Improved corrosion resistance and hydrophobic stability of sol-gel coatings by benzoxazine modification on aluminum alloys AA1060

A series of sol-gel coatings based on tetraethoxysilane (TEOS) was adopted in order to provide corrosion protection for aluminum alloys AA1060, which were modified by incorporating various ratios of silane-functionalized benzoxazine (Bz), labeled as Bz-based sol-gel coatings. Fourier transform infrared spectra were utilized to characterize the crosslinking network of Bz-based sol-gel coatings through calculating the conversion of Bz structure after the curing process, which was also further confirmed by the gel content test. Both hydrophobicity and corrosion resistance of Bz-based sol-gel coatings were fully investigated with the assistance of water contact angle (WCA) measurements, electrochemical impedance spectroscopy (EIS), and salt spray test. Bz incorporation could improve hydrophobic stability and corrosion resistance of Bz-based sol-gel coatings with increasing the Bz content during the 30-day immersion in a 3.5 wt% NaCl aqueous solution. Better performance of Bz-based sol-gel coatings than that of a control TEOS coating with a WCA above 93 degrees and a charge-transfer resistance over 100 k omega cm2 after 30-day EIS measurement shows their effective protective property for aluminum alloys.

Automated summary

A series of sol-gel coatings based on TEOS were used to provide corrosion protection for aluminum alloys AA1060. The addition of silane-functionalized benzoxazine (Bz) improved the hydrophobicity and corrosion resistance of the sol-gel coatings. The Bz-based sol-gel coatings showed better performance than the control coating in a 30-day test, demonstrating their effective protective property for aluminum alloys.