Effect of Fe content on microstructures and properties of Ti6Al4V alloy with combinatorial approach
(1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. ZIK Virtuhcon, TU Bergakademie Freiberg, Fuchsmühlenweg 9, D-09596 Freiberg, Germany;
3. Key Laboratory of Non-ferrous Metallic Materials Science and Engineering of Ministry of Education, Central South University, Changsha 410083, China)
2. ZIK Virtuhcon, TU Bergakademie Freiberg, Fuchsmühlenweg 9, D-09596 Freiberg, Germany;
3. Key Laboratory of Non-ferrous Metallic Materials Science and Engineering of Ministry of Education, Central South University, Changsha 410083, China)
Abstract: A combinatorial approach was applied to investigating the influence of Fe content on the microstructures and properties of Ti6Al4V alloy. A diffusion couple was manufactured with Ti6Al4V and Ti6Al4V20Fe alloys and annealed at 1000 °C for 600 h to obtain a wide range of compositions. By combining electron probe micro-analysis (EPMA), scanning electron microscopy (SEM) and nanoindentation, the relationships between composition and microstructure as well as hardness were determined. It is found that after aging the Ti6Al4V5Fe sample contains reasonable (about 55%) volume fraction of fine α phase and shows the peak hardness among the Ti6Al4VxFe alloys. Therefore, it is a promising candidate for the development of titanium alloys. HAADF-STEM and XRD reveal that after quenching from the single β phase field, the metastable α'''''''' lamellae form in the Ti6Al4V5Fe alloy, and on subsequent isothermal aging, the α'''''''' lamellae become coarse and act as precursors/preferential nucleation sites for the stable α phase.
Key words: diffusion multiple; Ti6Al4VxFe alloys; composition; microstructure; hardness; HAADF-STEM