Recognition of Oriented Structures by 2D Fourier Transform

Oriented structures in metallography are usually evaluated by the intersection method or on the base of comparison against a series of standard micrographs. In this paper is introduced a new method for assessment of structures formed by elongated grains using the Fourier transform technique: The image is transformed into reciprocal (Fourier) space and use is made of the fact that the Fourier transform is very sensitive to the orientation distribution of grains. The Fourier transform of the micrograph is a specific pattern, which bears a clear relation to the original micrograph and can be evaluated both qualitatively and quantitatively.