Influence of Different Growth Velocities on Directional Solidification Microstructure of Ti-45%Al Peritectic Alloy

The experimental method connecting electromagnetic induction heating with liquid melting cooling was used to study microstructure and morphologies of directionally solidified Ti-45%Al (at%)peritectic alloy at different growth velocities.The results show that the interface morphology grows in cellular form when growth velocity is 10 μm/s, and the angel between the lamellar boundaries(α2+γ) and growth direction is 90°. However, when growth velocity is 50μm/s, the crystals grow in dendritic form, and the angel between the lamellar boundaries(α2+γ) in the grains and growth direction is 45°.The cellular spaces are bigger than dendritic spaces,which shows that the rapidly solidified process is good for minishing grain spaces in the directional solidification.