Studi Pengecoran Aluminium Dengan Metode Sand Casting Dan Centrifugal Casting Terhadap Komposisi Kimia, Massa Jenis, Porositas Dan Struktur Mikro

The purpose of this study was to determine the effect of sand casting and centrifugal casting methods on, chemical composition, porosity, massa jenis and microstructure with the main material used aluminum piston. In this study using the Sand Casting and centrifugal casting methods with pouring temperatures at 750 ° C and rotating speed of centrifugal casting motors of 700 rpm. Chemical composition testing using Emmision Spectrometry (ASTM E-1251). Calculation of massa jenis is done by calculating the mass and volume of the cast. Observation of porosity is done by macro photography using a digital microscope. Testing the microstructure of the results of castings using a metallographic microscope (ASTM E3-11). Chemical composition testing results show that this material contains composition (Al) 85.20%, (Si) 11.34%, (Cu) 1.499%, (Ni) 1.1024%, (Fe) 0.5736% and elements others, according to ASTM B-85-03 standards are classified into Aluminum Al-Si (Aluminum - Silicon) A413.0. The results of the calculation of massa jenis and porosity in sand casting have a massa jenis value of 2.6631 gr / cm3, while for the centrifugal casting method of 2.7054 gr / cm3. It can be concluded that the massa jenis affects the amount of porosity, the higher the massa jenis value, the less porosity that occurs. The results of the observation of the micro structure consists of α (Al) and β (Si) phases. In the Sand Casting casting method, it can be seen that the β (Si) phase has a large and more tenuous shape. In Centrifugal Die Casting the β (Si) phase is smaller and more eve