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

Electrochemical Characterisation to Study the Pitting Corrosion Behaviour of Beryllium

“…It was stated that the size of the passive range, or the ability of a solution to break the oxide layer on the surface of the beryllium, appeared to be a function of pH, and not of chloride concentration. This result on chloride effect is not in agreement with the findings of Hill and co-workers (1996) and a recent investigation by Punni and Cox (2010).…”

“…To accomplish this, the electrochemical characteristics of beryllium material containing differing impurity contents and distribution were assessed and the resulting localised corrosion sites evaluated. Earlier results of this investigation were published in a previous paper (Punni & Cox, 2010) and a brief account of this work with updated information is described here.…”

“…The key points for a typical cyclic polarisation curve from a recent polarisation study (Punni & Cox, 2010) for a commercial beryllium are displayed in Figure 2. It was observed that the anodic polarisation was characterised by a region of passivity followed by a logarithmic increase in the current density, which corresponded to the onset of pitting corrosion (E pit ).…”

“…Electrochemical techniques were widely used in the past (Hill, et al, 1996Punni & Cox, 2010;Lillard, 2000) to characterise pitting corrosion behaviour of beryllium in aggressive aqueous environments. In aqueous salt solutions beryllium develops a passive hydrated oxide film, either Be(OH) 2 or its hydrate (BeO (H 2 O)x) (Vaidya et al 1999) Electrochemical impedance spectroscopy (EIS) experiments had shown that the oxide growth rate on beryllium was 6.4 angstroms/V over the range of 0-4V.…”

“…This technique is described in greater detail in a previous investigation (Punni & Cox, 2010). Samples for polarisation tests were ground down to a 600 grit silicon carbide paper finish.…”