Influence of Magnesium Addition on Mechanical Properties and Microstructure of Al-Cu-Mg Alloy

Abstract

The influence of Mg addition on mechanical properties and microstructure of Al-Cu-Mg alloy was investigated. Cast Al - Cu- Mg alloys have widely been used in aircraft, aerospace, industrial and architectural applications for their good mechanical properties, high strength-to-weight ratio. An intensive study of these cast aluminium family has been found in many literature as a source for enhancing the mechanical properties and microstructure of aluminium alloys. The main objective of this paper was to investigate the effect of magnesium on mechanical properties and microstructural changes of Al4Cu alloys. The modifications of Al4Cu by adding Mg of 0.5 to 2.5 % in the interval of 0.5% mixing with stirrer and casted by gravity die casting, subsequently the specimens were subjected T6 type heat treatment for 6 hr at 180 0 C. The effect of Mg and ageing on microstructure was studied by using optical microscope. The mechanical properties such as tensile strength and hardness were studied using universal tensile testing machine and Brinell hardness tester respectively. It was observed that the tensile strength and hardness increased with increase of percentage of Mg. The addition of 2.5% Mg increases the tensile strength by 69.9% while hardness increased by 22%. Samples that were aged showed that with addition of 1% of Mg had effect on grain refinement and mechanical properties of the alloy because of smaller grain size.