Characterization of the microstructure and texture of nanostructured electrodeposited NiCo using electron backscatter diffraction (EBSD)

A Co-20 at.% Ni polycrystal produced by electrodeposition has been investigated in planar and cross sections using orientation microscopy in conjunction with high-resolution scanning electron and focused ion beam microscopy. The local crystallographic texture, grain size, phase content and distribution, and grain boundary character distribution were characterized using electron backscatter diffraction (EBSD). This technique allows for a detailed microstructure characterization, particularly regarding the crystallographic character of the interfaces, which plays a special role in such nanostructured materials. However, the spatial resolution of 30-50 nm reduces the characterization to this regime. Exploring the limits of the spatial resolution of the EBSD method, we present a detailed study of the microstructure with the aim of better understanding the complexity of the material. The microstructure of the Co-20 at.% Ni electrode-posited polycrystal consists of columnar grains extending in the growth direction and pronounced clusters of coarse and fine grains. The columnar grains reveal inner orientation gradients along their longitudinal axis. The process parameters used for the deposition of the sample under investigation generate a strong (1120)//ND texture, with a face-centered cubic/hexagonal cobalt phase microstructure. (c) 2006 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.