Phase transformation kinetics of Ti-1300 alloy during continuous heating

The α + β → β phase transformation kinetics of Ti-1300 alloy during continuous heating at different heating rates were investigated using dilatometric method. Results show that the curves of the α + β → β phase transformation exhibit a typical S-shaped pattern, which indicates that the α + β → β phase transformation is a nucleation-growth-controlled process. The overall activation energy of the α + β → β transformation of the alloy is 797 kJ·mol⁻¹. The nucleation and growth mechanism of the α + β → β transformation was also investigated using the non-isothermal Avrami exponent. The Avrami exponent during α + β → β transformation process significantly changes with transformed volume fraction increasing, which indicates that the α + β → β transformation mechanism in the Ti-1300 alloy varies at different sections.