Abstract
Graphite is an important microstructural constituent in cast irons, which plays a key role in determining the material performance. This work aims at understanding the microstructural phenomena taking place in compacted graphite cast iron (CGI), and in particular the effect of the anisotropy of graphite particles, on the microscale strain partitioning. To this end, an experimental-numerical
approach is followed. First, in-situ micro-tensile tests on CGI samples are carried out in the
scanning electron microscope (SEM). From these tests, high resolution images of
deforming graphite particles within CGI are obtained. These images are then used
to calculate the strains within the graphite particles via the Global Digital Image
Correlation (GDIC) procedure. To correct for the inherent SEM imaging artifacts the use of external reference frame is proposed. The results from the tests confirm the mechanical anisotropy of compacted graphite particles in cast irons.
Next, the strain partitioning is studied numerically through a 2D microstructural model based on the SEM micrographs. Good qualitative agreement is found between the computed and measured strains within the graphite particles, validating the hypothesis on graphite mechanical anisotropy. Moreover, the numerical study reveals that graphite anisotropy has a high impact on the elasto-plastic response of the matrix material and the CGI as a whole.
approach is followed. First, in-situ micro-tensile tests on CGI samples are carried out in the
scanning electron microscope (SEM). From these tests, high resolution images of
deforming graphite particles within CGI are obtained. These images are then used
to calculate the strains within the graphite particles via the Global Digital Image
Correlation (GDIC) procedure. To correct for the inherent SEM imaging artifacts the use of external reference frame is proposed. The results from the tests confirm the mechanical anisotropy of compacted graphite particles in cast irons.
Next, the strain partitioning is studied numerically through a 2D microstructural model based on the SEM micrographs. Good qualitative agreement is found between the computed and measured strains within the graphite particles, validating the hypothesis on graphite mechanical anisotropy. Moreover, the numerical study reveals that graphite anisotropy has a high impact on the elasto-plastic response of the matrix material and the CGI as a whole.
Original language | English |
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Pages (from-to) | 439-449 |
Journal | Materials Science and Engineering A |
Volume | 658 |
DOIs | |
Publication status | Published - 2016 |
Keywords
- cast iron; graphite; digital image correlation; strain partitioning; microstructural model