Ti-Glass Biocomposite Coating Materials and their Crystallization Dynamics
Ti-bioglass was sprayed on Ti6Al4V substrate. The crystallization dynamics of Ti-bioglass was analyzed by differential scanning calorimetry(DSC). The structure and morphology of the coatings were studied by SEM, TEM and AFM. The results showed that new phase Ca5(PO4)3F formed at 695.2°C when bioglass crystallized. The formation activation energy was 147.76KJ/mol and the crystallization exponent was less than 3 (n<3). It indicated that the crystallization happened on the surface. When 20 wt% bioglass was mixed with Ti powders, the formation activation energy was 324.6KJ/mol and the crystallization exponent was larger than 3 (n>3), which indicated that an integrated crystallization happened. Micro- or nano-scale R-TiO2, A-TiO2 and Na2Ti6O13 crystals precipitated on the surface of the coating after crystallization treatment. These crystals have a function of self-seal on the cracks on the coatings and form a metallurgical interface between the substrate and the coating.
Zhong Wei Gu, Yafang Han, Fu Sheng Pan, Xitao Wang, Duan Weng and Shaoxiong Zhou
M. Q. Li et al., "Ti-Glass Biocomposite Coating Materials and their Crystallization Dynamics ", Materials Science Forum, Vols. 610-613, pp. 1211-1214, 2009