Pengaruh Penambahan Magnesium (Mg) terhadap Sifat Mekanik dan Komposisi Paduan Alumunium Daur Ulang dari Velg Motor

Abstract

This study aims to investigate the effect of magnesium (Mg) addition on the mechanical properties and composition of recycled aluminum alloy from used motorcycle wheels using the sand casting method. The Mg addition variations used were 4%, 6%, and 8%, with tests including Vickers hardness test, Charpy impact test, tensile test, and composition analysis using spektrometer emisi optik (OES). The results showed that Mg addition increased hardness from 79.6 VHN (4% Mg) to 86.2 VHN (8% Mg), and improved impact toughness with absorbed energy up to 4.65 Joules and impact value of 0.057 J/mm² at 8% Mg. However, the maximum tensile strength reached an optimal value at 6% Mg (56.14 N/mm²) and decreased at 8% Mg (41.06 N/mm²) due to the formation of brittle phases. Composition analysis confirmed an increase in Mg distribution that supports material strengthening. Overall, 6% Mg addition provides the best balance for mechanical properties, supporting the utilization of wheel waste as a sustainable material.