Among the environmentally friendly marine energies,tidal current power plants require low cost because they do not need to construct a large dam.Tidal power is particularly reliable energy source because the power generation capacity is predictable regardless of weather or season.Composite materials or stainless steel have been used as materials of blades for current power plant.However,their strength and welding performance generated many problems in field application.Copper alloys with excellent cavitation resistance and corrosion resistance were applied as blade materials to improve the durability of copper alloys.They were coated with WC-27NiCr and WC-10Co4Cr using the high velocity oxy-fuel (HVOF) method.The metal spray coating technology has the advantage in terms of the selection of materials for cost effectiveness and environmental effects of corrosion because the properties of the coat layer can be controlled intentionally.Coating with WC-27NiCr and WC-10Co4Cr by HVOF,WC-27NiCr shows better corrosion resistance overall.The reason for this seems to be that corrosion resistance improves and a stable passive film forms due to the effects of Ni and Cr. Among the environmentally friendly marine energies, tidal current power plants require low cost because they do not need to construct a large dam .idal power is particularly reliable energy source because the power generation capacity is predictable regardless of weather or season .Composite materials or stainless steel have been used as materials of blades for current power plant. How, their strength and welding performance generated many problems in field application. Copper alloys with excellent cavitation resistance and corrosion resistance were applied as blade materials to improve the durability of copper alloys. They were coated with WC-27NiCr and WC-10Co4Cr using the high velocity oxy-fuel (HVOF) method. metal spray coating technology has the advantage in terms of the selection of materials for cost effectiveness and environmental effects of corrosion because the properties of the coat layer can be controlled intentionally. Coating with WC-27NiCr and WC-10Co4Cr by HVOF, WC-27NiC r shows More corrosion resistance overall. reason for this seems to be that corrosion resistance improves and a stable passive film forms due to the effects of Ni and Cr.