Unlike chemical conversion coating or frequently-used metal plating, coating material of epoxy coated Neodymium magnet is belongs to the organic substance. Coating protection is referring to apply coating material to form a dense film on the workpiece surface to realize isolation and protection. Coating protection can be divided into organic type and inorganic type. For organic coating, resins applied over the workpiece through different painting processes after dispersed in solvent. Organic substance will be cured under the action of physical or chemical reaction and thus formed dense film on the workpiece surface. Organic coating protection has relatively lower requirement on the matrix, thereby, the majority of organic coatings and corresponding painting processes can be served to the surface protection of Neodymium magnets, especially spray epoxy coating and electrophoretic epoxy coating.
Electrophoretic Epoxy Coating of Neodymium Magnet
Epoxy coating is also a routine surface treatment technology for Neodymium magnet, especially for electrophoretic epoxy coating. Electrophoresis is referred to the phenomenon that charged colloidal particles in the conductive dispersion medium move to opposite electrodes directionally under the action of external electric field. Electrophoretic coating just taks advantage of this characteristic to make charged organic molecules firmly adsorbed on the magnet surface, then formed continuous and dense film after curing treatment. Electrophoretic epoxy coated Neodymium magnet exhibit superior binding force, uniform thickness, salt fog resistance, acid resistance, and alkali resistance. However, electrophoretic epoxy coated Neodymium magnet shows weakness in humidity resistance. For sintered Neodymium magnet, epoxy coating is normally accomplished on the basis of Zinc plated Neodymium magnet or Nickel plated Neodymium magnet. This is equivalent to append another organic coating to further isolate the influence of outer environments. Black and grey are the two most common colors for epoxy coated Neodymium magnet.
Spray Epoxy Coating of Neodymium Magnet
Spray epoxy coating doesn’t require complex electrochemical process like electrophoretic epoxy coating. Spraying process need only ensure film to obtain homogenous distribution and appropriate thickness, then processed levelling and curing treatment. Spray epoxy coated Neodymium magnet is free of hanging point, therefore, spray epoxy coating can be combined with electrophoretic epoxy coating to eliminate the affection of hanging point. In addition, multiple spraying can provide maximum satisfaction to surface protection requirements.
