Improvement of the corrosion resistance of Cr–N coated aluminum matrix composite by magnetron sputter

Cr–N coatings were deposited on alumina borate whisker reinforced pure aluminum matrix composite substrates by radio frequency (RF) magnetron sputtering. The phase and chemical state of coatings were characterized using X-ray photoelectron spectroscope and X-ray diffraction techniques. Corrosion behaviors were investigated in 3.5%NaCl solution at room temperature. Potentiodynamic polarization curves confirm that the Cr–N coated composite shows not only much lower susceptibility to pitting but also significantly improved corrosion resistance in comparison with untreated composite.