PURPOSE: To obtain an alloy having variable spectral reflectance and maintaining partially different spectral reflectances at the same temp. by partially subjecting a Cu alloy contg. specified amounts of Ge and Al to rapid cooling and nonrapid cooling to form different crystal structures.
CONSTITUTION: A Cu alloy contg. 20W28wt% Ge and 0.01W3.0wt% Al is prepd. The alloy is a nonbulky material, has ≤0.1μm grain size, and is in the form of a thin film, foil, a strip, powder or a fine wire of ≤about 0.1mm thickness or diameter. The surface of the alloy has different crystal structures at the 1st temp. above room temp. and at the 2nd temp. below the 1st temp. in the solid state. Part of the surface of the alloy is rapidly cooled from the 1st temp. to the 2nd temp., and the remainder is nonrapidly cooled from the 1st temp. to the 2nd temp. to form different crystal structures. Thus, an alloy having variable spectral reflectance and producing ≥5% difference in spectral reflectance is obtd.
MINEMURA TETSUO
ANDO HISASHI
NAKAMURA MITSUO
KATO YOSHIMI
