Efficient Preparation of Ultrahigh-Strength Nanostructured Nickel by Ultranarrow Slit-Jet Scanning Electrodeposition Without Additives.

Electrodeposition of nanostructured metals often suffers from a trade-off between mechanical performance and efficiency. This study introduces ultranarrow slit-jet scanning electrodeposition (USJS-ECD), an additive-free technique employing a planar jet confined by a slit with opening width of <100 μm to scan the cathode. Numerical simulations coupling fluid flow and electric fields were conducted to optimize jet dynamics and scanning parameters. Experimental analyses reveal that USJS-ECD creates a highly localized, uniformly intensified energy field enabling direct fabrication of ultrahigh-strength nickel. The resulting deposits exhibit 98.82 wt% purity, an ultrafine grain size of 21.86 nm, and a mirror finish with surface roughness (Ra) of ~22 nm. Mechanical testing demonstrates a microhardness of 623 HV, a tensile strength of 756 MPa, and an elongation of 9.33%, achieving a superior strength-ductility synergy. Crucially, the deposition rate reaches 1.72 μm/min, significantly outperforming advanced ultrafine anode scanning electrodeposition (UAS-ECD) techniques. USJS-ECD presents a promising, efficient methodology for producing high-performance nanocrystalline metallic materials.