THE HARDNESS, MICRO STRUCTURE AND SURFACE ROUGHNESS OF ALUMINIUM SILICON CASTINGS USING EVAPORATIVE CASTING METHOD WITH VARIATION OF STYROFOAM DENSITY
By : I Wayan Sahenndra
Email : email@example.com
Faculties : Fakultas Teknik
Department : S1 Teknik Mesin
Evaporative casting is one of the metal casting method using polystyrene foam as the mold. Moulds that made of polystyrene foam patterns are easy to make and cheap.The purpose of this research is to know the differences in hardness, surface roughness and microstructure of casting product by using variations Styrofoam density. This research was conducted by making a mold of styrofoam with density 0.038 g / cm3, 0.016 g / cm3 and 0.011 g / cm3. Casting process starting from smelting aluminum silicon alloy with a temperature of 750 ? C and then cooled to room temperature, then examined the results castings. After that, the researcher make the speciment to do hardness , surface roughness, and microstructure testing. These results show that the molds with different densities have the different hardness, surface roughness, and microstructure. Based on the results of hardness test, surface roughness, and the micro structure observation of styrofoam molds can obtained the maximum results is specimens with styrofoam molds density 0.011 g / cm3, the hardness value is 44.44 and the value of surface roughness is 0.07mm.
Keyword : evaporative castings, the hardness, surface roughness, styrofoam density, microstructure.