Effect of Na2WO4 Concentration on the Microstructure and Corrosion Behavior of Ni-W-P Ternary Alloy Coatings

Ni-W-P ternary coating was successfully deposited on AZ91D magnesium alloy by electroless plating with low energy consumption. The effect of Na2WO4 concentration the microstructure, deposition rate, corrosion behavior, adhesion force, porosity test and micro-hardness coatings were evaluated. Results reveal that when is 15 g/L in solution, average thickness 17 μm uniform dense, content phosphorus tungsten reached 9.63 wt.% 1.14 respectively, which presents amorphous structure. Meanwhile, g/L, has best resistance, among Ecorr -0.326 V, Icorr 0.003 A/cm2 3.5 NaCl solution. In addition, mechanisms resistance for substrate exploded.