Abstract
β alloys based on the Ti–Nb alloy system are of growing interest to the biomaterial community. The addition of small amounts of Fe and Cr further increases β-phase stability, improving the properties of Ti–Nb alloy. However, PM materials sintered from elemental powders are inhomogeneous due to restricted solid state diffusion and mechanical alloying provides a route to enhance mixing and elemental diffusion. The microstructural characteristics and bend strength of Ti–Nb–(Fe–Cr) alloys obtained from elemental powder mixture and mechanical alloyed powders are compared. Mechanical alloying gives more homogeneous compositions and particle morphology, characterised by rounded, significantly enlarged particles. In the sintered samples α and β phase are observed. The α phase appears at the grain boundaries and in lamellae growing inward from the edge, and is depleted in Nb. The β phase is enriched with Nb, Fe and Cr. The addition of Fe and Cr significantly increases the mechanical properties of Ti–Nb alloys, providing increased ductility.
Acknowledgements
This paper is based on a presentation at Euro PM 2014, organised by EPMA in Salzburg, Austria on 21–24 September 2014. This work was funded by UPV by the Staff Training Program for Predoctoral Researchers dated 28 February 2014. The Ministry of Science and Innovation of Spain by project research MAT2011–28492–C03 and Generalitat Valenciana by ACOMP / 2014/151.