Influence of RE elements on the performances of Ni-P coelectrodeposition bath

Through adding the chlorides of La and Ce into Ni-P coelectrodeposition bath, the effects of rare earth （RE） elements on the performances of the bath have been investigated by hull cell tests, far and near cathodes tests, and so on. It is shown that the optimum contents of CeCl3, LaCl3 and their mixture are all 2 g/L. The bright zones of the Ni-P coelectrodeposition bath are greatly widened by the addition of RE, and this effect is more obvious in the low current density range. By the addition of RE, the current efficiency of the Ni-P coelectrodeposition bath is greatly increased. The results also show that RE elements can improve the dispersing capacity of the bath. It can be theoretically deduced that RE ions improve the cathodic polarization degree of Ni-P codeposition. This deduction has been confirmed by the cathodic polarization curves measured in the baths.

Influence of RE elements on the performances of Ni-P coelectrodeposition bath

Through adding the chlorides of La and Ce into Ni-P coelectrodeposition bath, the effects of rare earth (RE) ele- ments on the performances of the bath have been investigated by hull cell tests, far and near cathodes tests, and so on. It is shown that the optimum contents of CeCl3, LaCl3 and their mixture are all 2 g/L. The bright zones of the Ni-P coelectrode- position bath are greatly widened by the addition of RE, and this effect is more obvious in the low current density range. By the addition of RE, the current efficiency of the Ni-P coelectrodeposition bath is greatly increased. The results also show that RE elements can improve the dispersing capacity of the bath. It can be theoretically deduced that RE ions improve the ca- thodic polarization degree of Ni-P codeposition. This deduction has been confirmed by the cathodic polarization curves measured in the baths.