Evolution of γ′ phase in DD6 single crystal turbine blade

The evolution rule of γ′ phase in typical cross sections of DD6 single crystal superalloy turbine blade was investigated experimentally by SEM. The results show that comparing with the as-cast microstructures, the γ′ phase sizes of typical cross sections in the interdendrite regions of the heat-treated turbine blade are obviously refined, the γ′ phase sizes of the interdendritic (ID) region and dendritic core (DC) tended to be the same, and the γ′ phase size dispersion tended to decrease, the γ′ phases cubed degree increased. The sizes of as-cast and heat-treated γ′ phase in the dendrite core and interdendritic region of each cross section of the blade follow the normal distribution law. The size of γ′ phase in the section of the heat-treated blade is smaller than that of the tenon, and the size of the γ′ phase in the middle of the section is larger than that of the leading edge and trailing edge.