PENGARUH FRAKSI BERAT FLY ASH PADA KOMPOSIT MATRIK SERBUK LIMBAH ALUMINIUM TERHADAP SIFAT KEKERASAN

This study aims to determine the effect of weight fraction of fly ash on the hardness properties of composite aluminum/fly ash. This research uses fly ash powder and aluminum waste powder is processed through water atomization method. Fly ash powder as much as 10%, 20%, and 30% of the weight fraction was mixed with powder from aluminum waste (size ≤ 53 μm). Each mixture is stirred using a mixer for 2 hours. A mixture of fly ash powder and powder from aluminum waste is uniaxially compressed at a pressure of 120 MPa and sintering in atmospheric environments with temperatures of 525 ℃, 550 ℃ and 575 ℃, then hardness testing. The test results show that along with the increase in the weight fraction of fly ash at the same temperature the hardness value decreases and the hardness value increases at a higher temperature. The highest hardness value is at sintering temperature of 525 °C with a weight fraction of 10% fly ash of 32.83 BHN, while the lowest hardness value is at a temperature of 575 °C with a weight fraction of 30% fly ash of 17.55 BHN