Formability, fracture and void coalescence analysis of a cryorolled Al-Mg-Si alloy

This paper deals with the combined analysis of the forming and the fracture limit diagrams and the void coalescence for AA 6061 sheets that were rolled up to a 50% reduction at two different temperatures, viz.room temperature and cryogenic temperature. Rolled sheets were examined for their microstructure, tensile properties, formability, and void coalescence. The tensile properties and the formability of the sheet metals were correlated with the fractography features and a void-parameter analysis. The cryorolled (CR) samples exhibited better mechanical properties than the room temperature rolled (RTR) samples. Lower values of ‘n’ were observed for both of the rolled conditions than for the base material due to the large dislocation densities in the rolled sheets. Further, the void sizes were observed higher in the CR sample than in the RTR samples. It is believed that the heterogeneous slip in the CR condition contributed to a higher necking percentage and larger void sizes