|About this Abstract
|2020 TMS Annual Meeting & Exhibition
|Microstructural Template Consisting of a Face-Centered Cubic Matrix with Ordered Precipitates: Microstructural Evolution and Properties
|Precipitation and Deformation Mechanisms of γ’/γ” Co-precipitates in Alloy 718
|Hariharan Sriram, Kamal Kadirvel, Rongpei Shi, Longsheng Feng, Michael J Mills, Yunzhi Wang
|On-Site Speaker (Planned)
Alloy 718, widely used in aerospace and power industries, is strengthened by both γ’ (L12) and γ” (D022) intermetallic phases that are coherently embedded in a γ (FCC) phase matrix. Experimental characterizations have revealed a rich variety of γ’/γ” co-precipitate microstructures and puzzling deformation microstructures. We present a simulation study of the nucleation, growth and coarsening mechanisms associated with the formation and stability of such γ’/γ” co-precipitates, as well as their deformation mechanisms, in contrast to those of individual precipitates, using a combination of CALPHAD, ab initio, and phase-field approaches. Co-precipitation is found energetically favorable during nucleation because of the synergistic effect in reducing the coherency elastic strain. Co-precipitates have significantly different growth and coarsening behaviors, and their deformation mechanisms are extremely complicated. This work is supported by DOE/NETL.
|Planned: Supplemental Proceedings volume