|About this Abstract
||2016 TMS Annual Meeting & Exhibition
||Ultrafine Grained Materials IX
||Thermal Stability of Ultra-fine Grained Microstructure of Biomedical Ti-6Al-7Nb Alloy
||Josef Stráský, Kristina Vaclavova, Petr Harcuba, Pavel Zhanal, Jakub Cizek, Veronika Polyakova, Irina P Semenova, Milos Janecek
|On-Site Speaker (Planned)
Ultra-fine grained (UFG) biocompatible alpha + beta titanium alloy Ti-6Al-7Nb was prepared by equal channel angular pressing. Highly deformed UFG structure contains high density of dislocations and vacancy clusters. Thermal stability of UFG structure was studied by scanning electron microscopy, electrical resistance measurement and by positron annihilation spectroscopy techniques. According to the electrical resistance measurement, we selected three heating treatments: heating up to 440, 550 and 660°C using heating rate 5°C/min followed by water quenching. Vacancy clusters anneal out already at 440°C. Density of dislocations decreases between 440°C and 550°C, but comparatively high density remains even after heating up to 660°C. Recrystallization is apparent from SEM imaging for the condition heated up to 660°C. Electrical resistivity is capable of identifying the onset of recovery/recrystallization process.