Copper Alloys Evaded by Marine Organisms

A Copper Alloy with Both Anti-fouling and Anti-corrosion Properties

Abstract

In the previous paper, two types of corrosion tests (so-called erosion-corrosion and flow velocity difference induced corrosion) were conducted on various beryllium-copper-nickel alloys. Of the alloys tested, the 30CuNi and Be30CuNi alloys performed the best. However, a 70CuNi and a Be70CuNi alloy showed a performance comparable to the level of 30CuNi, provided the flow velocity over the alloy surface was maintained within a certain velocity range. The anti-fouling performance of the above alloys was determined by using mussels as a model foulant. As a result the 70CuNi and the Be70CuNi alloys showed the best anti-fouling performance even though it was less soluble than pure Cu metal or BeCu alloy. This is due to the fact that mussels avoided regions that contained high concentrations of copper ions, located in the gaps of the corrosion products film in those alloys. Thus, the 70CuNi and the Be70CuNi alloys were judged to be the most useful alloy, since it had an excellent anti-fouling property as well as satisfactory anti-corrosion properties.