Experimental investigation of the influence of magnesium on the hardness, wear resistance and impact resistance of Al 6013 alloy

The research investigates the effect of magnesium on the microstructure, hardness, wear resistance, and impact toughness of Al 6013 alloy manufactured by stir casting. The composition of the alloy was changed by adding 2 wt.% Mg and 4 wt.% Mg to determine their effects on the mechanical and tribological properties of the material. Apart from other methods to improve a material's properties, microstructural analysis along with 4 wt.% Mg was confirmed to be one of the strongest factors for the enhancement of the mechanical properties. It contributed to the homogeneous distribution of magnesium silicide precipitates whereas minor phases of aluminum copper intermetallic and aluminum–magnesium–silicon intermetallic as well as finer grain morphology were also present. The homogeneous distribution of secondary phases and strengthening in a solid solution revealed that 4 wt.% Mg was best for improving hardness, wear resistance, and impact toughness. Surpassing the magnesium limit of more than 4 wt.% could harm many aspects like that wear resistance and toughness were negatively affected, the excessive formation of intermetallic phases was resulted, and brittle behavior was increased in combination with other factors. Based on the results, a formula with 4 wt.% Mg is best suited for high performance structural works.