Automatic classification of fracture surface morphology using computer image processing technique.

The software which enables us to classify the mixed mode fracture surfaces without human assistance has been developed based upon computer image processing and pattern recognition techniques, computing co-occurrence matrices of small divided rectangles. Two types of software have been developed; one is the mapping method, and the other the clustering method. Applying this software to the mixed mode fracture surfaces of cyclic stress corrosion cracking of an austenitic stainless steel, SUS 304, the fracture surfaces were quickly and accurately classified into intergranular, brittle transgranular, and ductile transgranular cracking. The merits and the demerits of two methods and how to improve the accuracy of classification are also discussed.