Zirconia biomedical-grade

Biomedical-grade zirconia was introduced 20 years ago to solve the problem of alumina brittleness, and the consequent potential failure of implants. The reason for this is that biomedical-grade zirconia exhibits the best mechanical properties of oxide ceramics as a consequence of transformation toughening, which increases its resistance to crack propagation. Likewise, partially stabilized zirconia shows excellent biocompatibility, and it has therefore been applied to orthopedic uses such as hip and knee joints [255]. 

Figure 1.21 Schematic of the transformed zone in aged biomedical-grade zirconia, leading to extensive microcracking and surface roughening. The transformed grains are shown in gray. The dark gray path represents the penetration of water due to microcracking around the transformed grains [257. ...

S. (2007) Electrochemical and structural characterisation of zirconia reinforced hydroxyapatite sol-gel coatings on surgical grade 316L SS for biomedical applications. Ceram. Int., 33 (4), 605-614. 

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