PURPOSE: To obtain an alloy having partially different spectral reflectances at the same temp. by preparing an alloy having silver as a principal component, containing specific amounts of specific elements such as zinc, Cd, etc., and having a spectral reflectance which differs according to the methods of cooling.
CONSTITUTION: The alloy having silver as a principal component and containing 30W46wt% Zn, ≤10wt% Cd and ≤15wt% of 1 or ≥2 elements among the elements of groups Ia, IIa, IVa, Va, VIa, VIIa, VIII, Ib, IIIb, IVb and Vb and rare earth elements is prepared. In this alloy, the crystal structure in a condition of primary temp. (high temp.) higher than room temp. differs from that in a condition of a temp. (low temp.) lower than the primary temp. in the form of solid. Therefore the spectral reflectance in the case where a high-temp. phase is cooled rapidly differs from that in the case of a low-temp. phase of normal condition unsubjected to rapid cooling, so that the spectral reflectance changes reversibly according to heating and rapid cooling in a temp. region of high-temp. phase and heating and cooling in a temp. region of low-temp. phase. Further, the difference in the spectral reflectance is ≥5% and it is preferable to use nonbulk material as the above alloy.
KATO YOSHIMI
MINEMURA TETSUO
ANDO HISASHI
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