Friction and wear reduction via an Ni-B electroless bath coating for metal alloys

Abstract

Improvements to an Ni-(5-6 wt.%)B coating have resulted in exceptional hardness and wear resistance that meet or exceed many of the performance standards set by hard chromium. Currently, no other bath plating technologies offer properties competitive with hard chromium, including electroless nickel-phosphorous derivatives and older versions of Ni-B. In this article, the improved Ni-B is discussed in terms of microstructural features, performance properties, coating methodology, and applications.

Effect of Annealing Temperature on the Corrosion Resistance of Electroless Ni-B-Mo Coatings

“…These nodules are formed due to the precipitation of crystalline nickel and nickel borides (Ni 2 B and Ni 3 B). A cauliflower-like appearance, which is a typical view for the Ni-B coatings (Ref [34][35][36][37], was also observed. This surface structure reduces the friction coefficient by acting like naturally lubricious (Ref 33, 38).…”

Wear and corrosion resistance behaviours of autocatalytic electroless plating

“…Borohydride-reduced nickel-boron coatings were discovered later and their use is not yet as common. Nevertheless, they are actively studied by the scientific community [11][12][13]. However, most of the studies are focussed on the deposition processes and the fundamental characteristics of those coatings and few are dedicated to their in-service properties.…”

Surface Engineering for Tribology

“…5.20. However, recent proprietary Ni-B coatings have shown a wear resistance that is comparable or better than that of chromium coatings [29]. In case of abrasive interaction, the phosphorous (or boron) content and the treatment cycle should be optimized to avoid an excessive plating brittleness that would increase wear by favouring brittle contact.…”