Influence of thermomechanical ageing on tensile properties of 2014 aluminium alloy

Abstract

2014 aluminium alloy was subjected to various thermomechanical ageing (TMA) treatments which included partial peak ageing (25% and 50%), warm rolling (10% and 20%) and further ageing to peak hardness level at 160 ° C. The tensile tests reveal that TMA treatments cause a substantial improvement in tensile properties and thermal stability. The electron microscopic studies reveal that the TMA treatments affect substantially the ageing characteristics. The TMA Ib treatment yields the finest θ′ needles having longitudinal dimensions of ∼40nm. The TMA treatments also lead to precipitate-dislocation networks of different densities. It is observed that TMA IIb treatment results in the densest precipitate-dislocation tangles of all the TMA treatments. As a result, a significant improvement in the tensile properties of 2014 aluminium alloy has been observed.