Effect of melt temperature on primary crystallization and thermal stability of Al₈₆Ni₆Y_4.5Co₂La_1.5 metallic glass

In this paper, the correlations between the melt temperature of Al₈₆Ni₆Y_4.5Co₂La_1.5 alloy and its crystallization behavior were studied. The results of differential scanning calorimetry (DSC) showed that the primary crystallization of Al₈₆Ni₆Y_4.5Co₂La_1.5 alloy was greatly affected by the melt temperature: compared with the amorphous ribbons prepared at 1373 K and 1673K, the primary crystallization of the ribbons prepared at 1523 K was significantly advanced; The calculation of the activation energy indicated that the amorphous ribbon prepared at 1523 K has a lower energy barrier to be overcome during the first crystallization stage, which means that its thermal stability is worse, and fcc-Al is more likely to be precipitated; Abnormal melt structural changes were observed by electrical resistivity(ER), and liquid-liquid structure transition(LLST) occurred after 1402 K, which can be proved by the results of x-ray diffraction (XRD); Compared with the amorphous ribbons prepared at 1523 K and 1673K, the one prepared at 1373 K were more likely to precipitate intermetallic compounds during crystallization, which may be related to the disappearance of some atomic clusters caused by the increase of melt temperature. (paper)