Mechanical Properties and Dislocation Structure Evolution in Ti6Al7Nb Alloy Processed by High Pressure Torsion |
| |
Authors: | Miloš Janeček Josef Stráský Jakub Čížek Petr Harcuba Kristína Václavová Veronika V. Polyakova Irina P. Semenova |
| |
Affiliation: | 1. Department of Physics of Materials, Charles University, Ke Karlovu 5, 12116, Prague 2, Czech Republic 2. Department of Low Temperature Physics, Charles University, Prague, Czech Republic 3. Ufa State Aviation Technical University, Ufa, Russia
|
| |
Abstract: | Ultrafine-grained biocompatible Ti-6Al-7Nb alloy was produced by high pressure torsion (HPT). Lattice defects—vacancies and dislocations—investigated by positron annihilation spectroscopy, observations by scanning electron microscopy, and microhardness evaluation are linked to the strain imposed by different numbers of HPT revolutions and to the distance from the specimen center. Positron annihilation spectroscopy showed significant increase of dislocation density and concentration of vacancy clusters after ½ of the HPT revolution. Microhardness increases by 20 pct with increasing strain, but it is heterogenous due to duplex microstructure. The heterogeneity of the microhardness increases with increasing strain, suggesting that a heavily deformed and fragmented α + β lamellar microstructure is more hardened than primary alpha grains. The defect structure is homogenous after ½ HPT revolution, while the microhardness becomes homogenous after 3 HPT revolutions only. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|