Investigation of Portevin-LeChatelier Bands in 5754 Aluminum Alloy under Various Strain Paths


Aytuna O. B. , EFE M.

1st International Workshop on Plasticity, Damage and Fracture of Engineering Materials (IWPDF), Ankara, Türkiye, 22 - 23 Ağustos 2019, cilt.21, ss.120-129 identifier identifier

  • Cilt numarası: 21
  • Doi Numarası: 10.1016/j.prostr.2019.12.093
  • Basıldığı Şehir: Ankara
  • Basıldığı Ülke: Türkiye
  • Sayfa Sayıları: ss.120-129

Özet

This work investigated the mechanical and microstructural effects of Portevin-LeChatelier bands in aluminum 5754 alloy under different loading conditions. For these conditions (equibiaxial and uniaxial), an in-plane biaxial test apparatus was utilized with a miniature cruciform specimen. The amount and magnitude of load jumps and drops (serrations) due to the PLC bands were monitored by load cells and strain distributions were measured by digital image correlation technique. Under biaxial stretching, PLC bands nucleated and propagated repeatedly at the same region of the sample, while their formation was random under uniaxial tension. Overall contribution of PLC strain to the total strain was higher under equibiaxial stretching, yet there were no visible shear bands as the PLC bands were suppressed. Conversely, the shear stress state in tension promoted PLC bands and evolved them into sharp shear bands. Texture analysis confirmed the emergence of shear components and cube texture with increasing strain. The eventual failure of the sample was from the shear band(s). The main benefit of biaxial loading was prevention of undesired fracture from shear bands, without changing the overall forming characteristics and the initial copper texture of the material. (c) 2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the 1st International Workshop on Plasticity, Damage and Fracture of Engineering Materials organizers