Incorporating graphene-modified mica and conductive nickel particles for enhanced corrosion resistance in epoxy zinc-rich coatings

Epoxy zinc-rich coatings usually require high zinc content to ensure its anti-corrosion performance. However, excessive zinc powder content will reduce the mechanical properties of the coating, increase the economic cost, harm the environment, etc. Therefore, this paper aims to reduce the amount of zinc powder and improve the corrosion performance of epoxy zinc-rich coatings by introducing two kinds of conductive particle materials, conductive graphene-mica powder and conductive nickel. Conductive graphene was first loaded on mica powder and the obtained conductive graphene-mica powder and the conductive nickel were introduced to the epoxy zinc-rich coatings to partially replace zinc component. The anti-corrosion properties of the coating were systematically evaluated by EIS and salt spray test. The resulting epoxy zinc-rich coating with nickel powder or conductive graphene-mica demonstrates outstanding salt spray resistance, lasting up to 2,000 h, exhibiting superior anti-corrosion performance at reduced zinc content of 60% or 45% compared to conventional coatings with 70% pure zinc powder. This study introduces a novel conductive mica material and investigates conductive metal nickel additive, effectively reducing zinc content in epoxy zinc-rich coatings, which offers valuable insights for developing high-performance anti-corrosion coatings.