Pengaruh Kerapatan Polystyrene Foam Terhadap Mampu Alir Dan Kualitas Coran Paduan Aluminium 356.1 Yang Dicor Dengan Metode Evaporative

Abstract

Abstract : Evaporative casting model is a casting method using polystyrene foam as a mold pattern is embedded in the molding sand. Molten metal will fill the mold pattern after pattern evaporates due to heat molding. Evaporative casting has good accuracy for objects that are produced in accordance with the pattern established molds. Objects with large size and complexity can be produced in this way. The study was aimed to observe the effect of density polystyrene foam, the thickness of the mold pattern to fluidity, microstructure, and mechanical properties of 356.1 aluminum alloy casted by evaporative casting method. The aluminum alloy 356.1 was melted in a crucible furnace, then performed at a temperature of 740oC castings, using polystyrene foam mold pattern density variation 0007, 0018 and 0020 g/cm3, and a thickness of 3, 5, 7, and 11 mm, which solidified in the container which uses silica sand molds with sand diameter distribution variation <0.2,> 0.2 – <0.5 and> 0.5 – <0.8 mm. Increasing the density of polystyrene foam to reduce the fluidity. Able best fluidity obtained at the lowest density of polystyrene foam and the highest casting thickness. Capable of fluidity up to 116% decreased with increasing density of foam polystyrene. Increased thickness of the mold pattern to a fluidity increase of 185%. 60.8 VHN casting hardness value reached on the type of polystyrene foam mold pattern density 0007 g/cm3, a decrease of 5.3% with increasing density polystyrene foam mold pattern g/cm3. The strength 0020 147.7 MPa tensile, for casting with a density of polystyrene foam mold pattern g/cm3 0007 , a decrease of 0.5% with increasing density polystyrene foam mold pattern 0020 g/cm3.

Keywords : Evaporative casting method, Aluminium alloy 356.1, Polystyrene foam