Influence of forming methods on the microstructure of 3Y-TZP specimens

Nanosized 3Y-TZP powders with particle size of 10–40 nm were formed by gelcasting, dry pressing and cold isostatic pressing. The influence of particle size as well as forming methods on the microstructure and mechanical properties of specimens were investigated. Both SEM images and the analysis on pore size distribution reveal that the gelcast sample possessed more homogenous microstructure. 3Y-TZP powders with particle size of 10 nm have been gelcast with green density as 37.5% of theory and sintered density as high as 96% was achieved. Its fracture toughness was up to 11.9 MPa m1/2 and the hardness value HV10 is of 15.2 GPa. The difference of microstructure and mechanical properties is explained in terms of the differences in grain size and the forming methods.