CORROSION AND INHIBITION OF COPPER IN DIFFERENT ELECTROLYTE-SOLUTIONS

The inhibition action of p-chlorobenzohydroxamic acid (p-Cl-BHA) and d ibenzylsulphoxide (DBSO) on copper corrosion in 0.5 M NaCl at pH appro ximate to 6.5 and 0.1 M Na2SO4 at pH approximate to 3, respectively, w ere studied. The corrosion and inhibition processes were monitored by in-situ atomic force microscopy, and morphological changes on the elec trode surface were registered. The p-Cl-BHA greatly enhanced the resis tance of copper to pitting corrosion in an aqueous solution containing chloride ions. This effect is attributed to the formation of a contin uous protective chemisorbed layer on the corroding metallic surface th rough which Cu2O will be stabilized. The DBSO, because of its adsorpti on and conversion to a more stable, less soluble sulphide compound, gr eatly hindered the copper corrosion in the sulphate-containing solutio ns.