Effect of Ag addition on the glass-forming ability and thermal stability of Mg–Cu–Y alloys

Effects of silver addition on a range of Mg65Cu25−zAgzY10 (z=0–15 at.%) bulk metallic glasses have been studied. No correlation could be seen between the glass-forming ability of these alloys and the thermal stability of the glasses on subsequent heating. Transmission electron microscopy and differential scanning calorimetry reveal that this discrepancy is not attributable to phase separation in the supercooled liquid. Silver addition enhances the glass-formability of these alloys because of a significant reduction in crystal growth rate, but reduces the thermal stability of these glasses, apparently by allowing growth on quenched-in nuclei.