ADVANCED SEM METHODS IN FATIGUE AND FRACTURE RESEARCH

A comparative analysis of advanced results in the quantitative micra f ractography is performed. Fatigue crack propagation micro-mechanisms a re discussed with respect to the fatigue striation spacing and feature s as well as to the retrospective of the FCP process. The correlation between statistics of local cleavage crack growth directions and main crack propagation direction provides an evidence of both the ''coalesc ence'' fracture mechanism and local approach to fracture acceptance. S tretched zone formation at crack initiation and its relation to fractu re toughness of material is described. Intercrystalline rupture fracto graphy is characterized with respect to the fatigue and stress corrosi on cracking. Applications of fractography are given.