Mechanical Properties And Fracture Studies Of Ultrafine Grained Al 2014 Alloy Processed Through Different Rolling Methods

Abstract

This work focuses on fabrication of UFG Al 2014 alloy processed by various rolling processes like RTR, CR, CGR and WR. Firstly, the ST Al 2014 alloy were processed through RTR, CR and CGR at different thickness reduction values like 50, 75 and 90 percent, and then inspected by tensile and 3PB test, and correlated with microstructural features by EBSD, SEM and TEM. Study shows the development of UFG for all processing routes. The significant enhancement in the tensile and fracture properties of CGR sample were observed for all thickness reductions in comparison to other processing routes. This augmentation can be attributed to the grain boundary strengthening, dislocation strengthening and formation of much finer UFG grains w.r.t. the other rolling processes as observed from EBSD, TEM and SEM micrographs. newlineThen, the ST Al 2014 alloy were processed through CR and CR followed by WR at dissimilar temperatures like 110, 170 and 210 degree Celsius, and then inspected by tensile and 3PB test, and correlated with microstructural features by OM, SEM and TEM. The CR followed by WR samples at 170 degree Celsius exhibited an enhanced hardness, tensile and fracture properties w.r.t. ST alloy. This enhancement can be attributed to combined recovery and recrystallisation, grain boundary strengthening, precipitation hardening and dynamic aging effect during the deformation. newlineLastly, the effect of artificial ageing treatment on processed alloys indicates that the peak aged CGR rolled Al 2014 alloy sample has shown the enhanced mechanical properties compared to the other processed sample conditions. The enhancement in mechanical characteristics were attributed to precipitation hardening, strengthening of grain boundary, dynamic ageing and combined recovery and recrystallization effect during the process of deformation. It was observed that precipitation due to the metastable spherical phase Al2Cu was accountable for the enhanced fracture and tensile properties of CR followed by WR and for CGR at PA Al 2014 alloy. newline