|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||Deformation and Damage Mechanisms in High Temperature Ni, Co and Fe-based Superalloys
||Integrated Modeling of Creep in Ni-base Superalloys
||Pengyang Zhao, Chen Shen, Michael Mills, Yunzhi Wang, Stephen Niezgoda
|On-Site Speaker (Planned)
We have developed a creep model for γ/γ' Ni-base superalloys that integrates dislocation-based crystal plasticity (CP) and phase-field (PF) approach. The linkage between CP and PF is through the dislocation density that serves as both a plasticity carrier and a microstructure descriptor. Depending on the volume faction of γ' and testing conditions, different dislocation-particle interaction mechanisms need to be incorporated in CP. The model is first applied to Haynes 282 (< 20% γ') to document the influence of microstructural heterogeneities (e.g., non-uniformly distributed γ' and grain boundary denuded zone) on the mechanical properties. For superalloys with high volume fraction (>50%) of γ', the model is applied to the high-temperature-low-stress regime where rafting occurs during primary creep, and the individual role of modulus misfit, lattice misfit, and plasticity are assessed quantitatively. For low-temperature-high-stress regime, a physics-based model is developed to predict dislocation drag coefficient and activation volume during primary creep.
||Planned: Supplemental Proceedings volume