Preparation, biocompatibility, and biotribological properties of TiN-incorporated graphite-like amorphous carbon bio-ceramic composite films

D.G Liu,L Zheng,Y Liang,H Li,J.Q Liu,L.M Luo,Y.C Wu

doi:10.1016/j.ceramint.2018.01.102

Abstract

In this work, TiN-incorporated graphite-like amorphous carbon (a-GLC) bioceramic films were successfully fabricated on Ti alloy (Ti6Al4V) using the magnetron sputtering technique. The biocompatibility and biotribological properties of the TiN/a-GLC-coated Ti alloy were evaluated. Based on the clinical application, the microstructure, biocompatibility, histomorphological observation, and mechanical properties were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, nanoindentation test, and in vitro and in vivo tests including MTT, cell adhesion test, and slice observation of hard tissues. These techniques confirmed that there was strong bonding between the Ti alloy and the TiN/a-GLC film. In addition, face-centered cubic TiN and hexagonal close-packed Ti were clearly detected in the TiN/a-GLC films. A partial nanocomposite structure, comprised of homogeneous nanoclusters and crystalline particles, was detected in the amorphous matrix. Cell adhesion and MTT test results indicated that the TiN/a-GLC film could promote cell attachment and proliferation. Phase composition and the film morphology were determined to be the crucial factors that contributed to the improved biocompatibility. The biotribological property test showed that the TiN/a-GLC film with a Ti content of 7.8at% had the lowest coefficient of friction (COF) of 0.076 and the lowest wear rate of 1.76 × 10–6mm3(Nm)–1. The low COF was attributed to the superior mechanical properties of the TiN/a-GLC composite film. The TiN/a-GLC-coated Ti alloy implants were placed subcutaneously into rabbits for different time periods, and the tissue response decreased significantly as compared to that of the pure a-GLC film. The excellent biocompatibility and function reliability of the TiN/a-GLC bioceramic films showed that they are potential candidates for bone tissue implants.

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