Microstructure, Mechanical and Superelastic Properties of Ti-Zr-Nb Alloy for Biomedical Application Subjected to Equal Channel Angular Pressing and Annealing
Vadim Sheremetyev,
Mikhail Derkach,
Anna Churakova,
Aleksander Komissarov,
Dmitry Gunderov,
Georgy Raab,
Vladimir Cheverikin,
Sergey Prokoshkin,
Vladimir Brailovski
Affiliations
Vadim Sheremetyev
Metal Forming Department, National University of Science and Technology MISIS, 119049 Moscow, Russia
Mikhail Derkach
Metal Forming Department, National University of Science and Technology MISIS, 119049 Moscow, Russia
Anna Churakova
Laboratory of Nanostructured Materials Physics, Institute of Molecule and Crystal Physics, Ufa Federal Research Center RAS, 450075 Ufa, Russia
Aleksander Komissarov
Laboratory of Hybrid Nanostructured Materials, National University of Science and Technology “MISiS”, 119049 Moscow, Russia
Dmitry Gunderov
Laboratory of Nanostructured Materials Physics, Institute of Molecule and Crystal Physics, Ufa Federal Research Center RAS, 450075 Ufa, Russia
Georgy Raab
Institute of Physics of Advanced Materials, Ufa State Aviation Technical University, 12 K. Marx Str., 450008 Ufa, Russia
Vladimir Cheverikin
Department of Physical Metallurgy of Non-Ferrous Metals, National University of Science and Technology “MISiS”, 119049 Moscow, Russia
Sergey Prokoshkin
Metal Forming Department, National University of Science and Technology MISIS, 119049 Moscow, Russia
Vladimir Brailovski
Department of Mechanical Engineering, École de Technologie Supérieure, 1100 Notre-Dame Street West, Montreal, QC H3C 1K3, Canada
Biomedical Ti-18Zr-15Nb (at.%) shape memory alloy was subjected to a low-temperature equal channel angular pressing (ECAP) at 200 °C for three passes and post-deformation annealing (PDA) in the 400–650 °C temperature range for 1 to 60 min. It was observed that ECAP led to the formation of an inhomogeneous highly dislocated substructure of β-phase with a large number of differently oriented deformation bands containing nanograined and nano-subgrained areas. In this state, the alloy strength increased significantly, as compared to the undeformed state, but its ductility and superelasticity deteriorated appreciably. As a result of a short-term (5 min) PDA at 550–600 °C, the processes of polygonization of an entire volume of the material and recrystallization inside the deformation bands were observed. After PDA at 600 °C for 5 min, the alloy manifested a relatively high strength (UTS = 650 MPa), a satisfactory ductility (δ = 15%) and a superior superelastic behavior with a maximum superelastic recovery strain of εrsemax = 3.4%.
