|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Gamma (FCC)/Gamma-Prime (L12) Co-Based Superalloys II
||Dislocation Interactions during High-temperature Creep and Yield of Polycrystalline Co-Ni-Al-W-based Superalloys and L12 γ’ Phases
||Vassili A Vorontsov, Caroline Taylor, Henry Chan, Paul Mulvey, Mark C Hardy, David Dye
|On-Site Speaker (Planned)
||Vassili A Vorontsov
Using conventional and high-resolution TEM/STEM, we investigate the active plastic deformation mechanisms in polycrystalline Co-Ni-Al-W superalloys during creep and yield at elevated temperatures. The effects of chemical composition and material processing on the factors which define the mechanical properties are considered in detail. In addition to the microstructural factors, the compositional effects on the energetics of planar defects, such as antiphase boundaries and stacking faults, are also evaluated. This includes both the contribution from the γ’ forming elements as well as the role of the cobalt to nickel ratio. Our study considers prototype multi-component systems, as well as ternary and quaternary model alloys and isolated L1<SUB>2</SUB> γ’ phases. Finally, we discuss the implications of our findings for the development of mathematical models for prediction and optimisation of high-temperature mechanical properties.