Formation of amorphous alloys with significant supercooled liquid region by mechanical alloying

Abstract

Amorphization and undercooling of Zr-, Mg-, and Al-based transition metal alloys prepared by mechanical alloying of elemental powders are investigated. The progress of alloying and the resulting phases are characterized by X-ray diffraction and differential scanning calorimetry. Zr-and Mg-based alloys were found to exhibit a large glass-forming ability and an extended supercooled liquid region. In contrast, the mechanically alloyed Al-based alloys consist of two-phase mixtures of a small amount of amorphous material and nanocrystalline phases and show no extended supercooled liquid region. The results are compared with data for quenched bulk amorphous alloys. First results on bulk samples obtained by consolidation of as-milled powders above glass transition temperature are presented.