Manganese is an effective element used for the modification of needle intermetallic phases in Al-Si alloy. These particles seriously degrade mechanical characteristics of the alloy and promote the formation of porosity. By adding manganese the particles are being excluded in more compact shape of “Chinese script” or skeletal form, which are less initiative to cracks as Al5FeSi phase. In the present article, AlSi7Mg0.3 aluminium foundry alloy with several manganese content were studied. The alloy was controlled pollution for achieve higher iron content (about 0.7 wt. % Fe). The manganese were added in amount of 0.2 wt. %, 0.6 wt. %, 1.0 wt. % and 1.4 wt. %. The influence of the alloying element on the process of crystallization of intermetallic phases were compared to microstructural observations. The results indicate that increasing manganese content (> 0.2 wt. % Mn) lead to increase the temperature of solidification iron rich phase (TAl5FeSi) and reduction this particles. The temperature of nucleation Al-Si eutectic increase with higher manganese content also. At adding 1.4 wt. % Mn grain refinement and skeleton particles were observed.
 Taylor, J.A. (2012). Iron-containing intermetallic phase in Al-Si based casting alloys. Procedia Materials Science. 1, 19-33.
 Shabestari S.G., 2004. The effect of iron and manganese on the formation of intermetallic compounds in aluminium-silicon alloys. Materials Science and Engineering A. 383, 289-298.
 Dinnis, C.M. et al. (2005). As-cast morphology of iron-intermetallics in Al-Si foundry alloys. Scripta Materialia. 53(8), 955-958.
 Tillová, E., Chalupová, M. (2009). Structural analysis of Al-Si cast alloys. Žilina: EDIS.
 Bolibruchová, D., Macko, J., Brůna, M. (2014) Elimination of negative effect of Fe in secondary alloys AlSi6Cu4 (EN AC 45 000, A 319) by nickel. Archives of Metallurgy and Materials. 59(2), 717-721.
 Pastirčák, R., Ščury, J. (2016). Effect of technological parameters on microstructure in alloy AlCu4Ti using squeeze casting. American Institute of Physics Publising. 1745.