Electroless nickel–phosphorus coating on boron carbide particles

The present work aimed at studying electroless coating of nickel–phosphorus (Ni–P) onto boron carbide (B4C) particles with average particle sizes of 93 and 32 μm. Prior to the coating process, B4C particle surfaces were sensitized using SnCl2 and HCI solution and activated in PdCl2 and HCl solutions. In the electroless coating bath, nickel sulphate (NiSO4·6H2O), sodium hypophosphite (NaH2PO2·H2O) and sodium citrate (Na3C6H5O7.5, 5H2O) were used as Ni2 + source, reducing agent and complexing agent, respectively. The morphology and the chemical composition of the coating layers were characterized by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). Characterization results showed that B4C particle surfaces were successfully coated by a homogeneous and continuous Ni–P layer.

► We report a study of Ni–P coatings on B4C particles in alkaline bath.
► Uniform and continuous Ni–P layer coated successfully on B4C particles.
► Coating Ni–P on B4C particles has not been studied in literature up to now.