The results of experimental studies of the AK7ch Al–Si alloy before and after modifying with compositions—(i) the K2ZrF6 industrial modifier, (ii) modifying mixture based on refractory metal oxides and cryolite, and (iii) the Arsal 2120 foreign flux—are presented. It is established that modification of the AK7ch alloy leads to the uniform distribution of eutectics (α-Al + β-Si) and structural components, diminishing silicon crystals by a factor of 1.5–2.0 on average, refining, and variation in shape of Fe-containing phases. It is shown that an increase in relative elongation by a factor of 2 and more is characteristics of all modified samples, and the tensile strength, hardness, and densities of casts for all the samples are different and have an ambiguous character.