Investıgatıon of the effect of thermomechanıcal process onmechanıcal propertıes of A360 alumınum alloys wıth SR doped

In this thesis study, strontium was added to the A360 alloy produced by sand mold casting method at the rates of 0.0144, 0.0441 and 0.0767 wt% to examine its effect on the microstructure and mechanical properties. Then, the samples were pre-aged and the effect of the heat treatment was observed. As a result of these processes, thermomechanical processes were applied to the samples with the highest tensile strength. In the first stage of this process, 10, 20, 30, 40, 50, 60, 70% cold deformation was applied to the samples. Re-aging was applied to the samples with the highest tensile strength after deformation. While pre-aging processes were carried out at 160, 180, 200 °C and 2, 4, 6 hours, re-aging processes were carried out at 160, 180, 200, 280, 320 °C and 2, 4, 6 hours. Hardness and tensile tests were applied to the samples to determine mechanical properties at all processing steps. In addition, fatigue tests were performed on the samples that were pre-aged and as-cast. Microstructural studies were carried out by optical microscope, (SEM), (EDS), and (XRD). When the results were examined, it was seen that the strontium element had a significant effect on eutectic silicon. he highest tensile strength and hardness values of the samples containing strontium without heat treatment and with heat treatment were observed in the samples containing 0.0144 wt% strontium. The highest tensile strength of the cold deformed specimens was observed in the specimens deformed by 70%. Re-aging was applied to the samples deformed by 50, 60 and 70%. As a result of re-aging, the strength values of the samples decreased while the ductility values increased.