Mesoscale structure and segregation in electrodeposited nanocrystalline alloys

This paper discusses the relatively unexplored issue of micron-scale structural elements that exist in nanocrystalline materials produced by electrodeposition. For the Ni-W system, we investigate grain colonies that are orders of magnitude larger than the nanoscale grain size, and which influence crack propagation and electrochemical corrosion. Auger electron spectroscopy provides evidence for segregation of W to the intercolony boundaries at the supermicron scale. We also point out that the physical and chemical properties of these mesostructures are affected by, and may thus be manipulated through, the deposition conditions. (c) 2008 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.