Effects of mechanical agitation, extreme cold working, on the structural changes of splat-cooled amorphous alloy were investigated by the differential scanning calorimetry (DSC) and extended X-ray absorption fine structure (EXAFS) methods. The amorphous alloy composed of both matrix and Ni-enriched clusters did not have a detectable endothermic reaction. Since an amorphous alloy agitated by filing did have an endothermic reaction related to a decrease of glass transition temperature as measured by DSC, mechanical agitation has an effect on the structural relaxation and is interpreted with a proposed hierarchy diagram. The filed amorphous phase was changed by milling for 20 h into a chemically homogeneous amorphous state. Further, by milling for 100 h it eventually changed to an amorphous state such as a supercooled liquid matrix with small mean bond distance. Its glass transition temperature, Tg, was decreased to near room temperature. In this state, molecular clusters with large bone distance were separated as a precursor of metastable phase from the supercooled liquid.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Condensed Matter Physics
- Materials Chemistry