抄録
Cu-based amorphous alloys containing above 80 at%Cu are found to form in the Cu–Mg–Ce ternary system by rapid solidification. The composition range extends from 8 to 14 at%Mg and 4 to 8%Ce. No amorphous phase is formed in the Cu-rich Cu–Mg and Cu–Ce binary systems and hence the simultaneous dissolution of the three elements with significantly different atomic size ratios is essential for the glass formation. The increase of the glass-forming ability in the ternary system has been interpreted to be due to the difficulty of nucleation and growth reactions of crystalline phases through the formation of a higher degree of dense random packed structure. The crystallization for the Cu–Mg–Ce amorphous alloys takes place through two stages of Am→Am′+Cu+Cu6Ce→Cu+Cu6Ce+Cu2Mg in the range above about 84 at% Cu and Am→Am′+Mg2Ce→Mg2Ce+Cu+Cu6Ce+Cu2Mg in the range below 80 and 83 at% Cu. The Cu-based amorphous alloys exhibit a color tone typical for crystalline Cu metal and are expected to develop as an amorphous alloy with the distinguishable color.
