The effect of impurity inclusions on the pitting corrosion behaviour of beryllium

An electrochemical polarisation study has been conducted to determine the effect of impurity inclusions on the pitting corrosion behaviour of beryllium. Three grades of commercial beryllium differing in impurity levels were used. This work showed a strong relationship between the pitting potential of the beryllium and the level of impurity inclusions, the grade with the least number of overall inclusions being the most resistant to pitting corrosion. The work also revealed the preferred sites for pit initiation, with most corrosion pits initiating at intermetallic Fe/Al/Be inclusions, and to a smaller extent at inclusion sites containing either elemental silicon or carbides.