Behavior of hydrogen evolution and rate determining by electrochemical method during electroless Ni-W-P alloys plating

In the presented paper,the behavior of hydrogen evolution was investigated during electroless Ni-W-P alloy plating.The mechanism of Ni-W-P alloy deposition is a competition among the reduction of Ni²⁺,W⁶⁺,P⁺,H⁺.Besides hydrogen ions reduce separately,the same faradic amount hydrogen evolves with Ni-W-P alloy deposition together.Under most temperatures and pH values investigated bright and coherent coatings uniform in appearance have been produced.The deposition rate measurement by the means of Tafel slope analysis shows an agreement with gravimetric data.