Effect of Pr3Al11 nanoparticles on crystallite growth kinetics of nanocrystalline Mg

In order to understand the effect of Pr3Al11 nanoparticles on crystallite growth kinetics of nanocrystalline Mg, the crystallite growth characteristics in a Mg-Pr3Al11 composite and a pure Mg sample were comparatively investigated in this work. The crystallite growth exponents of nanocrystalline Mg in the Mg-Pr3Al11 composite and pure Mg were determined as n = 5 and n = 4, respectively. Meanwhile, the activation energy for crystallite growth in Mg-Pr3Al11 composite was calculated to be 118.8 kJ/mol, which is higher than 97.1 kJ/mol in pure nanocrystalline Mg. Further studies reveal that the rise of crystallite growth exponent and increase of activation energy in the Mg-Pr3Al11 composite are primarily attributed to the pinning effect of Pr3Al11 nanoparticles at crystallite boundaries of Mg. (C) 2019 Elsevier B.V. All rights reserved.