Effect of Cu and Zn Addition on the Mechanical Properties of Structural Aluminum Alloy
The effect of independently adding Cu and Zn on the mechanical properties of 6063 aluminium alloy has been examined. In this study, sand cast samples of aluminum alloy containing Cu/Zn (0-20 vol %) and homogenized at 5100C for 1hr are analyzed for ultimate tensile strength (UTS), hardness, elongation and impact energy. Addition of more than 15 vol % Zn to structural aluminum alloy raised its hardness and elongation. Copper additions above 4 vol % lowered the UTS, elongation and impact energy. However, the hardness increases with percent addition of Cu. These properties are functions of evolving microstructure. The intermetallic compound of Zn-Al has structure and crystal orientation similar to Mg2Si in the matrix with its influence on the aluminum alloy similar to that of Mg2Si. This occurrence is the reverse of the effect of Cu on the alloy. The addition of zinc to structural aluminum will improve the homogeneity of the matrix. The impact energy and hardness of the matrix are enhanced when Cu addition is within 2-4 vol %.