Abstract:
The purpose of this research is to know the influence of waiting time in mold and cooling media to porosity and hardness of foundry product. The casting method uses an evaporative casting. The material used Al-12,6%Si alloy (recycle) from piston. The melting furnace uses a crucible furnace. The Al alloy is heated in the furnace until it is melted, then poured into the mold at a temperature of 700 0C. Further cooled in a mold with a time variation of 10 and 15 minutes. Then the cast was removed from the mold and cooled with a variation of the cooling medium; air, water and brine for 30 minutes. The casting result is made specimen and the porosity and hardness testing is done. Test results show that : (1) the waiting time in the mold and the type of cooling medium has no significant effect on porosity. (2) the waiting time in the mold and the type of cooling medium strongly affect the hardness of the castings.