| 초록 |
Segregation during solidification and homogenization during thermal exposure in GTD 111 were investigated. The microstructures of as-cast, standard heat-treated, and thermally exposed specimens were observed by SEM. A compositional analysis of each specimen was conducted by EDS. The dendrite core was enriched in W and Co, though lower levels of Ti and Ta were observed. An unexpected phase, in this case like the ${ eta}$ phase, was observed due to segregation near the ${ gamma}-{ gamma}^{ prime}$ eutectic in the standard heat-treated specimen. Segregation also induced microstructural evolution near the ${ gamma}-{ gamma}^{ prime}$ eutectic during the standard heat treatment. A quantitative analysis and microstructural observations showed that the thermal exposure at a high temperature enhanced the chemical homogeneity of the alloy. |
