Orientation Characteristics of Single Crystal Superalloys with Different Preparation Methods

Single crystal superalloys have been prepared separately by a grain selector and a seeding technique in a high temperature gradient directional solidification furnace. The orientation characteristics were measured by XRD. Results indicate that for the grain selector method, the crystal solidification begins at the cooling plate with random nucleation, and through mutual competitive growth at the starter block. The grains enter the spiral selector, and finally the single crystal superalloys which are close to <001> direction are obtained. By the seeding technique, by epitaxial growth of partially melted seed crystals, single crystal superalloys which have the same orientation as the seed crystal are obtained.