Sintering of Ti-10V-2Fe-3Al and mechanical properties

Highlights: → Densification is only the first step for the sintering of Ti-10V-2Fe-3Al. → Master alloy selection or design of sintering pathway is the real challenge. → The use of 10V-2Fe-3Al master alloy is preferred to the use of 85V-15Al. → Sintering of Ti-10V-2Fe-3Al is mainly controlled by the self-diffusion of Ti. - Abstract: A comprehensive study has been made of the sintering and microstructural evolution of Ti-10V-2Fe-3Al compacted from titanium and master alloy powder blends. The densification of Ti-10V-2Fe-3Al at ≤1300 deg. C occurs by solid-state sintering with apparent activation energy of 163 ± 13 kJ/mol, which falls into the reported activation energy range for the self-diffusion of titanium. The sintered density depends primarily on the titanium powder size while the sintered microstructure and mechanical properties depend mainly on the master alloy type or diffusion of vanadium. The real challenge for the fabrication of Ti-10V-2Fe-3Al by sintering is not densification, which is trivial with relatively fine titanium powder. Rather, it is the realisation of a desired microstructure through master alloy selection or design of the sintering pathway, which determines the distribution of the principal alloying element V, a slow diffuser in β-Ti. This distinguishes it from the sintering of lean alloys, where the focus has predominantly been on densification. The use of 10V-2Fe-3Al master alloy produced more uniform microstructures and therefore much better ductility than the use of 85V-15Al at similar densities.