AgCl-induced hot salt stress corrosion cracking in a titanium alloy

Highlights: • AgCl-induced stress corrosion cracking of Ti-6246 was examined at 500 MPa/380 °C/24 h. • SEM and STEM-EDX showed that metallic Ag migrated along the crack. • TEM analysis also revealed the presence of SnO₂ and Al₂O₃ corrosion products mixed into TiO₂. • Long, straight, dislocations were observed in a facetted primary alpha grain at the surface. The mechanism of AgCl-induced stress corrosion cracking of Ti-6246 was examined at 500 MPa and 380 °C for 24 h exposures. SEM and STEM-EDX examination of a FIB-sectioned blister and crack showed that metallic Ag was formed and migrated along the crack. TEM analysis also revealed the presence of SnO₂ and Al₂O₃ corrosion products mixed into TiO₂. The fracture surface has a transgranular nature with a brittle appearance in the primary α phase. Long, straight and non-interacting dislocations were observed in a brittle appearance fractured primary α grain, with basal and pyramidal traces. This is consistent with a dislocation emission view of the cracking mechanism.