Composite shape memory alloy and preparation method thereof

Abstract

The invention belongs to the field of virtual reality equipment, and particularly relates to a shape memory polymer alloy and a preparation method thereof. The composite shape memory alloy comprises a thermal response shape memory polymer layer and metal layers symmetrical to the upper surface and the lower surface of the thermal response shape memory polymer layer. The thermal response shape memory polymer layer comprises thermosetting matrix resin, a thermal response filler and a thermosetting elastomer; the metal layer is a magnesium-aluminum alloy layer or a magnesium alloy layer with aluminum alloy deposited on the face, away from the thermal response shape memory polymer layer, of the metal layer. The prepared composite shape memory alloy is high in deformability, light in weight, high in strength and low in cost, the binding force between the thermal response shape memory polymer layer and the metal layer is high, no solvent is needed in the preparation process, natural curing can be achieved, and process energy consumption and environmental pollution are greatly reduced.

Description

Technical Field

[0001] The invention belongs to the field of virtual reality equipment, and in particular relates to a shape memory polymer alloy and a preparation method thereof. Background Art

[0002] With the continuous advancement of virtual reality technology and the continuous growth of the user population, shape memory alloy materials have begun to be used to prepare virtual reality equipment, such as AR / VR glasses frames. However, common shape memory alloys are mainly Ti / Ni alloys, which have excellent deformation ability, but are relatively expensive and bulky to wear. However, if we only pursue light weight and high strength, such as magnesium-aluminum alloys, their deformation ability is greatly reduced and cannot be well applied to virtual reality wearable devices.

[0003] Shape memory polymer alloy (SMP) is low-cost and lightweight, and its deformation ability is comparable to that of Ti / Ni alloy, but its overall strength is not as good as that of pure metal alloys, and the preparation method sometimes requires the use of a large amount of organic solvents and initiators, which is not environmentally friendly. Therefore, there is an urgent need for a shape memory alloy with strong deformation ability, light weight, high strength, simple preparation process and environmental protection. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a composite shape memory alloy and a preparation method thereof, aiming to.

[0005] According to a first aspect of the present invention, the present invention first provides a composite shape memory alloy, comprising:

[0006] A thermally responsive shape memory polymer layer, and a metal layer symmetrical to the upper and lower surfaces of the thermally responsive shape memory polymer layer;

[0007] The thermally responsive shape memory polymer layer comprises a thermosetting matrix resin, a thermally responsive filler and a thermosetting elastomer; the metal layer is a magnesium-aluminum alloy layer, or a magnesium alloy layer with aluminum alloy deposited on a side away from the thermally responsive shape memory polymer layer.

[0008] According to one embodiment of the present invention, the thickness ratio of the thermal responsive shape memory polymer layer to the metal layer is (2-4):1.

[0009] According to one embodiment of the present invention, the thermosetting matrix resin is an epoxy resin or a phenolic resin, the thermosetting elastomer is a thermosetting polyurethane elastomer, the thermally responsive filler is one of carbon nanotubes, graphene, and aluminum nitride, and the mass fractions of the thermosetting matrix resin and the thermosetting elastomer are 40-44.9%wt and 45-59.9%wt, respectively.

[0010] According to one embodiment of the present invention, the thickness of the metal layer is not greater than 0.6 mm, and the ductility of the metal layer is not less than 3%.

[0011] According to one embodiment of the present invention, when the metal layer is a magnesium-aluminum alloy layer, the atomic ratio of magnesium to aluminum in the magnesium-aluminum alloy layer is (0.33-0.75):1; when the metal layer is a magnesium-aluminum alloy layer in which an aluminum alloy is deposited on the side away from the thermally responsive shape memory polymer layer, the thickness ratio of the aluminum alloy to the magnesium alloy is (1-3):1.

[0012] According to another aspect of the present invention, the present invention also provides a method for preparing the composite shape memory alloy, comprising:

[0013] S1: processing a plurality of evenly distributed mortise and tenon structures or snap-fit ​​structures on the surfaces of a pair of magnesium alloy layers or magnesium-aluminum alloy layers, and then fixing them in a die at intervals, so that the plurality of evenly distributed mortise and tenon structures or snap-fit ​​structures are symmetrical up and down, and using the pair of magnesium alloy layers or magnesium-aluminum alloy layers as an upper die and a lower die respectively to form a cavity;

[0014] S2: Mixing a thermosetting matrix resin, a thermally responsive filler and a thermosetting elastomer to form a mixed resin, pouring the mixed resin into the mold cavity, and naturally curing at 20-25 degrees to obtain a thermally responsive shape memory polymer layer;

[0015] S3: open the mold, and you’re done;

[0016] Alternatively, aluminum alloy powder is deposited on the magnesium alloy layer and laser scanned, and the surface of the aluminum alloy is anodized to obtain the product.

[0017] According to one embodiment of the present invention, the mixed resin in step S2 further includes a defoamer and / or a curing agent.

[0018] According to one embodiment of the present invention, the laser power of the laser scanning in step S3 is less than 3 kW, the vertical spot diameter range is less than or equal to 200 μm, and the scanning speed is 200 mm / min to 300 mm / min.

[0019] According to another aspect of the present invention, the present invention also provides application of the composite shape memory alloy in virtual reality equipment.

[0020] In general, the above technical solution conceived by the present invention has the following technical advantages compared with the prior art:

[0021] 1. The composite shape memory alloy of the present invention has strong deformation ability, light weight, high strength and low cost. The thermal responsive shape memory polymer layer has strong bonding with the metal layer. The preparation process does not require solvents and can be naturally cured, which greatly reduces process energy consumption and environmental pollution.

[0022] 2. The thermally responsive shape memory polymer layer at the preferred thickness of the present invention reduces the cost without significantly reducing the overall strength, and can also keep the overall deformation capacity of the composite shape memory alloy basically unchanged.

[0023] 3. The ratio of magnesium to aluminum in the preferred magnesium-aluminum alloy of the present invention is moderate, which can improve the comprehensive performance of the composite shape memory alloy. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the product process of Example 1 of the present invention.

[0025] Figure numerals: 1. upper mold; 2. lower mold; 3. thermally responsive shape memory polymer layer. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0027] Example 1

[0028] The present invention provides a method for preparing a composite shape memory alloy, comprising:

[0029] S1: 10 times 200 evenly distributed mortise and tenon structures are processed on the surface of a pair of 6 mm thick and 0.5 times 10 mm magnesium-aluminum alloy layers, and then fixed in a die pressing mold at intervals, so that the multiple evenly distributed mortise and tenon structures are symmetrical up and down, and the pair of magnesium-aluminum alloy layers are used as an upper mold 1 and a lower mold 2 to form a cavity;

[0030] S2: Mixing a thermosetting matrix resin, a thermally responsive filler and a thermosetting elastomer to form a mixed resin, pouring the mixed resin into the mold cavity, and naturally curing at 20-25 degrees to obtain a thermally responsive shape memory polymer layer 3;

[0031] S3: Open the mold and you are done.

[0032] Example 2

[0033] A method for preparing a composite shape memory alloy, comprising:

[0034] S1: 10 times 200 evenly distributed buckle structures are processed on the surface of a pair of 6 mm thick and 0.5 times 10 mm magnesium alloy layers, and then fixed at intervals in a die pressing mold, so that the multiple evenly distributed buckle structures are symmetrical up and down, and the pair of magnesium alloy layers are used as an upper mold 1 and a lower mold 2 to form a cavity;

[0035] S2: Mixing a thermosetting matrix resin, a thermally responsive filler and a thermosetting elastomer to form a mixed resin, pouring the mixed resin into the mold cavity, and naturally curing at 20-25 degrees to obtain a thermally responsive shape memory polymer layer 3;

[0036] S3: opening a mold, depositing aluminum alloy powder on the magnesium alloy layer and laser scanning after the mold opening, the thickness ratio of the aluminum alloy to the magnesium alloy is 3:1, and anodizing the surface of the aluminum alloy to obtain.

[0037] Comparative Example 1:

[0038] Different from Example 1, Comparative Example 1 is a pure thermal responsive shape memory polymer layer.

[0039] Comparative Example 2

[0040] Different from Example 1, the atomic ratio of magnesium to aluminum is 1:1.

[0041] Comparative Example 3

[0042] Different from Example 2, the thickness ratio of the aluminum alloy to the magnesium alloy is 5:1.

[0043] Application Testing

[0044] The composite shape memory alloys prepared in Example 1-2 and Comparative Example 1-2 were subjected to performance tests. The results are shown in Table 1.

[0045] project Mechanical strength (MPa) Recovery rate after 1000 deformations Cost (yuan / Kg) Example 1 116 92％ 61 Example 2 102 93％ 69 Comparative Example 1 58 95％ 35 Comparative Example 2 92 82％ 66 Comparative Example 3 123 79％ 73

[0046] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A composite shape memory alloy, characterized in that: include: A thermally responsive shape memory polymer layer, and a metal layer symmetrical to the upper and lower surfaces of the thermally responsive shape memory polymer layer; The thermally responsive shape memory polymer layer comprises a thermosetting matrix resin, a thermally responsive filler and a thermosetting elastomer; the metal layer is a magnesium-aluminum alloy layer, or a magnesium alloy layer with aluminum alloy deposited on a side away from the thermally responsive shape memory polymer layer.

2. The composite shape memory alloy according to claim 1, characterized in that: The thickness ratio of the thermal responsive shape memory polymer layer to the metal layer is (2-4):

1.

3. The composite shape memory alloy according to claim 1, characterized in that: The thermosetting matrix resin is epoxy resin or phenolic resin, the thermosetting elastomer is thermosetting polyurethane elastomer, the thermal responsive filler is one of carbon nanotubes, graphene, and aluminum nitride, and the mass fractions of the thermosetting matrix resin and the thermosetting elastomer are 40-44.9%wt and 45-59.9%wt, respectively.

4. The composite shape memory alloy according to claim 1, characterized in that: The thickness of the metal layer is not greater than 0.6 mm, and the elongation of the metal layer is not less than 3%.

5. The composite shape memory alloy according to claim 1, characterized in that: When the metal layer is a magnesium-aluminum alloy layer, the atomic ratio of magnesium to aluminum in the magnesium-aluminum alloy layer is (0.33-0.75):1; when the metal layer is a magnesium-aluminum alloy layer in which an aluminum alloy is deposited on the side away from the thermally responsive shape memory polymer layer, the thickness ratio of the aluminum alloy to the magnesium alloy is (1-3):

1.

6. A method for preparing the composite shape memory alloy according to any one of claims 1 to 5, characterized in that: include: S1: processing a plurality of evenly distributed mortise and tenon structures or snap-fit ​​structures on the surfaces of a pair of magnesium alloy layers or magnesium-aluminum alloy layers, and then fixing them in a die at intervals, so that the plurality of evenly distributed mortise and tenon structures or snap-fit ​​structures are symmetrical up and down, and using the pair of magnesium alloy layers or magnesium-aluminum alloy layers as an upper die and a lower die respectively to form a cavity; S2: Mixing a thermosetting matrix resin, a thermally responsive filler and a thermosetting elastomer to form a mixed resin, pouring the mixed resin into the mold cavity, and naturally curing at 20-25 degrees to obtain a thermally responsive shape memory polymer layer; S3: open the mold, and you’re done; Alternatively, aluminum alloy powder is deposited on the magnesium alloy layer and laser scanned, and the surface of the aluminum alloy is anodized to obtain the product.

7. The preparation method according to claim 6, characterized in that: The mixed resin in step S2 further includes a defoamer and / or a curing agent.

8. The preparation method according to claim 6, characterized in that: In step S3, the laser power of the laser scanning is less than 3 kW, the vertical spot diameter range is less than or equal to 200 μm, and the scanning speed is 200 mm / min to 300 mm / min.

9. An application of the composite shape memory alloy according to any one of claims 1 to 5 in a virtual reality device, wherein the virtual reality device is VR glasses or AR glasses.

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