# Preparation and long-term corrosion resistance of epoxy resin coatings modified by Fe-Co-Ni-Cr-Ti high-entropy alloy

## TL;DR

Researchers improved epoxy coatings with a high-entropy alloy to enhance their long-term resistance to corrosion in harsh environments.

## Contribution

A low-cost high-entropy alloy modification method for epoxy coatings is introduced, offering superior corrosion resistance.

## Key findings

- Nano-sized HEA filled pores and enhanced the coating's barrier effect.
- HEA induced in situ passive film formation to inhibit corrosion.
- The 2 wt% HEA coating showed a charge transfer resistance of 4.27 × 10⁸ Ω cm⁻² after 60 days in NaCl.

## Abstract

Traditional epoxy resin coatings easily form pores and microcracks in corrosive media such as NaCl, resulting in insufficient long-term corrosion resistance. To solve this problem, this work fabricated low-cost Fe-Co-Ni-Cr-Ti high-entropy alloy (HEA)-modified novolac epoxy coatings (HEA/EPN) via optimized dispersion and preparation processes. HEA/EPN coatings with 1–4 wt% HEA were prepared. The effects of HEA content and dispersion on coating micromorphology and phase composition were characterized, and their long-term corrosion resistance was evaluated using electrochemical impedance spectroscopy (EIS). Results showed that nano-sized HEA not only filled pores to enhance the coating barrier effect but also induced in situ passive film formation to inhibit corrosion. HEA dispersion directly determined coating corrosion resistance, with the 2 wt% HEA coating exhibiting optimal performance—its charge transfer resistance (Rct) remained 4.27 × 108 Ω cm−2 after 60 days immersion. This study provides a viable low-cost solution to the poor long-term corrosion resistance of conventional epoxy coatings. The as-prepared HEA-modified epoxy coating presents promising application prospects in marine engineering facilities, petrochemical pipelines and storage tanks, as well as metal components in infrastructure and transportation equipment under severe corrosive environments.

Fe-Co-Ni-Cr-Ti high-entropy alloy (HEA) modified epoxy coatings were prepared. The optimized 2 wt% HEA coating showed excellent long-term corrosion resistance in NaCl solution via a synergistic barrier-passivation mechanism.