Microstructure and properties of Zn-β-tricalcium phosphate/Ti biocomposites

Zn doped β-tricalcium phosphate (β-TCP) powder was prepared by the chemical coprecipitation, mixed with Ti powder at 3:7 (mass ratio) and pressed evenly, and Zn doped β-TCP/Ti composite samples were obtained by vacuum sintering. The microstructure, surface morphology and phase analysis were carried out by metallographic observation, SEM and XRD, and microhardness, abrasive wear, uniaxial compression and in vitro bioactivity tests were carried out. The results show that the particle size (D₅₀) in Zn-β-TCP powder is focus on 1-20 μm. The component of Zn-β-TCP/Ti composite are TiO₂, β-TCP and CaTiO₃. The phases of Zn-β-TCP/Ti composites consist of TiO₂, β-TCP, CaTiO₃ and ZnO. When Zn²⁺ is dissolved into β-TCP lattice, the diffraction peak is shifted, and the Zn-β-TCP/Ti biocomposite with 10mol% Zn has the largest migration angle. The crystallinity of β-TCP decreases with the increase of Zn. The TiO₂ phase of the β-TCP/Ti composite is dispersed in the net β-TCP phase. The pore size of the Zn-β-TCP/Ti composite with 10mol% Zn is 200-300 μm, which meets the requirements of engineering scaffold materials, with the highest microhardness of HV 346.2, the lowest wear loss of 0.051 mgmm^-2, the compressive strength between 130-180 MPa, and the maximum elastic modulus of 8.021 GPa. The addition of Zn improves the microhardness and wear resistance of the Zn-β-TCP/Ti composites. The accumulation of carbonate hydroxyapatite increases with the soaking in simulated body fluid, and the Zn-β-TCP/Ti biocomposites have good bioactivity.