Abstract
In order to investigate the effect of grain size on the mechanical properties of stabilized ZrO2 ceramics, fine grained ceramics were prepared by adding carbon derived from novolak phenol resin by thermal decomposition. A stabilized ZrO2 ceramic with an average grain size of 0.6μm and relative density of above 99% was obtained by adding 0.23wt% of carbon and sintering at 1500°C. It was speculated that the carbon at grain boundaries prevents the grain growth of ZrO2. Hardness and Young's modulus of the fine grained ZrO2 ceramics were nearly the same as those with large grains. However, the fracture toughness of the fine grained ZrO2 was smaller than that of large grained one, which may have resulted from the reduced crack deflection effect of increasing fracture toughness in fine grained ZrO2 ceramics.
