Preparation and properties of Al2O3/Al in-situ composites by reactive meltpenetration

Al2O3/Al ceramic matrix in-situ composites were prepared by reacting vitreo us silica, mullite, or fireclay preforms with molten aluminium. Microstruct ure of the composites was found to consist of a network of aluminium channe ls embedded in the ceramic matrix. Properties of the composites like densit y, hardness, and fracture toughness were determined. Composites made from v itreous silica exhibited low hardness, relatively easy machinability and im proved fracture toughness. The process is suitable for producing net-shape or near net-shape composites.