Evolution of defect substructure of metal alloys at microscopic and mesocopic level under tension

摘要

Transmission electron microscopy was used to investigate the reorientation of crystal lattice during the formation of ultrafine-grained copper, nickel, and an alloy of Ni-18% Al-8% Cr-1% Zr-0.15% B(%atomic wt) under severe plastic deformation by equal-channel angular pressing and twisting at a high qasi-hystrostatic pressure. The crystal lattice was found to transform into a ultrafine-grain state; it is fragmented at the nano-, micro-, and meso-scale levels. Possible mechanisms for the reorientation of the crystal lattice under deformation at the micro- and meso-scale level are discussed.