Deformation behaviours of Al2014-T6 at different strain rates and temperatures

Abstract

The lightweight metallic materials such as aluminium alloys are increasingly important for crashworthy structures due to high strength to weight ratio. These structures withstand different kinds of loads during service. Therefore, the aim of the present investigation is to study the tensile, compressive and flexural behaviours of the aluminum alloy Al2014-T6 at different strain rates and temperatures. Electromechanical universal testing machine with suitable fixtures is used to perform tensile and compressive tests at quasi-static strain rates (0.0001, 0.001, 0.01 and 0.1 s−1), and for flexure/3-point bending tests at cross-head speeds (1, 10 and 100 mm/min) whereas dynamic tensile tests are conducted on split Hopkinson tension bar (SHTB) setup at high strain rates (600, 900 and 1200 s−1) in room temperature 25 °C. The above compression tests are done for different L/D ratios (0.5, 1 and 1.5) and, the 3-point bending tests are conducted for different span lengths (90, 120 and 150 mm) and orientations (flat and transverse). Effects of high temperatures (250 °C, 350 °C and 450 °C) are observed on the strain hardening and ductility of the alloy under quasi-static tensile loads. Nature of fracture surfaces of the broken tensile specimens are studied using scanning electron microscope (SEM). Also, the suitability of the existing Johnson-Cook and Cowper-Symonds models are discussed.