| abstract |
The present invention offers a surface treatment method for magnesium alloys that can form a uniform, thin, and dense conversion coating on a magnesium alloy surface where mold release agent, oxide layer, and a layer of Segregation of alloy components (for example, aluminum and zinc) are potentially present, and also offers magnesium alloy members whose surface has been treated by the surface treatment method mentioned above. The surface treatment method of the present invention comprises a degreasing process to degrease the surface of the magnesium alloy, a chemical attack process to chemically attack the alloy, and a conversion treatment process to form a conversion coating. The chemical attack forms a magnesium phosphate coating having a coating weight of 10 to 2,000 mg / m2, measured as phosphorus, putting the surface of the magnesium alloy in contact with the aqueous solution containing a phosphoric acid compound . |