Enhanced mechanical properties of Sr-modified Al–Mg–Si alloy by thermo-mechanical treatment

Abstract In this study, the effect of thermomechanical treatments applied to strontium-modified A360 alloy on the microstructure and mechanical properties of the alloy was investigated. Optical microscopy, XRD, and SEM were employed to examine the microstructural properties, while tensile and hardness tests were conducted on the samples to evaluate the mechanical properties. It was observed that the strength values increased as the deformation amount increased, and subsequently, optimum conditions (tensile strength and ductility) were determined after the subsequent aging treatment. Following cold deformation, dendritic structure shifted towards the direction of deformation along with the eutectic silicon structure. After aging, it was found that the dendritic structure transformed into equiaxed grains at certain temperature. The highest tensile strength of 383 MPa was achieved in the sample with a deformation amount of 70 %. In this case, the ductility value was 2.85 %. Subsequently, the optimum conditions after aging were determined as 160 °C & 4 h, resulting in a tensile strength of 341 MPa and ductility of 3.62 %.