Defects in High Entropy Alloy HfNbTaTiZr Prepared by High Pressure Torsion

Abstract

High entropy alloy HfNbTaTiZr was successfully processed by severe plastic deformation using high pressure torsion (HPT) and ultrafine grained microstructure was achieved. The microstructure of HPT-deformed HfNbTaTiZr alloy was characterized by X-ray diffraction and compared with conventionally cast ingots. The lattice defects introduced by HPT processing were characterized by positron annihilation spectroscopy. The X-ray diffraction profiles of HTP-deformed samples were extremely broadened due to small sizes of coherently diffracting domains and a high microstrain introduced by severe plastic deformation.