The purpose of this study is to develop chitosan/phosphate composite films on magnesium alloys to improve their corrosion resistance and broaden their applications in aerospace.Phosphate/chitosan composite films were ...The purpose of this study is to develop chitosan/phosphate composite films on magnesium alloys to improve their corrosion resistance and broaden their applications in aerospace.Phosphate/chitosan composite films were successfully prepared by adding ultra-high deacetylated chitosan in a phosphate bath.The chemical composition of the prepared composite film was investigated by X-ray photoelectron spectroscopy(XPS)and Fourier trans-form infrared spectroscopy(FT-IR),and the morphology and fracture of the composite film were characterized by scanning electron microscope(SEM).Potentiodynamic polarization curves and electrochemical impedance spec-troscopy were used to study the corrosion behavior of the coated alloys.The results showed that when pH=2.5 and the chitosan concentration was 5.0 g/L,chitosan was deposited in the phosphate coating in the form of inclusions.In addition,the potentiodynamic polarization curves of the composite films show that the corrosion potential is positively shifted by 0.6 V compared to the monolayer phosphate coating,indicating improved corro-sion resistance.This work shows that highly deacetylated chitosan can be co-deposited with phosphate to form a dense composite film on the surface of magnesium alloys in one step,thereby improving the corrosion resistance of the alloy.展开更多
基金supported by the National Natural Science Founda-tion of China(52075112,51971071,52011530025)Natural Science Foundation of Heilongjiang Province(JJ2019LH1520).
文摘The purpose of this study is to develop chitosan/phosphate composite films on magnesium alloys to improve their corrosion resistance and broaden their applications in aerospace.Phosphate/chitosan composite films were successfully prepared by adding ultra-high deacetylated chitosan in a phosphate bath.The chemical composition of the prepared composite film was investigated by X-ray photoelectron spectroscopy(XPS)and Fourier trans-form infrared spectroscopy(FT-IR),and the morphology and fracture of the composite film were characterized by scanning electron microscope(SEM).Potentiodynamic polarization curves and electrochemical impedance spec-troscopy were used to study the corrosion behavior of the coated alloys.The results showed that when pH=2.5 and the chitosan concentration was 5.0 g/L,chitosan was deposited in the phosphate coating in the form of inclusions.In addition,the potentiodynamic polarization curves of the composite films show that the corrosion potential is positively shifted by 0.6 V compared to the monolayer phosphate coating,indicating improved corro-sion resistance.This work shows that highly deacetylated chitosan can be co-deposited with phosphate to form a dense composite film on the surface of magnesium alloys in one step,thereby improving the corrosion resistance of the alloy.
