Microstructure/mechanical properties relationship in electrodeposited Ni/Cu nanolaminates

Laminated Ni/Cu structures were made by electrodeposition using a single bath sulfamate solution. The texture of deposits was found to depend on their thickness, purity of the electrolyte and its copper content, deposition temperature, and the bi-layer thickness. The deformation and fracture of these structures were characterized by testing free-standing tensile specimens. The fracture behavior varied drastically among the specimens — from so-called knife-edge behavior to complete cleavage-like fracture. The purity of the solution and nodule formation was found to be the most important factors that affected the ductility of the deposits. The observations made in this study suggest that co-deposition of hydrogen is responsible for the embrittlement of specimens produced from impure electrolytes.