Studi Pengaruh Penambahan Silikon Karbida (SiC) pada Paduan Al-Cu-Mg terhadap Sifat Mekanis dan Struktur Mikro dengan Metode Metalurgi Serbuk

Abstract

Materials science and technology is the application of technology regarding the relationship between metal composition and processing, with properties and uses that are in accordance with existing needs and demands. Aluminums copper alloys will produce properties that are hard and strong but brittle. This study aims to determine the effect of the composition of SiC (silicon carbide) on the mechanical properties of hardness, compression, density, microstructure, and macrostructure of various variations of SiC in powder metallurgy processes. Specimens were made by mixing aluminum powder, 4.5% copper, 0.5% magnesium, and SiC powder with 1%, 1.5%, and 2% (wt) SiC, respectively, using a horizontal ball milling machine for 1 hour. A mixture of aluminum and SiC was put into the mold and then compacted at a pressure of 240 MPa with a holding time of 15 minutes. The specimens were compacted (green compact) and then sintered at 500 °C and held for 1 hour. The compressive strength, Vickers hardness, density, and macrostructure were tested, and the microstructure was observed using an optical microscope. In the test, it was found that there was an increase in the values of density, hardness, and compressive strength along with the increase in the SiC composition. The results for the highest density, hardness, and compressive strength values were at 2% SiC composition with a value of 1.6806 gr/em, a hardness value of 39.9 VHN, and a maximum compressive strength value of 103.08 MPa. The microstructural test showed that the grain boundaries were getting tighter and the size between the grains was getting smaller as the added SiC content increased.