A new method is proposed in order to improve the surface properties of titanium alloys used in biomedical applications. This paper considers the surface modification that appears after the reaction between metaphosphate glasses and titanium alloys (TA6V). The structural characterization of this material has been realized by several spectroscopic methods of investigation such as scanning electron microscopy, energy-dispersive X-ray analysis and wavelength-dispersive spectroscopy. Measurements of Vickers microhardness exhibit a correlation between the phosphorus profile and the evolution of hardness of the modified titanium alloy surface. The relative increase in the Vickers microhardness is about 65%. By application of the composite model, the absolute hardness of the coating was found to be HV0 = 550.