Effect of severe plastic deformation realized by rotary swaging on the mechanical properties and corrosion resistance of near-α-titanium alloy Ti-2.5Al-2.6Zr

The research aims to analyze the impact that severe plastic deformation arising during Rotary Swaging has on mechanical properties and corrosion resistance of a near-α-titanium alloy Ti-2.5Al-2.6Zr (Russian industrial name PT7M). The nature of corrosion decay in fine-grained alloys caused by hot salt corrosion is known to vary from pit corrosion to intercrystalline corrosion at the onset of recrystallization processes. Resistance to hot salt corrosion in a fine-grained titanium alloy Ti-2.5Al-2.6Zr is shown to depend on the structural-phase state of grain boundaries that varies during their migration as a result of “covering” corrosive doping elements (aluminum, zirconium) distributed in the crystal lattice of a titanium alloy. •Fine-grained (FG) structure in near-α-alloy Ti-2.5Al-2.6Zr was formed with Rotary Swaging.•Hot salt corrosion mechanisms in coarse-grained (CG) and FG alloys are studied.•Corrosion defects of type I in a CG alloy are stitched as a result of β-phase particles precipitation.•Corrosion defects of type II in a CG alloy look similar to intercrystalline corrosion (ICC).•Corrosion decay in a FG alloy changes from pit corrosion to ICC when the migration of grain boundaries starts.