Аннотация:Thermodynamic assessment of the influence of alloying elements (Si, Cu, Mg, Ni, Mn, and Zn) on the phase formation in cast aluminum matrix composites Al/B4C is carried out. It is shown that doping with silicon promotes the primary crystallization of Al8C7Si phase, the region of existence of which expands with an increase in the silicon content. In the range of 700-900 degrees C, the addition of silicon slightly changes the B4C fraction. The effect of copper is manifested in decrease in the solidus temperature and the solid-phase formation of Al2Cu. Doping with magnesium changes the phase composition, contributing to the additional formation of the AlB2 phase and free carbon in the four-phase region AlB2 + B4C + (Al) + C. The direct effect of zinc is recorded at its concentration of more than 0.7 wt.%, at which a solid solution (Zn) is formed in the solid state. The influence of manganese is fixed in solid-phase transformations; in the range of manganese concentrations up to 1 wt.%, crystallization ends in the Al12Mn + (Al) + B4C phase region. Nickel addition works similarly; crystallization of alloys containing up to 1 wt.% Ni ends in the phase region Al3Ni + (Al) + B4C.