| Mechanical alloying of Al-8wt%Fe alloy powders has been studied to understand the mechanical alloying process. Various analytical techniques including microvickers hardness test, SEM, optical microscopy, and X-ray diffraction were used to find optimum conditions for mechanical alloying. On the bases of these optimum conditions, Al-8wt%Fe powders with Mo and Si have been mechanically alloyed to investigate the effects of alloying elements. The mechanically alloyed powders were hot pressed and heat treated from 250℃ to 650℃ for various times to study the morphologies, sizes, and the kinds of precipitates. In the case of Al-8wt%Fe and Al-8wt%Fe-1.5wt%Mo, the precipitate was Al₃Fe, and in the case of Al-8wt%Fe-1.5wt%Si alloy were Al₃Fe and silicide. High temperature (250℃, 350℃) tensile strengths of the hot extruded mechanically alloyed powders were superior to those of conventional precipitation hardened Al alloy. This superiority was due to effects of thermally stable intermetallic compounds, oxide, and carbide. |
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