Self-reinforcing and self-healing shape memory composite material preparation device and process

Abstract

This invention relates to a device and process for preparing self-reinforcing and self-healing shape memory composite materials. It innovatively employs a vacuum-assisted injection method to composite and cure epoxy-based shape memory polymers (SMP) with tensioned NiTi shape memory alloy (SMA) wires. The thermotropic shrinkage properties of the NiTi alloy wires are utilized to improve the stiffness of the epoxy matrix while simultaneously healing internal microcracks. This preparation process and supporting equipment can minimize defects in the preparation and use of composite materials and enable semi-automatic control of the composite material's stiffness.

Description

Technical Field

[0001] This invention relates to the field of composite material preparation technology, and in particular to a device and process for preparing self-reinforcing and self-healing shape memory composite materials. Background Technology

[0002] The main problems and shortcomings of existing preparation equipment and processes are:

[0003] 1) In the currently published patents, the preparation method of epoxy-based molded products is mostly direct casting molding. However, in actual applications, composite materials made by this method are prone to defects such as uneven surface and internal air bubbles.

[0004] 2) The epoxy-based molded products prepared in the currently published patents have relatively low strength and cannot meet the requirements of working under various conditions.

[0005] 3) Among the currently disclosed patents, there are no good methods for repairing damage to epoxy-based molded products, resulting in a short lifespan of the materials. Summary of the Invention

[0006] In view of this, the purpose of the present invention is to provide a self-reinforcing and self-healing shape memory composite material preparation device and process, which can minimize defects in the preparation and use of composite materials and realize semi-automatic control of composite material stiffness.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: a self-reinforcing and self-healing shape memory composite material preparation device, comprising an upper molding die, a lower molding die, a NiTi alloy wire fixing device, and a sealing device; the upper molding die is provided with a connecting boss with an inclined surface, and the lower molding die is provided with a connecting groove with a positioning inclined surface; the connecting boss is inserted into the connecting groove to connect the upper molding die and the lower molding die; the upper molding die is provided with a guide hole, and the lower molding die is provided with a semi-cylindrical boss and a cylindrical boss; the NiTi alloy wire fixing device includes the semi-cylindrical boss and the cylindrical boss; one end of the metal wire is fixed as a ring, then fitted onto the semi-cylindrical boss, and then passes around all the cylindrical bosses in an S-shape, so that the NiTi alloy wire is fixed on the last semi-cylindrical boss under tension.

[0008] In a preferred embodiment, the sealing device includes rubber rings, a sealing bag, and sealant; first, two sealing rings are placed above the guide hole, then the entire device is placed into the sealing bag, and finally the sealant is used to seal it.

[0009] In a preferred embodiment, a vacuum drainage device is also included; the vacuum drainage device includes a guide tube, a vacuum pump, and a solution; first, a small hole is made in the sealing bag above the rubber ring, then one end of the guide tube is inserted into the rubber ring, and the other end is connected to the vacuum pump or the solution, and the guide tube is controlled to open and close by a tube clamp.

[0010] This invention provides a process for preparing a self-reinforcing and self-healing shape memory composite material, employing the aforementioned preparation device. The process includes the following steps: Step 1: Winding a NiTi alloy wire in an S-shape onto a mold; Step 2: Tightening the alloy wire and then fixing the end to a semi-cylindrical boss; Step 3: Placing the upper mold over the lower mold with the wound alloy wire; Step 4: Placing two rubber rings above the guide holes; Step 5: Placing the device into a sealing bag and sealing the bag; Step 6: Cutting two guide tubes of suitable length, inserting the guide tubes through small holes in the sealing bag into the rubber rings, connecting one guide tube to a vacuum pump, and controlling the opening and closing of the two guide tubes using a pipe clamp. The vacuum pump is then turned on. Step 7: Place one end of the guide tube into the container containing the solution. First, open the vacuum pump and the clamp at one end of the vacuum pump. Then, open the clamp at one end of the container containing the solution to allow the liquid to flow into the mold. When a certain amount of solution is seen flowing from the guide tube at the vacuum pump end, close both clamps and disconnect from the vacuum pump. Step 9: Place the device in a constant temperature chamber for curing. Step 10: After curing, disassemble the device to obtain the semi-finished product. Step 11: Cut the semi-finished product with a saw to expose part of the alloy wire to obtain the required size. Step 12: Weld the cut alloy wire to form a complete circuit, which is the finished product.

[0011] Compared with the prior art, the present invention has the following beneficial effects:

[0012] 1) This product mainly improves the preparation method and process of epoxy-based shape memory polymers (SMP). It creatively adopts a vacuum flow method to increase the intermolecular connection, reduce the generation of bubbles and cracks, and meet the stability requirements of high-intensity working environment in practical applications.

[0013] 2) The innovative method of pre-embedding NiTi alloy wires allows the product to have a self-reinforcing effect, greatly improving the mechanical properties of the material.

[0014] 3) A creative preparation method is adopted to preserve the complete alloy wire circuit. By utilizing the memory characteristics of NiTi alloy wire, the local temperature can be increased by energizing it, which can self-repair the cracks generated during use.

[0015] 4) Based on the shape memory properties of NiTi alloy wire, the overall shape of the product can be controlled by changing its shape memory, which has extremely high development value.

[0016] 5) This product has a simple and reliable overall structure and good compatibility with different size requirements. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the combination of the upper mold and the lower mold of the molding die according to a preferred embodiment of the present invention.

[0018] Figure 2 This is a schematic diagram of a NiTi alloy wire fixing and tensioning device according to a preferred embodiment of the present invention, wherein (a) shows the NiTi alloy wire being pulled taut when passing around the last semi-cylindrical boss, and (b) shows the wire being tied to the boss in a tensioned state.

[0019] Figure 3 This is a schematic diagram of a sealing device according to a preferred embodiment of the present invention.

[0020] Figure 4 This is a schematic diagram of a vacuum drainage device according to a preferred embodiment of the present invention.

[0021] Figure 5 This is a schematic diagram of the preparation process of a preferred embodiment of the present invention.

[0022] Reference numerals in the attached diagram: 1: guide hole; 2: positioning bevel; 3: semi-cylindrical boss; 4: cylindrical boss; 5: guide hole. Detailed Implementation

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0024] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0025] It should be noted that the terminology used herein is for the purpose of describing particular implementations only and is not intended to limit the exemplary implementations according to this application; as used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise; furthermore, it should be understood that when the terms “comprising” and / or “including” are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0026] This invention relates to a method and process for preparing shape memory composite materials. It integrates tensioned NiTi shape memory alloy (SMA) wire with epoxy-based shape memory polymer (SMP), and combines wire winding, sealing, and vacuum drainage into a single system. Each component can be individually assembled and disassembled, facilitating the manufacturing process and the removal of the finished product. Each component is simple to operate, and the manufacturing method is straightforward.

[0027] A device for preparing self-reinforcing and self-healing shape memory composite materials. (Reference) Figure 1-5 It is composed of multiple devices, specifically including an upper forming mold, a lower forming mold, a NiTi alloy wire fixing device, and a sealing device. Detailed information about each device is as follows:

[0028] Connection method:

[0029] Both the upper and lower molds of the forming mold have a 45° slope, and the upper mold can be placed directly on the lower mold to complete the self-positioning.

[0030] The wire fixing and tensioning device mainly includes cylindrical bosses and semi-cylindrical bosses, as shown in the attached figure. Figure 2 As shown. First, fix one end of the metal wire into a loop, then slip it onto the semi-cylindrical boss, and then wrap it around all the cylindrical bosses in an S-shape, ensuring that the NiTi alloy wire is fixed to the last semi-cylindrical boss under sufficient tension.

[0031] Method to maintain tension in NiTi alloy wire: Tighten the NiTi alloy wire as it passes over the final semi-cylindrical boss (e.g., Figure 2 (a) is attached to the boss under tension (e.g.) Figure 2 (b).

[0032] The sealing device mainly consists of rubber rings, a sealing bag, and sealant. First, place the two sealing rings above the guide hole, then put the entire device into the sealing bag, and finally seal it with sealant to ensure the airtightness of the entire device.

[0033] The vacuum diversion device mainly includes a diversion tube, a vacuum pump, and a prepared solution. For example... Figure 4 As shown, first make a small hole in the sealing bag above the rubber ring, then insert one end of the guide tube into the rubber ring, and connect the other end to the vacuum pump or solution. The guide tube is controlled to open and close with a tube clamp, and the solution flows in the direction indicated by the arrow.

[0034] The molding die error of this invention must not be too large to prevent excessive leakage of the resin mixture from the cavity, which would result in an uneven surface on the finished product. The NiTi alloy wire must be wound taut before fixing to ensure a certain pre-tension. After sealing the bag, it must be carefully checked for leaks; only a completely sealed condition can guarantee the reliability of the produced material.

[0035] The preparation process includes the following steps: When preparing shape memory polymer composite materials, firstly, according to step 1, NiTi alloy wire is wound into the mold in an S-shape; secondly, the alloy wire is tightened and the end is fixed to the semi-cylindrical boss; thirdly, the upper mold is placed on the lower mold with the alloy wire wound on; fourthly, two rubber rings are placed above the guide hole; fifthly, the device is placed in a sealing bag and the sealing bag is sealed; sixthly, two guide tubes of appropriate length are cut, and the guide tubes are inserted into the rubber rings through the small holes on the sealing bag. One of the guide tubes is connected to a vacuum pump, and the opening and closing of the two guide tubes are controlled by a tube clamp. At this time, the tube clamp of the vacuum pump is opened and the tube clamp of the other end is closed, and the vacuum pump is turned on to make the device in a vacuum state. Step 7 involves placing one end of the guide tube into a container filled with solution. First, open the vacuum pump and its clamp. Then, open the clamp on one end of the container filled with solution, allowing the liquid to flow into the mold. When a certain amount of solution is seen flowing from the guide tube on the vacuum pump end, simultaneously close both clamps and disconnect from the vacuum pump. Step 9 involves placing the device in a constant temperature chamber for curing. Step 10 involves disassembling the device after curing to obtain a semi-finished product. Step 11 involves cutting the semi-finished product using a saw to expose part of the alloy wire, obtaining the required dimensions. Step 12 involves welding the cut alloy wire to form a complete circuit, resulting in the finished product.

Claims

1. A device for preparing self-reinforcing and self-healing shape memory composite materials, characterized in that... The device includes an upper forming mold, a lower forming mold, a NiTi alloy wire fixing device, and a sealing device. The upper forming mold is provided with a connecting boss with an inclined surface, and the lower forming mold is provided with a connecting groove with a positioning inclined surface. The connecting boss is inserted into the connecting groove to connect the upper forming mold and the lower forming mold. The upper forming mold is provided with a guide hole, and the lower forming mold is provided with a semi-cylindrical boss and a cylindrical boss. The NiTi alloy wire fixing device includes the semi-cylindrical boss and the cylindrical boss. One end of the alloy wire is fixed as a ring, then fitted onto the semi-cylindrical boss, and then passes around all the cylindrical bosses in an S-shape, so that the NiTi alloy wire is fixed on the last semi-cylindrical boss under tension. The sealing device includes rubber rings, a sealing bag, and sealant; first, place the two sealing rings above the guide hole, then put the entire device into the sealing bag, and finally seal it with sealant. It also includes a vacuum drainage device; the vacuum drainage device includes a guide tube, a vacuum pump and a solution; first, a small hole is made in the sealing bag above the rubber ring, then one end of the guide tube is inserted into the rubber ring, and the other end is connected to the vacuum pump or solution, and the guide tube is controlled to open and close by a tube clamp.

2. A process for preparing self-reinforcing and self-healing shape memory composite materials, characterized in that... The self-reinforcing and self-healing shape memory composite material preparation device according to claim 1 includes the following steps: Step 1: Winding NiTi alloy wire into a mold in an S-shape; Step 2: Tightening the alloy wire and then fixing the end to a semi-cylindrical boss; Step 3: Covering the lower mold with the wound alloy wire with the upper mold; Step 4: Placing two rubber rings above the guide holes; Step 5: Placing the device into a sealing bag and sealing the bag; Step 6: Cutting two guide tubes of suitable length, inserting the guide tubes into the rubber rings through the small holes in the sealing bag, and connecting one of the guide tubes to a vacuum pump. The opening and closing of the two guide tubes are controlled by a tube clamp. At this time, the tube clamp of the vacuum pump is opened and the other end is closed. Step 7: Place one end of the guide tube into the container containing the solution. At this time, first open the vacuum pump and the tube clamp at one end of the vacuum pump, then open the tube clamp at one end of the container containing the solution to allow the liquid to flow into the mold. When a certain amount of solution is seen to appear from the guide tube at one end of the vacuum pump, close both tube clamps and disconnect from the vacuum pump. Step 8: Place the device in a constant temperature chamber for curing. Step 9: After curing, disassemble the device to obtain the semi-finished product. Step 10: Cut the semi-finished product with a saw to expose part of the alloy wire to obtain the required size. Step 11: Weld the cut alloy wire to form a complete circuit to obtain the finished product.

Images