FORMATION OF AMORPHOUS-ALLOYS WITH SIGNIFICANT SUPERCOOLED LIQUID REGION BY MECHANICAL ALLOYING

Amorphization and undercooling of Zr-, Mg-, and Al-based transition me tal alloys prepared by mechanical alloying of elemental powders are in vestigated. The progress of alloying and the resulting phases are char acterized by X-ray diffraction and differential scanning calorimetry. Zr- and Mg-based alloys were found to exhibit a large glass-forming ab ility and an extended supercooled liquid region. In contrast, the mech anically alloyed Al-based alloys consist of two-phase mixtures of a sm all amount of amorphous material and nanocrystalline phases and show n o extended supercooled liquid region. The results are compared with da ta for quenched bulk amorphous alloys. First results on bulk samples o btained by consolidation of as-milled powders above glass transition t emperature are presented.