Stir casting and atmospheric pouring of A380 alloy with Sr addition

The actual trend in order to supply lightweight critical components to automotive and aeronautical industries is the enhancement of mechanical properties of Al-Si alloys by modifying chemical composition, heat treatments and novel forming processes. Nowadays the top in manufacturing is the development of components reduced in weight replacing in many cases of typical heavy steel and cast iron applications. This work describes the rheological treatment in a binary alloy with 8.79%w of Si and A380 commercial alloy performed by mechanical stirring at low cooling rate, with addition of 100 ppm of Sr, 0.33 of solid fraction, 28.33 s−1 of shear rate and atmospheric pouring in a ductile iron mold. It is reported the accomplishment of control of solid fraction during solidification, aided by a thermodynamic model for calculation of real percent of primary α-Al solid phase during freezing as a function of temperature. The microstructural characterization in both alloys shows a globular α(Al) phase surrounded by fine Si eutectic structure. High Resolution SEM-EDS micrographs and mapping shows the Si distribution in the binary alloy with the most content of the eutectic structure and less in the primary solid. In commercial alloy, Cu and Fe forming coarse precipitates are located outside from α(Al) and eutectic structure, it is reported the chemical microanalysis in this region of the commercial alloy.