Scalable Corrosion-Resistant Coatings for Thermal Applications

Area of Science:

• Materials Science
• Corrosion Engineering
• Surface Chemistry

Background:

• Metallic substrate corrosion is a significant industrial challenge.
• Existing ultrathin coatings (e.g., silicon dioxide, Parylene C) offer good protection but are difficult to apply on complex shapes.
• Thick coatings impede heat transfer, making ultrathin (<10 μm) solutions desirable for thermal systems.

Purpose of the Study:

• To develop a facile and scalable sol-gel method for applying ultrathin, conformal silicon dioxide (SiO2) coatings on arbitrary metal shapes.
• To evaluate the anticorrosion performance of the developed SiO2 coating against various benchmarks and commercial standards.
• To assess the durability and scalability of the coating under simulated realistic working conditions.

Main Methods:

• Developed a sol-gel solution for dip coating arbitrary metal substrates.
• Applied ultrathin (~3 μm) SiO2 coatings with low roughness (<5 nm).
• Conducted electrochemical tests (potentiodynamic polarization, electrochemical impedance spectroscopy) and a corrosion flow loop test using coated copper tubes.

Main Results:

• The sol-gel SiO2 coating demonstrated excellent uniformity, smoothness, and conformality.
• Electrochemical tests showed a 95% decrease in corrosion rate for sol-gel SiO2 and Parylene C coatings.
• Coated copper tubes experienced a 75% reduction in weight loss in a seawater corrosion flow loop test.

Conclusions:

• The developed sol-gel SiO2 coating provides a scalable and effective method for ultrathin anticorrosion protection.
• This technology offers a viable alternative to existing methods, particularly for complex geometries.
• The study enhances understanding of corrosion mechanisms on functionalized surfaces and substrates.