A series of grain boundary engineering procedures was performed on samples of 800H, a common iron-nickel base alloy. The effects of varying the grain boundary engineering parameters (deformation percentage and annealing temperature/time) were examined using electron back-scattering diffraction orientation mapping. grain boundary engineered samples exhibited up to a 70% increase in Σ3n boundary length fraction compared to the as-received condition. The incorporation of these Σ3n boundaries was also measured using a simplified model of two-dimensional grain boundary transport and its electrical analogy. The results showed that grain boundary engineering resulted in increased resistance to grain boundary diffusion compared to the as-received condition. The evolution of a grain boundary engineered microstructure was also studied on a per-cycle basis, and the results were shown to be consistent with previous studies.

A Microstructural Study of Grain Boundary Engineered Alloy 800H. D.J.Drabble, C.M.Bishop, M.V.Kral: Metallurgical and Materials Transactions A, 2011, 42[3], 763-72