Effect of Composition on Properties of Alumina/Titanium Silicon Carbide Composites

In the present study, the room-temperature properties of Al2O3-Ti3SiC2 composites with different Ti3SiC2 contents are determined. The composites are prepared by attrition milling Al2O3 and Ti3SiC2 mixture powders followed by spark plasma sintering (SPS) under vacuum. From a closer examination of the dependencies of the electrical conductivity on compositions in this system, we determined the percolation threshold at which an interconnected network of electrically conductive phase arises. Since the hardness of Ti3SiC2 is lower than that of Al2O3, the Vickers hardness decreased with the increasing of Ti3SiC2 content while the fracture toughness and the strength increased. The maximum strength (673 MPa) and the maximum toughness (9.3 MPa·m1/2) were reached in the pure Ti3SiC2 material.