Fabrication and Properties of Hydroxyapatite-Ti Network Composites

Abstract

Hydroxyapatite (HA) powder was synthesized by a sol-gel method with Ca(OH)2 and H3PO4 as reactants. The HA granules were then coated with TiH2 powder using a mechanical mixing method. The HA-TiH2 material system produced HA-Ti composites after hot-pressing at 1050°C. The HA-Ti composites are mainly composed of HA and Ti, with small amounts of Ca2P2O7 and Ca3(PO4)2 phases. Fracture toughness and bending strength are 2.4 MPa·m1/2 and 54.3 MPa, respectively for the HA-20vol%Ti composite, higher than those of the pure HA ceramic. The improvement in properties is because of the unique 3D network structure of Ti, which is an ideal reinforcement structure for the weak and brittle HA. According to ISO/TR 7405-1984, hemolysis test was performed to evaluate the blood compatibility of the material. The results show that the hemolysis rate of the HA-20vol%Ti composite is 0.56%. Relative growth rates (RGR) of L-929 cells soaked after 6 days in the HA-20vol%Ti group, pure Ti group, black group and pure Pb group were 132%, 100%, 90% and 6% respectively, while the level of cytotoxicity was grade 0 in HA-Ti composite group. These results imply that the HA-20vol%Ti composite has good biocompatibility and bioactivity.

Processing and Properties of BioCeramic Coatings onto 3D Ti‐Mesh by DipCasting Method

“…Different coating techniques, such as plasma spray and solgel, have been used to deposit bioceramic coatings on Ti‐implants. Even 3D interpenetrating HA and Ti network composite structures have been tried using the powder metallurgy technique . Although the plasma spray technique is commonly adopted for coating, it may not be suitable for bioceramic coating deposition on 3D Ti‐mesh as only coating on the outside exposed surface is assured.…”

“…Even 3D interpenetrating HA and Ti network composite structures have been tried using the powder metallurgy technique. 22,23 Although the plasma spray technique is commonly adopted for coating, it may not be suitable for bioceramic coating deposition on 3D Ti-mesh 2 as only coating on the outside exposed surface is assured. Furthermore, bioceramic coatings deposited by plasma spraying are typically thin, dense, and amorphous.…”

Novel porous calcium aluminate/phosphate nanocomposites: in situ synthesis, microstructure and permeability

“…Microceramic particles have been used to make the microstructural-engineered metal-ceramic network composite. 58,59 We hope the porous microparticles in combination with in situ gas release can increase the porosity of the CaP rich nanocomposite. Fig.…”

Effects of Sintering Conditions on the Properties of Al₂O₃/Ti(C,N) Ceramics

“…In fact, the optimum sintering temperature is related to the thermodynamic stability of Ti(C,N) phase. Detailed analysis is presented elsewhere [9].…”