Effects of Heat Treatment on Corrosion Resistance and Crystal Structure of Electroless Ni-P Alloy Coating

Ni-P alloy coatings with different mass fraction of P are prepared by electroless plating process,and the structure and surface morphology of the coatings are examined by X-ray diffraction and scanning electron microscopy respectively.The corrosion resistance of the Ni-P coatings at different heat treatment temperatures are investigated.The results show that the corrosion resistance of the coatings is directly influenced by heat treatment.Heat treatment at 200℃ for one hour can improve the corrosion resistance of the coatings,however if temperature exceeds 300℃,the coating structure will be changed,and the corrosion resistance reduced.