Fabrication of Al2O3/TiB2/AlN/TiN and Al2O3/TiC/AlN composites

Two master alloys as Al-Ti-B and Al-Ti-C were, respectively, introduced in alumina matrix ceramic materials. Composites of Al2O3/TiB2/AlN/TiN and Al2O3/TiC/AlN are fabricated by the technology of hot-pressing liquid phase sintering, during which AlN and TiN phases are produced by the chemical reactions taking place among Al, Ti and N2 (the protective atmosphere). The hardness, fracture toughness and bending strength of the new fabricated composites were tested. The relations of volume content of Al-Ti-B and Al-Ti-C master alloys and mechanical properties of alumina matrix ceramic materials are analyzed. The influences of Al-Ti-B and Al-Ti-C additions were studied by mechanical properties evaluations and microstructural observations. Meanwhile, the expected improvement of mechanical properties compared with pure alumina was indeed observed. The fracture mechanism of alumina matrix ceramic composites was analyzed together with the refining performances of the two master alloys.