|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Gamma (FCC)/Gamma-Prime (L12) Co-Based Superalloys II
||The Microstructure and Hardness of Ni-Co-Al-Ti-Cr Quinary Alloys
||Katerina A. Christofidou, Nicholas G. Jones, Roxana Flacau, Mark C Hardy, Howard J. Stone
|On-Site Speaker (Planned)
||Katerina A. Christofidou
Elevated concentrations of Co and Ti in conventional Ni-based superalloys have been identified as beneficial to alloy properties, conferring improved strength and stability over conventional superalloy compositions. However, the metallurgical origins of this behaviour remain unknown and further studies are required to facilitate our understanding. To address this need, a series of 27 alloys from the Ni-Co-Al-Ti-Cr system have been examined following super-solvus homogenisation heat treatments using neutron diffraction, DSC and SEM. In addition, the phase stability of these compositions following exposures at 800˚C for 1000 hours has been determined with regards to the susceptibility of the alloys towards the formation of deleterious phases. Consequently, the effects of varying the Ni:Co, Al:Ti ratios and Cr concentration on the microstructural evolution and hardness of the material were assessed, and thermodynamic modelling was used to complement the results. This work was supported by Rolls-Royce plc and the EPSRC under EP/H022309/1 and EP/H500375/1.