|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Gamma (FCC)/Gamma-Prime (L12) Co-Based Superalloys II
||Gammaprime Precipitation in Model CoAlW Alloys
||Ahmad Azzam, Frederic Danoix, Annie Hauet, Didier Locq, Pierre Caron, Didier Blavette
|On-Site Speaker (Planned)
Cobalt-based superalloys are promising materials for high temperature applications, especially for advanced turbine engines. They derive their potential from a high volume fraction of ordered Co3(AlW) L12 gammaprime precipitates embedded in a disordered face centered cubic (FCC) matrix. Understanding the formation of gammaprime precipitates from supersaturated matrix is therefore critical for controlling and tailoring the final microstructures. The aim of this work is to study the transformation paths in model ternary CoAlW alloys at the sub nanometer scale using Atom Probe Tomography (APT) and Transmission and Scanning Electron Microscopies (TEM, SEM). We will first focus on characterizing the nano gammaprime particles already present in the as quenched condition. The temporal evolution of average size of the γ’ precipitates (growth and coarsening) as a function of aging time at 900°C will then be studied experimentally with particular emphasis on phase compositions, in order to assess the currently available phase diagrams.