Glass forming and thermal properties of the Mg₆₅Cu ₂₅Gd_10-xNd_x(x=0 ∼ 10) amorphous alloys

The Mg₆₅Cu₂₅Gd_10-xNd_x(x=0 ∼ 10) amorphous alloy rods with 3-6 mm in diameter were prepared by Cu-mold injection method. The thermal properties and mechanical properties of these amorphous alloys have been investigated by DSC, SEM with EDS capability, X-ray diffractometry (XRD) and Vickers hardness test. The XRD revealed that these entire as-quenched Mg₆₅Cu₂₅Gd_10-xNd_x alloy rods exhibit a broaden diffraction pattern of amorphous phase. A clear Ts (glass transition temperature) and supercooled region (about 30-60 K) were revealed for all of those Mg₆₅Cu₂₅Gd_10-xNd _x alloys. In addition, the single stage crystallization of the Mg₆₅Cu₂₅Gd₁₀ alloy was found to change into two stages crystallization when the Nd element was added into this alloy. In parallel, the crystallization temperature (T_x) and supercooled region (ΔT_x) presents a decreasing trend with increasing Nd content, The lowest liquidus temperature (T₁, about 721 K) occurs at the Mg₆₅Cu₂₅Gd₈Nd₂ alloy. In addition, The Mg₆₅Cu₂₅Gd₈Nd₂ alloy exhibits the high y value (0.416, defined as y= T_x/T₈+T ₁), a relatively high T_rg (0.59, defined as T_rg = T_g/T₁/) and the highest hardness in these alloys.