Evaluation of microstructural transformation during superplastic deformation of thermomechanically processed Ti-6A1-4V alloy

• Autorzy: Motyka M.
• Języki publikacji: EN

Abstrakty

EN

It is generally accepted that fine-grained and equiaxial microstructure of two-phase titanium alloys enables their superplastic forming. The results of previous studies prove that ß-solution treatment - initial heat treatment preceding plastic deformation in thermomechanical process - distinctly increase superplasticiry of Ti-6A1-4V alloy despite the fact that obtained microstructure considerably differs from equiaxial one. In this work fine-grained microstructure was obtained in thermomechanical process consisting of (3-solutioning followed by forging in alfa+ß range. Superplastic deformation tests were carried out at temperature T= 875°C and at strain rate in the range of ?= 10-3-10-2 s-'. The tests were interrupted at the characteristic points of stress-strain curve: maximum and steady plastic flow stress, in order to analyse microstructural transformation during superplastic deformation. Digital image analysis methods were employed for evaluation of changes of stereological parameters of Ti-6A1-4V alloy microstructure.

Słowa kluczowe

EN

fine-structure superplasticity; ihermomechanical process; microstructure; Ti-6Al-4V alloy

• Wydawca: Politechnika Gdańska
• Czasopismo: Advances in Materials Science
• Rocznik: 2007
• Tom: Vol. 7, nr 4(14)
• Strony: 95--101
• Opis fizyczny: Bibliogr. 11 poz., rys., tab.

Twórcy

autor

Motyka M.

• Rzeszów University of Technology, Faculty of Mechanical Engineering and Aeronautics, Department of Materials Science, Rzeszów, Poland

Bibliografia

• 1. Meier M. L., Lesuer D. R., Mukherjee A. K.: The effects of the α/β phase proportion on the superplasticity of Ti-6A1-4V and iron-modified Ti-6A1-4V. Materials Science and Engineering A154 (1992), pp. 165-173.
• 2. Nich T. G., Wadsworth J., Sherby O. D.: Superplasticity in Metals and Ceramics. Cambridge University Press, Cambridge, 1997.
• 3. Inagaki H.: Mechanism of enhanced superplasticity in thermomechanically processed Ti-6A1-4V. Zeitschrift fur Metallkunde 87 (1996), pp. 179-186.
• 4. Jain M., Chaturvedi M. C., Richards N. L., Goel N. C.: Microstructural characteristics in a phase during superplastic deformation of Ti-6A1-4V. Materials Science and Engineering A145 (1991), pp. 205-214.
• 5. Meier M. L., Lesuer D. R., Mukherjee A. K.: a Grain size and (3 volume fraction aspects of the superplasticity of Ti-6A1-4V. Materials Science and Engineering A136 (1991), pp. 71-78.
• 6. Inagaki H.: Enhanced superplasticity in high strenght Ti alloys. Zeitschrift fiir Metallkunde 86 (1995), pp. 643-650.
• 7. Kim J. S., Kim J. H., Lee Y. T., Park C. G., Lee C. S.: Microstructural analysis on boundary sliding and its accommodation mode during superplastic deformation of Ti-6A1-4V. Materials Science and Engineering A263 (1999), pp. 272-280.
• 8. Motyka M., Kubiak K., Sieniawski J., Filip R.: Effect of heat treatment on superplasticity of forged Ti-6A1-4V alloy. Lutjering G., Albrecht J. [eds]: Proc. 10th World Conf. "Ti-2003 - Science and technology", Willey-VCH Verlag GmbH&Co.KGaA, Weinheim, 2004, pp. 597-602.
• 9. Motyka M, Sieniawski J.: The influence of thermomechanical process conditions on superplastic behaviour of Ti-6A1-4V titanium alloy. Advances in Manufacturing Science and Technology 28 (2004), pp. 31-43.
• 10. M. Motyka, J. Sieniawski, W. Ziaja: Wpływ warunków procesu cieplno-plastycznego na nadplastyczność stopu Ti-6A1-4V. Mat. Konf. "Tytan i jego stopy", Warszawa-Serock 2005, s. 245-252.
• 11. Wojnar L.: Image analysis - Application in materials science, CRC Press, New York, 1999.