Structure and characteristics of Nb2O5 nanocoating thin film for biomedical applications

Abstract

Nanocoating thin films are a synthesize of coatings layers to improve different required properties especially corrosion resistance for various biomedical applications. In this study, Nb2O5 thin film has been synthesized on Ni-Cr-Mo alloy surface by hydrothermal technique at 150 °C for 160 hr immersing time with surface annealing at 600 °C. Scanning electron microscope (SEM)/ Energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), atomic force microscopy (AFM) and Ellipsometry spectroscopy were used to characterize the microstructure and morphology. The electrochemical test was studied in simulated body fluid (SBF) at 37 °C. The results indicated that there is no contamination, defects, or micro-cracks with spherical nanoparticles morphology for Nb2O5 thin-film with 200–500 nm diameter range. The created thin film presented Nb as a major element with crystal structure peaks related to ultra-thin-film of Nb2O5, with 1.87 nm roughness average (Ra) and 2.75 nm root mean square (Rq). The localized electrochemical corrosion resistance of nanocoated sample was improved compared to the uncoated substrate by decreasing the icorr. from 1.9 (µA.cm−2) to 1.2*10-2 (µA.cm−2) and increasing the Ecorr from 172 mV to 293 mV. The corrosion rate by miles per year (mpy) was also decreased from 0.6 to 0.004 with 99.3 % corrosion resistance improvement.