Constructing bioinspired mineralization interface between carbon fiber and epoxy coating with robust anti-corrosion and anti-erosion performances

The extremely intricate deep-sea environment, characterized by elevated hydrostatic pressure, low temperatures, and low diminished dissolved oxygen levels, poses great challenges to the long-term corrosion resistance of steel structures serving in the deep sea. Carbon fiber (CF)-reinforced composites are applied in more domains owing to CF's amazing mechanical strength, chemical stability, corrosion resistance, and high thermal conductivity (TC). Nevertheless, the protective efficacy of CF-reinforced composites in harsh oceanic environments is constrained due to the inadequate interfacial bonding strength between CFs and polymers. Here, a bioinspired mineralized layer (Ca₃(PO₄)₂) was constructed on CFs (M − CF) via in-situ growth method, which markedly improved the interfacial adhesion strength between CFs and epoxy resin. In comparison, the tensile strength, which increased by 79.8 % relative to EP, and interfacial shear strength, which rose by 73.6 % compared with CF/EP, were most pronounced in the case of M-CF/EP. The bioinspired mineralized layer on CFs provided exceptional corrosion resistance and anti-erosion properties to the composite coating. The findings of the erosion studies indicated that the mass loss and volume loss of M-CF/EP were just 182.3 mg and 165.2 mm³, respectively. The M-CF/EP coating exhibited a TC of 0.75 W m⁻¹ K⁻¹, which greatly surpassed that of other coatings. Finally, the protective mechanism of the coatings were analyzed, and the interfacial failure processes induced by the effect of SiC particles were discussed.