The ZrC and Ti-Ni nanostructures in epoxy coatings: An anticorrosion and tribological study

The work herein describes the effect of the dispersion of ZrC and Ti-Ni nanostructures, produced by mechanosynthesis, on the anticorrosion and tribological properties of epoxy resin (ER) coatings. Electrochemical impedance spectroscopy (EIS) showed that the addition of the nanostructured materials in the polymer matrix improved by three to four orders of magnitude the corrosion resistance of a pristine epoxy resin coated steel exposed to a 3.5 wt% NaCl solution. The chemical and nanocrystalline nature as well as the particle size of the reinforcements played an important role in the penetration of aggressive agents and corrosion of the steel. Interestingly, Ti-Ni promoted a corrosion inhibiting effect through the deposition of its cations on the steel surface. On the other hand, scratch tests as well as electron and atomic force microscopy analysis revealed that the particle size of the reinforcements was a dominant effect on the scratch resistance of the nanocomposite coatings due to the modification of the surface roughness as well as the stress distribution during the scratch tests. The scratch resistance of the pristine epoxy resin was higher than that of the Ti-Ni powder nanocomposite, but lower than that of the ZrC coating. In addition, ZrC promoted a lubricating effect during the scratch test. Up to similar to 20 wt% of TiNi shape memory phase in Ti-Ni reinforcement did not provide evident enhancement of the coatings scratch resistance.