Carbodeon Ltd. Oy, Finland, announces that wear resistance of electroless nickel plating is improved by a factor of three by the controlled addition of nanodiamonds that are synthesised by a detonation process. The process produces nanoparticles that have a positive charge in solution, enabling them to deposit together with the metal ions in the plating process. Nanodiamond particles are hardwearing, 4 to 6 nm in diameter, and offer very low surface friction.
Platers have added liquid suspensions containing clusters of these diamond particles into the electrolyte and experienced significant improvements in durability of the plating for such applications as gun barrels and machine parts.
For plating applications, the result is that the particle charge or “zeta potential” is much higher, around 50% more than traditional nanodiamonds. This creates an additional separation force between the nanodiamond particles, and has enabled Carbodeon to develop a liquid dispersion of individual particles 4-6 nm in diameter, rather than the traditional clusters that range from 100 m up to a few microns in size. The result is that the surface-area/volume ratio of the diamonds increases by one to two orders of magnitude.
By depositing true nanoscale particles into metal plating, Carbodeon aims to make the addition of nanodiamond to metal plating more economical. While the traditional dosage rate for plating with agglomerated nanodiamonds is 10g/liter of electrolyte, the optimum dose using dispersed nanodiamond in electroless nickel has been found to be just 0.05 g/liter.
