Influence of recrystallization on the high-temperature properties of a directionally solidified Ni-base superalloy

The effect of recrystallization (RX) on the high-temperature tensile and creep properties of a directionally solidified (DS) Ni-base superalloy was studied. The tensile properties were not apparently influenced by RX, the depth of which is up to 18 pct of the overall gage thickness. However, an almost linear reduction of the creep rupture life was observed with the increase of the local RX depth. The failure mechanisms of the specimens were discussed based on the microstructural observations.