Abstract
ESCA examination of films formed on Si-Fe alloys after immersion in 0.1 M NaCl for 24 h has hown that the thickness of passive films decreased with an increase in silicon content. A thick passive film containing oxidized silicon and oxidized iron was formed on Fe-20 wt% Si and the oxidized iron was about three times higher than the oxidized silicon in the passive film. However, an obvious reduction in the oxidized iron in the film on Fe-30 wt % Si was observed. Oxidized iron was detected up to a depth of 1.0 nm and at a depth greater than 1.0 nm from the surface, the film was exclusively in oxidized silicon. The film was exclusively silicon oxide when the silicon content was increased to 50 wt %. Electrochemical techniques according to ASTM G59 and ASTM G5 were used for the determination of the relative corrosion rate. Fe-50 wt % Si was found to have a corrosion rate smaller than those lower silicon alloys. This relates to the surface film composition and structure as determined by ESCA.
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References
E.S. Greiner et al.: The Alloys of Iron and Silicon (McGraw-Hill, New York 1933)
L.L. Shreir: Corrision, Vol. 1 (Butterworths, London 1976) p. 119
V. Brusic et al.: In Passivity of Metals, ed. by R.P. Frankenthal, J. Kruger (Electrochemical Society, Princeton, NJ 1978) p. 170
S. Jin, A. Atrens. Appl. Phys. A 42, 149–165 (1987)
M. Stern, R.M. Roth: J. Electrochem. Soc. 104, 390 (1967)
M. Stern: Corrosion 14, 440t (1958)
F. Mansfeld: In Corrosion Science and Technology (Plenum, New York 1976) Vol. VI, p. 163
C.D. Wagner et al: In Handbook of X-ray Photoelectron Spectroscopy, ed. by G.E. Muilenberg (Perkin-Elmer, Eden Prairie 1978)
N.S. McIntyre: In Practical Surface Analysis, ed. by D. Briggs, N.P. Seah (Wiley, Chichester 1983)
K. Asami, K. Hashimoto: Corros. Sci. 17, 559 (1977)
D. Briggs, J. Riviere: In Practical Surface Analysis, ed. by D. Briggs, N.P. Seah (Wiley, Chichester 1983) p. 131
C.D. Wagner: J. Electron Spectrosc. Relat. Phenom. 32, 99 (1983)
S. Hofmann: Surf. Int. Anal. 2, 148 (1980)
P. Bruesch et al.: Appl. Phys. A 38, 1 (1985)
I. Abbati et al.: J. Vac. Sci. Technol. 21, 409 (1982)
A. Cros et al.: Surf. Sci. 110, 352 (1981)
J. Derrien et al.: Passivity of Metals and Semiconductors, ed. by M. Froment (1983) p. 457