PSI - Issue 35

E. Emelianova et al. / Procedia Structural Integrity 35 (2022) 203–209 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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all the models, the non-crystallographic bands of localized strain lie at the same angle to the axis of tension. A strong basal texture reduces the material ability to deform perpendicular to the loading axis, while the prismatic slip gives rise to in-plane shear banding (Fig. 7a). In this case, the grains possess close orientations and behave like a single crystal. As the basal texture becomes weaker, the contribution of strain components directed across the free surface increases and higher plastic strain is accumulated in the strain localization regions (Fig. 7d).

Fig. 7. Plastic strain fields for BT10 (a), BT20 (b), BT40 (c), and BT60 (d) model microstructures at a strain of 15%.

4. Conclusion The effect of the basal texture severity on deformation- induced surface roughening in α -titanium was numerically investigated. A set of crystal plasticity finite-element calculations was performed for four polycrystalline models with a basal texture of different severity. The grain orientations were set to describe the deviation of the grain prismatic axes about the ND in the r anges of ±10˚, ±20˚, ±40˚ and ±60˚. Calculation results showed that the mesoscale roughness patterns were strongly affected by the material texture. Developed grain- and mesoscale roughness was formed in the models with a weak basal texture from the very onset of plastic deformation. A sharp basal texture effectively suppressed out-of-plane displacements of individual grains relative to the surrounding material and reduced peak-to-valley distance of mesoscale hills and valleys formed by grain clusters. The basal orientation of grains reduced the material ability to deform perpendicular to the loading axis, while the prismatic slip gave rise to in-plane shear banding. Acknowledgments This work is supported by Russian Science Foundation (Project No. 20-19-00600). References Becker, R., 1998. Effects of Strain Localization on Surface Roughening during Sheet Forming, Acta Mater. 46, 1385 – 1401. Diard, O., Leclercq, S., Rousselier G., Cailletaud G., 2005. Evaluation of Finite Element Based Analysis of 3D Multicrystalline Aggregates Plasticity, Int. J. Plast. 21, 691 – 722. Emelianova, E.S., Romanova, V.A., Balokhonov, R.R., Pisarev, M., Zinovieva, O.S., 2021. A Numerical Study of the Contribution of Different Slip Systems to the Deformation Response of Polycrystalline Titanium, Phys. Mesomech. 24, 166 – 177. Guilhem, Y., Basseville, S., Curtit, F., Stéphan, J.-M., Cailletaud, G., 2013. Numerical Investigations of the Free Surface Effect in Three Dimensional Polycrystalline Aggregates, Comput. Mater. Sci. 70, 150 – 162. Kardashev, B.K., Narykova, M.V., Betekhtin, V.I., Kadomtsev, A.G., 2020. Evolution of Elastic Properties of Ti and Its Alloys due to Severe Plastic Deformation, Phys. Mesomech. 23, 193 – 198. Li, H., Fu, M., 2019. Inhomogeneous Deformation-Induced Surface Roughening Defects, in: “ Deformation-based processing of materials ” . Elsevier, pp. 225 – 256. Mahmudi, R., Mehdizadeh, M., 1998. Surface Roughening during Uniaxial and Equi-Biaxial Stretching of 70-30 Brass Sheets, J. Mater. Process. Technol. 80, 707 – 712. Miller, K.J., 1987. The Behaviour of Short Fatigue Cracks and Their Initiation Part II-A General Summary, Fatigue Fract. Eng. Mater. Struct. 10, 93 – 113. Panin, A.V., Kazachenok, M.S., Perevalova, O.B., Sinyakova, E.A., Krukovsky, K.V., Martynov, S.A., 2018. Multiscale Deformation of Commercial Titanium and Ti – 6Al-4V Alloy Subjected to Electron Beam Surface Treatment, Phys. Mesomech. 21, 441 – 451.