Influence of Heat Treatment on Impact, Hardness and Fatigue Strength of 6061 Aluminium Alloy

This paper presents effects of heat treatment on toughness, hardness and fatigue strength of aluminum alloy 6061. The alloy specimens were heat treated in the furnace at different temperature levels and holding times; and then cooled in different media (water and oil). The mechanical properties such as hardness, impact and fatigue were examined using standard method. Result shows that mechanical properties of aluminum alloy can be improved by the heat treatment. It was found that through ageing processes at temperature 160 °C for one, three and five hours, decreased the hardness, while increased the toughness. The fatigue strength was decreased when the number of cycles increased. The fracture surfaces between specimens have a different appearance before and after heat treatment.