Densification of Alumina‐Silicon Carbide Powder Composites: II, Microstructural Evolution and Densification

Microstructural evolution adn densification kinetics of Al2O3-SiC powder composites were studied using two different SiC powders. Examination of the microstructural evolution of Al2O3-fine SiC powder composites showed three well-defined stages of densification: the first was characterized by constant pore size and no grain growth; the second involved rapid pore coarsening and grain growth; the third was characterized by pore shrinkage and slow grain growth. Studies of the densification kinetics of Al2O3-coarse SiC powder composites exhibited two stages of densification: in the first stage there were no significant differences in densification rate between pure Al2O3 compacts and composites; in the second stage, however, differences in densification behavior between pure Al2O3 compacts and composites became pronounced.