Spatial characteristics of the Portevin-Le Chatelier deformation bands in Al-4 at%Cu polycrystals

The Portevin-Le Chatelier (PLC) effect represents a typical plastic instability in many metallic alloys of industrial interest. In space domain, this effect commonly consists of repeated nucleation and propagation of band structure, in which the plastic deformation concentrates, along the tensioned specimen. In this paper, a novel digital speckle pattern metrology technique including digital speckle pattern interferometry (DSPI) and digital speckle correlation (DSC) has been applied to investigate the spatial features (geometrical shape, localized plastic deformation in band) and dynamic characteristics (propagation of the bands, details of the band migration) of the PLC deformation bands in Al-4 at%Cu polycrystals simultaneously and quantitatively.