Effect of carbon nanotube reinforcements on anti-corrosive and magneticproperties of Co-Fe based material

Surface coating technology is a promising route to protect bulk substrate material fromenvironmental corrosion, wear, and other surface attacking ailments [۱]. Of the widelyavailable coating materials, CoFe۲O۴ coatings, due to their inherent resistance tomacrofouling, superior corrosion resistance, tarnish resistance with a functionaltemperature range of ۲۰۰ °C to ۴۵۰ °C, makes it well suitable for marine applications,minting, automobile constructions, and magnetic sensors/actuators owing to itsferromagnetic properties [۲]. Recently, various types of smart composite coatings have been investigated, yet of them, the promising route to improve the material's sustainabilityis by embedment of second phase particles in the metal matrix [۳]. Carbonaceousreinforcements are recognized for their lubrication, anticorrosive nature, load-bearing capability, chemical inertness, and shielding structural defects. Recent reports have shownthat addition of carbonaceous materials such as graphene, graphene oxide and carbon nanotubes (CNTs) into the matrix of metallic coatings significantly enhances the corrosion resistance behavior of the coatings [۴]. The observed enhancement in the corrosion resistance property because of graphene or graphene oxide addition is essentially due totheir impermeability to the passage of the corrosive media. It has also been illustrated thatthe addition of graphene or graphene oxide produces changes in the coating microstructure and morphology that significantly affect the corrosion resistance performance of thecomposite coatings containing them. On the other hand, improvement in the corrosion resistance behavior of coating containing CNTs is attributed to the hydrophobic nature ofthe CNTs which repels the aqueous corrosive fluids from the coating surface. However, noliterature is presently available on the magnetic behavior of Co-Fe-based composite coatings. Also, a comparative study on the corrosion behavior of Co-Fe based composite coating with carbonaceous reinforcements like graphene, diamond, and CNT prepared by pulse electrodeposition route is scarcely studied. In the current work, synergistic study ofCoFe۲O۴ matrix with carbonaceous reinforcements CNT obtained from solvothermalmethod, has been studied for their anticorrosive and magnetic properties for successful adoption in batteries, automobiles, and other industries. Nyquist plot obtained throughelectrochemical impedance spectroscopy (EIS) for the both CoFe۲O۴ and CoFe۲O۴@CNThave been presented in Fig.۱. The entry of electrolyte accelerates the formation of localized blisters on the coating surface, initiating the corrosion. However, CNT reinforcements inthe CoFe۲O۴ matrix obstruct the mass transport of dissolved oxygen from reaching the Cusubstrate, increasing the total corrosion resistance.

کلیدواژه ها:

CoFe۲O۴ composite ، Electrochemical impedance spectroscopy ، Magnetic properties