Electroless Ni–P plating on Mg–10Li–1Zn alloy

The direct electroless Ni–P plating on Mg–10Li–1Zn alloy was undertaken using the sulfate nickel as the main salt. The pre-treatment function, the deposition process and the corrosion resistance of the Ni–P plating were investigated. Experimental results indicated that the pre-treatment processes were indispensable steps to obtain a compact and uniform Ni–P coating on Mg–10Li–1Zn alloy. The deposition process of the Ni–P coating on the substrate followed two steps, i.e. the induction period and the subsequent autocatalytic reactions. The obtained Ni–P coating showed amorphous structure and P content was about 7.5 wt.%. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) were used to study the corrosion behavior of the coatings. The results indicated that electroless Ni–P plating could obviously improve the corrosion resistance of Mg–10Li–1Zn alloy.