Tribo-mechanical properties evaluation of HA/TiO₂/CNT nanocomposite

In this study, a combination of reverse microemulsion and hydrothermal techniques were used to synthesize HA. A hydrothermal method was used to synthesize HA/TiO₂/CNT nanocomposite powders. Cold and hot isostatic pressing techniques were used to fabricate tablet-shaped samples. To investigate the biocompatibility and tribo-mechanical properties of HA/TiO₂ and HA/TiO₂/CNTs, four samples were prepared with different percentages of CNTs, namely, HA/TiO₂ (S0), HA/TiO₂/CNT (S1.0), HA/TiO₂/CNT (S2.0), and HA/TiO₂/CNT (S3.0). The microstructure and morphology of the HA/TiO₂/CNTs were characterized by transmission electron microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction. Hardness test results show that S3.0 displayed the highest surface hardness (285 HV) compared to other samples. The wear rate of HA/TiO₂/CNT with the highest CNT content showed a decrease compared with those of the other samples. The results from nanoindentation tests showed that Young's modulus of the S3.0 sample was 58.1% greater than that of the S0 sample. Furthermore, the human MDA-MB-231 cell line demonstrated good binding to the surface of the samples in the in-vitro biocompatibility evaluation of the HA/TiO₂/CNT composites.