Production and microstructural characterization of Ni/B electrodeposits with low B content

Nanocrystalline or amorphous Ni-B coatings can be prepared by electroless or electrochemical deposition. Electroless deposition is performed using strong reducing agents, high temperature and high pH values. The plating process and the maintenance of the solution is much easier when electrodeposition is used as production method. In this work, Ni/B coatings with low amounts of B have been produced using a Ni sulfamate plating bath with the addition of dimethylaminborane. The influence of the B content on the various properties of the Ni-B alloys produced by electrodeposition has been investigated. The microstructure of the obtained coatings has been observed by SEM both on top surface and cross section after metallographic etching and by X-ray diffraction. The B content on the produced deposits has been evaluated using GDOES. Selected specimens have been heat-treated at different temperatures and the effect of the heat treatment on the microstructure has been evaluated. Both as plated and heat treated deposits have been characterized regarding their microstructure and microhardness.