|About this Abstract
||Materials Science & Technology 2011
||Fatigue and Microstructure: A Symposium on Recent Advances
||Focused Ion Beam Tomography to Quantify the Fatigue Resistance of Grain Boundaries
||Michael Marx, Wolfgang Schaef
|On-Site Speaker (Planned)
From the emission of the first dislocations till short crack propagation fatigue is a local proc-ess determined by the microstructure. In the stage of short crack propagation, micro-cracks interact with grain boundaries resulting in a retardation of the crack growth rate. To quantify the resistance of a grain boundary against crack propagation, new experiments were performed. With a focused ion beam (FIB) artificial stage I micro-cracks were initiated with reproducible crack parameters like crack length and distance to the obstacle. By this unique technique the interaction of cracks with different grain boundaries could be investigated by keeping the crack parameters constant. After the fatigue tests, FIB tomography shows the three dimensional geometry of cracks passing a grain boundary. Thereby the inclination angle of the grain boundary was identified as a very important parameter. Finally the complex fluctuating crack propagation rate could be calculated based on standard models like the BCS-model.
||Definite: A CD-only volume