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

Abstract

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. © 2004 Elsevier Ltd. All rights reserved.