Characterization of macrosegregation in eutectic alloys

An image processing method has been developed to characterize the macrosegregation on cross-sections of castings produced from eutectic alloys. The method utilizes a combination of image segmentation, pixel-to-pixel analysis and tessellation techniques to construct a quantitative map of the solute distribution over large samples. Compared with methods reported previously in the literature, the current method is robust and can be applied to samples with large irregular cross-sections. The accuracy and validity of the method has been assessed through a series of artificially designed micrographs. An example application to an A356 aluminum alloy sample casting with irregular cross-section is presented.