Zirconia-Toughened Alumina ZTA

In the past, zirconia has been added routinely to a variety of ceramic materials in order to increase their toughness. Zirconia-toughened alumina was first developed by Claussen, who demonstrated a significant toughening effect of unstabilized, but transformable, tetragonal zirconia particles within the alumina matrix [214]. 

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C Properties of zirconia toughened alumina.. ZTA, depend on the specific microstiucture and the proportions of zirconia and alumina. d To convert MPa to psi, multiply by 145. 

Jang, H. M, and Moon, J. H., Homogeneous fabrication and densification of zirconia-toughened alumina (ZTA) composite by the surface-induced coating, J. Mater. Res., 5(3), 615 (1990). 

Controlled or graded microstructures, for example, zirconia toughened alumina (ZTA), can be made by depositing a Zr02 slurry onto an AI2O3 substrate (Gebhardt 2006). 

Zirconia-toughened alumina (ZTA) is an aluminum oxide (AI2O3) ceramic material in which stabilized zirconia (Z1O2) is present as a secondary... 

Alumina-based composites These comprise especially zirconia-toughened alumina (ZTA), and alumina-based nanocomposites with non-oxide second phases such as SiCorTiC. However, thelattertwo, in particular, are b ond the scopeofthis chapter. 

Bartolome JF, Bruno G, Deaza AH (2008) Neutron diffraction residual stress analysis of zirconia toughened alumina (ZTA) composites. J Eur Ceram Soc 28(9) 1809-1814... 

Zirconia-toughened alumina (ZTA) ceramics with high transformation toughening ability can be obtained if a high portion of tetragonal phase with the possibility to transform under applied stress is retained at room temperature. This requires that the... 

An important toughening mechanism involves a phase transformation in zirconia (ZrOi). The best-known example is zirconia-toughened alumina (ZTA), which contains 10-20 vol% of fine ZrOi, particles. At elevated temperatures the equilibrium structure of Zr02 is tetragonal (t) and at low temperatures it is monoclinic (m). On cooling ZTA from the high temperatures required for fabrication the t —> m transformation may occur in the zirconia particles. This transformation is accompanied by an increase in volume of about 3%. 

J. Wang, R. Stevens, Review Zirconia-toughened alumina (ZTA) ceramics. Journal of Materials Science 24, p.3421-3440, (1989)... 

FIGURE 6.19 Comparison of a ceramic revision femoral head fabricated from zirconia-toughened alumina (ZTA) with primary ceramic heads. The revision head has a metal sleeve to regenerate die trunnion of a femoral stem, which may become damaged in vivo. 

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