Toughened RE-TZP ceramics obtained by HPHT process

Effect of dopants and sintering temperature on microstructure and low temperature degradation of dental Y-TZP-zirconia

“…Dopants are present in zirconia either as a distinct phase (Al 2 O 3 ) or as a solid solution like Y 2 O 3 and Fe 2 O 3 in small quantities. [46][47][48][49][50][51][52][53][54][55][56] They, however, influence the grain morphology, microstructure, mechanical properties and the stability of zirconia against LTD. 10,21,23,31,32,36,37,40,45,47,[56][57][58]78 Today the sintering of highly porous (∼50 vol.%) and then machined zirconia is widely used to obtain a dense ceramic with the mechanical and chemical properties required for dental restorations. The sintering conducted in solid state involves the diffusion of the ions across grain boundaries without the involvement of a liquid phase and its ability of large rearrangements of particles.…”

“…The sintering conducted in solid state involves the diffusion of the ions across grain boundaries without the involvement of a liquid phase and its ability of large rearrangements of particles. Therefore the important process parameters are temperature, duration and sintering atmosphere (air, inert gases, vacuum, and gas pressure) [58][59][60][61][62][63][64][65][66][67][68][69][70][71][72][73][74] and the homogeneity of the porous blanks which is mainly determined by the agglomerates of the powders used for pressing the blanks. This agglomerate state of the powders used for the porous blanks, the coloring dopants as well as sintering temperature and time determine the final microstructure of the ceramic component characterized by its density, grain size and phase composition.…”