A new route for developing ultrafine-grained Al alloy strips using repetitive bending under tension

Materials & Design

Giribaskar Sivaswamy¹  Hadi Pirgazi²  Saeed Tamimi²  M. Amir Siddiq²  Shanmukha Moturu³  Babak Shalchi Amirkhiz⁴  Paul Blackwell⁵  Winfried Kockelmann⁶ 

[1] Corresponding author.;Advanced Forming Research Centre (AFRC), University of Strathclyde, Glasgow, United Kingdom;CanmetMATERIALS of Natural Resources Canada, Hamilton, ON, Canada;Department of Electromechanical, Systems and Metal Engineering, Ghent University, Ghent, Belgium;Rutherford Appleton Laboratory, Science and Technology Facilities Council (STFC), ISIS Facility, Harwell, United Kingdom;School of Engineering, University of Aberdeen, Aberdeen, United Kingdom;

关键词: Repetitive bending under tension;    Severe plastic deformation;    AA-7075 strip;    Grain refinement;   

DOI  :  

来源: DOAJ

【 摘 要 】

In this work, the mechanical behaviour and microstructure changes of AA-7075 alloy subjected to a repetitive-bending-under-tension (R-BUT) process were studied. In the R-BUT process, a metallic strip undergoes repeated localised bending and unbending. Load-displacement curves derived from R-BUT tested samples displayed a drastic increase in elongation to failure as compared to samples subjected to standard tensile tests. Additionally, the results confirmed that the force required to deform the R-BUT samples is much reduced as compared to the load required during simple tension. Finite element analysis confirmed that the sample subjected to the R-BUT process underwent intense shear deformation. Transmission-electron-microscopy (TEM) and electron-backscattered-diffraction (EBSD) analysis of the deformed matrix from the ND-RD plane (through-thickness) exhibited evidence for the formation of fine grains. TEM analysis confirmed that the fine grains formed were in the size range of 200–400 nm. Intense shear deformation experienced by the matrix led to shearing followed by spheroidization of precipitate particles. The influence of precipitate particles on the grain refinement process through Particle Stimulated Nucleation of fine grains in the matrix is also presented. EBSD analysis suggested that a Continuous Dynamic Recrystallisation process is the key mechanism behind the grain refinement in the sample during R-BUT processing.

【 授权许可】

Unknown