In this work we show the effect of various concentrations of strontium on the level of modification and on the mechanical properties in the AlSi8Cu3 alloy. The effect of strontium on the silicon in the eutectic structure was examined under operating conditions, in case of both higher (>100 ppm) amount of strontium content than usual in operating conditions and lower (~100 ppm) amount of strontium content, which is not used in practice.
Furthermore this paper presents the cross-effects of strontium and antimony on the level of modification and on the mechanical properties of AlSi8Cu3 alloy.
The extent of modification in the test bars casted with thermal analysis and on the final castings was determined with the help of cooling curves and by comparing them to images of reference standards. The reason of using these two methods was to determine the correlation between the levels of modifications determined by the temperature of supercooling, which can be calculated from the cooling curves, and the structure evaluation methods. The mechanical properties of castings which were casted in the given cooling conditions were also examined.