Dispersion and Structure Analysis of Nanocrystalline Ti-mZrO₂ Composite Powder for Biomedical Applications

Titanium and titanium alloys are widely employed in biomedical applications but these alloys have unsatisfactory tribological properties because of their low hardness. Much better biomaterials for hard tissue replacement implants may be acquired by the preparation of titanium composites. Therefore, the connection of excellent biocompatibility and bioactivity of ZrO₂ ceramics with good properties of titanium is considered to be a promising approach for the fabrication of more perfect hard tissue replacement implants. This study describes the formation of Ti-ZrO₂ nanostructure composite biomaterial. Weighted amounts with the composition corresponding to Ti-xZrO₂ (x = 10, 30 and 50 wt.%) were high energy milled in the planetary ball mill PULVERISETTE 7 premium line by Fritch at 10, 30 and 50 h milling times. Structural evolution and morphological changes of the powder particles during mechanical alloying were studied using the X-ray diffractometer, scanning electron microscopy and transmission electron microscopy analysis. The Rietveld method was applied for the verification of the qualitative and quantitative phase composition of the studied material. The parameters of diffraction line profiles were determined by PRO-FIT Toraya procedure. The crystallite sizes and lattice distortions were analyzed by Williamson-Hall method. It was found that during high-energy milling a significant decrease of crystallite size to nanoscale is observed for α-Ti and mZrO₂ phases. The images from scanning and transmission electron microscopes of the milled powders show that the size of the agglomerates of Ti nanocrystallites changes in a broad range and that ZrO₂ particles can be immersed in larger agglomerates or occur separately.