Annealing effects on the hardening of electroless plated Ni–P layer by boron implantation

Abstract Annealing effects of hardening of electroless plated Ni–P layer on an iron based alloy have been studied in connection with 200 keV boron ion implantation at a dose of 1×10 17 ions/cm 2 . Increases of Vickers hardness in the near-surface region were observed to an extent of 17% for the pre-annealed specimens compared to unimplanted ones. Post-annealed specimens did not show effective hardening by the implantation treatment. The chemical states of implanted ions were studied by X-ray photoelectron spectroscopy (XPS) and the results may suggest that the increase of hardness is not due to the precipitation of nickel borides, but rather due to amorphization of Ni and Ni 3 P.