Evaluation of tensile behaviour of 5754 aluminium–magnesium alloy at cold and warm temperatures

Abstract

Cost effective lightweight vehicles have recently become a key target for automotive manufactures due to increasing concerns about minimising environmental impact and maximising fuel economy without sacrificing the vehicle performance and comfort. Aluminium–magnesium alloys are the most important candidate materials due to their excellent high strength to weight ratio, good formability, good corrosion resistance and recycling potential. Although their deformations leave undesirable traces on the surface of the final product and their formability are not very favorable at room temperatures, the formability can be improved by changing the forming temperature to either cryogenic or warm. In this study, uniaxial tensile deformation behaviour of 5754 aluminium–magnesium alloy sheet was extensively studied at cold (–60 to 0°C) and warm (room to 250°C) forming temperatures and a strain rate range of 0·0016–0·042 s^–1. Results indicate that the formability of this material at cold and warm temperatures is better than at room temperature. Stretching lines were eliminated at both cold and warm temperatures especially above 175°C and 0·0016 s^–1 strain rate. The most suitable forming conditions were obtained at 250°C and 0·0083 s^–1 or 175°C and 0·0016 s^–1.