Microstructure, texture and interface integrity in sheets processed by Asymmetric Accumulative Roll-Bonding

CAMILO MAGALHÃES, DANIELLE CRISTINA; SORDI, VITOR LUIZ; AVALOS, MARTINA; KLIAUGA, ANDREA MADEIRA; DE GODOI, RENAN PEREIRA; BOLMARO, RAUL EDUARDO

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

ELSEVIER SCIENCE SA

Año: 2020 vol. 771

0921-5093

AccumulativeRoll-Bonding (ARB) and Asymmetric Rolling (AR) techniques were combined toproduce ultrafine grained aluminum sheets with the mechanical characteristicsof a Severe Plastic Deformation (SPD) process. Temperature and number ofbonding cycles were varied to promote grain refinement, texture randomizationand high-quality sheet bonding. Finite element simulation for a single pass wasperformed to clarify the strain distribution differences between symmetric andasymmetric roll -bonding. The microstructure and crystallographic texture weremeasured by Electron Backscatter Diffraction (EBSD) and X-ray diffraction.Hardness and tensiletests characterized strain distribution and bondingeffciency. A fne grain structure with a mean grain size of 1.0 μm was achieved at 350 ⁰C, whereas acoarser grain structure was obtained at 400 ⁰C. The grainsize and shape distribution were linked to enhancing the mechanical strength ina transversal direction. During repeated bonding cycles at both temperatures,extra shear in the interfacial region yielded favorable homogeneous strain distributionand a weak shear texture across the sheet. Rotated-cube orientation was thestrongest component in both processing temperatures. To increase theinterfacial strength, mainly on the last bond interface, an extra 50% reductionstep was added. This improved the adhesion in the last bonding interface, andthus enhanced the ductility. These fndings helped to provide a basis fordetermining the processing conditions for aluminum alloy