Effects of composite ferrotitanium on epoxy coating

PurposeThe purpose of this paper is to evaluate effects of different contents of composite ferrotitanium pigment on corrosion protection performance of epoxy resin coatings.Design/methodology/approachDifferent contents of composite ferrotitanium pigment were added to the epoxy resin coatings and the corrosion performance of the coatings were investigated by electrochemical test (in 5 wt.% KCl solutions at 60°C), salt spray test and simulated test. The morphology of the coating before and after corrosion was characterised by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS).FindingsThe composite ferrotitanium improved anti‐corrosion properties of the coating due to complex reaction of ferrous ions and phosphates as well as introduction of nano powder to the composite ferrotitanium. The coating with 10 wt.% composite ferrotitanium pigment had better anti‐corrosion properties than that of 5 wt.%. Simulated experiment in an autoclave indicated that the composite ferrotitanium pigment had the best protective performance among the three green pigments such as zinc phosphate, aluminium tri‐phosphate, and composite ferrotitanium.Research limitations/implicationsThe pigments were added into the coating by high energy ball milling. Some of them dispersed in the coating heterogeneously and affected property of the coatings.Practical implicationsComposite ferrotitanium can be used to replace red lead and chromate pigments to meet environmental requirements.Originality/valueThe paper shows how the anti‐corrosion mechanism of the composite ferrotitanium pigment was investigated and several green pigments were selected to compare their protective performance in the autoclave.