SiAlON-Al2O3 ceramics as potential biomaterials

When used as implants, Al2O3 is unable of directly achieving good chemical bonding with soft and hard tissues. To overcome this problem, SiAlON-Al2O3 ceramics were prepared in this study by direct nitridation. Phase composition, porosity, bulk density, and compression strengths were examined, and biological properties were evaluated by cell culture on ceramic surface. Major phase of SiAlON-Al2O3 ceramics was identified as Si4Al2O2N6 , formed by reaction of Si, Al and Al2O3 under nitrogen atmosphere at high temperature. As Al2O3 content increased, porosity and compressive strength decreased. Therefore, Si4Al2O2N6 phase could improve sintering, leading to formation of composites with better properties. The porosity and compression strength were found suitable for requirement of biomaterials. Cell culture experiments showed that cells could proliferate and survival well on ceramic surface, indicating good biocompatibility of Si4Al2O2N6 phase in SiAlON-Al2O3 ceramics. Overall, these data look promising and might provide novel strategies for development of future SiAlON-Al2O3 bioceramics.