Pengaruh Kandungan Serbuk Alumina Terhadap Kekerasan Dan Kekuatan Bending Komposit Paduan Al-Si/Alumina

This research aims to investigate physical and mechanical properties of Aluminum-Silicon Alloy Metal Matrix Composites reinforced with alumina powder produced using Powder Metallurgy method. The variation of alumina powder was 0, 3, 6, 9, 12 and 15 % weight. Each composition was mixed and blended for 2 hours and then uniaxially pressed using a pressure of 500 MPa to form cylindrical green bodies of 15 mm diameter and rectangular beam green bodies of (50 x 7 x 8) mm3. The green bodies were then pressureless sintered in argon atmosphere for 2 hours. The results show that the relative density decreases with increasing alumina contents. The Vickers hardness and bending strength increase and achieve the maximum of 35 HV and 23 MPa respectively at 6% weight of alumina. The composites contain alumina greater than 6 %weight exhibit decrease in Vickers hardness and bending strength. Keywords: alumina, aluminum, bending strength, composites, Vickers hardnes