A Zr- and Cr(III)-containing conversion coating on Al alloy 2024-T3 and its self-repairing behavior

作者：Cai, C.^*; Liu, X. -Q.; Tan, X.; Li, G. -D.; Wang, H.; Li, J. -M.; Li, J. -F.

来源：Materials and Corrosion-werkstoffe Und Korrosion, 2017, 68(3): 338-346.

DOI：10.1002/maco.201609067

• POWER ELECTRICAL CONDUCTORS
• ATMOSPHERIC CORROSION
• CARBON-STEEL
• NEURAL-NETWORKS
• PURE COPPER
• PREDICTION
• ALUMINUM
• METALS
• RAIN

A zirconium-and Cr(III)-containing conversion coating on Al alloy 2024-T3 was prepared in solution containing Cr-2(SO4)(3) and K2ZrF6. Its composition was analyzed by energy dispersive X-ray spectrometry (EDS), and its corrosion resistance was investigated using polarization curve, electrochemical impedance spectroscopy (EIS), and salt spray exposure. An artificial scratch cell was used to investigate its "self-repairing" effect by EIS and X-ray photoelectron spectroscopy (XPS). In addition to Al, the conversion coating contained Zr, Cr, O, and F. The conversion coating provided obvious corrosion protection for the Al alloy 2024-T3. The EIS measurement and corrosion morphology observation of bare samples (i.e., uncoated samples) in the artificial scratch cell confirmed that the conversion coating possessed "self-repairing" effect. XPS analysis showed that Cr(III) species, but not Zr species were transported from the conversion coating to the nearby bare area as in a scratch.

• 出版日期2017-3
• 单位宁夏大学; 中南大学