Experimental study on the effects of three alloying elements on the mechanical, corrosion and microstructural properties of aluminum alloys

Aluminum is widely used in industries such as automobile and aerospace due to its lightweight, but its pure form lacks sufficient strength and the properties of aluminum can be modified by adding alloying elements. This paper presents the effect of adding Magnesium (Mg), Copper (Cu), and Zinc (Zn) on the mechanical, microstructural, heat treatment properties, and corrosion behavior of aluminum-based alloys. The aluminum-based alloys were manufactured with varying percentages (1 %, 3 %, 5 %, 8 %, and 10 %) of the three alloying elements using sand casting. Tension, compression, Brinell hardness, and corrosion tests were conducted to examine the effect of these alloying elements on the alloys' properties. The tensile strength is improved significantly with the increase in alloying elements for all alloys but the compressive strength and hardness are improved for Al–Cu alloy only. After heat treatment, the hardness of Al–Mg alloy increased at 8 % and 10 % Mg content while the hardness of Al–Cu alloy decreased after heat treatment for all concentrations of Cu. The hardness of Al–Zn alloys remained unaffected by the heat treatment process. The corrosion rate is minimum for Al–Mg and it is maximum for Al–Cu alloys but at 10 % concentrations, the corrosion rate of Al–Mg alloy is higher than Al–Cu alloy. The microstructural observation before and after heat treatment revealed that the grain refinement occurred for Al–Mg and Al–Cu alloys but the microstructure remained unaffected for Al–Zn alloys. The outcomes of this study offer valuable insights into customizing the mechanical characteristics of aluminum-based alloys to suit particular applications.