SILVA, Aécio Cleber Santos.; CASTRO, Walman Benício de.
Abstract:
The advantages of effective grain refinement are: Improved feeding characteristics, increased tear
resistance, improved mechanical properties, increased pressure tightness, improved response to thermal
treatment, and improved appearance following chemical, electrochemical, and mechanical finishing. All
aluminum alloys can be made to solidify with a fully equiaxed, fine grain structure through the use of suitable
grain-refining addition. The most widely used grain refiners are master alloy of titanium, or of titanium and
boron, in aluminum. The objective of the present work was to verify the influence of salts coating in ceramic
moulds in microstructure of the Al-40%Cu alloy, and to compare with other sample cooled in a metallic mold.
The salts used for the cover of the ceramic mould were 3 salts (LiF, LiCl+LiF), that can to modify the
physical-chemical properties of the mould surface, acting as possible agents nucleantes. The alloy had no
addition of the titanium-boron based grain size. The results showed the ceramic mould that used LiF+LiCl as
salt coating produced a larger microstructural refined, probably for larger interaction physical-chemistry of
this salt with the alloy. However, the sample cooled in cooper mold produced a microstructural refined larger
than salt coating.
