Plastic anisotropic and damage evolution analysis of recycled aluminium alloy AA6061 at high rate of strain

Abstract

Aluminium alloys have been widely used in many applications, and its usage is increasing yearly due to its distinctive properties. Nevertheless, it required high energy consumption and pollution during the production of primary sources. This leads to the attention in producing secondary sources to substitute the primary aluminium. Recycling of aluminium alloys adopted in automotive structures is a great option to save thousands of energy and prevent tons of CO2 from being released to the atmosphere. Numerous investigations must be conducted to establish the mechanical behaviour before the specific applications can be identified. However, there is a challenge for such recycled aluminium to achieve the same application as the primary sources due to material properties degradation related to damage. It is still an open study area to be explored for a better understanding of the behaviours of recycled aluminium. Thus, in this work, the Taylor Cylinder Impact test is used to investigate anisotropic-damage behaviour of recycled aluminium alloy AA6061 undergoing high-velocity impact from 190m/s to 300 m/s using two length-to-diameter (L/D) ratios. The recovered samples are observed under an optical microscope (OM) and scanning electron microscope (SEM). A strong strain rate dependency can be seen as the damage evolution is increasing as the impact velocity increase. Further, the corresponding digitized footprints analysis exhibit plastic anisotropic and localized plastic strain in such recycled material. This can be clearly observed from the development of a non-symmetrical footprint within the impact surface. This test is the first to explore the deformation behaviour of recycled materials using high-velocity cylinder impact in a high rate of strain deformation regime.