Why is copper nickel suitable for the marine industry?
Copper-nickel alloys have a chemical composition that consists mainly of copper with a significant amount of nickel, ranging from 8% to 45 percent. Cu-Ni alloys are also known as Copper-nickel. They may contain additional elements. They can have benefits if they include additional alloyants, minerals such as Zinc, iron or manganese to their alloy. The addition of manganese or Cu-Ni alloys to an alloy improves its electrical conductivity. Iron alloyed with CuNi alloys enhances erosion-corrosion properties both in freshwater and high-velocity waters. The formation of a uniform, adherent protective layer in water is also promoted by iron. This protective layer is formed on the surfaces of these alloys and improves corrosion resistance, especially in high velocity seawater.
The passive layer that has accumulated on the surface not only increases resistance to corrosion but also protects it from stress-related cracking and pitting in marine environments. The addition of Chromium, on the other hand increases the alloy's tensile strength and has a positive impact on its resistance to erosion-corrosion in high velocity moving marine environments as well as erosion by solids. Some Cu-Ni grades contain aluminum that increases strength and seawater and scaling resistance.
For marine environments, alloys containing copper in the range of 90% to 70% will be well-suited. For applications such as heat exchangers and desalination plants (power generation), etc., grades like 70/30 CuNi or 90/10 CuNi should be considered. This metal is excellent for applications that involve seawater. One reason is copper's biostatic property. This biostatic metal does not encourage the growth of bacteria or other lifeforms. Cu-Ni alloys have long been used to line ship parts to prevent the growth of life forms such as barnacles or mussels. This alloy is also very resistant to microbes and inhibits biofouling in extreme environments. The effectiveness of copper-nickel alloys in reducing microfouling is impressive. They are also resistant to corrosion in saltwater and brine solutions.
These alloys are highly ductile and have high formability properties. This makes them easy to shape. It is therefore easier to make pipes, tubes, fasteners and other components with either one of these alloys. Maintenance cost is one of the most desirable aspects of 90/10 CuNi. This alloy is almost 25% less expensive than other steel grades. These alloys have a high salvage value, based on their economic evaluation. CuNi alloys, for example, have a salvage value of approximately 25% of their initial costs. A lot of copper-based alloys are used as marine cladding. These alloys protect the surface from corrosion and are useful for shipping vessels. They also reduce biofouling from seawater which results in a decrease or lowering of fuel consumption. They are therefore a cost-effective option for marine environments.