Glass forming ability and crystallisation processes within the Al-Ni-Sm system

Several melt-spun ribbons of different compositions in the Al-rich corner o f the Al-Ni-Sm ternary system were analysed by means of X-ray diffraction ( XRD) and differential scanning calorimetry (DSC) in order to determine thei r thermal stability and to understand the nanocrystallisation process. Out of all the compositions analysed, only three were found to be completely am orphous, whereas the others were partially crystallised. The activation ene rgies of the alpha -Al nanocrystallisation were evaluated using the Kissing er method. Isothermal DSC scans revealed the existence of quenched-in nucle i in the more unstable amorphous alloys. These quenched-in nuclei are proba bly due to the melt-spinning process and the crystalline structure after de vitrification is strongly dependent on them. (C) 2001 Elsevier Science B.V. All rights reserved.