Microstructural evolution in the surface of Ti–10V–2Fe–3Al alloy by solution treatments

By solution treatments in vacuum and in air, the surface region of Ti–10V–2Fe–3Al exhibits different microstructures from the interior region of the alloy. When solution treated in vacuum, the microstructure of the specimen is composed of dominant β phase and a few of α″ martensite in surface region, with a large amount of α″ martensite and a little of β phase in interior. When solution treated in air, the specimen is characterized by dominant surficial α phase and interior β phase. In addition, the lattice parameter evolutions of α and β phases were observed in the surface region of the specimens by solution treatment in air. The mechanism for the surface effects is discussed in light of the structural stability and phase evolution in Ti–10V–2Fe–3Al alloy with solution treatments.