Glass formation in mechanically alloyed transition-metal-Zr alloys

Abstract

A large number of TM-Zr alloys (where TM is a transition metal) have been produced by mechanical alloying from crystalline powders of the elements. The first milled products showed a layered microstructure of the powder particles, which became finer with increasing milling time. Longer milling led to amorphous powder. The formation of amorphous TM-Zr (TM ═ Cu, Ni, Co, Fe, Mn) was monitored by X-ray diffraction and differential thermal analysis. Amorphous V-Zr or Cr-Zr could not be produced. The experimental results are compared with the glass-forming ability predicted by free-enthalpy diagrams calculated from the Miedema model. The amorphization is found to depend strongly on a large negative heat of mixing.