PSI - Issue 68

Wenqi Liu et al. / Procedia Structural Integrity 68 (2025) 458–464 L. Wenqi et al. / Structural Integrity Procedia 00 (2025) 000–000

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5. Conclusions and outlook In this study, uniaxial tensile tests under temperatures from 25 °C to 650 °C and strain rate from 10 -5 s -1 to 10 -2 s -1 were designed for a Ti65 alloy. The key tensile properties like elastic modulus, strength, and ductility were analyzed to evaluate its temperature and strain rate sensitivities. Based on the experimental results, the Johnson–Cook model and support vector regression algorithm were employed to describe the temperature and rate dependence. It is concluded that the dynamic strain aging and creep effects lead to the complicated nonlinear temperature and strain rate dependence on the tensile properties of titanium alloys. The equation formats in the Johnson–Cook model restrict its prediction performance at higher temperatures and cannot be further improved by parameter optimization. The support vector regression algorithm can provide a comprehensive description of strength and ductility with 7 times better prediction performance than the Johnson–Cook model, which is an ideal machine learning solution for handling small amounts of data and brings potential applications in materials engineering. Acknowledgments This work was funded by the Chinese National Science and Technology Major Project (J2019 － VI-0012-0126). References Balasubramanian, S., Anand, L. 2002. Plasticity of initially textured hexagonal polycrystals at high homologous temperatures: application to titanium. Acta materialia, 50(1), 133-148. Gollapudi, S., Charit, I., Murty, K. L. 2008. Creep mechanisms in Ti–3Al–2.5 V alloy tubing deformed under closed-end internal gas pressurization. Acta materialia, 56(10), 2406-2419. Imran, S. M., Li, C., Lang, L., Guo, Y., Mirza, H. A., Haq, F., Han, H. 2022. An investigation into Arrhenius type constitutive models to predict complex hot deformation behavior of TC4 alloy having bimodal microstructure. Materials Today Communications, 31, 103622. Ji, H., Peng, Z., Pei, W., Xin, L., Ma, Z., Lu, Y. 2020. Constitutive equation and hot processing map of TA15 titanium alloy. Materials Research Express, 7(4), 046508. Li, C., Huang, L., Zhao, M., Guo, S., Su, Y., Li, J. 2022. Characterization of hot workability of Ti-6Cr-5Mo-5V-4Al alloy based on hot processing map and microstructure evolution. Journal of Alloys and Compounds, 905, 164161. Liu, W., Lian, J. 2021. Stress-state dependence of dynamic strain aging: Thermal hardening and blue brittleness. International Journal of Minerals, Metallurgy and Materials, 28(5), 854. Peng, W., Zeng, W., Wang, Q., Zhao, Q., Yu, H. 2014. Effect of processing parameters on hot deformation behavior and microstructural evolution during hot compression of as-cast Ti60 titanium alloy. Materials Science and Engineering: A, 593, 16-23. Qiao, L., Inoue, J., Zhu, J. 2024. Machine learning guided constitutive model and processing map for Fe2Ni2CrAl1. 2 multi-principle element alloys. Journal of Materials Research and Technology, 29, 353-363. Savaedi, Z., Motallebi, R., Mirzadeh, H. 2022. A review of hot deformation behavior and constitutive models to predict flow stress of high-entropy alloys. Journal of Alloys and Compounds, 903, 163964. Shi, Z. Y., Quan, G. Z., Chao, A. N., Qiu, H. M., Wang, W. Y., Zhang, Z. H. 2019. Artificial intelligence model of complicated flow behaviors for Ti− 13Nb− 13Zr alloy and relevant applications. Transactions of Nonferrous Metals Society of China, 29(10), 2090-2098. Viswanathan, G. B., Karthikeyan, S., Hayes, R. W., Mills, M. J. 2002. Creep behaviour of Ti-6Al-2Sn-4Zr-2Mo: II. Mechanisms of deformation. Acta materialia, 50(20), 4965-4980. Zhang, Z., Fan, J., Tang, B., Kou, H., Wang, J., Wang, X., Li, J. 2020. Microstructural evolution and FCC twinning behavior during hot deformation of high temperature titanium alloy Ti65. Journal of Materials Science Technology, 49, 56-69. Zhao, G. H., Xu, X., Dye, D., Rivera-Díaz-del-Castillo, P. E. 2020. Microstructural evolution and strain-hardening in TWIP Ti alloys. Acta Materialia, 183, 155-164. Zhu, P., Yang, S., Gao, Z., Liu, J., Zhou, L. 2024. Optimization of hot deformation parameters for multi-directional forging of Ti65 alloy based on the integration of processing maps and finite element method. Journal of Materials Research and Technology, 29, 5271-5281.