ANALISA PENGARUH PENAMBAHAN Mg PADA KOMPOSIT MATRIK ALUMINIUM REMELTING PISTON BERPENGUAT SiO2 MENGGUNAKAN METODE STIR CASTING TERHADAP KONDUKTIVITAS TERMAL DAN KETAHANAN AUS

Aluminum is one of the mining material that the existence is decline in the earth crust. However, the aluminum demand is increasing every year. The using of aluminum scrap (recycling) was began to demand by businesses. The reason of using aluminum scrap is more economical and environmental friendly, but disadvantage of aluminum scrap is a low mechanical strength. To enhance the mechanical strength of the aluminum scarp has required special treatment with the additional of another chemical element. This research aims to know the effect of additional Mg on Al-SiO2 composites for thermal conductivity and wear rate. This study used the mass fraction of SiO2 (270 mesh) by 9% wt and the variation of the additional Mg 0% wt, 1% wt, 1.5% wt, 2% wt, and 2.5% wt. The composite manufacturing process using stir casting method with a temperature of 650OC stirring speed of 600 rpm for 5 minutes, and the pouring temperature of 725OC. The results test was showed an increase the thermal conductivity along with the addition of Mg, from 14.061 W / mOC (without the addition of Mg) to 28.947 W / mOC (addition of Mg 2.5% wt). Unlike the case with the results of wear rate test, the wear rate was decreased value of 4.441x10-3 mm³ / s (without the addition of Mg) becomes 0.951x10-3 mm³ / s (addition of Mg 1.5 % wt) increased to 8.129x10-3 mm³ / s (additional 2.5% wt)