Sintering of HA/Zirconia composite for biomedical and dental applications: A Review

Hydroxyapatite (HA) is widely used in medical applications because of its excellent biocompatibility. However, many studies have been conducted to improve the inferior mechanical properties of this compound, which limit its application. HA-ZrO2 composites exhibit great potential because of the desirable advantages derived from both constituent materials, such as the excellent biocompatibility of HA and the considerable mechanical strength and toughness of ZrO2. The synergy of the two materials facilitates the development of a composite material with properties superior to those of monolithic ZrO2 and HA. In the development of a ceramic composite, the sintering and processing methods can significantly affect the mechanical properties of the composite. The conventional sintering, solid-state reaction, microwave sintering, and hot isostatic pressing of HA and ZrO2 were discussed in this study. Hot isostatic pressing was found to be the most promising method and yielded the most satisfying result.