Microstructure of alumina-matrix composites reinforced with nanometric titanium and titanium carbide dispersions

The synthesis of alumina (Al₂O₃)-composites having different amount of very fine titanium and titanium carbide reinforcement- particles has been explored. Two experimental steps have been set for the synthesis; the first step consisted of the pressureless-sintering of Al ₂O₃-titanium powders which were thoroughly mixed under high energy ball-milling and through the second step it was induced the formation of titanium carbide during different times at 500 °C by the cementation packing process. SEM and EDS analysis of the microstructures obtained in both sintered and cemented bodies were performed in order to know the effect of the activated carbon used as cementing agent on the titanium for each studied composite. It was observed that a titanium carbide layer growth from the surface into the bulk and reaches different depth as the titanium content in the composites increases. On the other hand, the use of ductile titanium notably enhanced density level and fracture toughness of the composites.