Glass formation in a multicomponent Zr-based alloy by mechanical attrition and liquid undercooling

The synthesis of a multicomponent Zr60Al10Ni9Cu18Co3 glass by mechanical alloying has been investigated using thermal and structural analysis and compared with a metallic glass produced by liquid undercooling. The solid-state amorphization reaction is preceded by rapid solution of smaller solute atoms in the Zr matrix with a concomitant reduction in grain size to 10 nm at the amorphization onset. A fully amorphous mechanically alloyed sample shows relaxation compared to a sample synthesized by liquid cooling probably due to removal of residual inhomogeneities on the scale of the nanocrystal size at amorphization. While the kinetic pathways for the two synthesis methods differ, the relaxed amorphous phases from each method exhibit identical thermodynamic properties. (C) 1997 American Institute of Physics.