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.