Solute distribution in nanocrystalline Ni-W alloys examined through atom probe tomography

Atom probe tomography is used to observe the solute distribution in electrodeposited nanocrystalline Ni-W alloys with three different grain sizes (3, 10 and 20 nm) and the results are compared with atomistic computer simulations. The presence of grain boundary segregation is confirmed by detailed analysis of composition fluctuations in both experimental and simulated structures, and its extent quantified by a frequency distribution analysis. In contrast to other nanocrystalline alloys previously examined by atom probe tomography, such as Ni-P, the present nanocrystalline Ni-W alloys exhibit only a subtle amount of solute segregation to the intergranular regions.