|About this Abstract
||2019 TMS Annual Meeting & Exhibition
||Coatings and Surface Engineering for Environmental Protection
||C-6: Mechanisms of Oxidation of Pure and Si-segregated α-Ti Surfaces
||Somesh Bhattacharya, Ryoji Sahara, Kyosuke Ueda, Takayuki Narushima
|On-Site Speaker (Planned)
Titanium and its alloys are used for high-temperature components of jet engines. Their high affinity for oxygen, particularly at elevated temperatures, severely limits their application above 650 ℃. Using first-principles molecular dynamics, we identified the mechanisms of the oxidation of α-Ti surfaces. Si segregation was found to suppress α-case formation in Ti, which was also confirmed experimentally. Charge transfer from the metal atoms to the gas molecules drives the initial stages of oxidation on the pure and Si-segregated α-Ti (0001) surfaces, while during the later stages, oxidation proceeds via oxygen penetration into the slab. Growth of the oxide network was strongly dependent on the oxidation state of the surface Ti atoms. Oxide growth in the Si-segregated material was retarded with the formation of TiOx (0.5≤x≤1) on the surface. The simulations and experiments clearly showed that Si reduces the ingress of oxygen into Ti, even at high temperatures.
||Planned: Supplemental Proceedings volume