Low-Temperature Sintering of 3Y-TZP/Glass Composites as All-Ceramic Dental Materials

摘要

3Y-TZP ceramics were fabricated with the addition of 10wt% MgO-Al_2O_3-SiO_2 glass additive by cold-isostatic pressing and afterwards liquid-phase sintering at 1200-1400°C for 2 h. The densities of samples sintered at 1300°C for 2 h reaches 99.1%, but further increase of sintering temperature results in the decrease of densities. XRD analysis showed that the cordierite crystals and a small amount of amorphous phase were presented at the grain junctions, and SEM observation indicated that the mean grain size of ZrO_2 with round-shape ranged from 200 to 300 nm, which was below the critical transformation size, and the increase in sintering temperature was accompanied with an increase in the mean grain size. The strength and toughness of samples were kept in the range of 396-528 MPa, 4.4-5.8 MPa·m~(1/2) respectively, which could meet the need of clinical applications of all-ceramic dental materials.