|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||Computational Design and Simulation of Materials (CDSM 2018): Atomistic Simulations
||L-12: Insights into the Effect of Zr on O-contaminated MoSi2 Grain Boundaries from Density Functional Theory Calculations
||Hui Zheng, Richard Tran, Balachandran Radhakrishnan, Shyue Ping Ong
|On-Site Speaker (Planned)
MoSi2 is an intermetallic ceramic with excellent oxidation resistance at high temperatures > 1000 °C due to the formation of passivating SiO2. However, its application at low temperatures is limited by oxygen embrittlement of its grain boundaries (GBs). In this work, we will provide insights into the effect of Zr on O-contaminated MoSi2 GBs using density functional theory calculations. We demonstrate that the presence of O interstitials leads to a significant decrease in the work of separation, leading to increased brittleness. We will show that while Zr dopants in the MoSi2 GB mitigates the weakening effect of O interstitials, the use of Zr nanoparticles as a getter material significantly improves the strength of MoSi2 GBs through the preferential capturing of O by Zr. These insights pave the way for rational engineering of MoSi2 and other alloys for improved oxidation resistance.
||Planned: Supplemental Proceedings volume