Wear and corrosion resistance behaviours of autocatalytic electroless plating

Initiation and formation of electroless nickel–boron coatings on mild steel: Effect of substrate roughness

“…The first step of the study was the observation of the formation and morphological evolution of the nickel-boron deposit on substrates submitted to the standard surface preparation method (that was used for most of our studies: mechanical polishing of all surfaces up to the grade 4000 SiC paper [33]). All the samples studied in Sections 3.1 and 3.2 were synthesized in a complete deposition bath containing the reducing agent, as opposed to the bath used in Section 3.3.…”

Effects of plasma nitriding on properties of electroless Ni–B coating

“…Increase in the microhardness with annealing is mainly attributed to the transformation from an amorphous to crystalline structure during precipitation hardening. [3][4][5][6][7][8][9][11][12][13][14][15][16] Further increase to a 1298 HV0?025 is evident when CPN was carried out as a post-deposition treatment of the coatings. The existence of different combinations of Fe with other atoms besides Ni 3 B phase is the main reason for superior properties of CPN coating in comparison to annealed one.…”

Electrochemical Impedance Spectroscopy of Ni-B Coatings and Optimization by Taguchi Method and Grey Relational Analysis

“…Also, the presence of sodium hypophosphite in Ni-B bath enhances the corrosion resistance of Ni-B by forming Ni-B-P [9]. The concept of Ni-P/Ni-B duplex coatings was found to have a noblest electrochemical performance than the individual Ni-P and Ni-B coatings [6,7]. The Nyquist plots obtained for electroless Ni-P, Ni-B and, Ni-P/Ni-B and Ni-B/Ni-P duplex coatings, both in as-plated and heat-treated conditions, at their respective open circuit potentials, in 3.5% sodium chloride solution, exhibit a single semicircle in the high frequency region.…”

“…Moreover, their ability to coat any material and with uniform thickness has a positive impact on their acceptance. Hypophosphite reduced Ni-P coating [3][4][5] has already been widely accepted and the quest for achieving a superior hard and wear resistant surface has brought Ni-B coatings at the focus of research [6][7][8][9][10][11][12].…”

“…With heat treatment, the hardness of Ni-B coating is found to increase even more [6,7]. The increase of hardness of Ni-B coating with heat treatment is generally attributed to the modification of deposit structure allowing the precipitation of Ni-B phases according to the Ni-B phase diagram [8].…”