Characterization and selection of aluminum-alloy boomerang grab for sea nodules collection - a case-study

Abstract

Imported aluminium alloy is presently being used by National Institute of Oceanography, Goa, in the Boomerang Grab system for collection of polymetallic sea nodules. The nodules. The alloy exhibits severe corrosion in sea water. Studies were carried out to characterise the imported alloy. Comparative studies on the corrosion behaviour of LM-5, LM-25 and C.C. aluminium were also carried out at both ambient and low temperatures (7-8°C). The studies indicated that the imported alloy may be useful in the cold countries where atmospheric temperature is low. For tropical countries like India, use of chill cast LM-5 is suggested on account of its superior corros-ion resistance at ambient and low temperatures.