Effects of saccharin and quaternary ammonium chlorides on the electrodeposition of nickel from a Watts-type electrolyte

The effect of the presence of quaternary ammonium chlorides (QACl) and saccharin on various electrodeposition parameters for nickel deposition on a stainless steel cathode from a Watts-type plating bath was investigated. The parameters included cathodic current efficiency, throwing power of the bath, cathodic polarization, crystal orientation, and quality of the deposit. The following additives were investigated: saccharin, 1-alkyloxymethyl 3-benzyl imidazolium chlorides [alkyl R=C2, C6, C10], 1-decyloxymethyl 3-alkyl imidazolium chlorides [alkyl R=C2, C6, C10], 1-cycloheksyloxymethyl 3-alkyl imidazolium chlorides [alkyl R=C2, C6, C10], benzyl-dimethyl-alkyl ammonium chloride [alkyl R=C2, C4, C8], benzyloxymethyl-dimethyl-alkyl ammonium chlorides [alkyl R=C2, C4, C8], benzyl-dimethyl-alkyloxymethyl ammonium chlorides [R=C2, C4, C8]. The results indicated that only one type of QACl fulfilled all requirements to be acceptable, namely: benzyl-dimethyl-alkyloxymethyl chlorides, and especially benzyl-dimethyl-buthyloxymethyl chloride. The mechanism of the action of this additive has also been discussed.