Processing of ultrafine-grained aluminum by cross accumulative roll-bonding

In this paper, the structural and mechanical characteristics of aluminum strips subjected to two severe plastic deformation processes, namely accumulative roll bonding (ARB) and cross accumulative roll bonding (CARB), are compared. Transmission electron microscopy studies on the strips showed that ultrafine grains are formed by both of the processing routes to eight passes. However, the structure of the CARB-processed specimen was less elongated than that of the ARB-processed specimens; that is, the aspect ratio of grains in the CARB case was less than that in the ARB specimens. Tensile tests indicated that the tensile strength is increased with the number of rolling passes, and the strength of the CARB specimens is higher than that of the ARB specimens.