Rapidly solidified Al-Si alloy powders containing Si from 7.1% to 23.7% produced by the Rotating-Water-Atomization Process were hot extruded, and the mechanical properties were examined. The results are summarized as follows: (1) Rapidly solidified powder was easily extruded at 593K and 673K without blister, and its surface quality was smoother, especially for higher Si alloys, than that of the cast material similarly extruded. (2) Si crystals were precipitated and grew during the hot

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... and their size depended on the extrusion temperature. (3) The tensile strength and hardness were much higher than the cast and extruded material without much loss of elongation. Finely dispersed Si crystals were evidently very effective in improving the tensile strength of the extruded Al-Si powder alloy. The tensile strength of Al-23.7%Si extruded at 593 K was about 360 MPa and its elongation was about 5%. The strength increased with decreasing extrusion temperature.