Journal article
Investigation of small crack behaviour under cyclic loading in a dual phase steel with an FIB tomography technique
Publication Details
Authors: | Brückner-Foit, A. |
Publication year: | 2007 |
Journal: | Fatigue and Fracture of Engineering Materials and Structures |
Pages range : | 556-564 |
Volume number: | 30 |
Start page: | 556 |
End page: | 564 |
ISSN: | 8756-758X |
Abstract
Damage accumulation is investigated in the early stage of fatigue life in a ferritic martensitic dual phase steel. Microcrack initiation and propagation are influenced by microstructure, such as grain boundaries, grain orientation and/or phase distribution morphology. The dominant crack initiation pattern is one in which microcracks are generated in a ferrite grain along slip bands inclined at a certain angle with respect to the loading direction. Subsurface observation with a focused ion beam (FIB) device and additional crystallographic characterization by means of the electron backscatter diffraction (EBSD) technique show that a slip system having a high Schmid factor value is activated and results in a crack nucleus. The FIB tomography technique with the help of EBSD measurement allows a three-dimensional investigation of small crack behaviour to be performed.
Damage accumulation is investigated in the early stage of fatigue life in a ferritic martensitic dual phase steel. Microcrack initiation and propagation are influenced by microstructure, such as grain boundaries, grain orientation and/or phase distribution morphology. The dominant crack initiation pattern is one in which microcracks are generated in a ferrite grain along slip bands inclined at a certain angle with respect to the loading direction. Subsurface observation with a focused ion beam (FIB) device and additional crystallographic characterization by means of the electron backscatter diffraction (EBSD) technique show that a slip system having a high Schmid factor value is activated and results in a crack nucleus. The FIB tomography technique with the help of EBSD measurement allows a three-dimensional investigation of small crack behaviour to be performed.
