Influence of T6 and T7 Heat Treatments on the Mechanical Properties of Rheocast Secondary AlSi7Cu3Mg Alloy

The effects of T6 and T7 heat treatmentsHeat treatment on the mechanical propertiesMechanical properties of a rheocast secondary AlSi7Cu3Mg alloyAlloys are investigated. A lower arm automotiveAutomotive suspension was cast as a demonstrator. While the solution treatment was optimized in previous research, the quenching rate and the ageing treatment were here studied. The influence of the quenching process on the component’s distortionDistortion was analysed by a coordinate-measuring technique. The results indicated a significant effect of the quenching rate on the tensile properties as well as the distortionDistortion of the component. Water quenching led to a greater distortionDistortion of the component compared to still-air cooling. The elongation to fractureFracture seemed to be less affected by the quenching process. Higher ductility was obtained after the over-ageing T7 treatment, while the yieldYield and tensile strengths were similar to those obtained after a peak ageing T6 treatment.