摘要 : The effects of sulfur on the microstructures and solidification characteristics of a second-generation single crystal superalloy were clarified through optical microscope (OM), scanning electron microscope (SEM), differential scan... 展开 The effects of sulfur on the microstructures and solidification characteristics of a second-generation single crystal superalloy were clarified through optical microscope (OM), scanning electron microscope (SEM), differential scanning calorimetry (DSC) and electron probe microanalysis (EPMA). When sulfur was added to the alloy, the area fraction of the eutectic and microporosity decreased with the area fraction of MC carbides increasing. The gamma / gamma' eutectic morphology changed from mosaic + fan + coarse gamma' to mosaic + fan as the sulfur content increased, and very few gamma / gamma' eutectic was found in the alloy with the highest sulfur content. Moreover, sulfur tended to segregate at the interdendritic regions and form Hf / Cr- rich sulfides, which were adjacent to the carbides or eutectic. This work not only uncovers some sulfides wrapped by eutectic or carbides, but also presents the solidification sequence of the interdendritic regions in high sulfur content alloy was discussed. 收起