Paper number 529
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INFLUENCE OF REACTIVE ALLOYING ELEMENTS ON THE MECHANICAL PROPERTIES OF CARBON/MAGNESIUM COMPOSITES |
Sarala Djanarthany1, Marie-Hélène Vidal-Sétif2, Roger Valle2, Jean-Louis Raviart3, Maurice Rabinovitch2
1Université de Marne-la-Vallée, IFI, 2 rue de la Butte Verte, 93166 Noisy-le-grand, France
2ONERA/DMSC, 3ONERA/DMMP, BP72, 92322 Châtillon Cedex, France
| Summary | Magnesium matrices containing carbon reactive elements are tested to improve the fibre/matrix bonding in C/Mg composites. Unidirectional composites reinforced with K139 fibres are fabricated by liquid infiltration of RZ5 and WE43 magnesium alloys under moderate pressure (25 MPa). As-cast and heat-treated composites are tensile tested in longitudinal and transverse directions. The interface microstructure is revealed through scanning and transmission electron microscope observations: a good wetting is observed between fibre and matrix. In both as-cast composites, second phases, Zn rich or rare earth rich, resulting from solidification are strongly concentrated at some fibre/matrix interfaces. These phases are not reaction products. However in both composites, Zr has reacted and a continuous layer of ZrC is observed at some interfaces but not in the whole composite. The presence of these numerous phases lying along the fibre/matrix interface, although being partly dissolved during the heat treatment, degrades the composite mechanical properties. Process improvements are suggested. |
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