Effect of overheating degree on the solidification parameters of AlSi17CuNiMg silumin

Melting technology, especially the temperature of overheating and pouring above the liquidus point Tliq as well as the cooling rate, determine alloy macro - and microstructure, and hence also casting performance properties. These parameters affect the solidification process and the formation of shrinkage cavities and porosity. So, it is important to choose the best parameters of the melting and pouring process, since on these parameters the process of crystal nucleation and growth as well as shaping of the alloy primary structure will depend. Hence it follows that the time-temperature treatment of molten alloys, hypereutectic silumins included, will also affect the solidification process. Therefore it is fully justified to examine in extenso the effect of overheating degree on parameters of the hypereutectic silumin solidification (Tliq, TE, Tsol) and temperature of complex eutectic crystallisation (due to additions of Cu, Ni and Mg), the more that these effects have not been so far fully investigated and understood.