Publication at Faculty of Mathematics and Physics |
2018
Abstract
Refractory metal high entropy alloy HfNbTaTiZr with ultrafine grained structure and grain size of approximate to 80 nm was processed by high pressure torsion. The development of microstructure, lattice defects and mechanical properties with increasing strain was examined.
Grain refinement of HfNbTaTiZr alloy deformed up to the equivalent strain e approximate to 50 resulted in a significant enhancement of strength while keeping sufficient ductility. However, further straining e > 100 led to a decrease of strength and the loss of ductility due to the decomposition of solid solution facilitated by vacancies introduced by severe plastic deformation.