Effect Of Zinc Addition on The Microstructure and Mechanical Properties of AA6063 Aluminium Alloy

This research work entails addition of Zinc metal to the 6063 aluminium alloy series. The Zinc addition ranged from a percentage of 1% - 5% at an interval of 0.5%. Charge calculations were made and the aluminium alloy and Zinc were melted in a crucible furnace. Permanent mold casting was utilized with dimension of 150mm * 15mm. The 6063 aluminium – Zinc alloy were machined to standard tensile dimensions of G.D 5mm, G.L 40mm, external diameter 8mm, two opposite external length of 30mm; hardness dimensions of 20mm * 20mm * 20mm;and impact dimensions of length 60mm, diameter 10mm, notch at 30mm with 3mm depth. The aluminium- zinc alloys were heat treated to 300oC and 400oC; and held at a soaking time of 2 hours, allowed to cool in the furnace and another series of aluminium - zinc alloy were not heat treated.

The specimens were destructively tested and the homogenized 400oC aluminium-zinc alloy possessed the greatest strength of 237MPa, a hardness value of 113HV, a maximum percentage elongation of 22.5% and a maximum impact energy of 70.5J. Thus, the alloy can be used for applications requiring high strength and hardness coupled with low ductility.