The effect of eutectic Si on the strength of short-fibre-reinforced Al

In situ neutron diffraction experiments were carried out during compression tests for Al-Si alloys with and without eutectic silicon with different architectures and reinforced with 20 vol.% of ceramic short fibres. The load partition between the aluminium matrix, the eutectic silicon and the short fibres was determined. The AlSi12 alloy in the as-cast condition and reinforced with ceramic short fibres, for which the eutectic silicon has the largest aspect ratio and forms bridges connecting the short fibres, presents the highest mechanical strength. The experimental results were rationalized using a mean field approach for which fibre fragmentation was taken into account. © 2009 Acta Materialia Inc.