Pitting corrosion of aluminum in aqueous amino acids solutions

The high purity aluminum samples were heated at different temperature for o ne hour to produce different thickness of oxide films. The samples with and without heat treatment were experimented by using Quasi-stationary method in different amino acids solutions. The effects of different thickness of t he oxide films on the rate of corrosion in aspartic acid were studied. The pure amino acids solutions have pitting corrosion tendency toward the sampl es. The effect of sodium chloride solution with respect to some amino acids on the pitting corrosion was studied. The aggressivity order of the tested solutions toward the samples are sodium chloride > aspartic acid > glutami c acid solution. The pits generated in aspartic and in glutamic acid soluti ons were irregular deep and elongated shallow in shape respectively as comp ared to irregular-shaped pits in sodium chloride solutions.