CHARACTERIZATION OF Ni-P COATING PREPARED ON A WROUGHT AZ61 MAGNESIUM ALLOY VIA ELECTROLESS DEPOSITION

摘要

A low-phosphorous Ni-P coating was prepared on a wrought AZ61 magnesium alloy via electroless deposition for 1 h after an adequate substrate-surface pre-treatment. The prepared coating with a thickness of 10 mu m was characterized by the uniform distribution of Ni (95.4 % mass fraction) and P (4.6 % mass fraction) in the cross-section. Microcavities present in the coating resulted in quite a low corrosion resistance of the coated magnesium alloy in a 0.1 M NaCl solution. On the other hand, the coating exhibits a high degree of adhesion, as evidenced by a scratch Lest, and significantly improves the AZ61 magnesium-alloy microhardness.