Various structural transitions have been obtained in the AI-Si eutectic by unidirectional solidification at different growth rates. Tensile and compressive properties of the same materials have been examined and interpreted in terms of structure. In tension, maximum reinforcement by the silicon fibreshas not been achievedowingto lack of alignment of the fibres in the growth direction. In spite of this, the quenchmodified eutectic containing a fibrous silicon morphology may be characterized as a fibre-reinforcedcomposite. In the presence of branched silicon dendrites, the eutectic exhibits an ultimate compressivestrength of 500 N/mm2 (72000 lbf/in2).
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