Solid-state amorphization of Cu + Zr multi-stacks by ARB and HPT techniques
A series of CuZr binary alloys with wide composition range were fabricated through ARB and HPT techniques using pure Cu and Zr metals as the starting materials. Bulk alloy sheets with thickness of about 0.8 mm after ARB process and alloy disks with 0.30 mm in thickness and 10 mm in diameter after HPT process can be obtained, respectively. The structures of all the alloys were found to be gradually refined with the increase of ARB cycles or HPT rotations. As a result, nanoscale multiple-layered structure was formed for the 10 cycled ARBed specimens, which could partially transform into amorphous phase during subsequent low temperature annealing. While for the as-HPTed sample, the alloy was completely amorphized after 20 rotations without any heat treatment. The thermal stabilities of the amorphous alloys were studied. The deformation behavior and the amorphization mechanism during the ARB and HPT process were put forward and discussed.
KeywordsEqual Channel Angular Pressing Accumulative Roll Bonding High Pressure Torsion CuZr Differential Scanning Calorimeter Curve
The present study was financially supported by the Grant-in-Aid for Scientific Research on Priority Area “Materials Science of Bulk Metallic Glasses” and the Global COE program “Center of Excellent for Advanced Structural and Functional Materials Design” in Osaka University both through MEXT, Japan.