A thermal training device and method for SMA wire

Abstract

This invention provides a thermal training device and method for SMA (Structure Memory Alloy) wire, relating to the field of shape memory alloys. The device includes: a mounting platform, a wire clamping module for fixing one end of the wire on the mounting platform, a training load configuration module for applying target loads to the wire, a control center, and connected to the control center a temperature control module, a position monitoring module, and a force monitoring module. The temperature control module provides a constant temperature zone to heat or cool the wire to achieve a martensitic or inverse phase transformation. The position monitoring module monitors the position changes of the wire and calculates the strain of the wire under thermal training conditions. The force monitoring module monitors the force values ​​experienced by the wire during the thermal training process. The control center has a pre-set thermal training program for the wire, used to receive monitoring data from each module to maintain or adjust the thermal training parameters until training is complete. This invention transforms the phase transformation process of SMA wire into an intuitive position change, efficiently exploring the thermal training parameters of the wire.

Description

Technical Field

[0001] This invention relates to the field of shape memory alloy technology, specifically to a thermal training device and method for SMA wire. Background Technology

[0002] Shape memory alloys are widely used in aerospace, microelectronics, robotics, and other fields due to their actuation properties. Depending on the application, they are typically used in the form of wires, tubes, springs, etc. With the continuous development of shape memory material fabrication processes and control algorithms, actuation devices based on shape memory alloy wires are increasingly replacing micromotors.

[0003] Shape memory alloy (SMI) devices are subjected to thermo-mechanical coupled cyclic loading during service. Processes such as martensitic repositioning, martensitic transformation, and inverse transformation induce dislocation slip within the material, leading to residual strain accumulation and cyclic degradation of the shape memory effect. This means the drive stroke decreases with increasing service life. To ensure the stability of the drive stroke in SMI drive devices, the SMI material needs to be trained. The effectiveness of the training is crucial to maintaining the stability of the drive stroke at high cycles; insufficient training will result in a continuous decrease in drive stroke, while overtraining will sacrifice drive stroke.

[0004] Literature indicates that numerous parameters influence training effectiveness, such as the number of training iterations, training load, and training amplitude. The coupling of these multiple parameters makes the process of determining and exploring the optimal training parameters complex and labor-intensive. Existing technologies have proposed some wire training schemes to achieve relatively simple wire training. For example, patent application CN117469114A proposes a process for training shape memory alloy wire using an electrical pulse method. This method indirectly controls the wire temperature by adjusting the electrical pulse, thereby controlling the training amplitude. However, when the diameter of wire varies at different locations within the same batch, using the same current parameter for training will lead to temperature differences due to the different wire diameters, resulting in variations in the training amplitude of wires with different diameters, affecting the uniformity of the overall wire performance. Furthermore, when different products have wire diameters, the electrical training parameters need to be re-determined, impacting training efficiency. For example, the device for training shape memory alloy wire disclosed in patent application CN115261748A not only cannot intuitively measure the actual strain of the wire during the training process, but also the training process it achieves makes it difficult to adjust the aforementioned parameters that affect the training effect separately. At the same time, the temperature control component of the training device has problems such as slow heating and cooling speed and limited temperature range, which directly affects the efficiency of training.

[0005] Therefore, when training shape memory alloy wires based on their structural characteristics, a new training plan needs to be developed to adjust several parameters that affect the training effect, ensure training efficiency, and improve the fatigue stability of the material. Summary of the Invention

[0006] The purpose of this invention is to provide a thermal training device and method for SMA filaments. By constructing modular equipment components, multiple coupled parameters affecting the training effect can be adjusted separately. The heating module design ensures parameter stability during the material training process, improving material fatigue stability. Simultaneously, it transforms microstructural changes that are difficult to observe directly within the material into readily observable strain variables of the SMA filaments during thermal training. This guides rapid exploration and dynamic adjustment of SMA filament thermal training parameters, enabling rapid response to parameter adjustments during the training process, significantly improving parameter exploration efficiency and reducing raw material waste. Furthermore, because SMA filament training is temperature-sensitive, and this equipment allows for direct temperature adjustment / observation, parameters explored using this equipment can be quickly transferred to SMA filaments of different diameters, further reducing development costs and improving work efficiency.

[0007] To achieve the above objectives, the present invention proposes the following technical solution:

[0008] In the first aspect, a thermal training device for SMA filament is proposed, comprising: an installation platform, a filament clamping module, a training load configuration module, a temperature control module, a position monitoring module, a force monitoring module, and a control center, wherein the temperature control module, the position monitoring module, and the force monitoring module are respectively controlled and connected to the control center;

[0009] The wire clamping module includes a clamping unit, which is disposed on the mounting platform and is used to load and fix one end of the wire.

[0010] The training load configuration module is located on the side of the filament away from the clamping unit and is connected to the free end of the filament, and is used to configure the target load onto the filament;

[0011] The temperature control module includes a temperature control unit and several heating elements. The heating elements are controlled and connected to the temperature control unit to provide a constant temperature zone so as to heat or cool the filament and realize martensitic phase transformation or its reverse phase transformation.

[0012] The position monitoring module is installed on the installation platform, located on one side of the filament, and is used to monitor the position changes of the target points on the filament and calculate the strain of the filament under the corresponding thermal training conditions, so as to adjust the parameters of the thermal training.

[0013] The force monitoring module is connected to the filament and is set on the same side of the mounting platform as the filament clamping module. It is used to monitor the force value of the filament during each heat training process.

[0014] The control center is pre-programmed with a thermal training program for the filament, which receives data from the temperature control module, position monitoring module, and force monitoring module, and maintains or adjusts the parameters of the thermal training program according to the data until the training is completed; wherein, the pre-programmed parameters for the thermal training include the number of training sessions for the filament, training load, training temperature, and heating and cooling parameters of the filament.

[0015] Furthermore, the temperature control module also includes a heating base that is movably mounted on the mounting platform and several temperature sensing elements;

[0016] The heating base is configured as a cube structure; the platform surface of the mounting platform is horizontal, the heating base is placed horizontally on the platform surface, and a rectangular groove is provided on one side of the heating base. The rectangular groove extends horizontally and penetrates the two adjacent sides of the side surface; the heating element is evenly embedded in the parallel and opposite side walls of the rectangular groove, forming a constant temperature area within the rectangular groove.

[0017] Several temperature sensing elements are electrically connected to the temperature control unit, extending into the constant temperature area and arranged in a rectangular pattern within the constant temperature area; the temperature sensing elements are used to monitor the temperature of the constant temperature area and feed it back to the temperature control unit so that the temperature control unit can adjust the operating parameters of the heating element.

[0018] Furthermore, after being positioned by the wire clamping module and the training load configuration module, the wire is distributed horizontally on the surface of the mounting platform, and a portion of the wire on the surface of the mounting platform is designated as thermal training wire.

[0019] The mounting platform is provided with a pair of slide rails, one end of which is located at the bottom of the thermal training filament; a slider is provided on the bottom surface of the heating seat that contacts the mounting platform, and the slider is adapted to the slide rail;

[0020] When the filament begins heat training, the heating seat, preheated to the target temperature, is moved to the position of the heat training filament via the slide rail, and the heat training filament is brought into the constant temperature zone through the opening of the rectangular groove.

[0021] Furthermore, the rectangular groove has a thickness of 1-30 mm in the vertical direction, a depth of 20-300 mm in the horizontal direction, and a length of 10-500 mm along the extension direction of the wire.

[0022] Furthermore, it also includes a filament cooling module, which is symmetrically arranged with the temperature control module on the mounting platform to cool the filament after heat treatment.

[0023] Furthermore, the diameter of the wire loaded in the clamping unit is 0.02mm to 2.0mm.

[0024] Furthermore, the position monitoring module calculates the strain of the filament under the corresponding thermal training conditions to be 3% to 10%.

[0025] Furthermore, the training load configuration module is configured with a load of 150–850 MPa.

[0026] Furthermore, the temperature control module has a temperature control range of 20 to 250°C, and the training temperature for thermal training is 80 to 200°C.

[0027] Secondly, a thermal training method for SMA filaments is proposed, employing the aforementioned SMA filament thermal training equipment, including: clamping the filaments onto an installation platform using a filament clamping module; configuring a target load in a training load configuration module; and setting the thermal training program for the filaments through a control center. When the filaments begin thermal training, the filaments are heated or cooled by the temperature control module to induce a martensitic phase transformation or its reverse phase transformation, changing the filament length. The position monitoring module monitors the position changes of the target points on the filaments in real time and calculates the strain of the filaments. The force monitoring module collects the force data of the filaments in real time and feeds it back to the control center. The control center maintains or adjusts the parameters of the thermal training program based on the received data until the filaments complete the thermal training.

[0028] As can be seen from the above technical solutions, the technical solutions of the present invention have achieved the following beneficial effects:

[0029] This invention discloses a thermal training device and method for SMA filaments. The device includes: an installation platform, a filament clamping module for fixing one end of the filament on the installation platform, a training load configuration module for configuring target loads on the filament, a control center, and a temperature control module, a position monitoring module, and a force monitoring module connected to the control center. The temperature control module provides a constant temperature zone to heat or cool the filament to achieve a martensitic phase transformation or its inverse phase transformation. The position monitoring module monitors the positional changes of target points on the filament and calculates the strain of the filament under corresponding thermal training conditions. The force monitoring module monitors the force on the filament during each thermal training process. The control center has a pre-set thermal training program for the filament, which receives monitoring data from each module to maintain or adjust the parameters of the thermal training program until training is completed. This invention transforms the martensitic phase transformation or its reverse phase transformation process of SMA filament under heat or cooling into an intuitive position change by combining a temperature control module, a position monitoring module, and a force monitoring module. This allows for a more intuitive view of the temperature at which the phase transformation occurs and the actual strain of the filament at that temperature, thus enabling efficient exploration of thermal training parameters for the filament.

[0030] The training process of shape memory alloys requires controlling the preferred orientation of the phase transformation variants during the martensitic-austenitic phase transformation, suppressing the loss of transformable volume due to the generation of slip dislocations, and optimizing the density of phase transformation dislocations. This stabilizes the microstructure and achieves excellent fatigue resistance. The type and number of dislocations are determined by the force applied to the wire and the temperature variation range during the training process, which is reflected in the corresponding changes in the strain of the wire during training. This invention provides a method for directly adjusting and monitoring the temperature, tension, and strain during the training process, thereby directly controlling the density of phase transformation dislocations, enabling the wire to have a stable microstructure and stress field, and achieving excellent fatigue stability.

[0031] The thermal training device for SMA filaments disclosed in this invention can quickly confirm and explore training parameters for SMA filaments of different diameters. On one hand, the temperature control module of this invention can directly control the training temperature of the filament, establishing a correspondence between training temperature and training effect. Furthermore, the structural design of the temperature control module not only provides a stable constant temperature region but also offers fast temperature control response, a wide temperature range, and high training efficiency. On the other hand, the position monitoring module and force monitoring module in the thermal training device of this invention can collect real-time data on the position changes of the target point and the force changes of the filament during thermal training, further aiding in the adjustment of thermal training parameters. In addition, each module of this invention is independently set, thus enabling separate adjustment of core training parameters, reducing the difficulty of exploring training parameters due to the coupling effect of multiple factors. Compared with existing technologies, this invention not only efficiently completes the parameter exploration of the filament thermal training process but also makes the exploration process less susceptible to environmental influences and easier to operate.

[0032] It should be understood that all combinations of the foregoing concepts and the additional concepts described in more detail below can be considered part of the inventive subject matter of this disclosure, provided that such concepts do not contradict each other.

[0033] The foregoing and other aspects, embodiments, and features of the teachings of the present invention will be more fully understood from the following description in conjunction with the accompanying drawings. Other additional aspects of the invention, such as features and / or beneficial effects of exemplary embodiments, will become apparent from the following description or may be learned through practice of specific embodiments according to the teachings of the present invention. Attached Figure Description

[0034] The accompanying drawings are not drawn to scale. In the drawings, each identical or nearly identical component shown in the various figures may be denoted by the same reference numeral. For clarity, not every component is labeled in each figure. Embodiments of various aspects of the invention will now be described by way of example and with reference to the accompanying drawings, wherein:

[0035] Figure 1This is a schematic diagram of the thermal training device for SMA filaments proposed in Embodiment 1 of the present invention;

[0036] Figure 2 This is a schematic diagram of the thermal training device for SMA filaments proposed in Embodiment 2 of the present invention;

[0037] Figure 3 The tensile test data diagrams of the comparative examples and embodiments disclosed in the embodiments are shown.

[0038] Figure 4 The diagram shows DMA test data for the comparative and exemplary embodiments disclosed in the examples.

[0039] The specific meanings of each mark in the diagram are as follows:

[0040] 1-Installation platform; 100-Temperature control module, 101-Heating seat, 102-Temperature control unit, 103-Condenser tube; 200-Wire clamping module, 201-Clamping unit; 300-Training load configuration module, 301-Weights, 302-Load steering device, 303-Tension spring; 400-Position monitoring module; 500-Force monitoring module; 600-Control center; 2-Wire; 3-Installation bracket. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are within the scope of protection of the present invention. Unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by those skilled in the art to which this invention pertains.

[0042] The terms "first," "second," and similar words used in the specification and claims of this patent application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, unless the context clearly indicates otherwise, the singular forms of "an," "a," or "the," etc., do not indicate a quantity limitation, but rather indicate the presence of at least one. Terms such as "comprising" or "including" mean that the element or object preceding "comprising" encompasses the features, integrals, steps, operations, elements, and / or components listed following "comprising" or "including," and do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or collections thereof. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; these relative positional relationships may change accordingly when the absolute position of the described object changes.

[0043] Shape memory alloy (SMA) components experience cyclic degradation due to residual strain accumulated from internal dislocation slip during service. Existing technologies address this by training to ensure the stability of the drive stroke of SMA components. However, electrical pulse training schemes are rudimentary and produce uneven training results. Using training equipment for whole-roll training presents technical problems such as inconvenient parameter adjustment and low training efficiency. Therefore, this invention aims to propose a thermal training device and method for SMA filaments. By transforming the phase transformation process of SMA filaments under high and low temperature environments into a visually observable change in filament length, the thermal training device significantly improves the efficiency of exploring thermal training parameters for SMA filaments and enhances the stability of the drive stroke of shape memory alloy components.

[0044] The thermal training device for SMA filament disclosed in this invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0045] Example 1

[0046] like Figure 1 The SMA filament thermal training equipment shown includes: an installation platform 1, a filament clamping module 200, a training load configuration module 300, a temperature control module 100, a position monitoring module 400, a force monitoring module 500, and a control center 600, wherein the temperature control module 100, the position monitoring module 400, and the force monitoring module 500 are respectively connected to the control center 600.

[0047] During installation, the wire clamping module 200 is fixed on the surface of the installation platform 1, including a clamping unit 201. The clamping unit 201 is disposed on the installation platform 1 and is used to load and fix one end of the wire 2. Figure 1The clamping unit 201 uses commercially available metal wire clips and bolts for fastening. The clamping unit 201 can load wires with a diameter of 0.02mm to 2.0mm; in this embodiment, 0.02mm is selected. The training load configuration module 300 is located on the side of the wire 2 away from the clamping unit 201 and is connected to the free end of the wire 2. It is used to configure the target load onto the wire 2. In this embodiment, the training load configuration module 300 uses weights 301 to configure the load, and transfers the precise load by adding or subtracting weights 301. Figure 1 In the illustrated embodiment, to facilitate the configuration of the load on the weight 301, the training load configuration module 300 is also provided with a load steering device 302 to turn the load of the weight 301 in the vertical direction to the horizontal direction. In this embodiment, the load steering device 302 is a fixed pulley, and the target load can be configured to be 150-850MPa, preferably 300MPa-800MPa, depending on the diameter of the wire 2. In this embodiment, the target load is configured to be 800MPa.

[0048] Temperature control module 100 includes a temperature control unit 102 and several heating elements. The heating elements are controlled and connected to the temperature control unit 102 to provide a constant temperature zone so as to heat or cool the filament 2, realize the martensitic phase transformation or its reverse phase transformation, and achieve the purpose of training the filament 2.

[0049] In this embodiment, the temperature control module 100 further includes a heating seat 101 movably disposed on the mounting platform 1 and several temperature measuring elements; as shown in the figure, the heating seat 101 is configured as a cubic structure; the platform surface of the mounting platform 1 is horizontal, the heating seat 101 is placed horizontally on the platform surface, and a rectangular groove is provided on one side of the heating seat 101, the rectangular groove extending horizontally and penetrating the two adjacent sides of the side; the heating elements are evenly embedded in the parallel and opposite side walls of the rectangular groove, forming a constant temperature area within the rectangular groove; in order to ensure the temperature uniformity of the constant temperature area, the size of the rectangular groove needs to be limited, the thickness of the rectangular groove in the vertical direction is 1-30mm, the depth in the horizontal direction is 20-300mm, and the length along the extension direction of the filament is 10-500mm; in this embodiment, the thickness of the rectangular groove in the vertical direction is 30mm, the depth in the horizontal direction is 300mm, and the length along the extension direction of the filament is 80mm. Several temperature sensing elements, such as thermocouples, are electrically connected to the temperature control unit 102. The thermocouples are partially embedded in the groove wall and partially extend into the constant-temperature area, forming a rectangular distribution within the constant-temperature area. This rectangular distribution resembles the vertical cross-section of the rectangular groove. The temperature sensing elements monitor the temperature of the constant-temperature area and feed it back to the temperature control unit 103, allowing the temperature control unit 102 to adjust the operating parameters of the heating elements, such as the heating current. The temperature control module 100 can intuitively and conveniently adjust and measure the heating temperature of the wire 2. In this embodiment, the adjustable temperature range of the temperature control module 100 is 20–250°C, and the heat training temperature range is 80–200°C. The preferred heat training temperature range is 100–180°C. In this embodiment, the heat training temperature is set to 120°C.

[0050] In some embodiments, the temperature control module 100 is composed of a liquid tank with controllable temperature adjustment, and the target effect is achieved by immersing the filament 2 in a liquid heated to a fixed temperature.

[0051] To facilitate the thermal training of the filament 2, in this embodiment, the filament clamping module 200 is fixed in position, while the temperature control module 100 is configured as a movable structure for convenient operation. Specifically, after being positioned by the filament clamping module 200 and the training load configuration module 300, the filament 2 is distributed horizontally on the surface of the mounting platform 1, and a portion of the filament 2 on the surface of the mounting platform 1 is designated as the thermal training filament. A pair of slide rails are provided on the platform surface of the mounting platform 1, with one end of each slide rail located at the bottom of the thermal training filament. A slider is provided on the bottom surface of the heating seat 101 that contacts the mounting platform 1, and the slider is adapted to the slide rail. When the filament 2 begins thermal training, the heating seat 101, preheated to the target temperature, is moved along the slide rail to the position of the thermal training filament, and the thermal training filament is incorporated into the center of the constant temperature zone through the opening of the rectangular groove. Figure 1 The assembly effect is shown. Of course, the temperature control module 100 has a simple and lightweight structure and can be transported directly without the need for a slide rail; in addition, even if the wire clamping module 200 is not fixed, the wire 2 can be moved to keep the temperature control module 100 fixed.

[0052] Optionally, to improve the working efficiency of the thermal training equipment, the equipment also includes a filament cooling module. This module is symmetrically arranged on the mounting platform 1 with the temperature control module 100 to cool the filament 2 after thermal training, allowing it to quickly proceed to the next thermal training cycle. The filament cooling module can be made of a fan, a temperature-controlled condenser, or a condenser pipe 104 installed inside the heating base 101; of course, the filament 2 can also be cooled naturally.

[0053] A position monitoring module 400 is mounted on the installation platform 1, located on one side of the filament 2. It monitors the positional changes of target points on the filament 2 and calculates the strain of the filament 2 under corresponding thermal training conditions. This allows for evaluation of whether each thermal training session achieves the ideal strain and adjustment of the thermal training parameters. In this embodiment, the position monitoring module 400 is a high-precision displacement sensor with an accuracy of ±0.5%. An angle sensor or similar device can also be used. By measuring the positional movement of the moving side of the filament 2, it monitors the positional changes of target points on the filament 2 in real time during each training session. The target points are pre-defined reference points on the filament 2. The training strain of the filament 2 during thermal training ranges from 3% to 10%, preferably 5% to 8%. Therefore, by comparing the actual strain calculated by the position monitoring module 400 with the ideal strain, timely adjustments to the thermal training parameters can be provided.

[0054] The force monitoring module 500 is connected to the filament 2. The force monitoring module 500 is set on the same side of the filament clamping module 200 on the mounting platform 1. It is used to monitor the force value of the filament 2 during each heat training process. In this case, the main body of the force monitoring module 500 is composed of a high-precision force sensor with an accuracy of ±0.2%. It can monitor the force value of the filament during each training process in real time. The force monitoring module 500 indirectly determines the force on the filament 2 by monitoring the tension of the filament 2 received by the filament clamping module 200. After reporting, it can clearly know the accurate force on the filament 2 during each heat training to help explore the heat training parameters.

[0055] The control center 600 is pre-programmed with a thermal training program for the filament 2. This program receives data from the temperature control module 100, position monitoring module 400, and force monitoring module 500, and maintains or adjusts the parameters of the thermal training program based on this data until training is complete. The pre-programmed parameters for thermal training include the number of training cycles, training load, training temperature, and heating / cooling parameters for the filament. The number of training cycles is typically 20–200, preferably 40–160. Naturally, the control center 600, as an integrated system for data collection, recording, and processing, includes a central processing unit and a display device for data presentation.

[0056] The method for thermal training using the aforementioned SMA filament thermal training equipment is as follows: filament 2 is clamped onto the mounting platform 1 using the filament clamping module 200; a target load is configured in the training load configuration module 300; after the filament 2 passes over the fixed pulley, a weight 301 corresponding to the target load is fixed to the free end of the filament 2; and the thermal training program of the filament 2 is set through the control center 600, including setting the number of training sessions, training load, training temperature, and filament heating and cooling parameters, such as heating temperature, heating time, cooling temperature, and cooling time. When the filament 2 begins thermal training, it is heated or cooled by the temperature control module 100, causing the filament 1 to undergo a martensitic phase transformation or its reverse phase transformation, thus changing the length of the filament 2. The position monitoring module 400 monitors the position changes of the target point on the filament 2 in real time, calculates the strain of the filament 2, and the force monitoring module 500 collects the force data of the filament 2 in real time and feeds it back to the control center 600. The control center 600 maintains or adjusts the parameters of the thermal training program based on the received data until the filament 2 completes the thermal training. After the filament is loaded into the device, in the non-heating state, the heating seat 101 is not on the edge of the filament, and the weight 301 is positioned lower. In the heating state, the filament is placed into the rectangular groove of the heating seat 101, and the filament 2 transforms from martensite to austenite under heat, shortening the filament 2, and the weight 301 moves upward.

[0057] Example 2

[0058] like Figure 2 As shown, the difference between Embodiment 2 and Embodiment 1 is that the wire 2 is arranged vertically on the mounting platform 1 using the mounting bracket 3, and the rectangular groove of the heating seat 101 extends vertically. The training load configuration module 300 can directly act on the wire 2 without the load steering device 302, and this is achieved through the tension spring 303. During training, the wire 2 remains stationary while the heating seat 101 moves. After the equipment is loaded with wire, the tension spring 303 is in a compressed state when not heated, and in an extended state when heated.

[0059] Examples 1, 2, and 3 respectively conducted thermal training of SMA filaments under different thermal training parameters. The equipment structure of Example 3 is the same as that of Example 1. The specific parameters and strain data of the filaments are shown in Table 1 below. Comparative Examples 1 and 2 are a comparison of the filament effects of thermal training of SMA filaments using the electric pulse method. Examples 1-3 only have some parameters listed in the table that have changed, while other parameters remain unchanged.

[0060] Table 1. Training process parameters and dependent variables for SMA filament

[0061]

[0062]

[0063] As shown in Table 1, the thermal training method of this invention exhibits low sensitivity of the process parameters to the wire diameter; changes in wire diameter do not significantly alter the training parameters. Combined with… Figure 3 and Figure 4 As shown, Examples 1-3, using the thermal training equipment of this invention with wires 2 of different diameters, exhibited similar performance after training with the same thermal training parameters, achieving the same strain. Furthermore, the stretching platform showed consistency, the DMA curves showed good overlap, and the phase transition temperature was also consistent. In contrast, Comparative Examples 1-2, which used an electrical pulse method for training, required adjusting multiple electrical parameters to achieve similar stretching platform and strain performance as this method. Moreover, the coupling of these parameters resulted in a significant workload in finding the optimal parameters, making the implementation process much more complex.

[0064] In principle, the training process of shape memory alloys involves controlling the preferred orientation of the phase transformation variants during the martensitic-austenitic phase transformation, suppressing the loss of transformable volume due to the generation of slip dislocations, and optimizing the density of phase transformation dislocations. This stabilizes the microstructure and achieves excellent fatigue resistance. The type and number of dislocations are determined by the force applied to the wire and the temperature range during the training process, manifested as corresponding changes in the strain of the wire during training. This invention provides a method for directly adjusting and monitoring the temperature, tension, and strain during the training process, thereby directly controlling the density of phase transformation dislocations, enabling the wire to have a stable microstructure and stress field, achieving excellent fatigue stability.

[0065] Therefore, based on the above embodiments and data, it is fully demonstrated that the thermal training equipment and method proposed in this invention achieve the technical effect of transforming the difficult-to-observe SMA filament phase transition process into an intuitively evaluable quantity of positional change. This allows for a more direct observation of the temperature at which the filament undergoes a phase transition and the actual strain of the filament at that temperature, thus efficiently exploring thermal training parameters. Compared to existing technologies, this invention allows for parameter exploration using shorter filaments, reducing filament waste. The temperature control module allows for direct observation of the temperature's impact on training effectiveness, with fast temperature control response, a wide temperature range, and a broad parameter exploration range. Each module of the equipment can collect real-time data on filament positional and force changes during training, enabling timely parameter adjustments. Each module can independently adjust key core training parameters, reducing the difficulty of exploring training parameters due to the coupling effect of multiple factors.

[0066] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Those skilled in the art can make various modifications and refinements without departing from the spirit and scope of the invention. Therefore, the scope of protection of the present invention shall be determined by the claims.

Claims

1. A thermal training device for SMA filament, characterized in that, include: The system includes an installation platform, a wire clamping module, a training load configuration module, a temperature control module, a position monitoring module, a force monitoring module, and a control center. The temperature control module, position monitoring module, and force monitoring module are respectively connected to the control center. The wire clamping module includes a clamping unit, which is disposed on the mounting platform and is used to load and fix one end of the wire. The training load configuration module is located on the side of the filament away from the clamping unit and is connected to the free end of the filament, and is used to configure the target load onto the filament; The temperature control module includes a temperature control unit and several heating elements. The heating elements are controlled and connected to the temperature control unit to provide a constant temperature zone so as to heat or cool the filament and realize martensitic phase transformation or its reverse phase transformation. The position monitoring module is installed on the installation platform, located on one side of the filament, and is used to monitor the position changes of the target points on the filament and calculate the strain of the filament under the corresponding thermal training conditions, so as to adjust the parameters of the thermal training. The force monitoring module is connected to the filament and is set on the same side of the mounting platform as the filament clamping module. It is used to monitor the force value of the filament during each heat training process. The control center is pre-programmed with a thermal training program for the filament, which receives data from the temperature control module, position monitoring module, and force monitoring module, and maintains or adjusts the parameters of the thermal training program according to the data until the training is completed; wherein, the pre-programmed parameters for the thermal training include the number of training sessions for the filament, training load, training temperature, and heating and cooling parameters of the filament.

2. The thermal training equipment for SMA filaments according to claim 1, characterized in that, The temperature control module also includes a heating base that can be movably mounted on the mounting platform and several temperature sensing elements; The heating base is configured as a cube structure; the platform surface of the mounting platform is horizontal, the heating base is placed horizontally on the platform surface, and a rectangular groove is provided on one side of the heating base. The rectangular groove extends horizontally and penetrates the two adjacent sides of the side surface; the heating element is evenly embedded in the parallel and opposite side walls of the rectangular groove, forming a constant temperature area within the rectangular groove. Several temperature sensing elements are electrically connected to the temperature control unit, extending into the constant temperature area and arranged in a rectangular pattern within the constant temperature area; the temperature sensing elements are used to monitor the temperature of the constant temperature area and feed it back to the temperature control unit so that the temperature control unit can adjust the operating parameters of the heating element.

3. The thermal training equipment for SMA filaments according to claim 2, characterized in that, After being positioned by the wire clamping module and the training load configuration module, the filaments are distributed horizontally on the surface of the mounting platform, and a portion of the filaments on the surface of the mounting platform is designated as thermal training filaments. The mounting platform is provided with a pair of slide rails, one end of which is located at the bottom of the thermal training filament; a slider is provided on the bottom surface of the heating seat that contacts the mounting platform, and the slider is adapted to the slide rail; When the filament begins heat training, the heating seat, preheated to the target temperature, is moved to the position of the heat training filament via the slide rail, and the heat training filament is brought into the constant temperature zone through the opening of the rectangular groove.

4. The thermal training equipment for SMA filaments according to claim 2, characterized in that, The rectangular groove has a thickness of 1-30 mm in the vertical direction, a depth of 20-300 mm in the horizontal direction, and a length of 10-500 mm along the extension direction of the wire.

5. The thermal training equipment for SMA filaments according to claim 1, characterized in that, It also includes a filament cooling module, which is symmetrically arranged with the temperature control module on the mounting platform to cool the filament after heat treatment.

6. The thermal training equipment for SMA filaments according to claim 1, characterized in that, The diameter of the wire loaded in the clamping unit is 0.02mm to 2.0mm.

7. The thermal training equipment for SMA filaments according to claim 1, characterized in that, The position monitoring module calculates that the strain of the filament under the corresponding thermal training conditions is 3% to 10%.

8. The thermal training equipment for SMA filaments according to claim 1, characterized in that, The training load configuration module is configured with a load of 150–850 MPa.

9. The thermal training equipment for SMA filaments according to claim 1, characterized in that, The temperature control module has a temperature control range of 20 to 250°C, and the training temperature for thermal training is 80 to 200°C.

10. A method for thermally training SMA filament, characterized in that, The thermal training equipment for SMA filament according to any one of claims 1 to 9 includes: clamping the filament onto an installation platform using a filament clamping module; configuring a target load in a training load configuration module; and setting the thermal training program for the filament through a control center. When the filament begins thermal training, the filament is heated or cooled by the temperature control module to cause a martensitic phase transformation or its reverse phase transformation, changing the filament length. The position monitoring module monitors the position changes of the target point on the filament in real time and calculates the strain of the filament. The force monitoring module collects the force data of the filament in real time and feeds it back to the control center. The control center maintains or adjusts the parameters of the thermal training program according to the received data until the filament completes the thermal training.

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