Critical pitting potential of aluminium in automobile cooling systems

Abstract

The traditional copper radiators and heaters in automobiles are being replaced by more lightweight versions made of aluminium. Since different halide fluxes are used in the manufacture of the two types of radiator or heater, it is possible for the coolant to be contaminated by more than one halide when the two types of heat exchanger are used in the ·same system. This may give rise to pitting corrosion of the aluminium. Potentiostatic experiments have enab(ed the critical pitting potential of aluminium in 50% ethanediol solution to be determined to within 5 m V and it has been shown that the Ep value becomes less noble with increase in halide ion concentration. The pitting potential of aluminium in solution containing thefluoride ion has bee:nfound to be more noble than expected.

Get full access to this article

View all access options for this article.

References

Evans

U. R.

: J. Chem. Soc., 1927, (II), 1020.

Rosenfeld

I. L.

and Danilov

I. S.

: Corros. Sci., 1967, 7, 129.

Hoar

T. P.

, Mears

D. C.

, and ROTHWELL

G. P.

: Corros. Sci., 1965, 5, 279.

Swette

L. L.

and coacs

F. H.

(Gifler Inc., Waltham, Mass.): ‘Study of aluminium corrosion in aluminium solar heat collectors using aqueous glycol solution for heat transfer’, Final Report 30 July 1979–31March 1981, DE81027582, NTIS, Springfield, Va, 1981; Corros. Abst., 1982, 21, (3), 158.

Bohni

and Uhlig

H. H.

: J. Electrochem. Soc., 1969, 116, 906.

DE MICHELL

S. M.

Corros. Sci., 1978, 18, 605.

Lorking

K. F.

and Mayne

J. E. O.

: Br. Corros. J., 1966, 1, 181.

Davies

D. E.

and Prigmore

R. M.

: Proc. 9th Int. Cong. on ‘Metallic corrosion’, Toronto, Ont., June 1984, National Research Council of Canada, 356.

Valand

and Nilsson

: Corros. Sci., 1977, 17, 449.