Effect of Nickel Content and Heat Treatment on the Electro-Mechanical Properties and Microstructural Evolution of Aluminium

Abstract

Aluminium is a very important metal among the engineering materials. Owing to its importance, several researches are being conducted on its characteristics and the effects of other materials on its characteristics. This paper investigated the effects of various composition of nickel on the characteristics of aluminium. The characters of interest were strength, hardness, electrical conductivity and microstructural evolutions. Alloys were developed with variation of nickel from 2%, 4%, 6%, 8%, to 10%, these included the tensile specimens, hardness specimens, electrical conductivity specimens, and the microscopic specimens. Each set were produced in threes: one annealed, one age-hardened and the other left untreated. The results of the various test show that CN5 has the highest hardness, with hardness value of 435, followed by HN4, with the value of 416 and then AN4 with 403. All the rest are below these three values. The cast samples produced more elongations than the annealed and hardened samples, while there is more strength in the case of the hardened samples compared to annealed and as cast samples. As for electrical conductivity AN3 has the highest conductivity value of 6.1 x 10⁷ S/m.