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F. Lasagni, G. Requena, E. Soppa:
"In Situ Measurements of Local Strain in Heterogeneous Materials";
Advanced Engineering Materials, 10 (2008), 1-2; 73 - 78.

In this study, the local deformation of an Al-7wt.% Si alloy, a 10vol.% particle reinforced and 20vol% short fibre reinforced metal matrix composites is studied. The strain field at the surface of the materials is determined by combining an in-situ tensile tester inside a scanning electron microscope (SEM) with a software for image analysis.
The AlSi7 alloy presents about 25vol.% of eutectic Al-Si phase, composed of thin Si-lamellae, which spheroidize into rounded particles during solution treatment (ST). For this material the deformation occurs mainly in the Al a-phase, while considerably lower strain values are recorded in the eutectic region. Correlation between the Si orientation and inhomogeneity in the local strain is also presented. The particle reinforced material (PRM) presents deformation bands at 45° (with respect to the loading axis), which can be deflected by clustering of particles. In case of the short fibre reinforced material (SFRM) the deformation of the matrix is small along the fibres in regions were fibres are aligned with the tensile direction. On the other hand, the deformation of the matrix surpasses the global strain of the sample for fibres oriented perpendicularly to the load direction. The experimental results are analysed and compared with simulations based on the real microstructure using Finite Element Method (FEM). The inhomogeneities in the plastic deformation can be correlated qualitatively and quantitatively to the simulations not only regarding their location but also in magnitude.

nicht vorhanden

metal matrix composites, eutectic alloys, in situ tensile tests

http://dx.doi.org/10.1002/adem.200700250