An Experimental Investigation on the Deformation Behaviour of Recycled Aluminium Alloy AA6061 Undergoing Finite Strain Deformation

Abstract

Finite strain deformation behaviour of recycled aluminium alloy AA6061 is investigated in this paper via uniaxial tensile test and Taylor cylinder impact test implementations. The uniaxial tensile tests are performed at different elevated temperature from 100 to 300 °C, at the strain rate of 10−4 s−1 and 10−3 s−1 and the Taylor cylinder impact tests are conducted at different impact velocity ranging from 170 to 370 m/s. The deformation behaviour of tensile test specimen is evaluated in term of the stress–strain curve and the anisotropic behaviour, including fracture mode, of the impact test specimen, is analyzed according to the geometric profile of the deformed specimen. Besides, the damage characteristic of both the experimental tests is characterized using Scanning Electron Microscope analysis and ImageJ software analysis. The recycled AA6061 exhibits strain-rate dependency behaviour and strong anisotropic behaviour. The flow stress and damage evolution are enhanced with the increment in strain rate. The anisotropic behaviour of such recycled material can be observed in the deformed specimen of impact test, where a non-symmetrical (ellipse shape) footprint is observed. Moreover, the damage is initiated in the undeformed specimen and it getting severe when a deformation is applied. This is due to the growth and coalescence of the micro-voids in the material resulting in formation of micro-cracks and dimples and increase in number of micro-voids.