Heat treatment of alloys

Aluminum AA6082 extruded plates are solutionized at 520°C, 540°C, 580°C for 30 min. One set of samples were subjected to the natural aging heat treatment for 20 days, and 40 days other set samples were further subjected to artificial aging heat treatment where they are heated at 180°C for four hr to obtain the peak aging condition. Electrical conductivity is measured at different situations and correlated with the microstructural features and mechanical properties. Precipitation analysis has been performed using the Scanning electron microscopy and optical microscopy. It is found that in T6 heat-treated samples as the solutionizing temperature increases tensile strength, yield strength, hardness increases, elongation decreases and electrical conductivity initially decreases after solutionizing and then increases when subjected to artificial aging. In natural Aging (T4) as the aging time increases tensile strength and elongation increases and there is decidedly less change in yield strength, electrical conductivity, and hardness. It is observed as the solutionizing temperature increases then is an increase in the volume fraction of the precipitate.