Nickel and zirconia toughened alumina prepared by hydrothermal processing

Two-phase and tri-phase composites of alumina toughened with nickel and/or zirconia particles were prepared by hydrothermal processing and it was shown that the zirconia and nickel particles with a narrow size distribution could be homogeneously dispersed in the alumina matrix by hydrothermal synthesis at relatively low temperatures. Measurements were made of the relative density and fracture toughness of the composites. It was found that the nickel inclusions enhanced the toughness of the alumina by pull-out and plastic deforming and toughening mechanisms using tetragonal zirconia included phase transition toughening, microcracking, and deflection. 19 refs.