2001 Volume 42 Issue 8 Pages 1710-1716
The microstructure evolution and grain growth behavior, of gas-atomized Al88Ni9Ce2Fe1 nanocomposite materials, were studied by means of the X-ray diffraction, transmission electron microscopy, and differential scanning calorimetry. The results showed that the microstructure of as-atomized powders are affected by the degree of solute supersaturation in matrix, the microstrain contained, the size, distribution and volume fraction of nanophase precipitated, and these are essentially sensitive to the powder particle sizes. Moreover, there appeared to be a two-stage phase transformation during thermal crystallization, i.e., the precipitation of α-Al and the growth of Al3(Ni, Fe) nanophase in preference to Al11Ce3 nanophase, respectively. Finally, the grain growth kinetics of α-Al at temperatures of 250 to 300°C, revealed that the volume-diffusion grain growth mechanism with an activation energy of 1.3 eV is controlling in the nanophase materials.