The electrochemical deposition of nickel from electrolytes containing malonic acid

The electrochemical deposition of nickel from a sulfate bath containing malonic or succinic acids in place of a boric acid was studied under different current densities, pH and temperatures of the solution. By changing these parameters it has been possible to scrutinize the buffer capacity and the throwing power of the new baths. The current efficiency of the plating process and some physical properties (hardness and brightness) of the nickel plated from these baths were investigated. The optimum conditions of deposition were established and it was shown that replacing the boric acid buffer by the malonic acid results in better properties of both: the bath and the deposits. The electrolyte is stable and permits the use of conventional brighteners.