Abstract
The ω-phase precipitates in β-Ti alloys increase the strength but significantly degrade the ductility of the alloys. In the present work, the mechanism of ω-strengthening and embrittlement is investigated by using a first principles method based on density functional theory. The generalized stacking fault energies of various slip systems in both the β and ω phases are calculated. The strengthening and embrittlement effects of the ω phase are discussed by comparing the slip energy barriers of slip systems in the β and ω phases with different orientation relationships. It is found that the slip energy barriers of slip systems in the ω phase, except for \((\bar 2020){[0001]_\omega },\) are much higher than those of slip systems in the β phase, which explains the ω-strengthening and embrittlement effects. The slip energy barrier of the most active slip system in the phase, \((\bar 2020){[0001]_\omega },\) increases with the depletion of Mo and increasing extent of structure collapse, suggesting that aging treatment enhances the -strengthening and embrittlement effects.
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Funding
This work is financially supported by Natural Science Foundation of China under grant Nos. 91860107, 52071315, and 52001307, National Science and Technology Major Project under grant No. J2019-VI-0012-0126, and China Postdoctoral Science Foundation under grant No. 2019M661149.
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Translated from Fizicheskaya Mezomekhanika, 2021, Vol. 24, No. 5, pp. 16–25.
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Cao, S., Chen, W., Yang, R. et al. Origin of the ω-Strengthening and Embrittlement in β-Titanium Alloys: Insight from First Principles. Phys Mesomech 24, 513–522 (2021). https://doi.org/10.1134/S1029959921050027
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DOI: https://doi.org/10.1134/S1029959921050027