Formation and thermal stability of Ca-Mg-Ag-Cu bulk glassy alloys

Calcium-based bulk glassy alloys in Ca-Mg-Ag and Ca-Mg-Ag-Cu systems were produced by a metallic mold casting method. The maximum rod diameter (d(max)) for the formation of a glassy phase was 4 turn for Ca60Mg20Ag20 and 7 mm for Ca60Mg20Ag10Cu10. The glass transition temperature (T-g), crystallization temperature (T-x), temperature interval of supercooled liquid region (DeltaT(x) = T-x-T-g) and melting temperature (T-m) were 401 K, 435 K, 35 K and 654 K, respectively, for the former alloy and 398 K, 428 K, 30 K and 624 K, respectively, for the latter alloy. The simultaneous addition of Ag and Cu in the Ca-Mg-(Ag, Cu) system causes a steep decrease in T-m and an increase in the reduced glass transition temperature (T-g/T-m), leading to an increase in the glass-forming ability.