| Various thermomechanical treatments were performed in order to optimize the strength and ductility of a Ti₃Al-based intermetallic, Super Alpha 2. Mechanical strength of the Super Alpha 2 was gradually improved without loss of ductility as the solution treatment temperatures were approached to the β-transus temperature. However, the elongation of specimens, heat-treated at temperature above β-transus, was reduced to almost zero percent. The improvement of hardness could be achieved depending upon aging time and temperature. Mechanical property improvement was attributed to phase transformation from B2 to α₂ and "O" phases. Not only the phase seperation, but also finely dispersed secondary phase of the lamellar type around the primary α₂ phase contributed to strength and hardness improvement. These phenomena were identified by SEM, TEM, XRD and Young`s modulus variation. |
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