Skull formation and change during ISM process of Ti-15-3 alloy

The change of the skull shape and size has been predicated through computer simulation technique and compared with the experimental results. The microstructure of the skull and the elemental line distribution in the skull have been analyzed with optical microscope and EPMA etc. The results show that the skull height and thickness become small with increasing melting power; the skull consists of two zones, that is, fine equiaxial crystal zone and coarse columnar crystal zone; there exists some segregation in the bottom of the skull.