ICAMS / Interdisciplinary Centre for Advanced Materials Simulation

Orientation relationships and variant selection in plate and lath martensite

Martensitic phase transformations exhibit close relationships between morphology and crystallography. Electron backscatter diffraction (EBSD), which allows the acquisition of spatially coupled crystallographic orientation data, is ideally suited for investigation of these relationships and their dependence on chemical composition. Binary and ternary Fe-based alloys, containing different amounts of Ni and Mn are investigated to describe the effect of varying alloy contents. Binary Fe-Ni alloys are known to transform to a plate-like martensite, whereas ternary Fe-Ni-Mn alloy compositions can be chosen to give a lath martensite microstructure after transformation. To extract, visualize and statistically analyze the information of interest from an EBSD data set, algorithms are developed using the open-source Matlab toolbox MTEX (http://code.google.com/p/mtex/).

Spatial distribution of the misorientation angle between the measured OR and the ideal N-W OR in Fe - 30 Ni.

The project is funded by the DFG (YA 326/2-1).

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