Sintering of partially-stabilized zirconia and partially-stabilized zirconia—hydroxyapatite composites by hot isostatic pressing and pressureless sintering

Biocomposites and hybrid biomaterials based on calcium orthophosphates

“…The main disadvantage of HA reinforced by PSZ is degradation of zirconia in wet environments. 923,932,933,955 Transformation of the tetragonal ZrO 2 to the monoclinic phase on the surface results in the formation of microcracks and, consequently, lowers the strength of the implant. 1089,1090 Interestingly, though, Fe 3 O 4 /HA composites possess photocatalytic properties.…”

Calcium orthophosphate-based biocomposites and hybrid biomaterials

“…The main disadvantage of HA reinforced by PSZ is degradation of zirconia in wet environments [755,760,761,783]. Transformation of the tetragonal ZrO 2 to the monoclinic phase on the surface results in formation of microcracks and consequently lowers the strength of the implant [888,889].…”

New Challenges in the Sintering of HA/ZrO2 Composites

“…However, there are still controversial results in the literature about the phase stability of these composites prepared by pressure sintering methods (e.g HIP, hot pressing). Indeed, some reaction has been reported between HA and ZrO 2 by some authors (Veljovic et al, 2007) but not by others (Li et al, 1996). However, there is a general conformity that HA/ZrO 2 composites were considerably stable especially after HIP (Wu & Yen, 1988), even though traces of reaction may be expected due to the increased contact area between HA matrix and dispersed ZrO 2 particles (Adolfsson et al, 2000).…”

“…So far, it has been well recognized that, by pressureless sintering of HA/ZrO 2 composites, it is very difficult to reach full densification in air (Li & Hermansson, 1996;Wu &Yeh, 1988). Therefore, only by introducing pressure water vapor it is possible to densify without any decomposition (Vasconcelos & Barreto, 2011).…”

“…4). A number of approaches have been tried to prepare HA/ZrO 2 composites containing higher fraction of ZrO 2 (20-40 vol%) (Rao & Kannan, 2002;J. Li et al, 1996).…”