Fabrication of Bulk Metallic Glass Sheet in Cu-47 at% Zr Alloys by ARB and Heat Treatment

Abstract

Pure Cu (99.96%) and pure Zr (99.8%) sheets were stacked and severely deformed up to equivalent strain of 16 by the accumulative roll bonding (ARB) process conducted at RT. The ARB processed sheets showed nanolamellar structure of Cu and Zr. The DSC curves of the ARB processed multi-layers exhibited characteristic exothermic peaks, which were similar to the previous results reported in a mechanical alloying study. When the ARB processed specimen was annealed at 400°C, at which the first exothermic peak appeared, most of the volume transformed into amorphous phase. The ARB processed and then 400°C annealed specimen showed obvious glass transition. That is, there is a possibility to fabricate bulk metallic glass sheet through severe plastic deformation and thermally activated amorphization.