Precipitation and dissolution kinetics in Al–Cu–Mg–Fe–Ni alloy 2618 and Al–alumina particle metal matrix composite

The kinetics of precipitation and dissolution of precipitate phases in AA2618 and AA2618–alumina particle-reinforced metal matrix composite were studied using differential scanning calorimetry (DSC). Thermal effect peaks due to GPB (Guinier-Preston-Bagaryatskii) zone formation, GPB zone dissolution, formation of the θ′ and S′ phases, and the dissolution of the θ′ and S′ phases were identified. The kinetic parameters for GPB zone formation and dissolution reactions, calculated by using both the modified Avrami–Johnson–Mehl (AJM) equation and the Kissinger-type expressions, were comparable. GPB zone formation was found to be suppressed in the composite material while, on the other hand, GPB zone dissolution was enhanced.