High‐Toughness Ce‐TZP/Al₂O₃ Ceramics with Improved Hardness and Strength

Abstract

Simultaneous additions of SrO and A1203 to ZrOZ(12 mol% CeO,) lead to the in situ formation of strontium aluminate (Sr0.6A1203) platelets (~0 . 5 pm in width and 5 to 10 pm in length) within the Ce-TZP matrix. These plateletcontaining Ce-TZP ceramics have the strength (500 to 700 MPa) and hardness (13 to 14 GPa) of Ce-TZP/AI2O3 while maintaining the high toughness (14 to 15 MPa-m'") of Ce-TZR Optimum room-temperature properties are obtained at SrO/A1203 molar ratios between 0.025 and 0.1 for Zr02(12 mol% CeOz) with starting A1203 contents ranging between 15 and 60 ~01%. The role of various toughening mechanisms is discussed for these composite ceramics. [

Shear bond strength between veneering ceramics and ceria-stabilized zirconia/alumina

“…1,2 Replacing yttria with ceria (Ce-TZP) results in a significantly increased fracture toughness; however, the flexural strength is affected. 1,2 To overcome its low flexural strength, Ce-TZP may be alloyed with alumina (Ce-TZP/A) 3 ; thus, the flexural strength is improved while the fracture toughness remains high. The homogeneous dispersion of Al 2 O 3 in a Ce-TZP matrix suppresses grain growth and increases hardness, elastic modulus, and the hydrothermal stability of tetragonal zirconia.…”

Densification and dielectric properties of SrO–Al2O3–B2O3 ceramic bodies

“…However, a very high sintering temperature at about 1750 • C is needed to obtain dense alumina bodies. Chemical processing of small-sized particles as starting materials, and adding glass or other low-melting materials effectively lower firing temperature with improvement in dielectric properties of the aluminous bodies (Cutler et al 1991;Chen and Chen 1992;Alford and Penn 1996;Erkalfa et al 1996;Liu et al 2001;Ota et al 2004;Huang et al 2005;Huang and Chen 2006;Vishista and Gnanam 2006;Lim et al 2007;Kargin et al 2008;Abdel Aziz et al 2009). The properties of alumina ceramic bodies are significantly affected by the liquid sintering temperature due to the development of microstructure at low sintering temperature or the reaction between the host materials.…”

“…While, addition of SrO content above 5 wt% showed slight decrease in density, owing to the formation of strontium hexaluminate plate-like grains. However, Cutler et al (1991) and Chen and Chen (1992) found that the plate-like grains of strontium hexaluminate (SrAl 12 O 19 ) are supposed to increase the mechanical properties of alumina ceramics.…”

“…Strontia (SrO) was added to Al 2 O 3 ceramic bodies to improve their physical and mechanical properties (Cutler et al 1991;Vishista and Gnanam 2006;Kargin et al 2008). Vishista and Gnanam (2006) studied the effect of strontia content (5-20 wt%) on the properties of sol-gel alumina bodies.…”

Fabrication of fibrous Al2O3-(m-ZrO2)/HAp-(t-ZrO2) core/shell composites with elongated grain formation

“…To take account the superior cell response for the HAp phase an interconnected rather than encapsulated HAp phase is desirable. Moreover, it was reported that the formation of elongated Al2O3 grain was observed in the presence of CaO, SiO2, 15) SrO, 16) La2O3 17) etc. This elongated grain improved the mechanical properties specially the fracture toughness.…”