|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Gamma (FCC)/Gamma-Prime (L12) Co-Based Superalloys II
||Developing Polycrystalline Ni-Co Rich Alloys, Strengthened by Co3AlW L12 Gamma Prime Precipitates for High Temperature Applications
||David Dye, Farah Ismail, Trevor C Lindley, Paul Mulvey, Richard Chater, Ioannis Bantounas, Barbara A Shollock, Mark C Hardy
|On-Site Speaker (Planned)
Since Sato et al reported the occurrence of a stable L12 phase (Co3AlW) in the Co-Al-W ternary system, there has been considerable interest in developing Co-based alloys for high temperature applications. Much activity has focused on single crystal aerofoil alloys, given the high melting temperatures and their reduced elemental segregation, which potentially reduces convective instabilities and therefore, freckle formation. The low solvus temperature has required significant Ni, Al, Ta and Ti additions, suggesting a potential for lower temperature polycrystalline applications. This presentation considers the design and manufacturing requirements for Ni-Co rich polycrystalline alloys in static and rotating applications, provides some insights from current research and suggests areas for future study. Given the temperature requirements, oxidation will be a particular concern, particularly in the context of fatigue, and therefore alloying effects on oxidation will be a particular focus. We acknowledge the EPSRC/Rolls-Royce Strategic Partnership for funding (EP/M005607/1, EP/H022309/1).