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The interfacial reactions between aluminosilicate ceramics doped with MgO, CaO, or BaO and Al-7 wt% Si alloy were investigated at 1023, 1173, and 1323 K under vacuum for 4 h. Alkaline-earth oxide additives defined phase formation and microstructure of the sintered ceramics and subsequently controlled the ceramic/metal interfacial reactions, which were always intensive. In general, reaction zones consisted of Al 2 O 3 , infiltrated with Al. In the case of CaO-and BaO-doped ceramics, precipitates formed into the metal phase and concentrated the reduced Ca and Ba, respectively. A reaction mechanism is proposed, which anticipates an active role of SiO 2 .