Crystallization and thermal stability of the Mg₆₅Cu_25-xGd₁₀Ag_x (x = 0-10) amorphous alloys

Mg₆₅Cu_25-xGd₁₀Ag_x (x = 0-10) amorphous alloy ribbons with 0.1 mm thickness were prepared by melt spinning. The thermal properties and microstructure development during the annealing of amorphous alloys have been investigated by the combination of differential scanning calorimetry (DSC), SEM with EDS capability, X-ray diffractometry (XRD) and TEM techniques. The XRD result reveals that all these as-quenched Mg₆₅Cu_25-xGd₁₀Ag_x alloy ribbons exhibit broad diffraction patterns of amorphous phase. A clear T_g (glass transition temperature) and supercooled region (about 40 K) were revealed for all Mg₆₅Cu_25-xGd₁₀Ag_x alloy ribbons. In addition, the single stage crystallization of the Mg₆₅Cu₂₅Gd₁₀ alloy was found to change into three stage crystallization when the Ag element was added. In parallel, the glass transition temperature for the Mg₆₅Cu_25-xGd₁₀Ag_x alloys exhibits an increasing trend with Ag content. However, the crystallization temperature T_x and supercooled region present a decreasing trend with Ag content.