Mapping of the granular flow during superplastic deformation of microsample of Zn-20.2%Al-1.8%Cu alloy at room temperature

A new technique for Scanning Electron Microscopy (SEM), which provides a me soscopic coordinate system inscribed on the surface of the center of a tens ion test specimen has been proposed. Such technique allows to establish in a repeatable way any angle relative to any axis of any coordinate system, o r distances between grains, or to measure local or global true deformation in parallel or perpendicular directions relatives to the tension axis. The application of such technique for a Zn-20.2%Al - 1.8% Cu alloy tension test specimen with a total length between shoulders of 412 mum length and a gag e length of 371 mum, deformed at room temperature, allows to obtain: The ma pping of the granular flow during superplastic deformation; this result is in qualitative agreement with similar flow-diagrams obtained previously by Ashby and Verral (Acta Metall. 21, 1973, p. 149) from their oil-emulsion mo del. (C) 2001 Kluwer Academic Publishers.