About this Abstract |
| Meeting |
MS&T25: Materials Science & Technology
|
| Symposium
|
Microstructural Control in Materials Processing: Role of Phase Transformation Pathways
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| Presentation Title |
Exceptional retardation of phase evolution by microstructural feedback under electric current treatment |
| Author(s) |
Siwhan Lee, Yijae Kim, Taehyeok Kang, Junyoung Chae, Howook Choi, Pyuck-Pa Choi, Kyeongjae Jeong, Heung Nam Han |
| On-Site Speaker (Planned) |
Siwhan Lee |
| Abstract Scope |
Electric current is widely recognized for accelerating microstructural evolutions by the athermal effect. In this study, we revealed a paradoxical retardation of phase transformation caused by microstructural feedback under electric current-induced kinetics acceleration in a Ni-Fe-Cr-Nb-C alloy. Electric current treatment and conventional heat treatment were performed at the same temperature to distinguish the athermal effect from the thermal effect by Joule heating. Under these conditions, the phase transformation from Cr7C3 to Cr23C6 and Cr23C6 precipitation were accelerated, whereas the transformation from NbC to Ni-Nb silicide was retarded. Rapid Cr23C6 precipitation formed core-shell structures surrounding NbC. The Cr23C6 shells acted as atomic diffusion barriers, leading to the retardation of NbC to Ni-Nb silicide transformation. This microstructural feedback-driven retardation indicates that the electric current treatment could be used as a new heat treatment strategy not only to accelerate transformations but also to design novel microstructural architectures unattainable by conventional heat treatments. |