Glass transition and crystallization of Mg-Ni-Nd metallic glasses studied by temperature-modulated DSC

Glass transition and crystallization behavior of several Mg-Ni-Nd metallic glasses has been systematically studied by temperature-modulated differential scanning calorimetry (TMDSC). The glass transition transformation of alloys Mg₇₅Ni₁₀Nd₁₅ and Mg₇₇Ni ₁₈Ni₅, which cannot be detected in conventional differential scanning calorimetry (DSC) heating scans, was observed through TMDSC measurements. It was concluded that the signal of the glass transition on the DSC scans overlapped with the relatively large heat release from the primary crystallization of either intermetallic Mg₃Nd phase in glassy Mg₇₅Ni₁₀Nd₁₅ alloy or Mg₂Ni phase in amorphous alloy Mg₇₇Ni₁₈Ni₅. Increasing the content of Ni in alloy Mg₇₅Ni₁₀Nd ₁₅ can suppress the precipitation processes of Mg₃Nd, and results in the appearance of glass transition transformation on DSC heating curves. This confirmed and verified our TMDSC measurements. Clear observation of glass transition and understanding of crystallization micro-mechanism in such alloys can offer us new alloying and processing strategies for the preparation of bulk glassy alloys and development of new nanocrystalline/amorphous composite materials.