|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Gamma (FCC)/Gamma-Prime (L12) Co-Based Superalloys II
||Deformation Microstructures of L12 Ordered Intermetallic Phases in Ni-, Co- and Co-Ni-base Superalloys
||Duchao Lv, Robert Rhein, Michael Titus, Tresa Pollock, Yunzhi Wang
|On-Site Speaker (Planned)
The gamma’ intermetallic phase (L12, cubic) is the primary strengthening phase in nickel-base, cobalt–base and cobalt-nickel-based superalloys. In this study, the deformation mechanisms in these three alloys are investigated at the elementary defect level by using a combination of ab initio calculations and phase field simulations. In particular, the composition-dependent generalized-stacking-fault energy surfaces of the gamma and gamma’ phases, as determined from ab initio calculations, and available experimental data are used in the phase field simulations. Sophisticated deformation pathways leading to various planar defects including antiphase boundary + superlattice intrinsic stacking fault and stacking fault ribbon configurations are predicted as a function of the alloy composition. The predicted stacking fault configurations are consistent with recent TEM observations. The approach can be used to study plastic deformation of other intermetallic phases, and the detailed deformation mechanisms uncovered could be incorporated in constitutive microstructure-property relationships in advanced crystal plasticity modeling.