Pengaruh Penambahan Magnesium Terhadap Struktur Mikro dan Nilai Kekerasan pada Pengecoran Alumunium dengan Metode Sand Casting

Abstract

This research aims to determine the effect of magnesium (Mg) addition on the microstructure, hardness value, and impact properties of aluminum casting using the sand casting method. The variations of magnesium addition used in this study were 2%, 4%, and 6% (weight). Tests were carried out on microstructure tests, hardness tests, and impact tests to assess the effect of magnesium addition on the mechanical properties of aluminum alloys. The highest Brinnell test results were in the 4% Mg variation of 53.41 HB, in the 2% Mg variation 52.52 HB, and there was a decrease in the 6% Mg variation to 51.26 HB which was caused by the presence of gas and oxygen that dissolved in the liquid metal but did not dissolve in the solid metal during the cooling process which made the alloy not spread properly. The impact test results showed that the energy absorbed by the material increased with increasing Mg content. in the 6% Mg variation the energy absorbed was 4.398 J with an average impact value of 0.0649 J/mm. The microstructure test results showed a solid mixture of aluminum and magnesium, with an increase in porosity at 6% magnesium variation.