The present research aims to study the effect of various combination of salt and metal modifiers (SrCl2, KCl and NaCl salts with NaF including Sb & Sr ) on the locally developed A356 Al-Si alloy. A series of different heats with these modifiers were prepared using a pit type furnace. Casting of the molten metal was carried out using sand casting technique and fluxes at various stages followed by degassing. Sr modifier was used as Al-Sr master alloy, while Sb metal was used in high purity form. However salt modifiers were thoroughly dried before plunging at the bottom of the crucible containing the molten metal. It was observed that the samples containing Sr as modifier showed the best results in terms of microstructure & tensile properties as compared to Sb modifier. A combination of SrCl2, KCl with NaF showed almost the similar and well modified microstructure with better tensile properties as compared to the samples containing NaCl with NaF salt modifier.

The present study aims to develop A356 Al-Si alloy using high purity aluminium and various master alloy in gas fired pit furnace. Three different ratio of salt modifier (1:1, 1:2 & 1:3) was used to prepare the casting. Sand casting and permanent mould casting techniques were used to prepare the alloys. Optical microscope and universal tensile testing machine were used for the metallurgical evaluation of the prepared alloy. It was observed that the addition of modifier improved the mechanical properties and microstructure of the alloy. It was also observed that modifying agent NaF with CaCl2in 1:1 ratio has shown the best results in terms of microstructure and the mechanical properties.