Pengaruh Jumlah Palm Oil Fly Ash Terhadap Microstruktur dan Sifat Mekanis Metal Matrix Composite (Mmc) dengan Metode Stir Casting

Abstract

The processing of palm oil in the MCC source utilizing energy resource derived from palm oil shell and fiber in which the process of fuel shell and fiber combustion in the boiler combustion chamber producing the remaining results in the form of palm oil fly ash which are quite plenty . This palm oil fly ash is usually left alone in the area of oil palm mills that certainly can cause environmental pollution and inconvenience to workers . Therefore, this study aims to look into the chance of the utilization of fly ash as the strengthening material in the manufacture of metal matrix composite ( MMC ) with wide variety of fly ash composition of palm oil . Palm oil fly ash used in this study were drawn from Palm Oil Factory ( PKS ) in the Deli Serdang, North Sumatra with a size 74 m and before being used, this palm oil fly ash is heated to 850o C in a furnace to remove moisture and fractions that are still can be burned . In the manufacture of fly ash composition variations MMC are carried out from 2.5 , 5 , 7.5 , 10 and 12.5 % fly ash mixing process is done at the time in which aluminum was melted in a crusibel graphite following the stirring for 5 minutes , addition of about 1.5 % Mg in the fluid to improve wettability of aluminum and casting is done at a temperature of 760o C . The result of the research shows that the addition of fly ash in the manufacture of MMC can increase hardness , in which 82.6 BHN where the highest hardness was obtained at the composition of 10 % fly ash and the lowest at 2.5 % fly ash composition . The impact test result shows that in general the addition of fly ash does not significantly decrease the impact strength . In the microstructure test result can be seen that palm oil fly ash exists among the aluminum matrix , but the distribution of the fly ash is not uniform in the all parts . The result of the above study shows that palm oil fly ash can be utilized for the manufacture of metal matrix composite with aluminium as the matrix , but the method of manufacture needs to be completed further to obtain optimum results because the stir casting method has not been able to achieve a homogeneous distribution of the fly ash.