Study on Asymmetric Rolling Process Applied to Aluminum Alloy Sheets

Asymmetric rolling (ASR) is a method to manufacture sheet metals with the aim of improving material performance. The objective of the present work is to investigate the effect of asymmetric rolling on an aluminum alloy used in the automotive industry. To this end, three parameters of the process were studied, namely the asymmetry factor (1, symmetric rolling (SR) and 1.36, asymmetric rolling (AR)), the thickness reduction per pass (10%, 15%, and 30%), and the rolling routes (asymmetric continuous (ARC) and asymmetric reverse (ARR)). After rolling, the material was tested by uniaxial tensile tests to measure its strength and formability. The results show similarity between all the rolling conditions, with a considerable increase in strength and a drastic decrease in formability. In addition, a prediction of forming limit diagram using an FLD code based on Marciniak-Kuczynski analysis was used to investigate the FLD evolution with rolling. The code was capable to capture the variation in formability during the rolling process, showing that it is a reliable numerical tool. A reasonable combination of high strength and acceptable formability was achieved by an adequate heat treatment applied after rolling.