A microtexture based analysis of the surface roughening behaviour of an aluminium alloy during tensile deformation

The development of surface roughening during uniaxial tensile deformation, with particular attention to the development of parallel ridges and valleys (ribbed profile), has been investigated for a commercial aluminium alloy. A comparison has been made between two samples which exhibit different propensities for roughening and a detailed microstructural characterisation of these samples has been performed in order to explain the differences. Microstructural characterisation techniques included polarised light microscopy, bulk texture and microtexture. In addition, yield properties were calculated from the microtexture data using polycrystal plasticity analysis. The results show that the differences in the roughening behaviour can be attributed to spatial differences in texture at the specimen surface whereby R-component colonies in a cube matrix produce differential straining, which eventually leads to strain localisation through the specimen thickness to produce a ribbed profile.