device design and engineering implementation specifically for controlling the hardness of amorphous materials. Therefore, although this technology proposes the effect of periodic mechanical stress on amorphous materials, it does not provide an engineering-feasible device, nor does it solve the core pain points in the hardness control process.

[0014] Currently, common cyclic loading equipment in the field of metal processing includes reciprocating fatigue testing machines, rotary load testing machines, and pressure roller mechanical extrusion equipment. However, these devices have the following problems: the stress waveform is uncontrollable or unsuitable for sub-yield loading of amorphous materials; they are mainly used for fatigue failure, not for structural relaxation or hardness control; the equipment is large in size, making it unsuitable for thin strip light-load scenarios; it is difficult to achieve low-friction, high-stability rolling contact; and it is unsuitable for processing continuous long strip materials. Therefore, they cannot be directly used for low-temperature hardness control of amorphous alloys. Summary of the Invention

[0015] To address the aforementioned technical problems and shortcomings in this field, the present invention provides a stress cycling device for reducing the hardness of amorphous alloys and its application. By designing a special periodic stress loading device consisting of a drive motor, a rotating three-arm connecting rod, and rolling bearings, the present invention achieves stable periodic stress disturbance on the amorphous strips on a conveyor belt. This allows the amorphous alloy to undergo reversible structural rejuvenation at room temperature, thereby significantly reducing hardness and improving mechanical flexibility. This provides a novel, low-energy-consumption, and highly stable technical route for the performance control of amorphous materials.

[0016] The specific technical solution of this invention is as follows: In a first aspect, the present invention provides a stress cycling device for reducing the hardness of amorphous alloys, comprising: The three-arm linkage includes a central connecting seat and three connecting rods that are fixedly connected to the central connecting seat and evenly distributed at 120° along the circumference; the ends of the connecting rods are fixedly connected to rolling bearings. The drive motor is rigidly connected to the central connecting seat via a coupling structure; A conveyor platform is used to carry and transport amorphous alloy strips to be processed.

[0017] In some preferred embodiments, the stress circulation device further includes a stress circulation control module; The stress cycle control module is used to control the operating status and speed of the drive motor in real time, as well as to monitor the frequency and stability of the stress loading process.

[0018] In a second aspect, the present invention provides the application of the stress cycling device described in the first aspect for reducing the hardness of amorphous alloys.

[0019] In some preferred embodiments, the amorphous alloy is a FeSiB series amorphous alloy, a ZrCuAlNi series amorphous alloy, or a MgNiNd series amorphous alloy.

[0020] In some preferred embodiments, the FeSiB series amorphous alloys are expressed as Fe in atomic ratio form. 82 Si 3.6 B 8.4 P 3.6 Ni 1.2 Mo 0.2 Cu1.

[0021] In some preferred embodiments, ZrCuAlNi series amorphous alloys are expressed in atomic ratio as Zr 65 Cu 15 Al 10 Ni 10 .

[0022] In some preferred embodiments, the MgNiNd series amorphous alloys are expressed as Mg... 66 Ni 20 Nd 14 .

[0023] Thirdly, the present invention provides a method for reducing the hardness of amorphous alloys, comprising: Using the stress cyclic device described in the first aspect, the conveying platform carries and transports the amorphous alloy strip to be processed. The three connecting rods rotate under the drive of the drive motor. During the rotation, the rolling bearing periodically rolls and contacts the amorphous alloy strip, thereby realizing the stress cyclic loading on the amorphous alloy strip.

[0024] In some preferred embodiments, the amorphous alloy is a FeSiB series amorphous alloy, a ZrCuAlNi series amorphous alloy, or a MgNiNd series amorphous alloy.

[0025] In some preferred embodiments, the FeSiB series amorphous alloys are expressed as Fe in atomic ratio form. 82 Si 3.6 B 8.4 P 3.6 Ni 1.2 Mo 0.2 Cu1.

[0026] In some preferred embodiments, ZrCuAlNi series amorphous alloys are expressed in atomic ratio as Zr 65 Cu 15 Al 10 Ni 10 .

[0027] In some preferred embodiments, the MgNiNd series amorphous alloys are expressed as Mg... 66 Ni 20 Nd 14 .

[0028] In some preferred embodiments, the drive motor speed is 1~10 r / min, the loading period (from the start of contact between the rolling bearing and the amorphous alloy strip to its departure from the amorphous alloy strip) is 2~20 s, and the peak loading strain is 0.2%~0.5%. The peak strain can be calculated by the ratio of the maximum elongation of the gauge length of the specimen to the initial gauge length. Actual measurements can be taken using extensometers, displacement sensors, high-speed cameras / DIC digital images, etc.

[0029] In some preferred embodiments, the method for reducing the hardness of the amorphous alloy is carried out at 0~30°C, such as 5°C, 10°C, 15°C, 20°C, 25°C, etc.

[0030] In some preferred embodiments, the amorphous alloy strip of the present invention has a thickness of 20~40 μm and a width of 1~5 mm.

[0031] Compared with the prior art, the beneficial effects of this invention are as follows: This invention addresses the problems of crystallization risk, uncontrollable energy input, and discontinuous processes associated with existing methods for controlling the hardness of amorphous alloys, which primarily rely on heat treatment or irradiation. It proposes a novel control approach based on periodic mechanical stress cycling. By constructing a collaborative loading structure of a drive motor, a three-arm connecting rod, and rolling bearings, continuous rotational motion is converted into a stable and adjustable stress pulse input, coupled with a conveyor belt system. This allows the amorphous strip to continuously undergo loading-unloading cycles during its movement. During this process, periodic mechanical excitation inputs appropriate energy into the amorphous system, activating the shear transition region and inducing local structures to transition to higher energy states, thereby producing a structural rejuvenation effect. This increases the number and more uniform distribution of soft regions within the material, ultimately resulting in an effective reduction in macroscopic hardness. Because a rolling contact method is used, almost no frictional heat is introduced during stress loading, fundamentally avoiding structural relaxation or crystallization problems caused by temperature rise, thus achieving a non-thermal control path dominated by pure mechanical energy.

[0032] Furthermore, this invention, through coordinated adjustment of motor speed, connecting rod structural parameters, bearing dimensions, and conveyor belt speed, can achieve precise control of stress frequency, amplitude, and duration, enabling the material's structural evolution process to possess excellent designability and repeatability. Simultaneously, the device employs continuous conveying and online loading, making it more suitable for large-scale processing of long strips and rolls compared to traditional batch processing methods, significantly improving processing efficiency and consistency. Without altering the material composition or relying on high temperatures or complex equipment, this invention achieves stable control of the hardness of amorphous alloys, combining low energy consumption, high safety, and good engineering applicability, providing a valuable new technological path for optimizing the performance of amorphous materials. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of a stress cycling device for reducing the hardness of amorphous alloys according to the present invention.

[0034] Figure 2 for Figure 1 The diagram shows a top view of the stress circulation device.

[0035] Figure 3 for Figure 1 The diagram shows a left-side view of the stress circulation device.

[0036] Figure 4 for Figure 1 Schematic diagram of the cross-sectional structure of BB.

[0037] Figure 5 This is a schematic diagram of a periodic stress waveform applied to an amorphous alloy strip using the stress cycling device of the present invention.

[0038] Figure 6This is a graph showing the hardness change of FeSiB series amorphous alloy strips after being treated with different stress cycles.

[0039] Figure 7 This is a graph showing the hardness change of ZrCuAlNi series amorphous alloy strips after being treated with different stress cycles.

[0040] Figure 8 This is a graph showing the hardness change of MgNiNd series amorphous alloy strips after being treated with different stress cycles. Detailed Implementation

[0041] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Operating methods not specifically specified in the following embodiments are generally performed under conventional conditions or as recommended by the manufacturer.

[0042] Iron-based amorphous alloys form high-energy, non-equilibrium structures during rapid solidification, containing significant residual internal stresses, resulting in high hardness and poor flexibility. To improve their machinability, structural control is typically required. Existing technologies primarily rely on hot annealing to achieve so-called structural relaxation, i.e., promoting atomic rearrangement to lower energy states through heating. However, causal analysis reveals that this method essentially uses thermal energy as the main driving force. While thermal energy promotes structural evolution, it also inevitably provides conditions for crystallization. Therefore, as the temperature approaches the effective control range, the risk of crystallization increases significantly, creating an inherent contradiction between the need for sufficient energy to promote structural change and the necessity to suppress crystallization, thus resulting in an extremely narrow process window. Furthermore, the reduction in free volume and structural densification caused by hot annealing makes the material locally more stable but also more brittle. Even without crystallization, it may lead to a decrease in toughness. This structural evolution path, determined by the energy input method, limits its effectiveness in balancing hardness reduction and mechanical property optimization.

[0043] Meanwhile, thermal annealing is a holistic heating process, and its energy input lacks spatial selectivity and is difficult to dynamically control, making it unsuitable for continuous processing of strips or rolls. For thin strip materials, it can easily cause problems such as warping, deformation, and redistribution of internal stress. To avoid the adverse effects of high temperatures, some technologies use high-energy beam methods such as ion irradiation or laser shock for structural control. However, these methods are essentially high-energy-density instantaneous inputs, often resulting in surface damage, local over-excitation, or even micro-area melting, making it difficult to achieve stable and controllable performance adjustment while ensuring material integrity. Therefore, fundamentally, the shortcomings of existing technologies stem from their energy input methods either being primarily thermal, making it difficult to avoid the risks of crystallization and embrittlement, or having excessively high energy densities, making non-destructive control difficult, and generally lacking stable execution structures suitable for continuous processing.

[0044] Based on the above analysis, the purpose of this invention is to provide a novel technical approach for controlling the hardness of amorphous alloys. By constructing a loading device based on periodic mechanical stress, an appropriate amount of mechanical energy is input into the material in a controllable manner at room temperature or low temperature, inducing a rejuvenation process in the amorphous structure instead of the traditional thermal relaxation process, thereby achieving hardness reduction while avoiding crystallization and significant embrittlement. Furthermore, this invention uses a three-arm connecting rod and rolling bearings to form a stable periodic stress loading mechanism, achieving a regular output of stress pulses. Combined with a conveyor belt system, it enables continuous processing of strip materials, ensuring good controllability and repeatability of stress input in both time and space. Simultaneously, the rolling contact method reduces friction and temperature rise, ensuring that the material does not suffer thermal damage or surface deterioration during processing. Therefore, this invention aims to solve the problem of existing technologies being unable to simultaneously achieve low-temperature control, structural stability, and continuous processing, establishing a new method for controlling the performance of amorphous alloys that is low-energy-consumption, highly controllable, and suitable for engineering applications.

[0045] This invention provides a periodic stress cycling device and its application method for hardness control of amorphous alloy strips, such as those based on iron. The device uses a drive motor to continuously rotate a three-arm linkage structure, causing rolling bearings mounted at the ends of the linkages to periodically contact and compress the amorphous strip running on a conveyor belt along a predetermined trajectory. This introduces stable and repeatable mechanical stress pulses onto the material surface, inducing controllable structural changes and atomic rearrangements in the amorphous structure, thereby effectively reducing the material's hardness. By transforming continuous rotational motion into a discrete, rhythmic loading process, this invention provides highly controllable stress input in both time and space. It not only avoids the crystallization risks associated with traditional heat treatment but also enables high-precision mechanical control of amorphous strips at room temperature. The device boasts advantages such as simple structure, strong applicability, and ease of engineering integration. The periodic stress cycling device consists of a drive actuator, a rotating three-arm linkage structure, a rolling contact loading unit, a conveyor platform, and a stress cycling control module. These components work together to achieve stable stress control.

[0046] Combination Figures 1 to 4 A stress-recycling device for reducing the hardness of amorphous alloys includes a three-arm linkage, a drive motor 1, a conveying platform (not shown), and a stress-recycling control module (not shown). The three-arm linkage includes a central connecting seat 2 and three connecting rods 3 fixedly connected to the central connecting seat 2 and evenly distributed at 120° intervals along the circumference, forming a periodically symmetrical spatial structure. Rolling bearings 4 are fixedly connected to the ends of the connecting rods 3. The drive motor 1 is rigidly connected to the central connecting seat 2 via a coupling structure. The conveying platform carries and transports the amorphous alloy strip 5 to be processed. The stress-recycling control module controls the operating status and speed of the drive motor 1 in real time, and monitors the frequency and stability of the stress loading process.

[0047] The drive motor 1, as the power source, can be a speed-adjustable motor, outputting continuous and adjustable rotational power during operation. The motor speed can be precisely adjusted through an external control module (stress cycle control module), thereby directly determining the frequency of stress pulses and controlling the material loading rhythm. By changing the speed, different loading modes, ranging from low-frequency slow disturbances to high-frequency rapid impacts, can be achieved over a wide range to adapt to amorphous alloys with different compositions or structural states.

[0048] The three-arm linkage structure ensures that the three loading units enter the contact state sequentially during rotation, thereby forming a stable phase difference in time and achieving continuous and uniform periodic stress output. The length and geometry of linkage 3 can be adjusted according to actual usage requirements to adapt to different equipment layouts and loading amplitude requirements.

[0049] The end of connecting rod 3 is equipped with a standardized mounting interface (connection hole) for fixing the rolling bearing 4. At the same time, the rounded corner design reduces stress concentration and improves structural reliability and service life. The entire connecting rod 3 can be made of lightweight, high-strength materials.

[0050] The rolling bearing 4, acting as a stress-loading unit directly on the surface of the amorphous alloy strip 5, moves along a circular trajectory driven by a three-arm connecting rod and periodically presses against the surface of the amorphous alloy strip 5. The outer ring of the bearing is finely polished, providing a stable and uniform local pressure distribution during contact. Simultaneously, the rolling contact significantly reduces frictional resistance and heat accumulation, preventing material property fluctuations due to localized temperature rises. During rotation, the three bearings sequentially contact and separate from the strip, subjecting the material surface to a typical loading-unloading-reloading cyclic stress process, thus forming a regularly repeating mechanical pulse input. This discrete stress application method, compared to continuous pressing, is more conducive to stimulating the activity of local shear transition regions within the amorphous alloy, promoting the evolution of atomic structure towards higher energy states.

[0051] The conveyor platform can adopt a flat belt or roller structure to ensure that the strip remains flat and stable within the loading area. The conveyor platform includes a conveyor belt, on which the amorphous alloy strip 5 is placed. The conveyor belt operates at a constant speed through an independent drive system, and its speed is adjustable, thereby controlling the residence time of the material within the stress loading area and the total number of cycles. By coordinating the motor speed and the conveyor belt speed, precise control over the number of load cycles and stress history at a single location can be achieved, giving the entire process good repeatability and adjustability. Furthermore, the height or support position of the conveyor platform can also be fine-tuned to change the bearing's pressure on the strip, thereby further controlling the stress amplitude.

[0052] In practical implementation, the stress cycle control module can be connected to a frequency converter or speed controller to achieve closed-loop control of the loading frequency by setting speed parameters, thereby ensuring the synchronization and stability of the three-arm linkage during operation. Based on the device's geometric relationship, when the motor runs at a certain speed, the three bearings will sequentially complete three loading processes per revolution. Therefore, the stress pulse frequency has a linear relationship with the motor speed, giving the system good predictability and adjustability.

[0053] Use the above Figures 1 to 4 The stress cyclic device shown has a conveyor platform that carries and transports the amorphous alloy strip 5 to be processed. Three connecting rods 3 rotate under the drive of a drive motor 1. During rotation, rolling bearings 4 periodically roll into contact with the amorphous alloy strip 5, achieving cyclic stress loading on the amorphous alloy strip 5. The three connecting rods 3, during rotation, drive the three rolling bearings 4 to sequentially roll into contact with the surface of the amorphous alloy strip 5 along a circumferential trajectory, applying periodic mechanical stress to the amorphous alloy strip 5 and thus controlling the material hardness.

[0054] Figure 5 A schematic diagram of a periodic stress waveform applied to an amorphous alloy strip using the stress cycling device of this invention is provided. The figure illustrates the stress pulse waveform generated by the three-arm linkage structure using an idealized linear black-and-white diagram. The stress peak corresponds to the moment when the rolling bearing presses the strip to its lowest point, and the trough corresponds to the material returning to a state without external force when the bearing leaves the strip. Because the three-arm structure is uniformly distributed at 120° intervals, the stress pulses are periodically stable, and the waveform repeats at equal intervals. This figure shows the key characteristics of periodic stress: the pulse interval is determined by the motor speed; the pulse amplitude is determined by the linkage radius, bearing type, and contact pressure; and the waveform has high repeatability, making it suitable for material structure relaxation studies and continuous industrial processing.

[0055] In addition to the number of loops, Figures 6 to 8 All experiments used the same loading conditions: the drive motor speed was 3.33 r / min, corresponding to a stress cycle frequency of approximately 0.167 Hz; the loading period was 6 s; the peak strain was approximately 0.30%; the strain rate was approximately 0.1% / s; the rolling bearing diameter was 16 mm; and the conveyor platform was used for fixed-point loading. By keeping the above parameters constant and only changing the number of stress cycles, the following results were obtained: Figures 6 to 8 The results show the hardness variations of different amorphous alloys.

[0056] To further illustrate the effect of the stress cycling device of the present invention on the control of hardness of amorphous alloys of different systems, the following specific operating method is used to obtain... Figures 6 to 8 The experimental results are shown.

[0057] First, prepare or provide materials with a nominal composition of Fe. 82 Si 3.6 B 8.4 P 3.6 Ni 1.2 Mo 0.2 Cu1, Zr 65 Cu 15 Al 10 Ni 10 and Mg 66 Ni 20 Nd 14 Amorphous alloy strips were prepared. All components are expressed as atomic percentages. The alloy raw materials were weighed according to the target composition and melted under a high-purity argon protective atmosphere to form a master alloy ingot. Subsequently, amorphous alloy strips were prepared using a single-roll rapid quenching method. The preferred thickness of the obtained strips was 20–40 μm, and the preferred width was 1–5 mm. X-ray diffraction analysis was performed on the obtained strips to confirm the presence of only amorphous diffuse scattering peaks and no obvious crystalline diffraction peaks. The strips were then cut into samples with a length of not less than 200 mm. Before processing, the strip surface was cleaned with anhydrous ethanol and allowed to air dry to remove surface oil, dust, and other contaminants.

[0058] Before stress cycling, the amorphous alloy strip to be treated is placed flat on the support surface of the conveyor platform, ensuring that the length direction of the strip is aligned with the rolling direction of the rolling bearing, and guaranteeing that the strip has no obvious warping, wrinkles, or offset within the loading area. To obtain... Figures 6 to 8 The cycle number-hardness relationship shown indicates that the strip to be tested is kept in a fixed position relative to the loading mechanism during the process. After the predetermined number of cycles is completed, the loading is stopped and the strip is removed for testing.

[0059] Before loading, adjust the height of the conveyor platform or the loading clearance between the rolling bearing and the strip. Use the position where the outer ring of the rolling bearing just contacts the strip surface without leaving a noticeable indentation as the zero point. Then, fine-tune the pressure by adjusting the height of the support platform or the position of the loading mechanism. The loading conditions are preferably calibrated through pre-experiments, ensuring that the peak strain of the amorphous alloy strip during loading is approximately 0.3%. Peak strain can be obtained by attaching strain gauges to the surface of a calibrated strip of the same specification or by using a displacement-load calibration method; peak stress can be calibrated by placing a thin force sensor or pressure sensor below the support surface. During processing, avoid any visible cracks, permanent creases, or breakage of the strip.

[0060] By adjusting the drive motor speed, the loading cycle is made approximately 6 seconds, corresponding to a stress cycle frequency of approximately 0.167 Hz. In the three-arm linkage structure, each rotation of the motor generates three stress cycles, therefore the motor speed is approximately 3.33 r / min. The strain rate during loading is approximately 0.1% / s, and the peak strain of a single load-unload cycle is approximately 0.30%. During loading, the amorphous alloy strip is subjected to periodic load-unload stress pulses; an example of the loading waveform is shown below. Figure 5 As shown. The entire process is carried out at room temperature, preferably 20~25 ℃. During the process, an infrared thermometer or thermocouple can be used to monitor the surface temperature of the strip. The surface temperature rise of the strip should preferably not exceed 5 ℃ to eliminate the dominant influence of heat treatment or friction heating on the change in material hardness.

[0061] In the three sets of experiments mentioned above, the nanoindentation method is preferred for hardness testing. A Berkovich diamond indenter is used during testing, with a maximum load preferably of 4 mN, or the maximum indentation depth controlled to not exceed one-tenth of the strip thickness to avoid the influence of the substrate effect on the test results. At least eight different locations are selected for indentation testing for each cycle of the sample, with a minimum spacing of 20 μm between adjacent indentations and a minimum distance of 50 μm from the strip edge. After removing invalid data due to surface defects, edge effects, or abnormal load-displacement curves, the average value and standard deviation of the effective indentation hardness are calculated, and the average value is used as the standard deviation. Figures 6 to 8The data points are represented using the standard deviation as the error bar. After stress cycling, the strip is removed and its hardness is tested. A nanoindenter is preferred. Experiments show that the strip hardness gradually decreases with increasing stress cycle count. Figures 6 to 8 .

[0062] Figures 6 to 8 This diagram illustrates the changes in hardness of amorphous alloy strips in different systems with the number of cycles after cyclic stress treatment according to the present invention. The hardness evolution trends of iron-based, zirconium-based, and magnesium-based amorphous alloys under the same treatment conditions are shown. It can be seen that all three materials exhibit a gradual decrease in hardness with increasing cycle count, eventually stabilizing. This result demonstrates that the cyclic stress treatment method proposed in this invention can not only effectively reduce the hardness of amorphous alloys but also has good applicability and universality for different composition systems.

[0063] In actual operation, after the device is started, the drive motor drives the three-arm connecting rod to rotate continuously, and the three rolling bearings sequentially contact the amorphous alloy strips on the conveyor belt surface according to a predetermined phase. As the conveyor belt continuously transports the material, the strips continuously enter the loading area in space and are subjected to periodic mechanical disturbances, while experiencing repeated loading-unloading cycles in time. This periodic stress pulse inputs external energy into the amorphous system through repeated mechanical excitation, causing some atomic structures to transform from low-energy states to relatively high-energy states, thereby achieving the rejuvenation effect of the amorphous structure. During this process, the shear transformation zones (STZs) inside the material are continuously activated and reconstructed, resulting in an increase in the number of locally softened regions and a more uniform spatial distribution, causing the originally non-uniform structural state to transform into a higher-energy, more active non-equilibrium state. This structural evolution process effectively improves the local plastic response capability of the amorphous alloy, weakens the material's resistance to external loads at the microscopic level, and thus manifests as a reduction in macroscopic hardness.

[0064] Furthermore, by adjusting key process parameters such as motor speed, conveyor belt speed, and rolling bearing dimensions, the frequency, amplitude, and duration of cyclic stress can be precisely controlled, thereby regulating the degree of rejuvenation and the evolution behavior of soft regions, achieving controllable adjustment of the mechanical properties of amorphous alloys. Different parameter combinations can correspond to different energy input levels and structural response modes, making this device not only suitable for hardness reduction but also expandable for controlling the plasticity, toughness, and functional stability of amorphous alloys.

[0065] In summary, this invention constructs an amorphous structure control method based on periodic mechanical excitation. Utilizing a three-arm symmetric structure, continuous rotational motion is transformed into stable and controllable stress pulse input, inducing structural rejuvenation and soft zone proliferation in amorphous alloys, thereby effectively reducing material hardness. This method breaks through the traditional control path primarily based on heat treatment, achieving active regulation of the energy state of the amorphous structure while avoiding the risk of crystallization. It combines high efficiency, controllability, and engineering applicability, demonstrating promising application prospects.

[0066] This invention has the following characteristics: 1. A rotary loading unit consisting of a drive motor, a three-arm connecting rod, and rolling bearings is constructed. Through a structural design with the three arms evenly distributed at 120°, continuous rotational motion is converted into periodic mechanical stress pulses with discrete time intervals and stable phase differences, enabling continuous cyclic loading of the amorphous alloy strip. This structure ensures the periodic stability and spatial uniformity of the stress input, which is a key foundation for achieving controllable mechanical modulation.

[0067] 2. Low-heat-input stress application method based on rolling contact. This invention uses rolling bearings as the stress loading medium, transforming the loading process from traditional sliding friction to rolling contact. This significantly reduces frictional resistance and interfacial heat generation, thereby avoiding uncontrollable changes such as structural relaxation or crystallization caused by local temperature rise in amorphous alloys. It ensures that the control process is mainly based on pure mechanical energy input, achieving a structural control path dominated by non-thermal effects.

[0068] 3. Cooperative Coupling Mechanism between the Rotary Loading System and the Conveyor Belt System. This invention combines a periodic rotary loading mechanism with a uniform-speed conveyor platform, enabling the amorphous strip to continuously enter the loading region and undergo multiple stress cycles during its movement, achieving a spatially continuous and time-controllable dynamic processing mode. This cooperative mechanism ensures that all locations of the material receive a uniform loading history, forming an online processing technology suitable for continuous production.

[0069] 4. A mechanism for regulating the rejuvenation of amorphous structures induced by periodic mechanical excitation. This invention differs from traditional structural relaxation paths by utilizing periodic stress cycles to input external energy into the amorphous system, activating the shear transition zone (STZ) and promoting the transformation of local atomic structures to higher energy states, thus achieving a rejuvenation effect on the amorphous structure. This process increases the number and uniformity of soft regions within the material, thereby reducing macroscopic hardness and improving local plastic response. This is one of the core innovative points of this invention at the material mechanism level. 5. Multidimensional adjustable characteristics of stress input parameters. This invention adjusts the stress pulse frequency by adjusting the motor speed, adjusts the loading amplitude by adjusting the connecting rod geometry and bearing diameter, and controls the application time by combining the conveyor belt speed. This enables independent or coupled control of stress frequency, amplitude, and number of cycles, making the material structure evolution process highly designable and repeatable.

[0070] 6. A Novel Process for Hardness Control of Amorphous Alloys Based on Cyclic Mechanical Stress. This invention proposes a novel process route for reducing the hardness of amorphous alloys without altering the material composition or requiring high-temperature heat treatment, relying solely on cyclic mechanical stress input. This method avoids the crystallization risks and performance degradation problems associated with traditional heat treatment, while also offering advantages such as low energy consumption, simple equipment, and high safety.

[0071] 7. Adjustable structural parameters and modular design capabilities. The dimensions of the three-arm connecting rod, bearing specifications, and loading clearance in this invention can all be adjusted according to different material dimensions and performance requirements, giving the device good adaptability and expandability. It can be applied to the processing of amorphous alloy strips of different thicknesses, widths, and composition systems.

[0072] Furthermore, it should be understood that after reading the above description of the present invention, those skilled in the art can make various alterations or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims.

Claims

1. A stress cycling device for reducing the hardness of amorphous alloys, characterized in that, include: The three-arm linkage includes a central connecting seat and three connecting rods that are fixedly connected to the central connecting seat and evenly distributed at 120° along the circumference. A rolling bearing is fixedly connected to the end of the connecting rod; The drive motor is rigidly connected to the central connecting seat via a coupling structure; A conveyor platform is used to carry and transport amorphous alloy strips to be processed.

2. The stress circulation device according to claim 1, characterized in that, The stress circulation device also includes a stress circulation control module; The stress cycle control module is used to control the operating status and speed of the drive motor in real time, as well as to monitor the frequency and stability of the stress loading process.

3. The stress cycling device according to claim 1 or 2 is used for reducing the hardness of amorphous alloys.

4. The application according to claim 3, characterized in that, The amorphous alloy is a FeSiB series amorphous alloy, a ZrCuAlNi series amorphous alloy, or a MgNiNd series amorphous alloy.

5. The application according to claim 4, characterized in that, FeSiB series amorphous alloys are expressed as FeSiB in atomic ratio form. 82 Si 3.6 B 8.4 P 3.6 Ni 1.2 Mo 0.2 Cu1; ZrCuAlNi series amorphous alloys are expressed by the atomic ratio formula Zr 65 Cu 15 Al 10 Ni 10 ; MgNiNd series amorphous alloys are expressed as follows based on atomic ratio: Mg 66 Ni 20 Nd 14 .

6. A method for reducing the hardness of an amorphous alloy, characterized in that, include: Using the stress cyclic device described in claim 1 or 2, the conveying platform carries and transports the amorphous alloy strip to be processed. The three connecting rods rotate under the drive of the drive motor. During the rotation, the rolling bearing periodically rolls and contacts the amorphous alloy strip, thereby realizing the stress cyclic loading on the amorphous alloy strip.

7. The method according to claim 6, characterized in that, The amorphous alloy is a FeSiB series amorphous alloy, a ZrCuAlNi series amorphous alloy, or a MgNiNd series amorphous alloy.

8. The method according to claim 7, characterized in that, FeSiB series amorphous alloys are expressed as FeSiB in atomic ratio form. 82 Si 3.6 B 8.4 P 3.6 Ni 1.2 Mo 0.2 Cu1; ZrCuAlNi series amorphous alloys are expressed by the atomic ratio formula Zr 65 Cu 15 Al 10 Ni 10 ; MgNiNd series amorphous alloys are expressed as follows based on atomic ratio: Mg 66 Ni 20 Nd 14 .

9. The method for reducing the hardness of amorphous alloys according to claim 6, characterized in that, The thickness of the amorphous alloy strip is 20~40 μm and the width is 1~5 mm.

10. The method for reducing the hardness of amorphous alloys according to claim 6, characterized in that, The drive motor speed is 1~10 r / min, the loading cycle is 2~20 s, and the peak loading strain is 0.2%~0.5%. The method for reducing the hardness of amorphous alloys is carried out at 0~30℃.

Images