Applied Surface Science, Vol.255, No.5, 2176-2179, 2008
Effects of Yb3+ on the corrosion resistance and deposition rate of electroless Ni-P deposits
Ni-P alloy coatings were deposited with the addition of Yb3+ in the electroless plating solution. The effects of Yb3+ concentration on the corrosion resistance and deposition rate of electroless Ni-P coatings were investigated. The results showed that the addition of Yb3+ could significantly improve the corrosion resistance of the coatings. When increasing Yb3+ up to 0.20 g L-1, the corrosion potential E-corr of the electroless Ni-P coating in 3.5% NaCl solution increased from -0.381 to -0.08 V, and the corrosion current density I-corr decreased from 7.36 to 0.62 mu A cm(2). At 0.20 g L-1 Yb3+, the coating could be as long as 960 h free of corrosion in the neutral salt spray. In addition, the deposition rate can also be accelerated by Yb3+ addition. The mechanisms of Yb3+ influencing on the corrosion resistance and deposition rate of electroless Ni-P coatings were discussed. (C) 2008 Elsevier B. V. All rights reserved.