Microstructural, mechanical, and optical characterization of an experimental aging-resistant zirconia-toughened alumina (ZTA) composite

Experimental 70% Al2O3 - 30% ZrO2 composites: structural, topographical and mechanical characterization before and after aging

“…The high flexural strength reported in Article 1 is compatible with published literature in the orthopedic field, (41) and with our previous work (26,28) where advantageous flexural strength for ZTA composites with reinforcements ranging from 15 to 30% of zirconia particles has been reported. The characteristic stress reported for the formulation with 30% of zirconia evaluated in the present work (914 MPa) was slightly higher to the results reported by Lopes et al (2020) for a ZTA reinforced with 20% of zirconia particles (860 MPa). ( 28) Moreover, it has been reported that the mechanical properties of ZTA composites tends to vary proportionally to the modifications in weight percentage of 3Y-TZP, as postulated by the rule of mixtures.…”

“…Such microstructure was similar to previous findings of our research group for ZTA composites synthesized with similar protocols but comprised by 85 and 80% of Al2O3, reinforced with 15 and 20% of 3Y-TZP, respectively. (26,28) Grain measurements presented in Article 2 depict a similar grain size of zirconia particles in both, the ZTA composite and the pure formulation (∼0.44 µm). Conversely, Al2O3 showed a smaller particle size in the composite (∼0.95 µm) when compared with the pure formulation (3.96 µm).…”

“…The optical properties presented in Article 1 were described in a previous Master's dissertation (54) and are consistent with the findings reported by our research group for other ZTA compositions. (26,28) The optical behavior of these composites may be explained due to the refractive index mismatch between the two polycrystalline phases that hampers light transmission, along with the presence of pores and defects associated with ceramic processing. (53,55) First and second generation 3Y-TZP presented intermediate and higher values of translucency regarding the ZTA composite.…”

“…(11,24) In light of the well documented limitations of 3Y-TZP systems currently used in dentistry, innovation in the synthesis of polycrystalline ceramic composites of zirconia and alumina for dental applications has been proposed. (25)(26)(27)(28) Such composites intend to improve the mechanical performance of pure alumina and provide high hydrothermal stability when compared to stabilized zirconia. (13) In the orthopedic field, composites of alumina reinforced with zirconia particles, (Zirconia-toughened-Alumina or ZTA) have been describe since early 2000s due to the dramatic failure of over 800 zirconia femoral head prostheses, associated with an accelerated process of low-temperature degradation.…”

Novel 8%‐TiO2‐nanoparticle‐reinforced dense polycrystalline bovine hydroxyapatite bioceramic

“…14 Seeking for improving one of the most important mechanical properties from ceramic materials, fracture toughness, which measures the stress concentration at a crack tip (intensity factor -K IC 15 ), TiO 2 , ZnO, Y-TZP, Al 2 O 3 , and graphene at nanoscale have been added to reinforce ceramic materials. 6,7,[16][17][18] For DPBHA, the mechanisms of nanostructure reinforcement are crack deflection, leading to energy absorption from the crack and tensile stress at the crack's tip. [18][19][20] Zirconia, alumina, mullite, titanium, and bioglass have been added to HA.…”