High Resolution Surface Studies of Superplastic Deformation


Article Preview

Previous studies of superplasticity using surface markers have tended to use either diamond paste scratches, with which it is difficult to make quantitative measurements, or regular grids with spacing greater than the grain size, which prevents measurements of any deformation occurring within the grains. This paper reports the etching of regular marker grids with submicron line spacings using Focused Ion Beams (FIB), as well as mesoscopic grids with line spacings many grains across. These have enabled us to make quantitative measurements of deformation within the surface grains, and at length scales up to 0.5 millimeters. Further refinements used include the use of Interferometric Surface Profilometry to measure the out-of-surface displacement during deformation. Results on Sn-Pb eutectic alloy tested in tension in Regions I and II showed that there was almost no intragranular deformation anywhere in any of the surface grains. Grain boundary sliding took place, particularly at Sn-Sn grain boundaries, and the accommodation mechanism was separation of interfaces normal to the tensile axis where sliding was blocked, particularly Pb-Pb grain boundaries. It is argued that this is a surface artifact not readily available in the bulk thus the case is made for testing under a different strain condition.



Materials Science Forum (Volumes 551-552)

Edited by:

K.F. Zhang




M. A. Rust and R. I. Todd, "High Resolution Surface Studies of Superplastic Deformation", Materials Science Forum, Vols. 551-552, pp. 615-620, 2007

Online since:

July 2007




[1] T.G. Langdon and J. Wadsworth: Superplasticity in Advanced Materials, p.847, Osaka, Japan (1991).

[2] W.A. Backofen, F.J. Azzarto, G.S. Murty and S.W. Zehr. Superplasticity,: Ductility, Metals Park, Ohio (1968).

[3] T.G. Langdon: Superplasticity: 60 Years after Pearson, (1994).

[4] M.J. Mayo and W.D. Nix: Acta Metall., Vol. 37(1989), pp.1121-1134.

[5] O.A. Kaibyshev, A.I. Pshenichniuk and V.V. Astanin: Acta Mater., Vol. 46 (1998), pp.4911-4916.

DOI: 10.1016/s1359-6454(98)00197-9

[6] R.S. Gates and R.N. Stevens, Metallography: Vol. 6 (1973), pp.269-271.

[7] R.Z. Valiev and T.G. Langdon: Acta Met. And Mat., Vol. 41 (1993), pp.949-954.

[8] P. Bate and P. Blackwell: Scripta Materialia, Vol. 38, No. 6 (1998), pp.901-907.

[9] R.C. Pond, D. A Smith and P.W. J Southerden: Philosophilcal Magazine, Vol. 37(1978), pp.27-40.

[10] D.G. Attwood and P.M. Hazzledine: Metallography, Vol. 9(1976), p.483.

Fetching data from Crossref.
This may take some time to load.