The paper deals with the effect of microstructure diversified by means of variable cooling rate on service properties of AlSi7Mg cast alloy
refined traditionally with Dursalit EG 281, grain refining with titanium-boron and modified with sodium and a variant of the same alloy
barbotage-refined with argon and simultaneously grain refining with titanium-boron and modified with strontium. For both alloy variants,
the castings were subject to T6 thermal treatment (solution heat treatment and artificial aging). It turned out that AlSi7Mg alloy after
simultaneous barbotage refining with argon and grain refining with titanium-boron and modified with strontium was characterised with
lower values of representative microstructure parameters (SDAS – secondary dendrite arm spacing, λE, lmax) and lower value of the
porosity ratio compared to the alloy refined traditionally with Dursalit EG 281 and grain refining with titanium-boron and modified with
sodium. The higher values of mechanical properties and fatigue strength parameters were obtained for the alloy simultaneously barbotagerefined
with argon and grain refining with titanium-boron and modified with strontium.