Fabrication of Ti3SiC2 and Ti4SiC3 MAX phase ceramics through reduction of TiO2 with SiC

Ti3SiC2 and Ti4SiC3 MAX phase ceramics were fabricated through high-temperature vacuum reduction of TiO2 using SiC as a reductant, followed by hot pressing of the products under 25 MPa of pressure at 1600 °C. It was found that both Ti3SiC2 and Ti4SiC3 may be obtained in good yields, depending on the annealing time during the reduction step. In addition to MAX phases, the products contained some amounts of TiC. The hot pressing step did not significantly affect the composition of the products, indicating good stability of Ti3SiC2 and Ti4SiC3 under these conditions. Analysis of the densification behavior of the samples revealed lower ductility in Ti4SiC3 compared to Ti3SiC2. The samples prepared herein exhibited the flexural strength, fracture toughness and microhardness typical of coarse-grained MAX-phase ceramics.