Abstract
Structural scale levels of plastic deformation and fracture of welded joints have been studied for two high-strength titanium alloys with a low (VT18U alloy) and a high (VT23 alloy) content of the bcc ß phase. Ultrasonic forging and its combination with high-current pulsed electron beam treatment were used to activate nanoscale structural levels of deformation and fracture in welds in order to increase the fatigue life of welded structures. Ultrasonic forging provides an effective dispersion and nanostructuring of surface layers in the VT18U welded joints with a 4.6-fold increase in their fatigue life. The dispersion and nanostructuring of the VT23 laser welded joints is achieved only by ultrasonic forging combined with high-current electric pulse treatment, in which longitudinal dispersion of ß bands occurs with the formation of orthorhombic a " nanolaths. In so doing, the fatigue life of the VT23 welds increases twice, but the effect depends on the power of the high-current generator and electrical pulse parameters. The fracture micrographs of the treated VT23 welded joints reveal nanofibrous bands responsible for ductile fracture and for the reduction of the fatigue crack growth rate. The structural changes and the increase in the fatigue life of the studied titanium alloy welds are associated with the activation of nanoscale structural levels of deformation and fracture induced by ultrasonic forging or by its combination with high-current pulsed electron beam treatment.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
Pleshanov, V.S., Kibitkin, V.V., and Panin, V.E., Mesomechanics of Fatigue Fracture for Polycrystals with Macroconcentrators, Theor. Appl. Fract. Mech., 1998, vol. 30, no. 1, pp. 13–18. doi 10.1016/S0167–8442(98)00039–1
Khorev, A.I., Development of Titanium Sheet Alloys for Welded Structures Working at High Temperatures, Welding Int., 2016, vol. 30, pp. 389–394.
Panin, V.E., Egorushkin, V.E., Elsukova, T.F., Surikova, N.S., Pochivalov, Y.I., and Panin, A.V., Multiscale Translation–Rotation Plastic Flow in Polycrystals: Handbook of Mechanics of Materials, Hsuch, C.–H. et al., Eds., Singapore: Springer Nature. doi 10.1007/978–981–10–6855–3—77–1
Tekoglu, C., Hutchinson, J.W., and Pardoen, T., On Localization and Void Coalescence as a Precursor to Duc–tile Fracture, Philos. Trans. R. Soc. A, 2015, vol. 373, pp.201N0121.
Panin, V.E., Surikova, N.S., Smirnova, A.S., and Pochivalov, Yu.I., Mesoscopic Structural States under Plastic Deformation of Nanostructured Metallic Materials, Phys. Mesomech., 2018, vol. 21, no. 5, pp. 39S–N00.
Yang, K.L., Huang, J.C., and Wang, Y.N., Phase Transformation in the ß–Phase of Super a2Ti3Al Base Alloys during Static Annealing and Super Plastic Deformation at 700–1000°C, Acta Mater., 2013, vol. 51, pp. 2577–2594.
Ivanova, V.S., Synergetics: Strength and Fracture oof Metallic Materials, Cambridge: Cambridge International Science, 1998.
Ivanova, V.S. and Terentiev, V.F., Fatigue of Metals, Moscow: Metallurgiya, 1975.
Terentiev, V.F. and Korableva, S.A., Fatigue of Metals, Moscow: Nauka, 2015.
Makhutov, N.A., Low–Cycle Fatigue, Moscow: Mashinostroenie, 2010, pp. 217–285.
Shanyavsky, A.A., Simulation of Fatigue Fracture of Metals. Synergetics in Aviation, Ufa: Monografiya, 2007.
Shanyavsky, A.A., Scales of Metal Fatigue Cracking, Phys. Mesomech., 2015, vol. 18, no. 2, pp. 1S3–173.
Frost, N.E., Marsh, K.J., and Pook, L.P., MetaïFatigue, Oxford: Oxford Univ. Press, 1978.
Murakami, Y. and Endo, M., Effect of Defects, Inclusions and Inhomogeneities on Fatigue Strength, Int. J. Fatigue, 1997, vol. 1S, pp. 163–182.
Botvina, L.R., Fracture Kinetics, Mechanisms, General Laws, Moscow: Nauka, 2008.
Barenblatt, G.I. and Botvina, L.R., Self–Similarity of Fatigue Fracture: Damage Accumulation, Izv. ANSSSR, Mekh. Tverd. Tela, 1983, no. IN, pp. 161–165.
Botvina, L.R. and Barenblatt, G.I., Self–Similarity of Damage Accumulation, Probl. Prochn., 1985, no. 12, pp. 17–2N.
Barenblatt, G.I., Scaling Phenomena in Fatigue and Fracture, Int. J. Fract., 2008, vol. 138, pp. 19–35.
Egorushkin, V.E., The Gauge Dynamic Theory of Defects in Structured Media under Inhomogeneous Deformation, Izv. Vuz. Fiz., 1990, vol. 33, no. 2, pp. 51–68.
Moiseenko, D.D. and Panin, V.E., Physical Fracture Mesomechanics of Solids Treated as Nonlinear Hierarchically Organized Systems, Mech. Solids, 2015, vol. 50, no. N, pp. N00–N11.
Egorushkin, V.E., Panin, V.E., and Panin, A.V., Lattice Curvature, Shear Bands, and Electroplastic Effect, Phys. Mesomech., 2018, vol. 21, no. 5, pp. 390–395.
Panin, V.E., Fracture Mechanisms of a Solid as a Nonlinear Hierarchically Organized System, Proc. Eur. Conf. Fracture 19, Kazan, Russia, 2012, Kazan: Kazan Sci. Center RAS, 2012.
Panin, V.E., Egorushkin, V.E., Surikova, N.S., and Pochivalov, Yu.I., Shear Bands as Translation–Rotation Mode of Plastic Deformation in Solids under Alternate Bending, Mater. Sci. Eng. A, 2017, vol. 703, pp. N51–N60.
Author information
Authors and Affiliations
Corresponding author
Additional information
Original Russian Text © V.E. Panin, S.V. Panin, Yu.I. Pochivalov, A.S. Smirnova, A.V Eremin, 2018, published in Fizicheskaya Mezomekhanika, 2018, Vol. 21, No. 4, pp. 33–44.
Rights and permissions
About this article
Cite this article
Panin, V.E., Panin, S.V., Pochivalov, Y.I. et al. Structural Scale Levels of Plastic Deformation and Fracture of High-Strength Titanium Alloy Welds. Phys Mesomech 21, 464–474 (2018). https://doi.org/10.1134/S1029959918050107
Received:
Published:
Issue Date:
DOI: https://doi.org/10.1134/S1029959918050107