Modelling and optimization of aging parameters for thermal properties of Al 6082 alloy using response surface methodology

In the present paper an effort is made to study the effect of aging parameters solution time, aging temperature and aging time on thermal conductivity and coefficient of thermal expansion (CTE) of Al 6082 alloy by using central composite rotatable design (CCRD) of response surface methodology (RSM). Three different parameters at five levels each are chosen for the experimentation. A second order polynomial mathematical model is developed for thermal conductivity and CTE to study the main and interactive effect of parameters on thermal conductivity and coefficient of thermal expansion. The aging parameters are also optimised for the optimum value of thermal properties. The results reveal that aging temperature is most significant parameter for change in thermal conductivity and CTE followed by aging time and solution time. Thermal conductivity and coefficient of thermal expansion has been improved by 17% and 20% respectively as compared as-received alloy. The improvement in thermal properties is attributed to the precipitation of Mg₂Si particles in the alloy matrix. (paper)