The purpose of this study is to determine the effect of variations in the type of mold
and the addition of dry cell powder marks on the porosity results remelting of Al-Si piston-based scars with 9% Si.This study used three different types of mold there were wet sand
mold, dry sand mold and metal mold. Variations addition of dry cell powder is used as much
as 0,30%, 0,50% and 0,70% by weight. Data obtained by calculating the porosity on each
specimen and taking macro photos. From the calculated porosity created graphs to analyze.
This research method using descriptive analysis.
The results of this study show that the highest porosity occurs in the variations wet
sand mold and additions powder dry cell by weight as much as 0.50% porosity by 3,1447%.
The lowest porosity occur in variations metal molds and adding powder dry cell as much as
0,70% by the porosity of 0,1635%. Trought macro photos, metal mold can product smooth
surface than sand mold.
By this research, the use of metal molds can produce castings with a smooth surface
and low porosity. In addition dry cell powder 0,30% and 0,50% led to increased porosity,
while the addition cell dry powder 0,70% can reduce the porosity in castings results. This
happens in all kinds of molds.
Keywords:, porosity, dry cell powder, Al-Si, piston use
