Mechanisms of surface deformation during cold rolling of aluminium

The deformation of a surface region results in a set of different topographical features. The main surface features found during the first few cold rolling passes of initially twin-roll cast aluminium are grooves, gorges and shingles. These are found to be related to each other and a description of the mechanisms creating and deforming the surface features are given. Grooves/shingles are formed at the exit side of the neutral plane during casting and these are deformed into gorges in the first pass and the shingle is smeared over the cavities. A large number of shingles are formed in the second pass.