Development of a Variant of Scalar Constitutive Equations Suitable for Description of the near Super-Plastic Regimes of Deforming

Abstract:

When deformations are carried out with fine grained microstructure and within a narrow range of strain rates and temperature, metals and ceramics have been shown to exhibit superplastic behavior. Under these conditions the material demonstrates unusually high elongation with a relatively stable microstructure. But when the above mentioned parameters lie beyond a limit, near superplastic behavior is observed. The microstructure changes actively during the process of deformation and the response of the material becomes dependant on the history of loading. A model to describe the dependence on loading history by taking into account the change in microstructure is proposed. The model predicts the general trends observed and also provides possible explanation to some of the effects observed in the experimental data.

• Periodical: Applied Mechanics and Materials (Volumes 110-116)
• Pages: 163-169
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.110-116.163
• Online since: October 2011
• Authors: K. Bhaskaran, B.B. Jha, B.K. Mishra, Olga I. Bylya, M.K. Sarangi, P.V. Chystyakov, A.V. Muravlev, R.A. Vasin
• Keywords: Microstructural Transformation, Model, Near Superplastic Deformation, Superplasticity

References

[1] S.S. Bhattacharya, O.I. Bylya, R.A. Vasin and K.A. Padmanabhan, Mechanical behaviour of titanium alloy Ti-6Al-4V with unprepared microstructure under jumpwise variations of the strain rate in the superplasdtic state, Mechanics of Solids, Vol. 44, No. 6, 951-958 (2009).

DOI: 10.3103/s0025654409060120

[2] N. Ridley, P.S. Bate, B. Zhang, Effect of strain rate path on cavitation in superplastic aluminium alloy, Materials Science and Engineering, A, in press. (2007).

DOI: 10.1016/j.msea.2006.07.154

[3] F. Booeshaghi and H. Garmestani, On the application of load relaxation in characterizing superplastic Al-Li 8090, Scripta Materialia, Vol. 40, pp.509-516, (1999).

DOI: 10.1016/s1359-6462(98)00344-3

[4] K.A. Padmanabhan, R.A. Vasin and F.U. Enikeev, Superplastic flow: phenomenology and mechanics, Springer Verlag, 2001, 430p.

[5] A.K. Ghosh and R. Raj, A model for the evolution of grain size distribution during superplastic deformation, Acta metall., Vol. 34, No. 3, pp.447-456, (1986).

DOI: 10.1016/0001-6160(86)90080-5

[6] A.K. Ghosh and C.H. Hamilton, Mechanical behavior and hardening characteristics of a superplastic Ti-6Al-4V alloy, Metallurgical transactions A, vol 10A, pp.699-706, (1979).

DOI: 10.1007/bf02658391