Atomic level insights into the Ti2AlC oxidation mechanism by the combination of density functional theory and ab initio molecular dynamics calculations

• Published in: Corrosion science Vol. 191; p. 109756
• Main Authors: Kang, Qingxin, Wang, Guofeng, Liu, Qing, Sui, Xiaochong, Liu, Yongkang, Chen, Yuqing, Luo, Shuyi, Li, Zhenlun
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Ltd 01.10.2021; Elsevier BV
• Subjects: A. Ceramic; Aluminum; B. Modelling studies; C. High temperature corrosion; C. Oxidation; Density functional theory; Electrons; Molecular dynamics; Orbitals; Oxidation; Oxide coatings; Titanium; C. High temperature corrosion; B. Modelling studies; C. Oxidation; A. Ceramic
• ISSN: 0010-938X; 1879-0496
• DOI: 10.1016/j.corsci.2021.109756

[Display omitted] •DFT and AIMD were combined to study the Ti2AlC oxidation mechanism.•Surface energy of different Ti2AlC (0001) surfaces was calculated.•The adsorption configuration and electronic structure were analyzed.•The dynamics process of O2 dissociation and adsorption was investigated by AIMD.•The PDOS changing process during AIMD simulation was analyzed. Ti2AlC oxidation mechanism was investigated by density functional theory (DFT) and ab initio molecular dynamics (AIMD). DFT results showed that the most stable adsorption site was HCP hollow sites, followed by FCC. O atom gained electrons, while Al atom lost electrons through the hybridisation of O-p and Al-s/p orbitals. AIMD results show that O2 molecule gradually dissociated into O atoms at 1273 K and formed Al-Ti mixed oxide film. The hybridisation between O-p and Al-s/p orbitals formed Al-O bond, while the hybridisation of O-p and Ti-d orbitals formed Ti-O bond.