Journal of Materials Science, Vol.31, No.4, 921-925, 1996
Undercooling and Supersaturation of Alloying Elements in Rapidly Solidified Al-8.5-Percent Fe-1.2-Percent V-1.7-Percent Si Alloy
Dispersion-strengthened Al-8.5% Fe-1.2% V-1.7% Si alloy was produced by inert gas atomization and atomized melt deposition processes. Differential scanning calorimetry was used to estimate the extent of undercooling in the alloy powders as a function of powder size a nd in the atomized melt-deposited alloy as a function of process parameters. The estimated undercooling was found to be a strong function of powder size and processing conditions and varied from 380-200 degrees C. Alloy powders of diameter greater than 180 mu m did not experience any undercooling during solidification. X-ray diffraction analysis was performed to study the dependence of supersaturation of alloying elements and metastable phase formation on the extent of undercooling. When the undercooled alloy was heated to about 400 degrees C, formation of Al-12(Fe, V)(3)Si phase with b cc crystal structure from the supersaturated matrix was observed.