Effects of Solution Treatment on the Microstructure and Mechanical Properties of Ti–22Al–25Nb Alloys

The effects of solution treatment on the microstructure and mechanical properties of Ti-22Al-25Nb alloy are investigated. Numerous equiaxed α₂ particles distribute in a B2 matrix after solution treatment in the α₂ + B2 region. The growth rate of the B2 grain increases with solution temperature and decreases with increasing holding time. When the solution temperature is lower than B2-transus, it is seen that both the strength and ductility decrease with increasing solution temperature and holding time. After being solution-treated at a super-transus temperature, the alloy with a fully B2 microstructure shows an ultralow elongation (∼5%) and a typical brittle fracture characteristic.