Tailoring and patterning the grain size of nanocrystalline alloys

TitleTailoring and patterning the grain size of nanocrystalline alloys
Publication TypeJournal Article
Year of Publication2007
AuthorsDetor, AJ, Schuh, CA
JournalActa Materialia
Pagination371 - 379
Date Published2007/01//

Nanocrystalline alloys that exhibit grain boundary segregation can access thermodynamically stable or metastable states with the average grain size dictated by the alloying addition. Here we consider nanocrystalline Ni-W alloys and demonstrate that the W content controls the grain size over a very broad range: similar to 2-140 nm as compared with similar to 2-20 nm in previous work on strongly segregating systems. This trend is attributed to a relatively weak tendency for W segregation to the grain boundaries. Based upon this observation, we introduce a new synthesis technique allowing for precise composition control during the electrodeposition of Ni-W alloys, which, in turn, leads to precise control of the nanocrystalline grain size. This technique offers new possibilities for understanding the structure-property relationships of nanocrystalline solids, such as the breakdown of Hall-Petch strength scaling, and also opens the door to a new class of customizable materials incorporating patterned nanostructures. (c) 2006 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.