Abstract
Wollastonite coating deposited on Ti-6Al-4V substrate was prepared using atmospheric plasma spraying technology. Scan electron microscopy, transmission electron microscopy and X-ray diffraction were used to investigate the microstructure, surface morphology and phase compositions of coatings. Simulated body fluid tests were carried out to evaluate the bioactivity of the coating. Osteoblasts culturing test was used to examine the cytocompatibility of wollastonite coatings. The tensile bonding strength of the coating was measured with ASTM C-633 methods. The results obtained indicated that the plasma sprayed wollastonite coating had a rough surface and lamellar structure including some pores and microcracks. The primary crystalline phase of the coating was triclinic wollastonite. Glassy phase with nanocrystals was also found in the coating. The bonding strength of wollastonite coating reaches to about 39 MPa. This was explained in term of that the thermal expansion coefficient of wollastonite coatings is close to the Ti-6Al-4V substrate. The apatite layer was formed on the surface of plasma sprayed wollastonite coating soaked in SBF solution, which indicates wollastonite coating had a good bioactivity. Osteoblasts survive and proliferate on the surface of wollastonite coating, which indicates plasma sprayed wollastonite coatings possess excellent cytocompatibility.
