Optimizing Mechanical Properties in Ternary Al-Si-Cu Alloys: Influence of Composition on Microstructure and Hardness

This study focused on optimizing the mechanical properties of ternary Al-Si-Cu alloys. Alloys near the eutectic composition (AS5U5, AS5U10, AS5U15, AS10U5, AS10U10, AS10U15, AS15U5, AS15U10, and AS15U15) were examined by melting and casting commercially pure metals (99.9% Al, 99.7% Si, and 99.9% Cu). Thermos-Calc software was used to analyze the precipitation phases and solidification process around the eutectic composition. Microstructural analysis, quantification of phases during solidification, and characterization using Scanning Electron Microscopy (SEM) with energy-dispersive X-ray analysis (EDX) were performed. Results revealed that the formation of the Al2Cu component was unaffected by silicon content, but as copper content increased, the percentage of precipitated Al2Cu increased, impacting the hardness of the alloys, especially at lower solidification temperatures.