Mechanism of boron codeposition in electrodeposited Ni-B alloy films and calculation of the amount of codeposited boron

We electrodeposited Ni-B alloy films using a rotary electrode under various plating conditions and investigated the mechanism of the codeposition of B into the plated films by analyzing the relationship between the electrodep osition conditions and the composition of the plated films, as well as by a nalyzing electrochemical measurements. We reached the following conclusions : 1) In Ni-B alloy plating by electrodeposition, use of a rotary electrode ex pands the useful current density regions compared to a static bath. 2) Unionized TMAB is present in the plating solution, and the deposition ra te of B is related to the thickness of the diffusion layer at the cathode s urface, regardless of the electrode potential. Accordingly, the amount of c odedeposited B can be calculated from v(0.7) and l/I i.e., peripheral speed and current density.