Electroless nickel-boron plating

The process involves dipping the substrate in a water solution containing nickel salt and a boron-containing reducing agent, such as an alkylamineborane or sodium borohydride.

Electroless nickel-boron plating developed as a variant of the similar nickel-phosphorus process, discovered accidentally by Charles Adolphe Wurtz in 1844.

[2] In 1969, Harold Edward Bellis from DuPont filed a patent for a general class of electroless plating processes using sodium borohydride, dimethylamine borane, or sodium hypophosphite, in the presence of thallium salts, thus producing a metal-thallium-boron or metal-thallium-phosphorus; where the metal could be either nickel or cobalt.

Eventually formulations were devised that were free from the toxic thallium ingredients, resulting in true nickel-boron ("Type 2") coatings.

[12] Actual and potential applications of electroless nickel-boron coating include saw blades,[11] ship propellers,[12] down-hole crude oil pumping equipment, bushings, thrust washers and paper guide plates.