Formation and corrosion-protective performance of zirconium conversion coating on aluminium heat exchanger componentsKraš, Ana (Avtor) Kapun, Barbara (Avtor) Kovač, Nina (Avtor) Podlogar, Matejka (Avtor) Šturm, Sašo (Avtor) Milošev, Ingrid (Avtor) Kralj, Marko (Avtor) Rodič, Peter (Avtor) zirconium conversion coatingThis study investigates the corrosion protection of aluminium heat exchangers used in freezers with a zirconium conversion coating (ZrCC). Tube and fins sections were subjected to a three-step surface treatment comprising (i) alkaline cleaning, (ii) acid desmutting, both with commercial SurTec® products, and (iii) deposition of conversion of Zr coating in a hexafluorozirconic acid (H2ZrF6) bath. The resulting surfaces were characterised for morphology, composition, and corrosion behaviour using scanning electron microscopy with energy-dispersive x-ray spectroscopy, x-ray photoelectron spectroscopy, potentiodynamic polarisation, and neutral salt spray (NSS) testing. Zr formed a ∼70 nm oxide–hydroxide layer that preferentially nucleated and grew on cathodic Fe-containing intermetallic particles in tubes and fins. The coating improved passivity and delayed pit initiation in chloride-containing environments by broadening the passivity span ΔE up to 500 mV. Accelerated corrosion testing in NSS (ASTM B117) demonstrates that ZrCC can provide efficient protection for up to 90 h on tube-and-fin substrates, thereby supporting their implementation in industrial heat-exchanger production.IOP Publishing 20262026-07-29 12:37:57Neznano31351UDK: 620.1/.2ISSN pri članku: 2515-7639DOI: 10.1088/2515-7639/ae80feCOBISS_ID: 286127107Združeno kraljestvosl© 2026 The Author(s).