Some aspects of the corrosion and protection of fully dense and porous beryllium

The corrosion behaviour of P1 and P10 beryllium materials has been investigated under immersion and moist atmosphere environments. Both fully dense and porous material have been subjected to test conditions of 600C 75%RH in an attempt to predict the effects of long term usage in ambient environments. An acceleration of the expected effects of chloride contamination has been achieved by the use of surface salt contaminations of up to 100 μg cm-2 and an evaluation of various protective measures has been performed under the same test conditions. The protectives have involved the techniques of anodising, conversion coating, painting, polymer coating and fluorination. (Glass coatings have been considered but no detailed corrosion data exist to date.) Comparisons with uncoated specimens have shown that Parylene-N and a chromated paint both give good protection against salt enhanced attack on fully dense and porous material. (author)