This paper deals with influence on segregation of iron based phases on the secondary alloy AlSi7Mg0.3 microstructure by chrome. Iron is

the most common and harmful impurity in aluminum casting alloys and has long been associated with an increase of casting defects. In

generally, iron is associated with the formation of Fe-rich phases. It is impossible to remove iron from melt by standard operations, but it is

possible to eliminate its negative influence by addition some other elements that affect the segregation of intermetallics in less harmful

type. Realization of experiments and results of analysis show new view on solubility of iron based phases during melt preparation with

higher iron content and influence of chrome as iron corrector of iron based phases. By experimental work were used three different

amounts of AlCr20 master alloy a three different temperature of chill mold. Our experimental work confirmed that chrome can be used as

an iron corrector in Al-Si alloy, due to the change of intermetallic phases and shortening their length.

This article deals with the fatigue properties of newly used AlZn10Si8Mg aluminium alloy where the main aim was to determine the

fatigue strength and compare it with the fatigue strength of AlSi7Mg0.3 secondary aluminium alloys which is used in the automotive

industry for cyclically loaded components. AlZn10Si8Mg aluminium alloy, also called UNIFONT 90, is self-hardening (without heat

treatments), which contributes to economic efficiency. This is one of the main reasons why is compared, and may be an alternative

replacement for AlSi7Mg0.3 alloy which is heat treated to achieve required mechanical properties. The experiment results show that the

fatigue properties of AlZn10Si8Mg alloy are comparable, if not better, than AlSi7Mg0.3 alloy. Fatigue properties of AlZn10Si8Mg alloy

are achieved after seven days of natural ageing, immediately after casting and achieving value of fatigue strength is caused by structural

components formed during solidification of the melt.