Superplasticity and cavitation in AZ31 Mg alloy at elevated temperatures

Superplasticity of AZ31 alloy at elevated temperatures was examined by uniaxial tension test. Optical microscopy (OM) and scanning electronic microscopy (SEM) were employed to observe the cavities and topography during the superplastic deformation of AZ31 alloy respectively. It is indicated that the intergranular cavities are formed by the continuous fracture of filaments along grain boundaries and the , filaments are not formed by liquid phase but by severe elongation of O-shaped cavities under tensile stress. Finally, a filament-induced cavitation model was proposed. (c) 2005 Elsevier B.V. All rights reserved.