Microstructural Development of Ti-B Alloyed Layer for Hard Tissue Applications

Microstructural development was analyzed due to the effect of different sizes of precursor powders during surface plasma alloying modification on titanium surface. Ti-B nano and micropowders with 10 wt% B were deposited onto microcrystalline titanium substrate by plasma alloying. As a result, modified surface layer composed of Ti matrix and TiB borides was obtained. The type of the powder precursor influenced recasting process, possible occurrence of porosity and finally the obtained properties and microstructure of the surface layer. Different morphologies and sizes of TiB phase from micro, submicro to even nano increased the hardness and wear resistance of the obtained surface layers. Discussed results referred to a strong TiB precipitation dispersion provided by a fine elements homogenization during mechanical alloying process. Additionally, results of in vitro test with normal human osteoblast cells revealed proper cellular adhesion to modified surfaces. Scanning electron microscopy observation revealed the influence of gas pore size on culturing osteoblast colony. The proposed surface alloying was an effective method of producing TiB phase dispersed in α-Ti matrix with high hardness, good corrosion resistance and good cytocompatibility. Results confirmed that different types of the precursor powders influenced the properties of the surface layer. TiB phase dispersed in α-Ti matrix layer can offer new structural and biofunctional properties for innovative products in hard tissue applications.