The study of the precipitation process in Al-Cu-Mg/bagasse ash particulate composites

The phase formation and dissolution in Al-Cu-Mg/bagasse ash particulate composites have been studied by means of microstructural and differential scanning calorimetry (DSC) method. The composites were produced by double stir-casting method. 4 and 8 wt% bagasse ash particles were used in producing the composites. The DSC studies were carried out on the material in the as-quenched and the scanning electron microscopy analysis was carried out on the as-quenched and thermal aged specimens. In the aluminium alloy the effects of the reinforcement are similar to those observed by other authors with some remarkable features of the results. These include: a smaller amount of Guinier-Preston (GP) zones, faster precipitation kinetic of the intermediate phases (theta(11) and theta(1)) and absence of the peak related to the formation of the theta phase. The microstructure of the thermally aged composites at 200 degrees C for 6h reveals the dissolution and distribution of the bagasse particle in the metal matrix and presence of precipitates at the particle matrix interfaces with precipitation and dissolution of the bagasse particles and (Al(2)CuMg) phase. (C) 2010 Elsevier B.V. All rights reserved.