Abstract
The purpose of the present study is to show possibility of a new scheme which can clarify fracture process by means of microstructure observation near fracture surface. In the present study, strip specimens of Cu-10%Zn alloy were fractured under monotonic tensile deformation, fatigue, and corrosive conditions. Microstructure near fracture surface was investigated by electron channeling contrast imaging (ECCI) technique and by electron backscatter diffraction (EBSD) analysis. For the specimen fractured under tensile deformation, the microstructure imaged by the ECCI technique consisted of blurred patches, which would be caused by heavily distorted grains. In the ECC image of the fatigued specimen, dislocation wall structure - which was self-organized by cyclic plastic deformation - was observed. No specific structure was detected for the stress-corrosion cracking. Through the EBSD analysis, distortion of a grain near fracture surface was investigated quantitatively. For the tensile deformation test, the maximum deviation angle from average grain orientation was amounted to about 10°, while those for the fatigue and the stress-corrosion cracking were less than 2°. It is hence suggest that fracture mode could be identified by the ECCI and EBSD analyses of the microstructures developed near fracture surface.
