1. Influence of Nonmetallic Interstitials on the Phase Transformation between FCC and HCP Titanium: A Density Functional Theory Study.
- Author
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Yang, Mengmeng, Hu, Jianan, Cao, Shuo, Feng, Guang, Yang, Yi, Liu, Renci, Li, Shujun, Zhao, Fu, Feng, Aihan, Hu, Qingmiao, Huang, Aijun, and Wang, Hao
- Subjects
FACE centered cubic structure ,DENSITY functional theory ,PHASE transitions ,TITANIUM ,BAND gaps ,MATERIAL plasticity ,TITANIUM alloys - Abstract
In addition to the common stable and metastable phases in titanium alloys, the face-centered cubic phase was recently observed under various conditions; however, its formation remains largely unclarified. In this work, the effect of nonmetallic interstitial atoms O, N, C and B on the formation of the face-centered cubic phase of titanium was investigated with the density functional theory. The results indicate that the occupancy of O, N, C and B on the octahedral interstitial sites reduces the energy gap between the hexagonal-close-packed (HCP) and face-centered cubic (FCC) phases, thus assisting the formation of FCC-Ti under elevated temperature or plastic deformation. Such a gap further decreases with the increase in the interstitial content, which is consistent with the experimental observation of FCC-Ti under high interstitial content. The relative stability of the interstitial-containing HCP-Ti and FCC-Ti was studied against the physical and chemical origins, e.g., the lattice distortion and the electronic bonding. Interstitial O, N, C and B also reduce the stacking fault energy, thus further benefiting the formation of FCC-Ti. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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