Temper rolling to control texture and earing in aluminium alloy AA 5050A

The evolution of crystallographic texture during the thermo-mechanical processing of aluminium sheet is accompanied by the development of plastic anisotropy and, most notably, the well-known earing phenomenon. In the present paper we analyse the formation of texture and earing properties in sheets of the Al-Mg alloy AA 5050A (ISO AlMg1.5(D)) along a process route resulting in temper H16 after cold rolling and temper H44 after lacquering. This process route, which is characterized by interannealing in combination with a mild final temper rolling pass, was established for the production of Al packaging sheet with medium strength and very good earing properties. Besides a detailed characterization of the development of microstructure, texture and resultant earing properties during standard processing, measures to improve the earing properties by adapting the ratio of the relevant rolling and recrystallization texture components are addressed.