|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Gamma (FCC)/Gamma-Prime (L12) Co-Based Superalloys II
||Multi-scale Modelling of High-temperature Deformation Mechanisms in Co-Al-W-based Superalloys
||Hikmatyar Hasan, David Dye, Peter Haynes, Vassili Vorontsov
|On-Site Speaker (Planned)
The chemical ordering present in the γ' intermetallic phase precipitates of Co-Al-W-based superalloys gives rise to complex dislocation configurations. These can feature a variety of possible planar fault structures, which have associated surface energies. In order to accurately model this complexity, we have calculated Gamma-surfaces for Co-Al-W superalloys using the Density Functional Theory, as implemented in CASTEP. Also known as Generalised Stacking Fault energies, these 2D energy surfaces describe the energy cost of associated local atomic displacements at the dislocation core. These ab initio data were incorporated into a Phase Field Dislocation Dynamics model to investigate the meso-scale interactions of the dislocations with the microstructure of the alloys over a range of loading conditions. The phase field approach has also been extended to investigate the effects of solute atom segregation to the site of the stacking faults during high-temperature creep and the resulting influence on the deformation resistance.