Abstract
Gas atomization is widely used for rapid solidification of aluminum alloys. However, ultra-rapid solidification process is required instead of gas atomization in order to modify the properties of P/M alloys, especially of the dispersion-strengthened Al-Fe alloys. To meet this requirement, atomization-rolling process, which was the combined process of gas atomization and single roller, has been being developed by the authors. In the present work, various Al-Fe alloys were rapidly solidified by means of atomization-rolling process, and consolidated by hot extrusion. Microstructure and tensile properties were evaluated in comparison with the alloys by gas atomization. Results obtained were (1) cooling rate of atomization-rolling process was 105-107°C/sec which was higher than gas atomization, (2) extruded alloys had higher strength at room and elevated temperature than the alloys by gas atomization, which was due to the finer dispersion of the intermetallic compounds by atomization-rolling process, and (3) Al-8%Fe-2%V-2%Mol%Zr alloy by atomization-rolling process had very high strength at elevated temperature. These results indicated that the atomization-rolling process was promising as the ultra-rapid solidification process.
