Studi Pengaruh Komposisi Magnesium terhadap Sifat Mekanik Hasil Sintesis Paduan Al-4,5Cu-Mg Menggunakan Teknik Metalurgi Serbuk

Abstract

The production of aluminum alloys through powder metallurgy processes is capable of producing products that have good size accuracy and material composition uniformity. Al-4.5Cu-Mg alloy belongs to the type 2xxx of aluminum group, which has better mechanical properties than pure aluminum and can also be heat treated. This study aims to determine the effect of the composition of Mg (magnesium) on mechanical properties such as Vickers hardness number (VHN), compressive strength, density, microstructure, and macrostructure. The materials used for the aluminum alloy manufacturing process in this experiment consisted of aluminum powder (Al), copper powder (Cu), and magnesium powder (Mg), with a composition of 0.5% Mg each, 1%, and 1.5% (wt.). After weighing and mixing, the powder is then put into the mold to be compacted with a pressure of 250 MPa, and then the greenbody specimen is put into the electric muffle furnace to be sintered at 600 °C for 1 hour. Then the compressive strength, Vickers hardness, density, and macrostructure were tested, and the microstructure was observed using an optical microscope. The best density value was obtained at 0.5% Mg composition, namely 1.6103, while the lowest value was obtained at 1.5% Mg composition, namely 1.5210. The highest value in the hardness test was obtained at the 1.5% Mg composition, with a value of 56.6 VHN, while the lowest value was obtained at the 0.5% Mg composition, with a value of 30.4 VHN. The results of the compressive strength test obtained the lowest average compressive strength value of 77.67 MPa at 0.5% Mg composition and the highest average compressive strength value of 84.05 MPa at 1.5% Mg composition. The microstructural test showed that the grain size was getting smaller and denser evenly as the composition of Mg increased.