Consolidation of gas atomized Cu47Ti34Zr11Ni8 amorphous powders

The dense, random atomic configuration of bulk metallic glasses enhances their stability against crystallization in the supercooled liquid state. This stability provides the opportunity to deform the material by plastic processing methods such as warm extrusion. Gas atomized Cu47Ti34Zr11Ni8 powders were consolidated at various temperatures above their glass transition temperature (688 K) at extrusion ratios of 5, 9 and 13. At extrusion temperatures approaching Tx (743 K), powders consolidated at an extrusion ratio of 5 were predominantly amorphous while at higher ratios the powders were completely devitrified, yet fully consolidated. Gradients in the degree of devitrification were observed along the length (i.e., top to bottom) of all extruded materials.