Coating of sintered NdFeB and its corrosive resistance features

Surface of NdFeB magnets are usually treated with different kinds of coatings to create self protection performance under all kinds of working conditions. The main coatings applied to magnet surface are listed as follows

Black Epoxy coating	Ni-Cu-Ni coating	Parylene coating	Zinc coating

Coating			Corrosive Resistance	Color	Application
Metal Coating	Nickel		Good	Sliver	Suitable for most working conditions with normal protective requirements
	Ni-Cu-Ni		Excellent	Sliver	Suitable for working conditions with high requirements on surface protection and treatment
	Zinc	Blue white	Good	Blue white	Suitable for working conditions with low corrosive and humidity requirements
		Color	Excellent	Multi color	Suitable for hot, humid and industrial atmosphere for its high self protection performance
	Ni-Cu-Ni+Epoxy		Excellent	Black	Usually applied to special working coditions with customized anti-corruption requirement
	Ni-Sn		Good	Sliver	Suitable for parts that may be  welded or placed into electric equipment.
	Ni-Au		Good	Gold	Suitable for parts that placed into the high reliable electronic equipments or top grade adornments
	Ni-Ag		Good	Sliver	Suitable for parts that may be  welded or placed into the electric equipment.
Epoxy			Very good	Black Grey	Suitable for parts used to insulate the electric equipments or placed in the high corrosive industrial atmosphere.
Parylene			Excellent	Transparent	Usually applied to special working coditions with super-higher customized anti-corruption requirement
Zn+Parylene			Excellent	Blue white	Usually applied to special working coditions with super-higher customized anti-corruption requirement