No abstract

An IF steel/Al6061 composite elaborated by Accumulative Roll Bonding at room temperature is proposed for shielding effectiveness applications. The obtained composite is lighter than the copper and the steel with a density of 3-4.5. In the earlier rollings, a multilayered composite is developed which is in favor of strength but not of shielding. On the contrary, after 3 roll bondings, fragments of IF steel appear in the Al6061 matrix and drastically reduce strength but improve shielding. A finite element simulation of the shielding effectiveness is performed and

Abstract. The present work aims to compare two processes: Accumulative Roll Bonding and Cross Accumulative Roll Bonding (CARB). Both processes consist in the repetition of rolling but the second technique adds a 90° rotation of the sheet around its normal direction between each rolling. Microstructure, mechanical properties and texture were compared for both processes on an AA5754/AA6061 composite. As a result a thinner and less elongated microstructure was obtained in the CARB process leading to an isotropy and an improvement of the mechanical properties. Besides, the texture was characterized by the rotated Cube component for both processes but for CARB it is of less strength.

Accumulative roll bonding (ARB) is performed at room temperature on an aluminum composite up to five rolling cycles, using two different paths: the conventional one (ARB) and the cross ARB (CARB) one consisting of a 90 rotation of the rolling direction before each rolling pass. The microstructure is refined faster by CARB than by ARB occasioning higher yield strength of the elaborated samples. Besides, CARB has the ability to delay the loss of stratification of the composite. The resulting textures are different: while ARB promotes typical rolling components (Brass {011}<211>, Goss {110}<001>, Dillamore {4 4 11}<11 11 8>), S {123}<634>), CARB promotes the ND-rotated Brass {011}<755> instead of Brass together with the S and Dillamore components. A Visco-Plastic Self-Consistent (VPSC) simulation highlights that the ND-rotated Brass had Brass and S components for origin. The ND-rotated Brass presence in the texture promotes a better mechanical isotropy of the composite sheet.

The present study aims to study the texture heterogeneity of an AA5754/AA6061 composite processed by cross accumulative roll-bonding at room temperature. Both Al alloys were first roll-bonded with a 50% reduction and the product was cut in half. Then, both parts were stacked and finally another roll-bonding was carried out but the initial rolling direction was turned by 90°. As a result, a strong gradient appears in the thickness of the composite because of shearing but also due to the alloys composition dissimilarity. As a consequence, it appears each of the four resulted layers has its own texture. In the bulk, AA5754 layer promotes the ND-rotated Brass {011}<755> and S {123}<634> components while AA6061 develops the ND-rotated Brass and Dillamore {4 4 11}<11 11 8> components. On the surface, AA5754 favors the Dillamore component whereas AA6061 shows the rotated-Cube {001}<110> component.