|About this Abstract
|MS&T23: Materials Science & Technology
|Advanced Materials for Harsh Environments
|Coarsening and Globularization in Eutectic Ni-Ce Alloys
|Syeda Bushra Haider, Eric A. Lass
|On-Site Speaker (Planned)
|Syeda Bushra Haider
Ni-Ce alloys are currently being studied as a castable alternative to conventional Ni-based superalloys. To understand the evolution of microstructure at elevated temperatures, in this study the mechanism of coarsening and globularization behavior of eutectic Ni-Ce is studied. The as cast eutectic Ni-Ce consists of a combination of fine lamellar and rod eutectic colonies with coarser boundary regions. The evolution of the microstructure at 800 °C and 900 °C exhibits discontinuous and continuous coarsening respectively. Moreover, globularization which can be described as a form of continuous coarsening, is prominent at the eutectic colony boundary which with time moves towards the center of the colony. The coarsening rate near the center of a colony is extremely slow, indicating the eutectic itself is very stable. Globularization starting from cell boundaries is found to be the prominent mechanism at 900 °C.