Effects of cold crucible directional solidification parameters on macro-structures of Ti-46Al-0.5Si-0.5W billets

A composition of Ti-46Al-0.5Si-0.5W was prepared with directional and fine grains in slab shape. The effects of technical parameters on the grain modalities are studied with orthogonal experiments. The results show that with increasing power grains trends to grow up while the direction of grains is improved. Grains trend to be finer but the direction is more deviated from the growth direction in some extension with increasing withdrawal velocity. When the preheating time is prolonged, the size and the direction of grains both trend to be disbennifit. All of the best directional structures are obtained with withdrawal velocity 1.0 mm/min for different crucibles and compositions.