Addition of Al-Ti-B master alloys to improve the performances of alumina matrix ceramic materials

In the present work, a new technique to improve the performances of alumina matrix ceramic materials is presented, in which Al, Al3Ti and TiB2 are incorporated into alumina matrix ceramic materials in the form of Al-Ti-B master alloys. Composites of Al2O3/TiB2/AlN/TiN are fabricated by the technology of transient liquid phase sintering, during which new phases such as AlN and TiN are produced by the chemical reactions taking place among Al, Ti and N2 (the protective atmosphere). The densification rate of the composites as a function of Al-Ti-B volume content is discussed. The fundamental properties of the composites such as hardness, fracture toughness and bending strength are examined. The relations of volume content of Al-Ti-B master alloys and mechanical properties of alumina matrix ceramic materials are analyzed. The effects of fracture mechanism on mechanical properties of the composites are researched together with the refining performances of Al-Ti-B master alloys.