TITLE:
Research on Low-Stress Cleaning and Composite Anti-Corrosion Process for Low-Stiffness Thin-Walled Curved Metal Cavity Components
AUTHORS:
Fei Long, Panlong Sun
KEYWORDS:
Thin-Walled Curved Metal Cavity, Inner-Cavity Surface Treatment, Vacuum Pulse Circulation, High-Frequency Ultrasonic Cavitation, Rare-Earth-Zirconium Chromium-Free Passivation, Hydrophobic Sealing, Gradient Anti-Corrosion Barrier
JOURNAL NAME:
Journal of Materials Science and Chemical Engineering,
Vol.14 No.10,
October
23,
2026
ABSTRACT: Thin-walled curved metal cavity components generally suffer from insufficient structural rigidity, sensitivity to geometric tolerances, and complex internal flow-channel bends. Conventional cleaning and anti-corrosion processes readily induce defects such as micro-deformation, uneven inner-wall cleanliness, and inadequate protective-layer durability. To achieve low-damage, high-precision, and long-life anti-corrosion treatment of the inner cavities of such precision components, this paper proposes an inner-cavity surface treatment process integrating low-temperature fluid-coupled purification, room-temperature nano-interface passivation, and hydrophobic sealing modification. The method employs vacuum pulse circulation coupled with high-frequency ultrasonic cavitation to remove oil, loose rust, and porous oxidation products attached to irregular inner cavities under non-rigid-contact and near-ambient-temperature conditions. A rare-earth-zirconium chromium-free passivation system is then applied to form a dense nano-scale transition film in situ on the metal inner wall, optimizing the substrate surface state and enhancing the interfacial bonding strength of subsequent coatings. Finally, a silane-microcrystalline-wax composite hydrophobic agent is used to build a water-repellent surface layer, yielding a gradient anti-corrosion barrier comprising a passivation underlayer and a hydrophobic sealing top layer. Experimental results show that the processing temperature of the entire route is kept below 38˚C and the maximum deformation of thin-walled components does not exceed 0.015 mm, effectively avoiding precision loss caused by thermal and mechanical stresses. No cleaning dead corners remain in curved, variable-diameter, or corner regions, and the film is continuous and uniform. After 720 h of neutral salt-spray accelerated aging, the protective system exhibits no pitting, blistering, peeling, or delamination, demonstrating excellent anti-corrosion stability. The process is green and low-carbon, retains geometric tolerances well, and is easy to retrofit into production lines, providing a feasible technical solution for precision inner-cavity protection of irregular thin-walled cavity parts in high-end equipment.