ABSTRACT
The processing of palm oil in the PKS utilizes energy resource derived from palm
oil shell and fiber in which the process of fuel combustion shell and fiber in the
boiler combustion chamber produces the combustion remaining results in the form
of palm oil combustion fly ash which is quite plenty . 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 utilization of fly ash as a reinforcing material in the manufacture of metal
matrix composite ( MMC ) with variations of pouring temperature of palm oil fly
ash . The 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 ) µm and before being
used palm oil fly ash is heated to 850oC in a furnace to remove moisture and
fractions are still can be burned . In the manufacture of MMC variation of casting
temperature are done from 685oC , 710oC , 735oC , 760oC , 785oC fly ash mixing
process is done at the time when aluminum was melted in a crusibel graphite
followed by the stirring for 5 minutes , addition of about 1.5 % Mg is done on the
fluid to improve wettability . The research result shows that 82.64 BHN which is
the highest hardness was obtained at the temperature of 760oC and lowest casting
temperature 685oC . The impact test result also shows the highest impact strength
occurs at the temperature of 760oC cast . at each point of the tensile test,
variations of temperature decrease . The increasement only occurs at the casting
temperature of 735oC . From the microstructure test result,it can be seen that the
palm oil fly ash exists between the aluminum matrix , but the distribution of the
fly ash is not uniform in all of the parts and the higher the temperature the greater
the Dendrite growth rate due to the longer freezingrate.
Keywords : Palm Oil Fly Ash , stir casting , MMC
