Formation of Solidification and Eutectic Microstructures with Solidification Rates in the Single Crystal Superalloy CMSX 10

Directional solidification experiments were carried out at $1-300\;{\mu}m/sec$ solidification rates in the single crystal superalloy, CMSX 10. The solid/liquid interface morphology changed from planar to dendritic, and the dendrite spacing became finer as the solidification rate increased. The pool size of the ${\gamma}/{\gamma} eutectic, formed between dendrites, reduced as the solidification rate increased. The phase formation temperatures, such as the solidus, liquidus and eutectic, were estimated by differential scanning calorimetry (DSC) analysis. The morphology of the ${\gamma}/{\gamma} phase, known to be eutectic, showed ${\gamma} cells with a $\gamma$ intercellular network, and this ${\gamma}/{\gamma} was composed of coarse and fine ${\gamma}/{\gamma} regions. In this study, it is suggested that the ${\gamma}/{\gamma} phase was a coupled peritectic.The solidification procedure of the ${\gamma}/{\gamma} between dendrites is also discussed.

단결정 초내열합금에서 응고속도에 따른 응고 및 공정조직의 형성 거동