|About this Abstract
||2016 TMS Annual Meeting & Exhibition
||High-Temperature Systems for Energy Conversion and Storage
||A Thermodynamics and Density Functional Theory Based Approach to Design Alloys with Passivating Oxide Layer for Silver-free SOFC Braze Application
||Tridip Das, Quan Zhou, Jason Nicholas, Thomas Bieler, Yue Qi
|On-Site Speaker (Planned)
The commonly used silver based (97.5Ag-2.5CuO) SOFC braze alloys have durability issues due to water pocket formation from the fast oxygen ion and protonic conductivity of silver at SOFC operating conditions. In order to develop an oxidation resistant alloy a systematic computational alloy design approach is taken. The CALPHAD approach, implemented in ThermoCalc is used to search new alloy systems and compositions with the specified liquidus and solidus temperatures. The stable surface oxide phase is identified from the DFT calculated free energies of oxidation for all the possible oxides that can be formed from the alloying elements. Oxygen diffusivity in the stable oxide layer is calculated from DFT and ab initio molecular dynamics. The calculated parameters are used to predict the oxide growth rate and compared with experiments. The alloy with the best passivating oxide layer is recommended as a potential candidate for SOFC brazing material.
||Planned: A print-only volume