Texture, Microstructure and Mechanical Properties of Ultrafine Grained Aluminum Produced by Accumulative Roll Bonding

Texture, microstructure, and tensile behavior of technically pure aluminum AA1050 and of the age-hardening alloy AA6016 produced by accumulative roll bonding (ARB) were studied for different numbers of ARB cycles. After eight cycles an ultrafine grained microstructure with grain sizes of the order of 0.5 mu m is reached. The grain size decreases with increasing alloying content. The texture consists of a major copper component and a minor brass component. The latter strengthens with alloying. Due to shear deformation in the surface region also a rotated cube component is found. It is stronger in the pure material and is partly added up in the bulk during ARB. Due to dislocation and grain boundary hardening the tensile strength increases with increasing ARB cycles following the Hall-Petch behavior while a moderate ductility is kept. Within the sheet plane no significant influence of the tensile direction on the observed mechanical properties was found.