THE INFLUENCE OF CHEMICAL COMPOSITION AND HEAT TREATMENT ON THE MECHANICAL PROPERTIES AND WORKABILITY OF THE ALUMINIUM ALLOY EN AW 5454

The influence of chemical composition and heat treatment on the mechanical properties and formability of the selected commercial aluminium alloy EN AW 5454 was investigated. The main properties of the Al alloy 5454 from the AA 5xxx series are very good corrosion resistant and good formability. From a cast slab a 50-mm-thick slice was taken from the width cross-section in the slab centre. One half of the slice was homogenised for 10 h at a temperature of 530 degrees C. The cast and homogenised samples were investigated using light and scanning electron microscopy. For the study of the influence of the heat treatment, samples in the as-cast state were annealed in a laboratory furnace at a temperature of 530 degrees C for (4; 6; 8; 10; 12) h. To study the influence of the chemical composition, four different samples were prepared: the first without additions, the second with an addition of 1 w/% Mn, the third with 3 w/% Mg and the fourth with an addition of both elements, Mn and Mg. The XRF analyses confirmed the desired chemical composition of all four alloys produced. Half of each alloy sample was homogenised at the same temperature and time as the base alloy in the as-cast state. The hot-deformation behaviour of the different alloys was investigated using cylindrical hot compression tests performed on a Gleeble 1500D thermo-mechanical simulator. By comparing the flow curves a strong influence of the thermo-mechanical parameters on the alloy formability can be seen. The alloy has good workability and with the addition of Mn and Mg, the stress values are higher than those of the base alloy.