Hot-deformation behaviour and hot-processing map of melt-hydrogenated Ti–6Al–4V/(TiB+TiC)

The hydrogen was straight-forward added to the Ti–6Al–4V/(TiC + TiB) composites (TiC[dbnd]TiB=5 vol.%) by melt hydrogenation. The results of hot compression show that the peak resistance of titanium matrix composites (TMCs) decreased by 17.2% when hydrogen content was 0.035 wt% compared with the TMCs without hydrogen. Therefore, the TMCs with a hydrogen content of 0.035 wt% was performed to a thermal compression experiment. Thermal-deformation characteristics and hot processing map of TMCs with a hydrogen content of 0.035 wt% were analyzed in the light of the flow stress curve, constitutive relations, and the dynamic-material model. The computed apparent activation energy was 284.54 kJ/mol, and the corresponding strain-rate sensitivity, power dissipation, and instability parameter were calculated. The hot-processing map exhibited maximum efficiencies of power dissipation at 780–840 °C/0.005–0.06 s ⁻¹ and there was only one instable region. The microstructures corresponding to the stable and instable region were verified, confirming the optimum processing parameters of hot-working that can be used as a reference for hot deformation of hydrogenated composites.