Abstract
The infiuence of sucrose, glucose, fructose, mannose and mannitol on the corrosion and anodic polarisation behaviour of aluminium (2S) in 1M sodium hydroxide solutions in the presence and absence of calcium has been studied from the point of view of employing aluminium as a galvanic anode. The objective to be achieved is a high degree of inhibition of self-corrosion combined with a large limiting current density. It has been found that a small degree of corrosion inhibition is obtained with sucrose and with a low concentration of glucose, but corrosion is accelerated by the other substances. In the presence of calcium chloride, sucrose, glucose and fructose give considerable inhibition of corrosion but mannose and mannitol accelerate corrosion even in these conditions. Ageing of the solution in general brings about a reduction in corrosion or, with afew exceptions, has a mitigating effect on the acceleration of corrosion.
Potentiostatic polarisation curves show inflections when obtained infresh and aged solutions containing sucrose alone and in aged solutions of sucrose containing calcium. In solutions of glucose, fructose and mannitol, inflections are observed only in presence of calcium. With mannose, inflections are observed only in the presence of calcium. With mannose, the inflection is not well defined irrespective of the presence of calcium. In the presence of calcium, the limiting currents obtained with glucose or fructose are higher than those obtained with sucrose.
Get full access to this article
View all access options for this article.