JPS5938291B2 - Alloy for color memory elements - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an alloy having thermoelastic martensitic transformation characteristics, and in particular, it is possible to reversibly change the color tone of gold and copper, which are known as colored metals, according to the transformation from the matrix phase to the martensitic phase. color memory element (color memory element)
copper-aluminum-nickel alloys suitable for use as ent).

In recent years, among intermetallic compounds, alloys with thermoelastic martensitic transformation characteristics have been discovered one after another, and the unique physical properties of these alloys (such as elastic constant electrical resistance and large damping capacity at the transformation temperature) have been discovered one after another. Basic and applied research focusing on mechanical properties (superelasticity, shape memory effect) and mechanical properties (superelasticity, shape memory effect) are being actively conducted.

Application examples include lunar antennas for space exploration that utilize shape memory effects, solid-state engines for energy equipment,
There are many medical devices (artificial heart valves, vertebra correction rods, clips for brain aneurysm surgery), electronic devices (fire alarms, socket integrated circuit soldering), mechanical devices (pins for tightening, pipe fittings), etc. Examples of reported applications of other unique properties include anti-vibration alloys that focus on the high damping ability of the martensitic phase, and gaskets that utilize superelasticity. There is a strong need for the development of applied products.

The present invention has been made in view of the above points, and has been made by focusing in particular on the optical properties of copper-based intermetallic compounds among the unique properties that occur in response to thermoelastic martensitic transformation. The alloy changes in color from red to bright yellow at the transformation temperature.
) is intended to provide an alloy for a color tone memory element that utilizes the reversible change in color.

That is, the present invention relates to an alloy for a color tone memory element, which is characterized by having a thermoelastic martensitic transformation characteristic, comprising 12 to 15 parts by weight of aluminum, 1 to 5 parts by weight of nickel, and the remainder copper.

In other words, the present invention provides that a copper alloy containing 12 to 15% by weight of aluminum and 1 to 5% by weight of nickel is
This is based on the fact that it has a characteristic transformation temperature in the temperature range from 0°C to 400°C, and the color tone changes from red to beautiful golden yellow once the characteristic transformation temperature is reached.

To explain this point in more detail, the copper alloy of the above composition according to the present invention has a transformation temperature in the temperature range of at most ~200°C, but the transformation temperature decreases mainly as the aluminum concentration increases, and at least Temperatures reach up to about -200℃.

However, when an external force is applied, the transformation temperature must exist in a temperature range higher than the transformation temperature under no external force.The upper limit temperature is the composition with the lowest aluminum concentration and a constant external force is applied. and
The temperature is at least about 400°C.

Therefore, by selecting an appropriate aluminum concentration and applying an appropriate amount of external force, the transformation temperature can range from ~-200°C to ~400°C.
Therefore, the temperature at which the color tone changes can be arbitrarily selected within the above temperature range.

It is also possible to apply a certain alternating stress to the alloy so that the color tone changes periodically in response to stress cycles.

Next, the present invention will be explained with reference to examples. Aluminum 1
An alloy consisting of 3.7% by weight of nickel, 4.0% by weight of nickel, and the balance copper was vacuum melted and cast into a mold to create an ingot.

After subjecting the ingot thus prepared to hot plastic working, it was sliced by cutting to create a test piece, solution treated at 950°C for 1 hour in an argon atmosphere, and then quenched in rapeseed oil at room temperature.

The color of the alloy at this point is red, but this is
When it was immersed in silicone oil at °C, it turned golden yellow, and when it was returned to room temperature, it turned red.

Similar operations were repeated 50 times, but the color tone characteristics changed reversibly.

The present invention utilizes such an alloy as an alloy for a color tone memory element.

For example, the color tone memory element alloy according to the present invention can be used, for example, in temperature-sensitive indicators (dials, thermometers), and the like.

It can also be used in indicators sensitive to alternating stresses.

Furthermore, if the alloy of the present invention contains an appropriate amount of aluminum, it is widely used as an alloy called imitation gold in arts and crafts, accessories, decorative items, furniture parts toys, etc. If it is combined with an alloy for color tone memory elements, it is possible to obtain a highly practical product in which various patterns partially change color depending on the ambient temperature, thereby increasing added value compared to conventional products.

Claims (1)

[Claims] 1 Aluminum 12~” 5 Weight 'L 2'7'y
An alloy for a color tone memory element, characterized in that the weight ratio is -/L/i~5, the remainder is copper, and the alloy has thermoelastic martensitic transformation characteristics.