THIN-WALL EFFECT OF A DIRECTIONALLY SOLIDIFIED SUPERALLOY

The thin-wall effect of a directionally solidified superalloy has been studied by using tubular hollow specimens (wall thickness l= 0.8, 1.2,1.6 mm) whose shape and thickness are similar to the hollow turbine blades made by the near-shape investigation cast procedure.The results show that stress-rupture properties of thin-wall specimens are not reduced remarkably comparing that of the standard ones (5 mm diamater), i.e., thin-wall effect of this alloy is not remarkable in this experiment. The results differing from that of previous works are discussed in term of cast process and microstructure.