Bulk nanocrystalline nickel-cobalt alloys were prepared by jet electrodeposition (JED) from a watts baths with the electrolyte using a high-speed jet plating device. Deposition rate and current efficiency, as well as the chemistry, microstructure, and properties of the Ni-Co deposit alloys under different cathodic current densities, were investigated. Experimental results indicate that the deposition rate and the current efficiency of JED compared with conventional electroplating are largely increased due to the increased limiting current density. Deposition rate is increased to 47.3 mu m/min, which is about 90 times that of conventional electrodeposition. The increase of the cathodic current density results in a linear increase of the deposition rate and an increase of current efficiency. Current density has little effect on the chemical composition of the deposited layer. Grain size decreases from 19 to 9 nm when the current density increases from 2.39 to 4.77 A/cm(2). At the same time, increased cathodic current density results in a remarkable increase of microhardness. (c) 2006 The Electrochemical Society.