Control of interface in SiC particulates reinforced Al-Li composite by sol-gel technique

This paper describes the control of the interface in SiC particulates reinforced AI-Li composites by a coat of metallic oxide film on the SiC particulates. The coating method employed to produce fine SiC powders covered with a thin metallic oxide film is the sol-gel technique. The film thickness was not affected by the hydrolysis time of the sol solution under a dried Ar atmosphere and the average thicknesses of SiO2, TiO2, ZrO2 were 10nm, 8nm, 27nm respectively. TEM observation of TiO2 coated SiC particulates reinforced Al-Li composites indicated that the TiO2 film was not damaged by the fabrication processing, and the production of Al4C3 at the interface between the matrix and the reinforcements could be controlled by the existence of a coating film. The tensile strength and the elongation of the extruded sample showed increase of 12% and 21% respectively when compared with non coated samples.