The porous titanium alloy containing 17.5 wt% molybdenum elements prepared by gel-casting methods was used as precursor. The composite coatings with hydroxyapatite and TiO2prepared on the precursor was treated respectively by NaOH solution, 30% H2O2+NH3solution, HF+HNO3and PdCl2solution to improve the characterization of coatings. The microstructure was examined by SEM, and part of the coatings was examined by EDS to indicate the linear distribution of HA and TiO2. The corrosion behavior of the coatings in the simulated body fluids (SBF) was evaluated by potentiodynamic polarization test and impedance plots. The results showed that the corrosion resistance of the coatings treated with PdCl2solution was better than the others. The passivation layer which played a key role in corrosion resistance was generated by PdCl2solution treatment; their surface morphologies was more uniform than the others and had no crack; the thickness of the coatings was 60~70μm.
The porous titanium alloy prepared by gel-casting methods was used as precursor and the composite coatings with hydroxyapatite HA/TiO2were prepared on the precursor which was treated by NaOH solution, H2O2+ NH3solution, HF+HNO3, PdCl2solution to improve the capability of coatings. The microstructure was examined by SEM and the corrosion behavior of the coating layers in the simulated body fluids (SBF) was evaluated by potentiodynamic polarization test and impedance plots. The results show that the corrosion resistance of samples using PdCl2treatment is superior to else others. The PdCl2processing provides the substrate surface an excellent oxide film, which plays a key role in the corrosion resistance of coating. The thickness of the coatings is about 60μm and the surface morphologies are more uniform than the others and have no crack.
In this paper, hydroxyapatite and TiO 2 biological coatings on TC4 titanium alloy substrate was prepared by electrophoretic deposition (EPD) method. The coatings were characterized by scanning electron microscopy (SEM). By subsequent different conditions of heat treatment process (vacuum and high purity argon), corrosion resistance of composite biological coatings were investigated by potentiodynamic polarization curves method. The results showed that the coatings were dense and can be tightly combined with substrate after sintering when TiO 2 content was 10 g•L-1. Corrosion resistance of specimens treated by heat treatment in argon atmosphere was superior to specimens treated by heat treatment in vacuum.
In this paper, the biological coatings were studied by adding different kinds of additives (TiO2, Al2O3 and ZnO) to hydroxyapatite (HA). The different mass ratio of additives and HA in suspension was mixed with n-butyl alcohol as solvent, triethanolamine as dispersant. The HA composite coatings with additives on titanium alloy substrate were prepared by the method of electrophoretic deposition (EPD). The coatings were characterized by scanning electron microscopy (SEM), Ca/P atomic ratio in composite coatings was analyzed by Energy Dispersive Spectrometer (EDS). The results showed that surface of HA coatings was more uniform and dense by adding TiO2 than Al2O3 or ZnO; and when adding the same kind of additive, the content was higher, there were more holes in HA coatings and surface of the coatings was less uniform. When HA was 15 g/L and TiO2 was 5 g/L in suspension, Ca/P atomic ratio was 1.56, that’s the most close to the body's natural bone (~ 1.61). HA coatings can be implanted in the body after a short time of ossification and exhibited a good bioactivity.
Based on the theory of Fabry-Perot interference, we analyzed the inherent relationship between single-wavelength and the spectrometry, established the mathematical model of transformation from angular spectrum measurement to spectral measurement,realized the data conversion between angular spectrum measurement and spectrum measurement; build the experimental platform and got the laser's transmittance by changing the incidence angle of the laser, and given the comparison experiment by using spectrophotometer, measured the spectral transmittance of filters. Comparison of the two measurement, the results show that:it is a feasible scheme that the angular spectrum measurement replace spectral measurement for filter transmittance .
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.