Determining continuous cooling phase transformation behaviour in Ti-46Al-8Nb using Jominy end quenching

Jominy end quenching has been used to investigate the continuous cooling phase transformation behaviour of as-cast Ti-46Al-8Nb. The samples were cooled from a solution treatment temperature of 1360°C, which is in the a phase field. Jominy end quenching provides a continuous change in cooling rate along the axis of the specimen and is a well-established technique for determining the hardenability of steels. Through examination of the microstructural changes along the axis of the sample, the resulting microstructure regimes and the a decomposition mechanisms can be determined and correlated with the cooling rates. In this study attempts have been made to measure the cooling rate along the lengths of TiAl Jominy bars and this information has been used to define the phase transformation regimes. The results have shown that Jominy end quenching is a simple and practical method in studying continuous cooling phase transformation behaviours in TiAl-based alloys.