[en] Electroless nickel-boron coatings are formed by spontaneous reduction of nickel, in aqueous solution, by sodium borohydride.
This process is initiated by a catalytic effect of the substrate on the oxidation of the borohydride ion.
Once the process is initiated, the growth occurs in several stages: colonization of the substrate by nodules, nodules coalescence and finally columnar growth. The resulting deposit is nanocristalline but presents an observable microstructure.
During plating, the decrease of reagent concentration leads to local variations of the chemistry of the coating, and of its microstructure. Agitation and cell geometry also influence the morphology of samples.
Research center :
CRIM - Ingénierie des matériaux
Disciplines :
Materials science & engineering Chemistry
Author, co-author :
Vitry, Véronique ; Université de Mons > Faculté Polytechnique > Métallurgie
