Microstructural evolution of Al-Ni-Y powders an with different sizes

Artikel i vetenskaplig tidskrift, 2005

An Al-10Ni-8Y (at.%) alloy was atomized by Ar gas atomization in a close-coupled nozzle atomizer. The microstructure, phase composition, and thermal stability of the as-atomized powder were investigated by scanning electron microscopy, transmission electron microscopy, X-ray diffraction analysis and differential scanning calorimetry. Activation energies for different crystallization reactions were calculated using both Kissinger and Ozawa methods. The supercooled liquid region DeltaT(x) (= T(x) - T(g), where T(x) and T(g) are crystallization onset temperature and glass transition temperature, respectively) was detected to be in the range of 14-24 K. Also presented were attempts to determine the critical particle size for amorphous structure.