Microstructure design of beta annealed Ti-15Mo using thermo-mechanical processing

Description

The behaviour of a metastable Ti-15Mo alloy during hot deformation was investigated through isothermal compression in both α+β- and β-phase domains. Hot compression tests were carried out using a Gleeble thermomechanical simulator in temperatures ranging from 680 to 910°C and at strain rates of 0.01 and 1s-1 and up to 0.85 of true strain. The experiments in the α+β domain were conducted in the presence and absence of the α-phase. The flow stress decreases with increasing temperature and decreasing strain rate. Light optical microscopy and scanning electron microscopy complemented by electron backscatter diffraction technique were employed to characterise the microstructure of deformed specimens. The flow curves show two regimes: I) a progressive work-hardening at the beginning of plastic deformation followed by II) a steady state due to dynamic recovery in the β-domain, or II) flow softening in the α+β domain due to globularisation of the α phase. Dynamic recovery is the dominant mechanism in β-phase, while grain boundary serration and geometric dynamic recrystallisation were also observed in some areas. The globularisation of the α phase is more pronounced at a lower strain rate. In contrast, no flow softening occurred when samples were deformed in the absence of α-phase in the α+β domain.

Period	15 Jun 2023
Event title	World Titanium Conference 2023
Event type	Conference
Conference number	15
Location	Edinburgh, United KingdomShow on map
Degree of Recognition	International