Microstructural evolution and mechanical properties off-titanium Ti-10V-2Fe-3Al during incremental forming

摘要

Forming of hollow shafts of high-strength beta titanium alloys is technologically demanding, as well as expensive. One approach to reduce costs is incremental forming by spin extrusion. The advantage of this process is the high utilization of material (80 %) in comparison to deep-hole drilling (40 %). In this study, we investigate the microstructural evolution and the mechanical properties of a Ti-10V-2Fe-3Al hollow shaft formed by spin extrusion, which results in varying stress-strain behavior across the wall thickness. Grain refinement from >1μm (edge) to 100 μm (center) is observed. Subsequent heat treatments can be used to achieve homogeneous properties throughout the shaft's cross section. Even higher strengths are associated with the precipitation of primary α-phase. Our results for the high-strength beta titanium alloy Ti-10V-2Fe-3Al illustrate the potential of spin extrusion, combined with suitable heat treatments, to produce hollow shafts with improved properties at lower costs.