Crystallographic texture influences on the thermal stability of nanocrystalline materials

The influence of crystallographic texture on the total amount of solute segregated at the grain boundaries (X_gb,tot) and consequently the weighted grain boundary energy (γ_w) of a nanocrystalline material is investigated. Toward this end, two different 3D nanostructures, one with random crystallographic texture and the other with {111} < 110 > texture, were generated. The grain boundary misorientation distribution was obtained from both the 3D nanostructures and converted into an equivalent grain boundary energy distribution using the data from Olmstead et al. It was found that both X_gb,tot and γ_w are higher for the nanostructure bearing random texture vis-à-vis the {111} < 110 > texture. This has implications in the development of thermally stable nanocrystalline materials. The effect of texture is also discussed through a case study on the Ni–W system by invoking the nanocrystalline stability criterion proposed by Kalidindi and Schuh.