Uniformity of the Dendritic Microstructure in Large-Sized Single-Crystal Superalloy Blades

The distribution of the dendrite arrays and the primary dendrite arm spacing (PDAS) in large-sized single-crystal superalloy blade was investigated by Voronoi tessellation. The dendrite arrays were hexagonal at the airfoil center and random at the trailing edge. The PDAS was gradually increased from the leading edge (about 370 μ m) to the trailing edge (about 500 μ m). With the solidification distance increasing, the PDAS in large-sized blade was decreased (about 380 μ m) at the middle blade.