Jf. Quinson et al., DEFORMATION CAPABILITY AND PROTECTIVE ROLE OF ZIRCONIA COATINGS ON STAINLESS-STEEL, Journal of Materials Science, 31(19), 1996, pp. 5179-5184
ZrO2 coatings were obtained by the alkoxide route and deposited on to
stainless steel using the dip-coating technique. The starting solution
s were prepared by mixing zirconium tetrabutoxide, isopropanol, acetyl
acetone. The water content for the hydrolytic reaction came from atmos
pheric moisture. These coatings were characterized by scanning electro
n microscopy, X-ray fluorescence, Fourier transform-infrared spectrosc
opy, and X-ray diffraction. Their deformation capability was studied b
y using the stretch deformation test. It is worth noting that these co
atings deposited on stainless steel have the capacity to deform extens
ively without apparent cracks or fracture. Their ability to protect th
e metallic substrate against corrosion, in a neutral chloride medium,
was investigated. For this purpose, the pitting potential of the coate
d metal was measured by the potentiodynamic polarization technique and
the a.c. impedance diagram of the coating was recorded in the potenti
ostatic mode at the rest potential. The variation in the pitting poten
tials revealed a temporary increase in the corrosion resistance of coa
ted stainless steel, which disappeared after ageing of the coatings in
the chloride solution. During ageing, the coating resistance deduced
from the complex diagram via an equivalent circuit, decreases, thus sh
owing a deterioration.