A Fourier image analysis technique to quantify the banding behavior of surface texture components in AA6xxx aluminum sheet

Roping is a major disadvantage for the use of AA6xxx aluminum alloys for the production of car body parts. Roping is a strain induced surface roughness, manifesting itself as a series of ridges along the rolling direction, and seems to be related to the macroscopic banding of specific texture components at the surface of the sheet. The present study will quantify this banding tendency. A numerical parameter, the banding severity, will be deduced from the frequency spectrum of an EBSD surface texture plot to quantify the banding tendency of the main texture components. Two AA6xxx aluminum sheets with contrasting industrial qualities will be investigated. It will be shown that the banding severity along the rolling direction is very high for the Cube and Goss texture components in the sheet highly susceptible to roping. The banding severities for the other texture components are not very pronounced. This observation suggests a plausible link between the macroscopic banding of the Cube and Goss texture components and the roping phenomenon.