The paper presents detailed analyses of solidification experiments performed on a refined Al-20wt.%Cu alloy using the SFINX (Solidification Furnace with IN situ X-radiography) laboratory facility. Directional solidifications of a sheet-like sample were carried out in a horizontal configuration, with the main surface of the sample parallel to the ground. The sample was solidified for a wide range of cooling rates to obtain various grain structures, from columnar to elongated and equiaxed. The formation of the grain structure was observed in-situ and in real-time by X-radiography, which allows the dynamic of solidification phenomena to be thoroughly analyzed. Based on the radiographs, quantitative measurements were performed to