JP2884701B2 - Manufacturing method of shape memory material - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method of manufacturing a shape memory material, and more particularly to a method of manufacturing a shape memory material that restores its shape in two stages.

[Prior Art] As a shape memory material, a metal material represented by a Ti-Ni material and a plastic material are known.

[Problems to be Solved by the Invention] However, any shape memory material restores its original shape (prestored shape) at its own temperature, and has only one-stage shape restoring action. There is no actual situation. Therefore, a known shape memory material may have a limited use range.

It is conceivable to combine a metal-based shape memory material and a plastic-based shape memory material in order to widen the usage mode. In order to obtain such a combination, a shape memory alloy is manufactured by dissolving and diffusing a predetermined metal (for example, Japanese Patent Application Laid-Open No. Sho 60-262929), and a shape memory plastic molded in advance is attached thereto. However, simply integrating the alloy and plastic as described above,
At the time of shape restoration, peeling or breakage occurs between them, and it is practically difficult to restore the shape in two stages.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method of manufacturing a shape memory material having a two-stage shape restoring action.

[Means for Solving the Problems] In the production method of the present invention, in order to achieve the above object,
The surface of the plastic powder is coated with a fine powder of a shape memory alloy, which is aggregated to sinter and bond only the fine powder of the shape memory alloy. And the plastic is gasified, and then the gasified portion is impregnated with the shape memory plastic.

[Function] After the plastic powder is coated with the fine powder of the shape memory alloy, and only the fine powder of the shape memory alloy is sintered and bonded,
By performing the heat treatment, the predetermined shape is stored in the bonded shape memory alloy, and at the same time, the plastic is gasified. Therefore, when the shape memory plastic is impregnated thereafter, the gasified portion is filled with the shape memory plastic, and a shape memory material in which the shape memory alloy and the shape memory plastic are mixed with each other can be manufactured.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows a method for producing a shape memory material according to the present invention.

First, a Ti-Ni alloy which is a shape memory alloy is powdered by an atomizing method or the like, and a plastic material is powdered (step A). The diameter of the plastic powder obtained at this time is set to be 5 to 10 times the diameter of the Ti—Ni alloy powder. Then, as shown in FIG. 2, the surface of the plastic powder 1 is coated with a plurality of Ti—Ni alloy powders 2. This coating can be performed, for example, by a high-speed airflow impact method. In the high-speed air current impact method, after the Ti-Ni alloy powder 2 is electrostatically adhered to the surface of the plastic powder 1 and then put on a high-speed air current to collide with a wall, the alloy powder 2 is further strengthened. It is a method of attaching to the.
By this method, a so-called capsule powder 3 in which the plastic powder 1 is the core and the outer surface of the core is coated with the alloy powder 2 is formed (Step B).

Next, after assembling the capsule powders 3 as shown in FIG. 3, electric current plasma sintering is performed (step C). Then, the alloy powders 2, 2,..., Which are the coating side members of the respective capsule powders 3, are sintered and bonded to form a sintered body 4. As shown in FIG. 4, the sintered body 4 includes a shape-memory alloy 5 which is sintered and bonded, and a plastic 6 which is surrounded by the shape-memory alloy 5.

Next, after the sintered body 4 is formed into a predetermined shape (use shape at a high temperature), a heat treatment is performed (step D). This heat treatment step is a step of storing the above-mentioned predetermined shape in the sintered body 4, and after the sintered body 4 is heated to a predetermined temperature in an electric furnace, is rapidly cooled. At this time, the plastic 6 in the sintered body 4 shown in FIG. 4 is gasified by the above-mentioned heating, and the portion becomes a cavity, leaving only the reticulated shape memory alloy 5. Therefore, the remaining shape memory alloy 5 undergoes a phase transformation by rapid quenching, and stores a predetermined shape.

Next, the shape memory alloy 5 is impregnated with a shape memory plastic (step E). That is, the shape memory alloy 5
Is placed in a plastic mold, and then the shape memory plastic is molded in the mold. Thereby, each cavity in the shape memory alloy 5 formed in the above step D has:
As shown in FIG. 5, the shape memory plastic 7 is filled. Then, the shape memory plastic 7 stores the above-mentioned predetermined shape at the end of the molding. In this way, as shown in FIG. 5, a composite shape memory material 8 composed of the shape memory alloy 5 and the shape memory plastic 7 is obtained. Here, as the shape memory plastic 7, polynorbornene, styrene / butadiene copolymer, or the like can be used.

Thereafter, the shape memory material 8 is further plastically deformed (step F), and is shaped into a use shape at a normal temperature.

As described above, in the present embodiment, the surface of the plastic powder 1 is coated with the Ti—Ni alloy powder 2 to form the capsule powder 3, and the capsule powder 3 is aggregated and sintered. Since the plastic 6 is gasified by heat treatment, a shape-memory alloy 5 combined in a network and having a large number of cavities therein is obtained, and the alloy 5 can store a predetermined shape. Therefore, the shape memory alloy 5 is then impregnated with the shape memory
And the shape memory plastic 7 are mixed at a uniform ratio over the entire area. Therefore, the obtained shape memory material 8 can have a very light weight and a good shape restoring effect. In addition, the adhesion between the shape memory alloy 5 and the shape memory plastic 7 is improved, the peeling thereof can be prevented, and the durability of the shape memory material 8 as a whole is also improved.

FIGS. 6 and 7 schematically show a state in which the plate-shaped shape memory material 8 is manufactured according to the above-described steps, and a restoring operation of the shape memory material 8, respectively.

The plate-shaped sintered body 4 obtained in the sintering step of FIG.
After being bent by a predetermined angle, heat treatment is performed (FIG. 4B), and the shape memory alloy 5 in which the substantially L-shape is stored is obtained. After that, the shape memory alloy 5 is impregnated with the shape memory plastic 7 (FIG. 3 (c)), and the shape memory plastic 7 also stores the same shape as the shape memory alloy 5. Finally, the obtained shape memory material 8 is press-formed into a flat plate shape (FIG. 4D).

This shape memory material 8 is usually used in the form of a flat plate as shown in FIG. 7 (a). Now, as the environmental temperature rises, the temperature of the material 8 itself rises, and when the temperature reaches the inherent temperature (glass transition point) of the shaped plastic 7, the shaped plastic 7 attempts to restore its shape. . However, in a state where the environmental temperature has not reached the inherent temperature (reverse transformation start point) of the shape memory alloy 5, the shape restoring action does not work on the shape memory alloy 5, so that the shape restoring operation of the shape plastic 7 is not performed. Is suppressed. As a result, the seventh
As shown in FIG. 2B, the shape memory material 8 is restored by a predetermined ratio (angle) with respect to the shape (L-shape) stored in advance. Thereafter, when the environmental temperature further rises and reaches the inherent temperature (reverse transformation start point) of the shape memory alloy 5, the restoration operation of the shape memory alloy 4 is started only there. Therefore, as shown in FIG. 7 (c), the shape of the shape memory material 8 returns to the memory shape (L-shape).

Such a shape memory material 8 can be used in various fields due to its two-stage shape restoring action. For example, if the present invention is applied to an automobile window or a radiator fan, the driving of the window or the fan can be controlled in two stages with an extremely simple configuration.

In the above embodiment, the surface of the plastic powder 1 was coated with the Ti-Ni alloy powder 2 by using the high-speed air impact method, but other methods may be used as the coating method. Good. Although the shape memory material 8 is composed of the Ti-Ni-based shape memory alloy 5 and the shape plastic 7, the types of the shape memory alloy 5 and the shape plastic 7 can be variously changed as necessary.

[Effects of the Invention] In summary, according to the method of the present invention, an excellent effect that a shape memory material having a two-stage shape restoring action can be surely produced is exhibited.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a method of manufacturing a shape memory material according to the present invention, FIG. 2 is a schematic diagram showing capsule powder, FIG. 3 is a view showing a state in which capsule powder is aggregated, and FIG. FIG. 5 is a schematic diagram showing a sintered body, FIG. 5 is a schematic diagram showing a shape memory material, FIG. 6 is a diagram schematically showing a state when a plate-shaped shape memory material is manufactured, and FIG. FIG. 7 is a view showing a restoring operation of the shape memory material obtained according to FIG. 6; In the figure, 1 is a plastic powder, 2 is a Ti-Ni alloy powder (fine powder of a shape memory alloy), 3 is a capsule powder, 4 is a sintered body, 5 is a shape memory material, 7 is a shape memory plastic, 8
Is a shape memory material.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Nobuo Yagi, No. 8 clay bowl, Fujisawa, Kanagawa Prefecture Isuzu Central Research Institute Co., Ltd. (72) Takashi Hino, No. 8 clay bowl, Fujisawa City, Kanagawa Prefecture Isuzu Motors Limited Fujisawa Inside the factory (72) Inventor Naotaka Yamamoto 8 Dosana, Fujisawa-shi, Kanagawa Pref.Isuzu Central Research Institute Co., Ltd. (72) Inventor Hidetaka Shibata 8 Dosana, Fujisawa-shi, Kanagawa Pref. Person Akira Ibuki 3-25-1, Tonomachi, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture Isuzu Motor Co., Ltd.Kawasaki Plant (72) Inventor Tokuro Yamashita 8 Tsuchiya, Fujisawa-shi, Kanagawa Prefecture Isuzu Central Research Laboratory Co., Ltd. (72) Inventor Yosuke Tanaka No. 8 Tsuchiya, Fujisawa-shi, Kanagawa Prefecture Isuzu Central Research Institute Co., Ltd. (72) Inventor Masayuki Munemura Kanagawa 8 Isuzu Central Research Laboratory, Fujisawa City Inside Isuzu Central Research Laboratories Co., Ltd. (72) Eiichi Nakagawa 8 Edo Tanabe City, Fujisawa City, Kanagawa Prefecture Inside the 72nd Isuzu Central Research Laboratories Co., Ltd. (56) References JP-A-60-221505 (JP, A) JP-A-62-267434 (JP, A) JP-A-3-146626 (JP, A) (58) Field (Int.Cl. ⁶ , DB name) B22F 3/00-3/26 C22C 1/04-1/05

Claims (1)

(57) [Claims] 1. A plastic powder having a surface coated with a fine powder of a shape memory alloy, which is aggregated to be sintered and bonded only to the fine powder of the shape memory alloy. A method of manufacturing a shape memory material, comprising storing a predetermined shape in a shape memory alloy, gasifying the plastic, and then impregnating the gasified portion with a shape memory plastic.