Localization of plastic deformation in commercially pure titanium in a complex stress state under high-speed tension
In this work, the effect of a triaxiality stress state on the mechanical behavior and fracture of commercially pure titanium VT1-0 (Grade 2) in the range of strain rates from 0.1 to 1000 s-1 is studied. Tensile tests are carried out using a servo-hydraulic testing machine Instron VHS 40 / 5020 on flat specimens with a constant cross-sectional area and on flat specimens with a notch. To study the effect of the complex stress state on the ultimate deformation before fracture, the samples with the notch of various radii (10, 5, 2.5 mm) are used in the experiments. Phantom V711 is employed for high-speed video registration of specimen’s deformation. Deformation fields in a working part of the sample are investigated by the digital image correlation method. It is shown that the effect of the strain rate on the ultimate deformations before fracture has a nonmonotonic behavior. An analysis of strain fields in the working part of the samples shows that the degree of uniform deformation of the working part decreases with an increase in the strain rate. At strain rates above 1000 s-1, the shear bands occur at the onset of a plastic flow. Commercially pure titanium undergoes fracture due to the nucleation, growth, and coalescence of damages in the bands of localized plastic deformation oriented along the maximum shear stresses. The results confirm that the fracture of commercially pure titanium exhibits ductile behavior at strain rates varying from 0.1 to 1000 s-1, at a triaxiality stress parameter in the range of 0.333 < n <0.467, and at a temperature close to 295 K.
Keywords
localization of plastic deformation,
commercially pure titanium,
high strain rate,
mechanical behavior,
stress triaxialityAuthors
| Skripnyak Vladimir V. | Tomsk State University | skrp2012@yandex.ru |
| Iokhim Kristina V. | Tomsk State University | iokhim.k@mail.ru |
| Skripnyak Vladimir A. | Tomsk State University | skrp2006@yandex.ru |
Всего: 3
References
Naseri R., Kadkhodayan M., Shariati M. (2017) Static mechanical properties and ductility of biomedical ultrafine-grained commercially pure titanium produced by ECAP process. Transactions of Nonferrous Metals Society of China. 27(9). pp. 1964-1975. DOI: 10.1016/s1003-6326(17)60221-8.
Fonda R.W., Knipling K.E., Levinson A.J., Feng C.R. (2019) Enhancing the weldability of CP titanium friction stir welds with elemental foils. Science and Technology of Welding and Joining, pp. 1-7. DOI: 10.1080/13621718.2019.1577034.
Li W.-Y., Ma T., Li J. (2010) Numerical simulation of linear friction welding of titanium alloy: Effects of processing parameters. Materials & Design. 31(3). pp. 1497-1507. DOI: 10.1016/j.matdes.2009.08.023.
Wang X.Y., Li W.Y., Ma T.J., Vairis A. (2017) Characterisation studies of linear friction welded titanium joints. Materials & Design. 116. pp. 115-126. DOI: 10.1016/j.matdes. 2016.12.005.
Sharkeev Yu.P, Legostaeva E.V., Vavilov V.P., Skripnyak V.A., Belyavskaya O.A., Eroshenko A.Yu., Glukhov I.A., Chulkov A.A., Kozulin A.A., SkripnyakV.V. (2019) Regular features of stage formation in the stress strain curves and microstructure in the zone of fracture of coarse-grained and ultrafine-grained titanium and zirconium alloys. Russian Physics Journal. 62(8). pp. 1349-1356. DOI: 10.1007/s11182-019-01854-1.
Sharkeev Y., Vavilov V., Skripnyak V.A., Belyavskaya O., Legostaeva E., Kozulin A., Chulkov A., Sorokoletov A., Skripnyak V.V., Eroshenko A., Kuimova M. (2018) Analyzing the deformation and fracture of bioinert titanium, zirconium and niobium alloys in different structural states by the use of infrared thermography. Metals. 8(9). Article 703. pp. 1-15. DOI: 10.3390/met8090703.
Sharkeev Y.P., Vavilov V.P., Belyavskaya O.A., Skripnyak V.A., Nesteruk D.A., Kozulin A.A., Kim V.M. (2016) Analyzing deformation and damage of VT1-0 titanium in different structural states by using infrared thermography. Journal of Nondestructive Evaluation. 35. Article 42. DOI: 10.1007/s10921-016-0349-5.
Skripnyak V.A., Skripnyak N.V., Skripnyak E.G., Skripnyak V.V. (2017) Influence of grain size distribution on the mechanical behavior of light alloys in wide range of strain rates. AIP Conference Proceedings. 1793. Article 110001. DOI: 10.1063/1.4971664.
Frost H.J., Ashby M.F. (1982) Deformation-Mechanism Maps. Oxford: Pergamon Press.
Lee M.-S., Hyun Y.-T., Jun T.-S. (2019) Global and local strain rate sensitivity of commercially pure titanium. Journal of Alloys and Compounds. 803. pp. 711-720. DOI: 10.1016/j.jallcom.2019.06.319.
Srinivasan N., Velmurugan R., Kumar R., Singh S.K., Pant B. (2016) Deformation behavior of commercially pure (CP) titanium under equi-biaxial tension. Materials Science and Engineering: A. 674. pp. 540-551. DOI: 10.1016/j.msea.2016.08.018.
Zhai J., Luo T., Gao X., Graham S.M., Knudsen E. (2016) Modeling the ductile damage process in commercially pure titanium. International Journal of Solids and Structures. 91. pp. 26-45. DOI: 10.1016/j.ijsolstr.2016.04.031.
Tu S., Ren X., He J., Zhang Z. (2019) Stress-strain curves of metallic materials and postnecking strain hardening characterization: A review. Fatigue & Fracture of Engineering Materials & Structures. pp. 1-17. DOI: 10.1111/ffe.13134.
Chichili D.R., Ramesh K.T., Hemker K.J. (1998) The high-strain-rate response of alpha-titanium: experiments, deformation mechanisms and modeling. Acta Materialia. 46(3). pp. 1025-1043. DOI: 10.1016/s1359-6454(97)00287-5.
Meyers M.A., Subhash G., Kad B.K., Prasad L. (1994) Evolution of microstructure and shear-band formation in a-hcp titanium. Mechanics of Materials. 17(2-3). pp. 175-193. DOI: 10.1016/0167-6636(94)90058-2.
Luan Q., Britton T.B., Jun T.-S. (2018) Strain rate sensitivity in commercial pure titanium: The competition between slip and deformation twinning. Materials Science and Engineering A. 734. pp. 385-397. DOI: 10.1016/j.msea.2018.08.010.
Huang W, Zan X., Nie X., Gong M., Wang Y., Xia Y. (2007) Experimental study on the dynamic tensile behavior of polycrystalline pure titanium at elevated temperatures. Materials Science and Engineering: A. 443. pp. 33-41. DOI: 10.1016/j.msea.2006.06.041.
Skripnyak V.V., Skripnyak E.G., Skripnyak V.A. (2020) Fracture of titanium alloys at high strain rates and under stress triaxiality. Metals. 10(3). Article 305. pp. 1-24. DOI: 10.3390/met10030305.
Skripnyak V.V., Kozulin A.A., Skripnyak V.A. (2019) The influence of stress triaxiality on ductility of a titanium alloy in a wide range of strain rates. Materials Physics and Mechanics. 42(4). pp. 415-422. DOI: 10.18720/MPM.4242019_6.
Bai Y., Wierzbicki T. (2008) A new model of metal plasticity and fracture with pressure and Lode dependence. International Journal of. Plasticity. 24. pp. 1071-1096. DOI: 10.1016/ j.ijplas.2007.09.004.
Bai Y., Teng X., Wierzbicki T. (2009) On the application of stress triaxiality formula for plane strain fracture testing. Journal Engineering Materials and Technology. 131. Article 021002. DOI: 10.1115/1.3078390.
Blaber J., Adair B., Ncorr A.A. (2015) Open Source 2D Digital Image Correlation Matlab Software. Experimental Mechanics. 55. pp. 1105-1122. DOI: 10.1007/s11340-015-0009-1.
Zheng G., Tang B., Zhou Q., Mao X., Dang R. (2020) Development of a flow localization band and texture in a forged near-а titanium alloy. Metals. 10. Article 121. DOI: 10.3390/met10010121.
Lindner D., Mathieu F., Hild F., Allix O., Minh C.-H., Paulien-Camy O. (2015) On the evaluation of stress triaxiality fields in a notched titanium alloy sample via integrated digital image correlation. Journal Applied Mechanics. 82. Article 071014. DOI: 10.1115/1.4030457.
