|About this Abstract
||Materials Science & Technology 2011
||Phase Stability, Diffusion, Kinetics and their Applications (PSDK-VI)
||Atomic Scale Investigation of Classical and Non-Classical Gamma Prime Precipitation in Nickel Base Alloys
||Antariksh Singh, Gopal B Viswanathan, Soumya Nag, Junyeon Hwang, Jaimie Tiley, Hamish L Fraser, Rajarshi Banerjee
|On-Site Speaker (Planned)
The compositional and microstructural evolution of gamma prime precipitates during continuous cooling at different rates, followed by isothermal aging, of a commercial nickel base superalloy, Rene 88DT, have been characterized by coupling multiple atomic scale characterization techniques. The primary focus was on investigating the mechanisms governing gamma prime precipitation as a function of cooling rate. Classical nucleation and growth is the dominant mechanism of precipitation in case of slower cooling rates, especially at lower undercoolings. In contrast, at faster cooling (quench) rates, the gamma prime precipitation appears to take place via a spinodal clustering (phase separation or compositional partitioning) within the disordered gamma matrix followed by chemical ordering. Direct experimental atomic scale evidence for such a mechanism will be presented based on results of aberration-corrected HAADF-STEM at atomic resolution and atom probe tomography.
||Definite: A CD-only volume