Influence of alumina addition on grain growth and room temperature mechanical properties of 8YSCZ/Al2O3 composites

The effect of the amount of alumina addition on grain growth and room temperature mechanical properties (hardness and fracture toughness) of 8YSCZ/Al2O3 composites were determined using 8 mol% yttria-stabilized cubic zirconia (8YSCZ) and various amounts of Al2O3 (0-10 wt%). The experimental results showed that the grain growth in Al2O3 doped 8YSCZs occured slowly and more sluggish than that in undoped 8YSCZ. Also, the grain growth rate decreased with increasing Al2O3 content. The grain growth exponent value and the activation energy for undoped 8YSCZ were found to be 2 and 289 kJ/mol, respectively. The addition of Al2O3 raised the grain growth exponent value to 3 and activation energy for the grain growth process was increased from 289 to 410 kJ/mol. Also, the introduction of Al2O3 enhanced the hardness and fracture toughness of 8YSCZ/Al2O3 composites. The hardness and fracture toughness increased with increasing Al2O3 content. The maximum hardness and fracture toughness values reached 1459 kgf/mm2 and 2.41 MPa m1/2, respectively, with the addition of 10 wt% Al2O3 while these values were 1314 kgf/mm2 and 1.5 MPa m1/2 for undoped 8YSCZ.