|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||Characterization of Minerals, Metals, and Materials
||In-situ TEM Study of Precipitation Behavior in Alloy 690-based MA Powders
||Man Wang, Heung Nam Han, Hee-Suk Chung, Young Bum Chun, Chang Hee Han, Jinsung Jang
|On-Site Speaker (Planned)
Oxide dispersion strengthening (ODS) alloy is one important candidate structural material for advanced nuclear reactors due to their good high temperature strength and irradiation resistance, which is mainly attributed to the dispersion of nano-sized particles. However, there are only limited studies about the precipitation behavior of nano-sized particles in nickel alloys. In this study, the structural evolution of alloy 690-based MA (mechanical alloying) powders during heating is investigated using in-situ TEM and XRD. The initial MA powders showed a nanocrystalline structure. Some faceted precipitates of Er2Ti2O7 are observed after heating to 950oC. It seems that the grain boundary migration plays an important role in the precipitation of very fine particles. A uniform and dense distribution of Er2Ti2O7 particles with the size of about 5 nm was obtained after heating to 1042oC. This in-situ TEM observation provides clear evidence for the dissolution-precipitation mechanism for the nano-sized particles in nickel alloy matrix.
||Planned: None Selected