Synthesis of an amorphous Zr-Al-Ni-Cu alloy with large supercooled liquid region by cold-rolling of elemental foils

Amorphous samples of a multicomponent Zr-Al-Ni-Cu alloy with a large supercooled liquid region of 98 K have been synthesized at ambient temperature from a layered array of individual elemental sheets by repeated low strain rate cold-rolling with intermediate folding. The alloying reactions during cold-rolling were monitored with electron microscopy, X-ray diffraction and thermal analysis. During the initial stage of processing a dissolution of solute into Zr along with a reduction in grain size to about 30 nm was observed and with further processing a fully amorphous sample was obtained after 120 deformation cycles. The characteristics of the amorphous phase developed by repeated cold deformation indicate that it is compositionally homogeneous, structurally more relaxed as compared to mechanically alloyed amorphous powders of similar composition and without the typical impurity levels obtained by mechanical alloying. (C) 1998 Acta Metallurgica Inc. Published by Elsevier Science Ltd. All rights reserved.