Evaluation of Aluminium Alloy for Plasticity Applications

Abstract

An evaluation of aluminium alloy for plasticity applications was undertaken to bridge the gap in appraising the impact of variation of alloying elements such as magnesium (Mg) and copper (Cu) on plasticity as a mechanical property of the aluminium alloy. To this end, twenty seven (27) samples of aluminium alloys were produced with constituents drawn from 6 % zinc (Zn), 2.5 % - 3.5 % magnesium (Mg), 1.8 % - 3.0 % copper (Cu), 0.03 % manganese (Mn), 0.23 % chromium (Cr) and aluminium (Al) as balance in all cases. 0.1 gram of sulphur (S), which the same as the quantity of iron (Fe) in chromium (Cr) and manganese (Mn), was added to oxidize (eradicate) iron (Fe). Samples were subjected to hardness test; to measure the ability of the alloy to resist plastic deformation and percentage elongation (% e) to unveil the mechanical properties of the alloy. Maximum Vickers hardness (Hv) of 130.7 was displayed by an alloy of 6 % zinc (Zn), 2.5 % magnesium (Mg), 1.8 % copper (Cu), 0.03 % manganese (Mn), 0.23 % chromium (Cr) and aluminium, quenched in water at 490°C and soaked for five (5) hours. The same alloy, non-heat treated, displayed a least Hv of 91.5. Hardness increased from 91.5 Hv in an alloy of 2.5 percentage weight of magnesium to 120.3 Hv in an alloy of 3.5 percentage weight of magnesium. Maximum percentage elongation (% e) of 130.00 was recorded by an alloy of 3.5 % Mg and 2.5 % Cu. A least percentage elongation of 12.00 % was established in an alloy of 3.5 % Mg and 3.0 % Cu. The experiment observed that with increase in percentage weight of magnesium from 2.5 % - 3.0 % - 3.5 %, there was variation from 25.67-18.67- 130.00 respectively in percentage elongation. The alloy with 3.5 % Mg, 1.8 % Cu was recommended for plasticity (% elongation) applications. Investigation of the impacts of other constituents on this alloy may be considered.