JPS60149763A - Manufacture of color tone memory element - Google Patents

Abstract

PURPOSE:To manufacture easily a color tone memory element of an arbitrary shape by forming an alloy film consisting of specified percentages of Cu, Al and Ni on the surface of a metallic or nonmetallic substrate by a physical film forming method. CONSTITUTION:An alloy consisting of 11-15wt% Al, 1-5wt% Ni and the balance Cu and having thermoelastic martensitic transformation characteristics is prepd. A film of the alloy is formed on the surface of a metallic or nonmetallic substrate by a physical film forming method such as flame spraying, plasma spraying, vacuum deposition, sputtering or ion plating. The alloy has a transformation characteristic temp. in the temp. range of about -200-+400 deg.C, and the color tone is reversibly changed from brown to golden yellow. When the Al content is low, the martensite producing temp. is high, and when the Al content is high, the martensite producing temp. is low.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for manufacturing a color tone memory element, and more particularly, to a method for manufacturing a color tone memory element, which has thermoelastic martensitic transformation characteristics and is capable of forming a color tone memory element upon transformation from a matrix phase to a martensitic phase. The present invention relates to a method for manufacturing a color tone memory element, in which a Cu-Al-N1 alloy film whose color tone reversibly changes from reddish to golden yellow is formed on the surface of a substrate using a physical film formation method.

[Technical background of the invention and its problems]

In recent years, alloys with thermoelastic martensitic transformation characteristics have been discovered one after another, and basic and applied research focusing on the shape memory effect and pseudoelastic (superelastic) effect of these alloys is underway.

Incidentally, in addition to mechanical properties such as shape memory effect and superelastic effect, optical properties are conventionally known as unique properties that occur in response to thermoelastic martensitic transformation.

For example, the color of certain copper-based alloys changes from reddish to golden yellow at the transformation temperature. As an alloy having such a color tone memory effect, C
u -Al-N1 alloy (e.g. AI/Co~/3C,
Ni/- is present, the remainder is Cu).
Year/170♂gu! Publication No.). That is, this Cu-A
The I-Ni alloy has a transformation characteristic temperature from the parent phase to the martensitic phase in the temperature range of -200 to 10ti-oo''C, and the color tone of the alloy changes to red at the transformation characteristic temperature. The color changes from golden brown to beautiful gold, and this change in color is reversible.Also, such a change in color can be caused by an external force, and the stress generated in the alloy causes stress. The color tone of the alloy changes reversibly due to the precipitation of induced martensite. Also, the transformation characteristic temperature can be adjusted as appropriate by adjusting the amount of Al added.

However, by utilizing these five color tone memory characteristics, it is also possible to use it as a color tone memory element that converts changes in temperature or external force into changes in color tone.

However, the Cu-AI-Ni alloy mentioned above has extremely low toughness and lacks machinability and workability.
There is a problem in that it is difficult to precisely process this into a thin wire, plate, or film shape, or to make it into a fine color tone memory element.

[Objective of the Invention] The present invention has been made in view of the above-mentioned problems, and it solves the difficulty in processing Cu-AI-Ni alloys having color tone memory properties, and provides color tone memory elements of any shape. The purpose is to provide a way to obtain

[Summary of the invention]

In order to achieve the above object, the method for manufacturing a color tone memory element of the present invention includes Al 11 to 75% by weight, Nt /~j% by weight
, a film made of an alloy having thermoelastic martensitic transformation characteristics with the remainder being Cu is formed on the surface of a metal or non-metal base material by a physical film forming method.

The color tone memory element obtained by the present invention can be used in a wide range of applications such as temperature-sensitive displays, temperature sensors, and measurement parts such as strain gauges and stress sensors that detect changes in external force, as well as arts and crafts, decorative items, and accessories. Can be used.

[Detailed description of the invention]

The present invention will be explained in more detail below. In the following description, "chi" representing the composition is based on weight.

The copper alloy used in the color tone memory element of the present invention is Al//~/
! i%, N1/~j%, balance CuO thermoelastic martenzite transformation characteristics, this alloy is -,2
It has a transformation characteristic temperature within the temperature range of 00°C to -4-aoo'c.

In the martensitic transformation in the Cu-AI-Ni system, υ is generated by decomposition of the β phase, but the martensite formation temperature (MI1 point) differs depending on the amount of Al. AI//~/30
When the amount of Al is small in J, the M8 point increases;
When the amount increases, the Ms point becomes 0°C or lower. In any case, the M8 point falls within the range of 10≠oo to -200°C. A
When it is less than 1//1, the α phase increases and the β phase involved in martensitic transformation decreases, and as a result, the change from reddish to golden yellow becomes small. When the AI becomes 1591+ or higher, the Ml1 point becomes sub-zero treatment (when the temperature drops below 0°C)
For example, it is difficult to generate martensitic transformation even by using dry ice (-10°C). Also r2
phase is formed, the β phase is reduced, and as a result, the change from reddish to golden yellow becomes smaller.

Generally, copper alloys with the above composition have a transformation temperature in a temperature range of up to 200°C, but as the amount of At added increases, there is a tendency for the transformation temperature to decrease. By adjusting the amount of A1 added, the transformation temperature can be adjusted as appropriate.

Further, when an external force is applied, the transformation temperature usually exists in a higher temperature range than the transformation temperature when no external force is applied. However, in addition to the amount of AI added, the transformation temperature can be arbitrarily adjusted within the range of 1200 to 200°C by applying an external force.

Nl is used as an alloying component to improve corrosion resistance.
If the content is less than 9I+, corrosion resistance deteriorates, and if it is 75% or more, the improvement in corrosion resistance is saturated, and adding more than 9I+ is not preferable from the viewpoint of corrosion resistance.

It is preferable that impurities incidentally included when adding the above components and Cu as the main component be as small as possible.

As the base material on which the layer of the alloy having the above composition is formed, a wide variety of organic materials such as element plastics and wood can be used.

In the present invention, a physical film forming method is used as a method for forming an alloy layer having the above composition on the surface of a base material. The physical film forming method used in the present invention includes a method in which a molten alloy is injected onto the surface of a substrate by physical means, and a physical vapor deposition method.
on, hereinafter referred to as PVD). For example, flame spraying, plasma spraying, and as PVD, vacuum evaporation, sputtering, and ion-jetting are preferably used.

The above-mentioned physical film forming methods are each applied according to conventional methods.

Furthermore, in order to improve the adhesion between the base material and the alloy layer, it is preferable to perform a surface treatment on the base material as a pretreatment for applying the above-mentioned physical film forming method, if necessary.

For details of these physical film forming methods, such as flame spraying and plasma spraying, please refer to the Bulletin of the Japan Institute of Metals [Vol. 22, No. 1 (/?lr3), 102/-1]
0, 21 pages], and PVD is further described in Metal Surface Technology [Volume 3S, No. 1 (/Ri♂Hiro), 2-
page 3].

[Embodiments of the invention]

Example/Al/3. ! 4. An alloy consisting of % Ni J and the balance Cu was vacuum melted and cast into a mold to create an ingot.

Next, this ingot-shaped alloy was powdered by an atomization method. The particle size of the alloy powder was set in the range of 100 μm to 1 μm.

Next, using this alloy powder, the surface of a wire rod with a diameter of 0.71111 mm (manufactured by SUS 30≠) was coated with a thickness of 0.0 mm by flame spraying. / j The sprayed layer was formed continuously. Furthermore, the sprayed layer coated in this way was polished by QOjmm to obtain a linear color tone memory element.

The obtained color tone memory element was placed in an argon atmosphere at 50°C.
and then oil quenching (at room temperature). The color tone at this point was golden yellow. Next, when this was immersed in silicone oil at Izo°C, the color changed from red to golden brown, and when the temperature was returned to room temperature, the color changed to gold. The above operation was repeated 3 times, but the color tone changed reversibly.

Example An alloy consisting of AI/3%, Ni j %, and the balance Cu was vacuum melted and cast into a mold to produce an ingot.

Next, this ingot-shaped alloy was pulverized by an atomization method. The particle size of the alloy powder was in the range of 1 to rrμm.

Next, using this alloy powder, a sprayed layer with a thickness of 03 rm was formed on the surface of an 8 US 30≠ plate with a width of 10 mm and a thickness of 7.0 mm by plasma spraying. Further, the sprayed layer thus coated was polished by Q, /vrrn to obtain a color tone memory element.

The obtained color tone memory element was placed in an argon atmosphere and heated to SO″C.
After heating it to 100%, it is quenched in oil at room temperature.

The color tone of the device at this point was a reddish-brown color. Then,
When this plate-shaped element was bent, the color of the stressed areas changed from reddish to golden yellow. This change in color tone was caused by the precipitation of stress-induced martensite in the coating alloy due to residual stress.

Example 3 Al/,? %, NiJ%, and the remainder Cu was vacuum melted and cast into a mold to create ingo 7).

Using this ingot as a deposition source, the surface of Fe-based metal parts was coated by vacuum deposition. This was heated to 50°C in argon.
and quenched in oil at room temperature. At this point, the color tone of the part surface was golden yellow, but when heated in silicone oil at 200°C, it changed to a reddish-brown color.

Then, when the temperature was returned to room temperature, the color became golden again.

Example≠ An alloy consisting of AI//%, Ni, t%, and the balance Cu was vacuum melted and cast into a mold to create an ingot.

As this ingot target, the surface of an Fe-based metal component was coated by sputtering in an Ar atmosphere. This was heated at 230° C. in argon and oil quenched at room temperature. At this time, the color tone of the part surface was golden yellow, but when heated to 300°C in vacuum, it became reddish-brown. When this was further returned to room temperature, it took on a golden color again.

Example j An alloy consisting of AI/, EiJ, 3% Ni, and the balance Cu was vacuum melted and cast into a mold to create an ingot.

Using this ingot as a vapor deposition source, a SUS 3017 plate (width 10 mm, thickness O9
The surface of (r) was coated with the above alloy. This was heated to SO 0 C in argon and oil quenched at room temperature. The color tone of the plate surface after oil quenching was a reddish color.

When this plate-shaped color tone memory element is bent to generate stress,
The color tone of the areas where stress remains changes to golden yellow.

Comparative Example AI/4 alloy, NIJ%, balance Cu, was vacuum melted and cast into a mold to create an ingot with a diameter of 0.

From this ingot, 10×1
I made a Kakuri of 0 friends.

Then, thickness/l! When cold rolling was performed to produce plate material No. 11, cracks occurred. Furthermore, an attempt was made to produce a plate material with a thickness of /III+ by warm rolling of jt00'c, but cracks still occurred. Furthermore, an attempt was made to produce a plate material with a thickness of /mm by hot rolling at rro°C, but cracks occurred along the grain boundaries. Further, an attempt was made to process the material into a wire rod using a method similar to that described above, but the process was difficult due to cracks and other problems.

〔Effect of the invention〕

As described above, the method for manufacturing a color tone memory element of the present invention includes:
Since a Cu-based alloy layer having color tone memory properties is formed on the surface of a base material having a desired shape by a physical film-forming method,
The difficulty of processing that the Cu-based alloy has is solved, and it becomes possible to manufacture color tone memory elements of any shape suitable for various uses.

Applicant's agent Kiyoshi Inomata

Claims (1)

[Claims] A film made of an alloy having thermoelastic martensitic transformation characteristics consisting of /, AI// ~13% by weight, Nl/-1% by weight, and the balance Cu is formed by a physical film forming method, metal Alternatively, a method for manufacturing a color tone memory element, characterized in that it is formed on the surface of a base material made of a nonmetal. 7. The method according to claim 7, wherein the physical film forming method is a flame spraying method, a plasma spraying method, a vacuum evaporation method, a sputtering method, or an ion blasting method.