Strategy for Electrodeposition of Highly Ductile Bulk Nanocrystalline Metals with a Face-Centered Cubic Structure

Abstract

A strategy for producing highly ductile electrodeposited bulk nanocrystalline metals with face-centered cubic structures was developed in a Ni–W alloy model system. Bulk nanocrystalline Ni–W alloys with similar grain size (20–30 nm), and varying crystallographic orientations were produced. The electrodeposited alloys showed tensile elongation ranging between 0 and 13%. Scanning ion microscopy reveled that all electrodeposited alloys had similar meso-scale structures that are typical of electrodeposited metals. This indicated the variation of ductility and fracture surfaces was not caused by cluster structures filled with nano-grains. The tensile behavior of the bulk nanocrystalline Ni–W alloys could be explained by considering the effects of growth processes during electrodeposition on the presence of hydrogen and defects. Our discussion surrounding Ni–W alloys outlines the conditions necessary to obtain the high tensile ductility. Our findings are in good agreement with those for other electrodeposited nanocrystalline face-centered cubic metals. We also provide guidelines for selecting electrodeposition conditions to produce bulk nanocrystalline metals with face-centered cubic structures and high tensile ductility.