Artigo Produção Nacional Revisado por pares

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

2019; Elsevier BV; Volume: 771; Linguagem: Inglês

10.1016/j.msea.2019.138634

ISSN

1873-4936

Autores

Renan Pereira de Godoi, Danielle Cristina Camilo Magalhães, Martina Ávalos, R.E. Bolmaro, Vitor Luiz Sordi, Andréa Madeira Kliauga,

Tópico(s)

Aluminum Alloys Composites Properties

Resumo

Accumulative Roll-Bonding (ARB) and Asymmetric Rolling (AR) techniques were combined to produce ultrafine-grained aluminum sheets with the mechanical characteristics of a Severe Plastic Deformation (SPD) process. Temperature and number of bonding cycles were varied to promote grain refinement, texture randomization and high-quality sheet bonding. Finite element simulation for a single pass was performed to clarify the strain distribution differences between symmetric and asymmetric roll -bonding. The microstructure and crystallographic texture were measured by Electron Backscatter Diffraction (EBSD) and X-ray diffraction. Hardness and tensile tests characterized strain distribution and bonding efficiency. A fine grain structure with a mean grain size of 1.0 μm was achieved at 350 °C, whereas a coarser grain structure was obtained at 400 °C. The grain size and shape distribution were linked to enhancing the mechanical strength in a transversal direction. During repeated bonding cycles at both temperatures, extra shear in the interfacial region yielded favorable homogeneous strain distribution and a weak shear texture across the sheet. Rotated-cube orientation was the strongest component in both processing temperatures. To increase the interfacial strength, mainly on the last bond interface, an extra 50% reduction step was added. This improved the adhesion in the last bonding interface, and thus enhanced the ductility. These findings helped to provide a basis for determining the processing conditions for aluminum alloys.

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