Table of Contents Author Guidelines Submit a Manuscript
Journal of Materials
Volume 2016 (2016), Article ID 4597271, 15 pages
http://dx.doi.org/10.1155/2016/4597271
Research Article

Influence of Grain Boundary Character and Annealing Time on Segregation in Commercially Pure Nickel

1Materials Science Program, University of Alabama in Huntsville, USA
2Department of Metallurgical & Materials Engineering, The University of Alabama, Tuscaloosa, AL, USA
3Mechanics of Materials, Sandia National Laboratories, Albuquerque, NM, USA
4The Central Analytical Facility, University of Alabama, Tuscaloosa, AL, USA
5Department of Mechanical and Aerospace Engineering, University of Alabama in Huntsville, USA

Received 18 October 2015; Revised 2 January 2016; Accepted 5 January 2016

Academic Editor: Bengt G. Svensson

Copyright © 2016 Shery L. Welsh et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Commercially pure nickel (Ni) was thermomechanically processed to promote an increase in Σ3 special grain boundaries. Engineering the character and chemistry of Σ3 grain boundaries in polycrystalline materials can help in improving physical, chemical, and mechanical properties leading to improved performance. Type-specific grain boundaries (special and random) were characterized using electron backscatter diffraction and the segregation behavior of elements such as Si, Al, C, O, P, Cr, Mg, Mn, B, and Fe, at the atomic level, was studied as a function of grain boundary character using atom probe tomography. These results showed that the random grain boundaries were enriched with impurities to include metal oxides, while Σ3 special grain boundaries showed little to no impurities at the grain boundaries. In addition, the influence of annealing time on the concentration of segregants on random grain boundaries was analyzed and showed clear evidence of increased concentration of segregants as annealing time was increased.