|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||Computational Design and Simulation of Materials (CDSM 2018): Atomistic Simulations
||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)
MoSi<SUB>2</SUB> is an intermetallic ceramic with excellent oxidation resistance at high temperatures > 1000 °C due to the formation of passivating SiO<SUB>2</SUB>. 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 MoSi<SUB>2</SUB> 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 MoSi<SUB>2</SUB> GB mitigates the weakening effect of O interstitials, the use of Zr nanoparticles as a getter material significantly improves the strength of MoSi<SUB>2</SUB> GBs through the preferential capturing of O by Zr. These insights pave the way for rational engineering of MoSi<SUB>2</SUB> and other alloys for improved oxidation resistance.
||Planned: Supplemental Proceedings volume