Study of full-mold casting process for Al–Si hipoeuthetic alloys

The full-mold casting process uses polystyrene foam as the pattern. The pattern is encased in a one-piece sand mold, with no bonding material. As the metal is poured, the foam vaporizes, and the metal takes its place. The gases from the foam flee through the sand. The advantage of the process is that complex shaped castings can be made without any draft or flash. Moreover the process has less energy consumption and less waste residues than other casting processes. The present study evaluated channel dimensioning, refractory coatings and casting sand, in order to adapt the system to a medium size foundry and, at the same time, optimize energy consumption and environmental damage. The results are encouraging. The used coating had shown good erosion resistance, and good permeability for gas escape. The surface finishing quality was satisfactory for the selected sand. Reusing the sand had adequate results. It seems that adjustments for green sand conventional systems conversion to full-mold system are viable.