Bonding strength of HA/ZrO2 biomaterials with different interlayers

Yttria-tetragonal zirconia polycrystal (Y-TZP) ceramic with hydroxyapatite (HA) coating has been recognized as one of the most common biomaterials. However, its lower interfacial bonding strength has restricted its clinical application. In this study, CaCO3, Ca-3(PO4)(2) (TCP), and Ag were added into the interface of the HA coating and Y-TZP substrate by a pressureless sintering process to increase interfacial bonding strength. The morphology and microstructure of the interlayers were analyzed by scanning electronic microscope. The results show that the comprehensive performances of HA/interlayer/ZrO2 biomaterials were much better than that of the sample without interlayer, and the shear and tensile strengths of the HA/CaCO3/ZrO2 biomaterial reached 15.19 and 16.88MPa, respectively, which were higher than those of TCP and Ag. The CaZrO3 and carbonated apatite, formed by decomposed products of CaCO3 and HA reacting with ZrO2 at the interface under sintering, increased the mechanical properties of the biomaterial.