Lattice contraction during amorphization by mechanical alloying

Abstract

Amorphization has been achieved in blended elemental Fe-based multicomponent alloy powders by mechanical alloying. The effect of Nb addition to the Fe(42)Ni(28)Zr(10-x)Nb(x)B(20) alloy in the composition range of 1-6 at. % Nb has been investigated and it was shown that the glass-forming ability (GFA) of the alloys, defined as the milling time required to produce an amorphous phase, improved with Nb addition. The improvement was not regular; the highest GFA was achieved at an Nb level of 2 at. %. Associated with the amorphization process, lattice contraction was noted. The processes of occurrence of the amorphous phase in this alloy system, maximum GFA in the alloy with 2 at. % Nb, and lattice contraction were explained on the basis of the atomic strain model developed first for binary alloys and extended later to ternary and multicomponent alloys, and the change in coordination number with the size ratio of the constituent atoms